Coffee is routinely consumed in countries within the Mediterranean basin. Coffee, an infusion of ground, roasted coffee beans, is the most widely consumed behaviourally active substance in the world. It contains several hundred different substances including, antioxidants, carbohydrates, lipids, vitamins, minerals, phenolic compounds and alkaloids. Nevertheless, the effects of coffee on the cardiovascular system have been mainly related to caffeine. Acute and chronic caffeine intake appears to have only minor negative consequence on health. However, high levels of caffeine intake have been related to ventricular arrhythmias.
Epidemiologic studies have already underlined the beneficial role of the Mediterranean dietary pattern on mortality, coronary artery disease, lipid metabolism and on blood pressure. The diet of people living in Mediterranean area, where olive oil is the principal source of dietary fat, encompasses all the beneficial dietary characteristics presented in previous studies. Little information is available on relationship between adherence to Mediterranean Diet and atrial fibrillation (AF).
"We aimed to investigate the relationship between diets and atrial fibrillation, one of the most common arrhythmias, and we focused on coffee and caffeine intake" explained Prof Mattioli from the University of Modena, Italy."We selected patients presenting with a first detected episode of AF. Nutrition habits were investigated by a self administered food frequency questionnaire that included 116 items, followed by an interviewer-administered 24 h diet recall questionnaire."
The adherence to Mediterranean Diet was assessed using a Mediterranean Score. The Mediterranean Diet is usually represented in the form of a pyramid, the base of which refers to foods which are suggested to be consumed most frequently (non-refined cereals and products, olive oil, vegetables and fruits) and the top of the pyramid to those foods to be consumed rarely (red meat and meat products). The score ranged from 0 to 55. Higher values of score indicate greater adherence to the Mediterranean diet.
Interviewers investigated coffee consumption and other sources of caffeine (i.e. soda drinks, cola, chocolate, tea). Coffee consumption was specifically estimated and we evaluated: type of coffee consumed (filtered or boiled), number of daily cup of espresso coffee, American coffee, decaffeinated and cappuccino.
Coffee intake was divided in 4 categories: low habitual (from 1 cup/day), medium habitual (2-3 cups/day), heavy habitual (more than 3 cups/day) and non-habitual (0 cup/day).
Caffeine intake was estimated adding the caffeine from other sources evaluated as number of chocolate snacks, number of cans of cola soda usually consumed, intake of tea and type of tea.
Findings include:
Total calorie intake was similar in patients with arrhythmia and in control patients. The intake of calories was normal in both groups.
Adherence to Mediterranean Diet was significantly lower in patients that developed atrial fibrillation. Patients that developed arrhythmias achieved a total calories intake similar to patients that did not develop AF, but the quality of food was different and the Mediterranean diet score was lower. Patients with arrhythmia had higher consumption of red meat, and full fat dairy.
Estimated intake of total antioxidants from food was lower in patients with atrial fibrillation.
Source of antioxidants were different in patients with atrial fibrillation. Patients with atrial fibrillation had higher intake of antioxidants from coffee compared to other source (vegetables, fruits, wine).
Patients with atrial fibrillation had higher intake of caffeine compare to control.
Patients with high intake of caffeine and coffee are more likely to develop atrial fibrillation.
In this population the adherence to Mediterranean Diet is scarce. In addition, the antioxidant intake from coffee is higher than antioxidant intake from vegetables and fruits. High antioxidant levels in coffee were reported in several studies. A major issue is whether the antioxidants from coffee are bioactive. Many epidemiologic studies found that coffee is associated with reduced early oxidative stress. Thus, coffee may contain several bioactive compounds, some of which may be beneficial, whereas others may increase the risk of disease. A second point is the synergistic and antagonist interactions between food components of diet and the complex of nutrients intake.
"Our study suggests that high intake of coffee increase the risk of arrhythmias in people without known cardiac disease", concludes Prof Mattioli.
Monday, August 31, 2009
'Watchful waiting' for prostate cancer?
'Watchful waiting' is a viable option for prostate cancer patients with low-risk tumors
No significant difference in mortality rates found among men who deferred treatment compared to those who sought immediate treatment
Appropriately selected prostate cancer patients, including older men and men with small, low-risk tumors, may safely defer treatment for many years with no adverse consequences, according to a new study in the Journal of Clinical Oncology (JCO). Led by researchers at Beth Israel Deaconess Medical Center (BIDMC), the study appears online today.
"With the advent of PSA [prostate antigen] screening nearly 20 years ago, we started to detect prostate cancers at much earlier stages," explains corresponding author Martin Sanda, MD, Director of the Prostate Cancer Center at BIDMC and Associate Professor of Surgery at Harvard Medical School.
"Consequently, while PSA testing has enabled us to successfully begin aggressive treatment of high-risk cancers at an earlier stage, it has also resulted in the diagnosis of cancers that are so small they pose no near-term danger and possibly no long-term danger," he adds.
Sanda, together with coauthors from Brigham and Women's Hospital, the Harvard School of Public Health and the University of California, San Francisco, looked at the Health Professionals Follow-Up Study, a large cohort study comprising 51,529 men who have been followed since 1986. Every two years, the participants respond to questionnaires inquiring about diseases and health-related topics, including whether they have been diagnosed with prostate cancer.
A total of 3,331 men reported receiving a diagnosis of prostate cancer between 1986 and 2007. Further analysis found that among this sub-group, 342 men – just over 10 percent – had opted to defer treatment for one year or longer. Ten to 15 years later, half of the men who had initially deferred treatment still had not undergone any treatment for prostate cancer.
"We wanted to find out how this group of men fared in the long-term," explains Sanda. "So we looked at the data they provided us at an average of eight years after their initial diagnosis, and compared it with data provided by prostate-cancer patients who had opted for aggressive treatment, such as surgery, radiotherapy or hormonal therapy.
"We found that the deaths attributed to prostate cancer were very low among the men with low-risk tumors," explains Sanda. "Our analysis showed that only two percent of the men who deferred treatment eventually died of the disease, compared with one percent of the men who began treatment immediately following their diagnosis. This is not a statistically significant difference."
There are three types of prostate cancer: High risk, which are large, faster-growing cancers; intermediate risk; and low-risk, which are small and slower growing cancers. While there is ample evidence that treating intermediate and high-risk cancers with either surgery, radiation or hormone therapy can save lives, whether and how best to care for low-risk cancers remains uncertain.
"These findings showed that men diagnosed with low-risk tumors who deferred treatment were still doing fine an average of eight years -- and up to 20 years -- following their diagnosis.
"Only half of these men wound up undergoing any treatment 10 to 15 years post-diagnosis," says Sanda. "This means that they were able to avoid the disruption in their quality of life which might have occurred had they undergone immediate treatment.
"If this approach was more broadly accepted as a standard care option for suitable low-risk prostate cancers, it might help us avoid throwing the baby out with the bathwater when it comes to the PSA test," he adds. "Instead of just abandoning the PSA test because it might be leading to an overdiagnosis of prostate cancer, we could conduct PSA screening in a way that allows more aggressive prostate cancers to be treated, while less aggressive tumors could initially be monitored. This would avoid problems due to treatment of 'overdiagnosed' low-risk cancers, while preserving the lifesaving benefits of treating aggressive cancers that have been detected through PSA testing."
Overdiagnosis since introduction of prostate cancer screening
The introduction of prostate-antigen screening, or PSA, has resulted in over 1 million additional men over the last 23 years being diagnosed and treated for prostate cancer—most of whom were likely overdiagnosed, researchers reported in a new study published online August 31 in the Journal of the National Cancer Institute.
Overdiagnosis has been associated with early diagnosis in prostate cancer, but there have been no previous national estimates of its magnitude.
Using data from the National Cancer Institute's Surveillance, Epidemiology, and End Results program, H. Gilbert Welch, M.D., MPH, of the White River Junction VA and The Dartmouth Institute for Health Policy & Clinical Practice., and Peter C. Albertsen, M.D., of the University of Connecticut, examined age-specific prostate cancer incidence rates to determine the excess (or deficit) in the number of American men diagnosed and treated in each year after 1986. PSA screening was introduced in 1987.
According to the study, an additional 1.3 million men were diagnosed—that would otherwise have never been diagnosed absent screening—and more than 1 million have been treated since 1986.
"Given the considerable time that has passed since PSA screening began, most of this excess incidence must represent overdiagnosis," the authors write. "All overdiagnosed patients are needlessly exposed to the hassle factors of obtaining treatment, the financial implications of the diagnosis, and the anxieties associated with becoming a cancer patient…"
The increased diagnosis has been most dramatic among younger men: more than tripling since 1986 in men aged 50-59 (from 58.4 to 212.7 per 100, 000) and more than a sevenfold increase in men under age 50 (from 1.3 to 9.4 per 100,000).
In an accompanying editorial, Otis W. Brawley, M.D., chief medical officer of the American Cancer Society, discusses how screening practices for prostate cancer have surged over the last 20 years, despite little evidence that it has saved lives.
According to Brawley, the highly pushed early-detection message has skewed public opinion and de-legitimized the questions concerning screening, causing many men to be overdiagnosed. Mortality has decreased since the early 1990s, the editorialist points outs, but reasons for this decline are unclear.
"We desperately need the ability to predict which patient has a localized cancer that is going to metastasize and cause suffering and death and which patient has a cancer that is destined to stay in the patient's prostate for the remainder of his life," he writes.
No significant difference in mortality rates found among men who deferred treatment compared to those who sought immediate treatment
Appropriately selected prostate cancer patients, including older men and men with small, low-risk tumors, may safely defer treatment for many years with no adverse consequences, according to a new study in the Journal of Clinical Oncology (JCO). Led by researchers at Beth Israel Deaconess Medical Center (BIDMC), the study appears online today.
"With the advent of PSA [prostate antigen] screening nearly 20 years ago, we started to detect prostate cancers at much earlier stages," explains corresponding author Martin Sanda, MD, Director of the Prostate Cancer Center at BIDMC and Associate Professor of Surgery at Harvard Medical School.
"Consequently, while PSA testing has enabled us to successfully begin aggressive treatment of high-risk cancers at an earlier stage, it has also resulted in the diagnosis of cancers that are so small they pose no near-term danger and possibly no long-term danger," he adds.
Sanda, together with coauthors from Brigham and Women's Hospital, the Harvard School of Public Health and the University of California, San Francisco, looked at the Health Professionals Follow-Up Study, a large cohort study comprising 51,529 men who have been followed since 1986. Every two years, the participants respond to questionnaires inquiring about diseases and health-related topics, including whether they have been diagnosed with prostate cancer.
A total of 3,331 men reported receiving a diagnosis of prostate cancer between 1986 and 2007. Further analysis found that among this sub-group, 342 men – just over 10 percent – had opted to defer treatment for one year or longer. Ten to 15 years later, half of the men who had initially deferred treatment still had not undergone any treatment for prostate cancer.
"We wanted to find out how this group of men fared in the long-term," explains Sanda. "So we looked at the data they provided us at an average of eight years after their initial diagnosis, and compared it with data provided by prostate-cancer patients who had opted for aggressive treatment, such as surgery, radiotherapy or hormonal therapy.
"We found that the deaths attributed to prostate cancer were very low among the men with low-risk tumors," explains Sanda. "Our analysis showed that only two percent of the men who deferred treatment eventually died of the disease, compared with one percent of the men who began treatment immediately following their diagnosis. This is not a statistically significant difference."
There are three types of prostate cancer: High risk, which are large, faster-growing cancers; intermediate risk; and low-risk, which are small and slower growing cancers. While there is ample evidence that treating intermediate and high-risk cancers with either surgery, radiation or hormone therapy can save lives, whether and how best to care for low-risk cancers remains uncertain.
"These findings showed that men diagnosed with low-risk tumors who deferred treatment were still doing fine an average of eight years -- and up to 20 years -- following their diagnosis.
"Only half of these men wound up undergoing any treatment 10 to 15 years post-diagnosis," says Sanda. "This means that they were able to avoid the disruption in their quality of life which might have occurred had they undergone immediate treatment.
"If this approach was more broadly accepted as a standard care option for suitable low-risk prostate cancers, it might help us avoid throwing the baby out with the bathwater when it comes to the PSA test," he adds. "Instead of just abandoning the PSA test because it might be leading to an overdiagnosis of prostate cancer, we could conduct PSA screening in a way that allows more aggressive prostate cancers to be treated, while less aggressive tumors could initially be monitored. This would avoid problems due to treatment of 'overdiagnosed' low-risk cancers, while preserving the lifesaving benefits of treating aggressive cancers that have been detected through PSA testing."
Overdiagnosis since introduction of prostate cancer screening
The introduction of prostate-antigen screening, or PSA, has resulted in over 1 million additional men over the last 23 years being diagnosed and treated for prostate cancer—most of whom were likely overdiagnosed, researchers reported in a new study published online August 31 in the Journal of the National Cancer Institute.
Overdiagnosis has been associated with early diagnosis in prostate cancer, but there have been no previous national estimates of its magnitude.
Using data from the National Cancer Institute's Surveillance, Epidemiology, and End Results program, H. Gilbert Welch, M.D., MPH, of the White River Junction VA and The Dartmouth Institute for Health Policy & Clinical Practice., and Peter C. Albertsen, M.D., of the University of Connecticut, examined age-specific prostate cancer incidence rates to determine the excess (or deficit) in the number of American men diagnosed and treated in each year after 1986. PSA screening was introduced in 1987.
According to the study, an additional 1.3 million men were diagnosed—that would otherwise have never been diagnosed absent screening—and more than 1 million have been treated since 1986.
"Given the considerable time that has passed since PSA screening began, most of this excess incidence must represent overdiagnosis," the authors write. "All overdiagnosed patients are needlessly exposed to the hassle factors of obtaining treatment, the financial implications of the diagnosis, and the anxieties associated with becoming a cancer patient…"
The increased diagnosis has been most dramatic among younger men: more than tripling since 1986 in men aged 50-59 (from 58.4 to 212.7 per 100, 000) and more than a sevenfold increase in men under age 50 (from 1.3 to 9.4 per 100,000).
In an accompanying editorial, Otis W. Brawley, M.D., chief medical officer of the American Cancer Society, discusses how screening practices for prostate cancer have surged over the last 20 years, despite little evidence that it has saved lives.
According to Brawley, the highly pushed early-detection message has skewed public opinion and de-legitimized the questions concerning screening, causing many men to be overdiagnosed. Mortality has decreased since the early 1990s, the editorialist points outs, but reasons for this decline are unclear.
"We desperately need the ability to predict which patient has a localized cancer that is going to metastasize and cause suffering and death and which patient has a cancer that is destined to stay in the patient's prostate for the remainder of his life," he writes.
How much omega-3 fatty acid do we need?
How much omega-3 fatty acid do we need
New research in the FASEB Journal identifies the 'Goldilocks dose' of DHA that is 'just right' for preventing oxidative stress and to prevent cardiovascular disease in men.
A team of French scientists have found the dose of DHA (docosahexaenoic acid) that is "just right" for preventing cardiovascular disease in healthy men. In a research report appearing in the September 2009 print issue of The FASEB Journal (http://www.fasebj.org), the scientists show that a 200 mg dose of DHA per day is enough to affect biochemical markers that reliably predict cardiovascular problems, such as those related to aging, atherosclerosis, and diabetes. This study is the first to identify how much DHA is necessary to promote optimal heart health.
"This study shows that regularly consuming small amounts of DHA is likely to improve the health status of people, especially in regards to cardiovascular function," said Michel Lagarde, co-author of the study.
To determine the optimal dose of DHA, Lagarde and colleagues examined the effects of increasing doses of DHA on 12 healthy male volunteers between ages of 53 and 65. These men consumed doses of DHA at 200, 400, 800, and 1600 mg per day for two weeks for each dose amount, with DHA being the only omega-3 fatty acid in their diet. Blood and urine samples were collected before and after each dose and at eight weeks after DHA supplementation stopped. The researchers then examined these samples for biochemical markers indicating the effects of each dose on the volunteers.
"Now that we have a very good idea about how much DHA is just right, the next step is to try it out in an expanded clinical trial that involves many more people," said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. "Until then, I'll stick with tasty foods that contain DHA, like fish, rather than getting a quick fatty-acid fix at the local vitamin store."
New research in the FASEB Journal identifies the 'Goldilocks dose' of DHA that is 'just right' for preventing oxidative stress and to prevent cardiovascular disease in men.
A team of French scientists have found the dose of DHA (docosahexaenoic acid) that is "just right" for preventing cardiovascular disease in healthy men. In a research report appearing in the September 2009 print issue of The FASEB Journal (http://www.fasebj.org), the scientists show that a 200 mg dose of DHA per day is enough to affect biochemical markers that reliably predict cardiovascular problems, such as those related to aging, atherosclerosis, and diabetes. This study is the first to identify how much DHA is necessary to promote optimal heart health.
"This study shows that regularly consuming small amounts of DHA is likely to improve the health status of people, especially in regards to cardiovascular function," said Michel Lagarde, co-author of the study.
To determine the optimal dose of DHA, Lagarde and colleagues examined the effects of increasing doses of DHA on 12 healthy male volunteers between ages of 53 and 65. These men consumed doses of DHA at 200, 400, 800, and 1600 mg per day for two weeks for each dose amount, with DHA being the only omega-3 fatty acid in their diet. Blood and urine samples were collected before and after each dose and at eight weeks after DHA supplementation stopped. The researchers then examined these samples for biochemical markers indicating the effects of each dose on the volunteers.
"Now that we have a very good idea about how much DHA is just right, the next step is to try it out in an expanded clinical trial that involves many more people," said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. "Until then, I'll stick with tasty foods that contain DHA, like fish, rather than getting a quick fatty-acid fix at the local vitamin store."
Friday, August 28, 2009
Fight Bone Loss: Milk/Calcium or Fruit/Veg/Exercise?
For years, doctors have told us to drink milk and take calcium supplements to improve bone health and prevent osteoporosis. The problem is they're wrong, according to new book co-authored by Amy Lanou, a professor at the University of North Carolina at Asheville.
Published by McGraw-Hill, “Building Bone Vitality: A Revolutionary Plan to Prevent Bone Loss and Reverse Osteoporosis” dispels the calcium myth and tells readers that eating low-acid foods like fruits and vegetables and taking daily walks are more effective than calcium in preventing bone loss.
Lanou holds a doctorate in human nutrition from Cornell University, and is the author of "Healthy Eating for Life for Children," and serves as senior nutrition scientist for the Physicians Committee for Responsible Medicine.
Published by McGraw-Hill, “Building Bone Vitality: A Revolutionary Plan to Prevent Bone Loss and Reverse Osteoporosis” dispels the calcium myth and tells readers that eating low-acid foods like fruits and vegetables and taking daily walks are more effective than calcium in preventing bone loss.
Lanou holds a doctorate in human nutrition from Cornell University, and is the author of "Healthy Eating for Life for Children," and serves as senior nutrition scientist for the Physicians Committee for Responsible Medicine.
Whole Grains = Whole Health
Lona Sandon, assistant professor of clinical nutrition at UT Southwestern Medical Center and spokesperson for the American Dietetic Association, says it’s important to keep whole grains in your diet.
“Research shows that whole grains are good for your heart, lower risk of diabetes and stroke, and may help prevent certain cancers,” she says. “They also help in managing weight.”
Ms. Sandon says whole grains are chock full of good-for-you nutrients including fiber, folate and niacin, vital B vitamins, and magnesium. “The phytochemicals found in whole grains have been shown to have health promoting and disease prevention benefits,” she adds.
Ms. Sandon recommends that adults aim for three servings, or 48 grams, of whole grains a day. Be sure to look for the words “Made with whole grain” and “100 percent whole grain” on packages.
Other going-with-the-grain tips include:
• Swap whole wheat breadstuffs for white rolls and breads;
• Use whole wheat bread crumbs for stuffing;
• Add wild rice or brown rice to dishes, and;
• Serve whole wheat crackers with hors d’oeuvres
“Research shows that whole grains are good for your heart, lower risk of diabetes and stroke, and may help prevent certain cancers,” she says. “They also help in managing weight.”
Ms. Sandon says whole grains are chock full of good-for-you nutrients including fiber, folate and niacin, vital B vitamins, and magnesium. “The phytochemicals found in whole grains have been shown to have health promoting and disease prevention benefits,” she adds.
Ms. Sandon recommends that adults aim for three servings, or 48 grams, of whole grains a day. Be sure to look for the words “Made with whole grain” and “100 percent whole grain” on packages.
Other going-with-the-grain tips include:
• Swap whole wheat breadstuffs for white rolls and breads;
• Use whole wheat bread crumbs for stuffing;
• Add wild rice or brown rice to dishes, and;
• Serve whole wheat crackers with hors d’oeuvres
Dealing with High-blood Pressure? Eat More Melons
Nutrition experts at UT Southwestern Medical Center say there’s no better way to lower your blood pressure than by indulging in some of the season’s potassium-rich fruit and vegetables.
“Melons like cantaloupe and watermelon are particularly high in potassium,” says Lona Sandon, assistant professor of clinical nutrition at UT Southwestern and spokesperson for the American Dietetic Association. “One fourth a cantaloupe contains 800 to 900 milligrams of potassium, roughly 20 percent of the recommended daily value.”
Two cups of watermelon contains nearly 10 percent of the daily recommended value.
Ms. Sandon said that dried apricots, avocados, figs, kiwi, oranges, raisins, dates, beans, potatoes, tomatoes and even grapefruit are other good sources of potassium.
The U.S. Department of Agriculture recommends that most adults get 4,044 milligrams of potassium from food and beverages each day.
“Melons like cantaloupe and watermelon are particularly high in potassium,” says Lona Sandon, assistant professor of clinical nutrition at UT Southwestern and spokesperson for the American Dietetic Association. “One fourth a cantaloupe contains 800 to 900 milligrams of potassium, roughly 20 percent of the recommended daily value.”
Two cups of watermelon contains nearly 10 percent of the daily recommended value.
Ms. Sandon said that dried apricots, avocados, figs, kiwi, oranges, raisins, dates, beans, potatoes, tomatoes and even grapefruit are other good sources of potassium.
The U.S. Department of Agriculture recommends that most adults get 4,044 milligrams of potassium from food and beverages each day.
Tuesday, August 25, 2009
Low-carb diets linked to atherosclerosis
Even as low-carbohydrate/high-protein diets have proven successful at helping individuals rapidly lose weight, little is known about the diets' long-term effects on vascular health.
Now, a study led by a scientific team at Beth Israel Deaconess Medical Center (BIDMC) provides some of the first data on this subject, demonstrating that mice placed on a 12-week low carbohydrate/high-protein diet showed a significant increase in atherosclerosis, a buildup of plaque in the heart's arteries and a leading cause of heart attack and stroke. The findings also showed that the diet led to an impaired ability to form new blood vessels in tissues deprived of blood flow, as might occur during a heart attack.
Described in today's Online Version of the Proceedings of the National Academy of Sciences (PNAS), the study also found that standard markers of cardiovascular risk, including cholesterol, were not changed in the animals fed the low-carb diet, despite the clear evidence of increased vascular disease.
"It's very difficult to know in clinical studies how diets affect vascular health," says senior author Anthony Rosenzweig, MD, Director of Cardiovascular Research in BIDMC's CardioVascular Institute and Professor of Medicine at Harvard Medical School. "We, therefore, tend to rely on easily measured serum markers [such as cholesterol], which have been surprisingly reassuring in individuals on low-carbohydrate/high-protein diets, who do typically lose weight. But our research suggests that, at least in animals, these diets could be having adverse cardiovascular effects that are not reflected in simple serum markers."
Rosenzweig and his coauthors found that the increase in plaque build-up in the blood vessels and the impaired ability to form new vessels were associated with a reduction in vascular progenitor cells, which some hypothesize could play a protective role in maintaining vascular health.
"A causal role for these cells has not yet been proven, but this new data is consistent with the idea that injurious stimuli may be counterbalanced by the body's restorative capacity," he explains. "This may be the mechanism behind the adverse vascular effects we found in mice that were fed the low-carb diets."
The study's first author Shi Yin Foo, MD, PhD, a clinical cardiologist in the Rosenzweig laboratory at BIDMC, first embarked on this investigation after seeing heart-attack patients who were on these diets – and after observing Rosenzweig himself following a low-carbohydrate regimen.
"Over lunch, I'd ask Tony how he could eat that food and would tell him about the last low-carb patient I'd admitted to the hospital," says Foo. "Tony would counter by noting that there were no controls for my observations."
"Finally," adds Rosenzweig, "I asked Shi Yin to do the mouse experiment – so that we could know what happens in the blood vessels and so that I could eat in peace."
The investigators proceeded to study a mouse model of atherosclerosis. These "ApoE" mice were fed one of three diets: a standard diet of mouse "chow" (65 percent carbohydrate; 15 percent fat; 20 percent protein); a "Western diet" in keeping with the average human diet (43 percent carbohydrate; 42 percent fat; 15 percent protein; and 0.15 percent cholesterol); or a low-carb/high-protein diet (12 percent carbohydrate; 43 percent fat; 45 percent protein; and 0.15 percent cholesterol).
"We had a diet specially made that would mimic a typical low-carb diet," explains Foo. "In order to keep the calorie count the same in all three diets, we had to substitute a nutrient to replace the carbohydrates. We decided to substitute protein because that is what people typically do when they are on these diets."
The scientists then observed the mice after six weeks, and again at 12 weeks. Consistent with experience in humans, the mice fed the low-carb diet gained 28 percent less weight than the mice fed the Western diet. However, further probing revealed that the animals' blood vessels exhibited a significantly greater degree of atherosclerosis, as measured by plaque accumulation: 15.3 percent compared with 8.8 percent among the Western diet group. (As expected, the mice on the chow diet showed minimal evidence of atherosclerosis compared with either of the other two groups.)
"Our next question was, 'Why do the low-carb mice have such an increase in atherosclerosis?'" says Foo. Searching for an explanation, she and her coauthors proceeded to measure the usual markers thought to contribute to vascular disease, including the animals' cholesterol and triglyceride levels, oxidative stress, insulin and glucose, as well as levels of some inflammatory cytokines.
"In each case, there was either no difference in measurements compared with the mice on the Western Diet [which contains the same amount of fat and cholesterol] or the numbers slightly favored the low-carb cohort," she adds. "None of these results explained why the animals' blood had more atherosclerotic blockages and looked so bad."
Since there was no difference in the noxious or inflammatory stimuli that the animals' blood vessels were exposed to, Foo wondered whether the restorative capacity of the animals might be contributing to the difference. The investigators, therefore, looked at the animals' endothelial or vascular progenitor cell (EPC) counts. Derived from bone marrow, the EPC cells may play a role in vessel regrowth and repair following injury.
"Examinations of the animals' bone marrow and peripheral blood showed that the measures of EPC cells dropped fully 40 percent among the mice on the low-carb diet – after only two weeks," says Rosenzweig. "Although the precise nature and role of these cells is still being worked out – and caution is always warranted in extrapolating from effects in mice to a clinical situation – these results succeeded in getting me off the low-carb diet."
Even more important, he notes, the findings point out that there can be a disconnect between weight loss or serum markers and vascular health, and that vascular health can be affected by macronutrients other than fat and cholesterol – in this case, protein and carbohydrates.
"Understanding the mechanisms responsible for these effects, as well as the potential restorative capacity that may counteract vascular disease, could ultimately help guide doctors in advising their patients," adds Rosenzweig. "This issue is particularly important given the growing epidemic of obesity and its adverse consequences. For now, it appears that a moderate and balanced diet, coupled with regular exercise, is probably best for most people."
Now, a study led by a scientific team at Beth Israel Deaconess Medical Center (BIDMC) provides some of the first data on this subject, demonstrating that mice placed on a 12-week low carbohydrate/high-protein diet showed a significant increase in atherosclerosis, a buildup of plaque in the heart's arteries and a leading cause of heart attack and stroke. The findings also showed that the diet led to an impaired ability to form new blood vessels in tissues deprived of blood flow, as might occur during a heart attack.
Described in today's Online Version of the Proceedings of the National Academy of Sciences (PNAS), the study also found that standard markers of cardiovascular risk, including cholesterol, were not changed in the animals fed the low-carb diet, despite the clear evidence of increased vascular disease.
"It's very difficult to know in clinical studies how diets affect vascular health," says senior author Anthony Rosenzweig, MD, Director of Cardiovascular Research in BIDMC's CardioVascular Institute and Professor of Medicine at Harvard Medical School. "We, therefore, tend to rely on easily measured serum markers [such as cholesterol], which have been surprisingly reassuring in individuals on low-carbohydrate/high-protein diets, who do typically lose weight. But our research suggests that, at least in animals, these diets could be having adverse cardiovascular effects that are not reflected in simple serum markers."
Rosenzweig and his coauthors found that the increase in plaque build-up in the blood vessels and the impaired ability to form new vessels were associated with a reduction in vascular progenitor cells, which some hypothesize could play a protective role in maintaining vascular health.
"A causal role for these cells has not yet been proven, but this new data is consistent with the idea that injurious stimuli may be counterbalanced by the body's restorative capacity," he explains. "This may be the mechanism behind the adverse vascular effects we found in mice that were fed the low-carb diets."
The study's first author Shi Yin Foo, MD, PhD, a clinical cardiologist in the Rosenzweig laboratory at BIDMC, first embarked on this investigation after seeing heart-attack patients who were on these diets – and after observing Rosenzweig himself following a low-carbohydrate regimen.
"Over lunch, I'd ask Tony how he could eat that food and would tell him about the last low-carb patient I'd admitted to the hospital," says Foo. "Tony would counter by noting that there were no controls for my observations."
"Finally," adds Rosenzweig, "I asked Shi Yin to do the mouse experiment – so that we could know what happens in the blood vessels and so that I could eat in peace."
The investigators proceeded to study a mouse model of atherosclerosis. These "ApoE" mice were fed one of three diets: a standard diet of mouse "chow" (65 percent carbohydrate; 15 percent fat; 20 percent protein); a "Western diet" in keeping with the average human diet (43 percent carbohydrate; 42 percent fat; 15 percent protein; and 0.15 percent cholesterol); or a low-carb/high-protein diet (12 percent carbohydrate; 43 percent fat; 45 percent protein; and 0.15 percent cholesterol).
"We had a diet specially made that would mimic a typical low-carb diet," explains Foo. "In order to keep the calorie count the same in all three diets, we had to substitute a nutrient to replace the carbohydrates. We decided to substitute protein because that is what people typically do when they are on these diets."
The scientists then observed the mice after six weeks, and again at 12 weeks. Consistent with experience in humans, the mice fed the low-carb diet gained 28 percent less weight than the mice fed the Western diet. However, further probing revealed that the animals' blood vessels exhibited a significantly greater degree of atherosclerosis, as measured by plaque accumulation: 15.3 percent compared with 8.8 percent among the Western diet group. (As expected, the mice on the chow diet showed minimal evidence of atherosclerosis compared with either of the other two groups.)
"Our next question was, 'Why do the low-carb mice have such an increase in atherosclerosis?'" says Foo. Searching for an explanation, she and her coauthors proceeded to measure the usual markers thought to contribute to vascular disease, including the animals' cholesterol and triglyceride levels, oxidative stress, insulin and glucose, as well as levels of some inflammatory cytokines.
"In each case, there was either no difference in measurements compared with the mice on the Western Diet [which contains the same amount of fat and cholesterol] or the numbers slightly favored the low-carb cohort," she adds. "None of these results explained why the animals' blood had more atherosclerotic blockages and looked so bad."
Since there was no difference in the noxious or inflammatory stimuli that the animals' blood vessels were exposed to, Foo wondered whether the restorative capacity of the animals might be contributing to the difference. The investigators, therefore, looked at the animals' endothelial or vascular progenitor cell (EPC) counts. Derived from bone marrow, the EPC cells may play a role in vessel regrowth and repair following injury.
"Examinations of the animals' bone marrow and peripheral blood showed that the measures of EPC cells dropped fully 40 percent among the mice on the low-carb diet – after only two weeks," says Rosenzweig. "Although the precise nature and role of these cells is still being worked out – and caution is always warranted in extrapolating from effects in mice to a clinical situation – these results succeeded in getting me off the low-carb diet."
Even more important, he notes, the findings point out that there can be a disconnect between weight loss or serum markers and vascular health, and that vascular health can be affected by macronutrients other than fat and cholesterol – in this case, protein and carbohydrates.
"Understanding the mechanisms responsible for these effects, as well as the potential restorative capacity that may counteract vascular disease, could ultimately help guide doctors in advising their patients," adds Rosenzweig. "This issue is particularly important given the growing epidemic of obesity and its adverse consequences. For now, it appears that a moderate and balanced diet, coupled with regular exercise, is probably best for most people."
Cranberry juice fails to cut it
Current clinical evidence for using cranberry juice to combat urinary tract infections is 'unsatisfactory and inconclusive', according to Raul Raz.
"An apple a day..." Not all medical problems require a state-of-the-art solution, and it would be nice to think that products from the corner shop could treat a widespread and uncomfortable ailment. Cranberry juice and related products have been touted as a simple solution for urinary tract infections, but Raul Raz, a member of F1000 Medicine, finds little to support this claim.
Urinary tract infections (UTIs) are a common complaint. Between 10% and 20% of women will suffer a UTI at least once, and a third of these will experience it recurrently. Some recent studies support the use of cranberry as a preventative, but Dr Raz, Director of Infectious Diseases at the Technion School of Medicine in Israel, and his associate Faculty Member, Hana Edelstein, advise the medical community that "cranberry should no longer be considered as an effective [preventative] for recurrent UTIs".
Cranberry contains hundreds of compounds, and it has been difficult to determine which might be responsible for any therapeutic effect, hindering its adoption. Raz and Edelstein point to differences in clinical trial design and the lack of standardization for doses and formulation. There is a range of potential side-effects including stomach upsets and weight gain. Cranberry can also interact badly with other medicines such as Warfarin, commonly used to treat heart disease.
In any event, up to 55% of patients discontinue cranberry therapy after a short time. It would seem that the public have already voted with their feet.
The full text of this evaluation is available here:
"An apple a day..." Not all medical problems require a state-of-the-art solution, and it would be nice to think that products from the corner shop could treat a widespread and uncomfortable ailment. Cranberry juice and related products have been touted as a simple solution for urinary tract infections, but Raul Raz, a member of F1000 Medicine, finds little to support this claim.
Urinary tract infections (UTIs) are a common complaint. Between 10% and 20% of women will suffer a UTI at least once, and a third of these will experience it recurrently. Some recent studies support the use of cranberry as a preventative, but Dr Raz, Director of Infectious Diseases at the Technion School of Medicine in Israel, and his associate Faculty Member, Hana Edelstein, advise the medical community that "cranberry should no longer be considered as an effective [preventative] for recurrent UTIs".
Cranberry contains hundreds of compounds, and it has been difficult to determine which might be responsible for any therapeutic effect, hindering its adoption. Raz and Edelstein point to differences in clinical trial design and the lack of standardization for doses and formulation. There is a range of potential side-effects including stomach upsets and weight gain. Cranberry can also interact badly with other medicines such as Warfarin, commonly used to treat heart disease.
In any event, up to 55% of patients discontinue cranberry therapy after a short time. It would seem that the public have already voted with their feet.
The full text of this evaluation is available here:
Apples Update
An apple a day can keep the breast-cancer away
Six studies published in the past year by a Cornell researcher add to growing evidence that an apple a day -- as well as daily helpings of other fruits and vegetables -- can help keep the breast-cancer doctor away.
In one of his recent papers, published in the Journal of Agricultural and Food Chemistry (57:1), Rui Hai Liu, Cornell associate professor of food science and a member of Cornell's Institute for Comparative and Environmental Toxicology, reports that fresh apple extracts significantly inhibited the size of mammary tumors in rats -- and the more extracts they were given, the greater the inhibition.
"We not only observed that the treated animals had fewer tumors, but the tumors were smaller, less malignant and grew more slowly compared with the tumors in the untreated rats," said Liu, pointing out that the study confirmed the findings of his preliminary study in rats published in 2007.
In his latest study, for example, he found that a type of adenocarcinoma -- a highly malignant tumor and the main cause of death of breast-cancer patients, as well as of animals with mammary cancer -- was evident in 81 percent of tumors in the control animals. However, it developed in only 57 percent, 50 percent and 23 percent of the rats fed low, middle and high doses of apple extracts (the equivalent of one, three and six apples a day in humans), respectively, during the 24-week study.
"That reflects potent anti-proliferative [rapid decrease] activity," said Liu.
The studies highlight the important role of phytochemicals, known as phenolics or flavonoids, found in apples and other fruits and vegetables. Of the top 25 fruits consumed in the United States, Liu reported in the same journal (56:18) that apples provide 33 percent of the phenolics that Americans consume annually._In a study of apple peel published in the same journal (56:21), Liu reported on a variety of new phenolic compounds that he discovered that also have "potent antioxidant and anti-proliferative activities" on tumors. And in yet another study in the same journal (56:24), he reported on his discovery of the specific modulation effects that apple extracts have on cell cycle machinery. Recently, Liu's group also reported the finding that apple phytochemicals inhibit an important inflammation pathway (NFkB) in human breast cancer cells.
Breast cancer is the most frequently diagnosed invasive cancer and the second leading cause of cancer deaths in women in the United States, said Liu._"These studies add to the growing evidence that increased consumption of fruits and vegetables, including apples, would provide consumers with more phenolics, which are proving to have important health benefits. I would encourage consumers to eat more and a wide variety of fruits and vegetables daily."
Saturday, August 22, 2009
Low vitamin D raises heart disease risks in diabetics
Research shows why
Low levels of vitamin D are known to nearly double the risk of cardiovascular disease in patients with diabetes, and researchers at Washington University School of Medicine in St. Louis now think they know why.
They have found that diabetics deficient in vitamin D can't process cholesterol normally, so it builds up in their blood vessels, increasing the risk of heart attack and stroke. The new research has identified a mechanism linking low vitamin D levels to heart disease risk and may lead to ways to fix the problem, simply by increasing levels of vitamin D.
"Vitamin D inhibits the uptake of cholesterol by cells called macrophages," says principal investigator Carlos Bernal-Mizrachi, M.D., a Washington University endocrinologist at Barnes-Jewish Hospital. "When people are deficient in vitamin D, the macrophage cells eat more cholesterol, and they can't get rid of it. The macrophages get clogged with cholesterol and become what scientists call foam cells, which are one of the earliest markers of atherosclerosis."
Macrophages are dispatched by the immune system in response to inflammation and often are activated by diseases such as diabetes. Bernal-Mizrachi and his colleagues believe that in diabetic patients with inadequate vitamin D, macrophages become loaded with cholesterol and eventually stiffen blood vessels and block blood flow.
Bernal-Mizrachi, an assistant professor of medicine and of cell biology and physiology, studied macrophage cells taken from people with and without diabetes and with and without vitamin D deficiency. His team, led by research assistants Jisu Oh and Sherry Weng, M.D., exposed the cells to cholesterol and to high or low vitamin D levels. When vitamin D levels were low in the culture dish, macrophages from diabetic patients were much more likely to become foam cells.
In the Aug. 25 issue of the journal Circulation, which currently is available online, the team reports that vitamin D regulates signaling pathways linked both to uptake and to clearance of cholesterol in macrophages.
"Cholesterol is transported through the blood attached to lipoproteins such as LDL, the 'bad' cholesterol," Bernal-Mizrachi explains. "As it is stimulated by oxygen radicals in the vessel wall, LDL becomes oxidated, and macrophages eat it uncontrollably. LDL cholesterol then clogs the macrophages, and that's how atherosclerosis begins."
That process becomes accelerated when a person is deficient in vitamin D. And people with type 2 diabetes are very likely to have this deficiency. Worldwide, approximately one billion people have insufficient vitamin D levels, and in women with type 2 diabetes, the likelihood of low vitamin D is about a third higher than in women of the same age who don't have diabetes.
The skin manufactures vitamin D in response to ultraviolet light exposure. But in much of the United States, people don't make enough vitamin D during the winter — when the sun's rays are weaker and more time is spent indoors.
The good news is when human macrophages are placed in an environment with plenty of vitamin D, their uptake of cholesterol is suppressed, and they don't become foam cells. Bernal-Mizrachi believes it may be possible to slow or reverse the development of atherosclerosis in patients with diabetes by helping them regain adequate vitamin D levels.
"There is debate about whether any amount of sun exposure is safe, so oral vitamin D supplements may work best," he says, "but perhaps if people were exposed to sunlight only for a few minutes at a time, that may be an option, too."
He has launched a new study of diabetics who are both deficient in vitamin D and have high blood pressure. He wants to learn whether replacing vitamin D will lower blood pressure and improve blood flow. For this study, Bernal-Mizrachi is recruiting patients with type 2 diabetes ages 30 to 80 who are not taking insulin to control their blood sugar. Study volunteers also must have high blood pressure.
For more information, contact mpetty@DOM.wustl.edu or call (314) 362-0934.
Oh J, Weng S, Felton SK, Bhandare S, Riek A, Butler B, Proctor BM, Petty M, Chen Z, Schechtman KB, Bernal-Mizrach L, Bernal-Mizrachi C. 1,25 (OH) vitamin D inhibits foam cell formation and suppresses macrophage cholesterol uptake in patients with type 2 diabetes mellitus. Circulation, vol. 120(8);pp. 687-698. Aug. 25. 2009. Published online August 10, 2009 doi:10.1161/CIRCULATIONAHA.109.856070
Funding for this research comes from a grant from the American Diabetes Association, the National Institutes of Health — through grants awarded to the Washington University Diabetes Research and Training Center and the Clinical Nutrition Research Unit — and the David M. and Paula S. Kipnis Scholar in Medicine Award.
Washington University School of Medicine's 2,100 employed and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children's Hospitals. The School of Medicine is one of the leading medical research, teaching, and patient care institutions in the nation, currently ranked third in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children's Hospitals, the School of Medicine is linked to BJC HealthCare.
Low levels of vitamin D are known to nearly double the risk of cardiovascular disease in patients with diabetes, and researchers at Washington University School of Medicine in St. Louis now think they know why.
They have found that diabetics deficient in vitamin D can't process cholesterol normally, so it builds up in their blood vessels, increasing the risk of heart attack and stroke. The new research has identified a mechanism linking low vitamin D levels to heart disease risk and may lead to ways to fix the problem, simply by increasing levels of vitamin D.
"Vitamin D inhibits the uptake of cholesterol by cells called macrophages," says principal investigator Carlos Bernal-Mizrachi, M.D., a Washington University endocrinologist at Barnes-Jewish Hospital. "When people are deficient in vitamin D, the macrophage cells eat more cholesterol, and they can't get rid of it. The macrophages get clogged with cholesterol and become what scientists call foam cells, which are one of the earliest markers of atherosclerosis."
Macrophages are dispatched by the immune system in response to inflammation and often are activated by diseases such as diabetes. Bernal-Mizrachi and his colleagues believe that in diabetic patients with inadequate vitamin D, macrophages become loaded with cholesterol and eventually stiffen blood vessels and block blood flow.
Bernal-Mizrachi, an assistant professor of medicine and of cell biology and physiology, studied macrophage cells taken from people with and without diabetes and with and without vitamin D deficiency. His team, led by research assistants Jisu Oh and Sherry Weng, M.D., exposed the cells to cholesterol and to high or low vitamin D levels. When vitamin D levels were low in the culture dish, macrophages from diabetic patients were much more likely to become foam cells.
In the Aug. 25 issue of the journal Circulation, which currently is available online, the team reports that vitamin D regulates signaling pathways linked both to uptake and to clearance of cholesterol in macrophages.
"Cholesterol is transported through the blood attached to lipoproteins such as LDL, the 'bad' cholesterol," Bernal-Mizrachi explains. "As it is stimulated by oxygen radicals in the vessel wall, LDL becomes oxidated, and macrophages eat it uncontrollably. LDL cholesterol then clogs the macrophages, and that's how atherosclerosis begins."
That process becomes accelerated when a person is deficient in vitamin D. And people with type 2 diabetes are very likely to have this deficiency. Worldwide, approximately one billion people have insufficient vitamin D levels, and in women with type 2 diabetes, the likelihood of low vitamin D is about a third higher than in women of the same age who don't have diabetes.
The skin manufactures vitamin D in response to ultraviolet light exposure. But in much of the United States, people don't make enough vitamin D during the winter — when the sun's rays are weaker and more time is spent indoors.
The good news is when human macrophages are placed in an environment with plenty of vitamin D, their uptake of cholesterol is suppressed, and they don't become foam cells. Bernal-Mizrachi believes it may be possible to slow or reverse the development of atherosclerosis in patients with diabetes by helping them regain adequate vitamin D levels.
"There is debate about whether any amount of sun exposure is safe, so oral vitamin D supplements may work best," he says, "but perhaps if people were exposed to sunlight only for a few minutes at a time, that may be an option, too."
He has launched a new study of diabetics who are both deficient in vitamin D and have high blood pressure. He wants to learn whether replacing vitamin D will lower blood pressure and improve blood flow. For this study, Bernal-Mizrachi is recruiting patients with type 2 diabetes ages 30 to 80 who are not taking insulin to control their blood sugar. Study volunteers also must have high blood pressure.
For more information, contact mpetty@DOM.wustl.edu or call (314) 362-0934.
Oh J, Weng S, Felton SK, Bhandare S, Riek A, Butler B, Proctor BM, Petty M, Chen Z, Schechtman KB, Bernal-Mizrach L, Bernal-Mizrachi C. 1,25 (OH) vitamin D inhibits foam cell formation and suppresses macrophage cholesterol uptake in patients with type 2 diabetes mellitus. Circulation, vol. 120(8);pp. 687-698. Aug. 25. 2009. Published online August 10, 2009 doi:10.1161/CIRCULATIONAHA.109.856070
Funding for this research comes from a grant from the American Diabetes Association, the National Institutes of Health — through grants awarded to the Washington University Diabetes Research and Training Center and the Clinical Nutrition Research Unit — and the David M. and Paula S. Kipnis Scholar in Medicine Award.
Washington University School of Medicine's 2,100 employed and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children's Hospitals. The School of Medicine is one of the leading medical research, teaching, and patient care institutions in the nation, currently ranked third in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children's Hospitals, the School of Medicine is linked to BJC HealthCare.
Friday, August 21, 2009
Jon's Health Tips - Eating Right
Quite a few research reports published in the last 2 weeks focus on good and bad food choices. I try to avoid the bad foods, not always with success, but make up for it by eating lots of the good foods (not great for weight loss, however.)
Here’s a summary of food related research published in the last 2 weeks. Other interesting research from the same time period follows.
Oxycholesterol may pose greatest heart disease risk
High levels of total cholesterol and LDL cholesterol (the so-called "bad" cholesterol) can increase the risk of heart attacks. Now scientists are reporting that another form of cholesterol called oxycholesterol — virtually unknown to the public — may be the most serious cardiovascular health threat of all.
Fried and processed food, particularly fast-food, contains high amounts of oxycholesterol. Avoiding these foods and eating a diet that is rich in antioxidants, such as fresh fruits and vegetables, may help reduce its levels in the body, the researchers note.
Scientists have known for years that a reaction between fats and oxygen, a process termed oxidation, produces oxycholesterol in the body. Oxidation occurs, for instance, when fat-containing foods are heated, as in frying chicken or grilling burgers or steaks. Food manufacturers produce oxycholesterol intentionally in the form of oxidized oils such as trans-fatty acids and partially-hydrogenated vegetable oils. When added to processed foods, those substances improve texture, taste and stability. Until now, however, much of the research focused on oxycholesterol's effects in damaging cells, DNA, and its biochemical effects in contributing to atherosclerosis. This is one of the first studies on oxycholesterol's effects in raising blood cholesterol levels compared to non-oxidized cholesterol.
Details here:
Whole grain cereals, popcorn rich in antioxidants
Snack foods like popcorn and many popular breakfast cereals contain "surprisingly large" amounts of healthful antioxidant substances called "polyphenols."
Polyphenols are a major reason why fruits and vegetables — and foods like chocolate, wine, coffee, and tea — have become renowned for their potential role in reducing the risk of heart disease, cancer, and other diseases.
Until now, however, no one knew that commercial hot and cold whole grain cereals — regarded as healthful for their fiber content — and snack foods also were a source of polyphenols.
Details here:
Asparagus Good For Hangovers, Livers
The amino acids and minerals found in asparagus extract may alleviate alcohol hangover and protect liver cells against toxins.
Details here:
Healthy Diet = No Kidney Stones
Researchers have found another reason to eat well: a healthy diet helps prevent kidney stones. Loading up on fruits, vegetables, nuts, low-fat dairy products, and whole grains, while limiting salt, red and processed meats, and sweetened beverages is an effective way to ward off kidney stones. Because kidney stones are linked to higher rates of hypertension, diabetes, increased body weight, and other risk factors for heart disease, the findings have considerable health implications.
Details here:
High-fat diets make us stupid and unfit
New research shows that high-fat diets are just as unhealthful in the short term as they are in the long term: an immediate decreased ability to exercise and significant short-term memory loss.
Details here:
Mediterranean Diet = Slower Cognitive Decline
Higher adherence to a Mediterranean-type diet is linked to lower risk for mortality and chronic diseases. In an examination of the association between adherence to a Mediterranean-type diet and cognitive performance and risk of dementia, researchers found that high adherence to the diet was associated with slower decline in some measures of cognitive function.
Details here:
Mediterranean diet, exercise fight Alzheimer disease
Elderly individuals who had a diet that included higher consumption of fruits, vegetables, legumes, cereal and fish and was low in red meat and poultry and who were physically active had an associated lower risk of Alzheimer disease
Details here:
A summary of earlier, but still relatively recent food research can be found here:
Meanwhile, from the last two weeks:
Healthy lifestyle = reduced risk of chronic disease
Four healthy lifestyle factors—never smoking, maintaining a healthy weight, exercising regularly and following a healthy diet—together appear to be associated with as much as an 80 percent reduction in the risk of developing the most common and deadly chronic diseases.
Details here:
But:
Physical inactivity poses greatest health risk
And something else to worry about:
Stress and Worry Can Be Hazardous to Your Health
But
Optimism=lower women’s risk of death/heart disease
And two of my old favorites re-appear, aspirin:
Aspirin fights colorectal cancer
Numerous studies demonstrate that regular aspirin use is associated with a lower risk of colorectal adenoma (a benign tumor) or cancer. According to a study in the August 12 issue of J o u r n a l o f t h e A m e r i c a n Medical Association..men and women who were diagnosed with colorectal cancer and began regular use of aspirin had a lower risk of overall and colorectal cancer death compared to patients not using aspirin.
Details here:
and red wine:
Drink Red Wine Daily For Best Results
Drinking Wine Protects Skin From Radiation
And lastly:
Danger in Herbal Supplements
Here’s a summary of food related research published in the last 2 weeks. Other interesting research from the same time period follows.
Oxycholesterol may pose greatest heart disease risk
High levels of total cholesterol and LDL cholesterol (the so-called "bad" cholesterol) can increase the risk of heart attacks. Now scientists are reporting that another form of cholesterol called oxycholesterol — virtually unknown to the public — may be the most serious cardiovascular health threat of all.
Fried and processed food, particularly fast-food, contains high amounts of oxycholesterol. Avoiding these foods and eating a diet that is rich in antioxidants, such as fresh fruits and vegetables, may help reduce its levels in the body, the researchers note.
Scientists have known for years that a reaction between fats and oxygen, a process termed oxidation, produces oxycholesterol in the body. Oxidation occurs, for instance, when fat-containing foods are heated, as in frying chicken or grilling burgers or steaks. Food manufacturers produce oxycholesterol intentionally in the form of oxidized oils such as trans-fatty acids and partially-hydrogenated vegetable oils. When added to processed foods, those substances improve texture, taste and stability. Until now, however, much of the research focused on oxycholesterol's effects in damaging cells, DNA, and its biochemical effects in contributing to atherosclerosis. This is one of the first studies on oxycholesterol's effects in raising blood cholesterol levels compared to non-oxidized cholesterol.
Details here:
Whole grain cereals, popcorn rich in antioxidants
Snack foods like popcorn and many popular breakfast cereals contain "surprisingly large" amounts of healthful antioxidant substances called "polyphenols."
Polyphenols are a major reason why fruits and vegetables — and foods like chocolate, wine, coffee, and tea — have become renowned for their potential role in reducing the risk of heart disease, cancer, and other diseases.
Until now, however, no one knew that commercial hot and cold whole grain cereals — regarded as healthful for their fiber content — and snack foods also were a source of polyphenols.
Details here:
Asparagus Good For Hangovers, Livers
The amino acids and minerals found in asparagus extract may alleviate alcohol hangover and protect liver cells against toxins.
Details here:
Healthy Diet = No Kidney Stones
Researchers have found another reason to eat well: a healthy diet helps prevent kidney stones. Loading up on fruits, vegetables, nuts, low-fat dairy products, and whole grains, while limiting salt, red and processed meats, and sweetened beverages is an effective way to ward off kidney stones. Because kidney stones are linked to higher rates of hypertension, diabetes, increased body weight, and other risk factors for heart disease, the findings have considerable health implications.
Details here:
High-fat diets make us stupid and unfit
New research shows that high-fat diets are just as unhealthful in the short term as they are in the long term: an immediate decreased ability to exercise and significant short-term memory loss.
Details here:
Mediterranean Diet = Slower Cognitive Decline
Higher adherence to a Mediterranean-type diet is linked to lower risk for mortality and chronic diseases. In an examination of the association between adherence to a Mediterranean-type diet and cognitive performance and risk of dementia, researchers found that high adherence to the diet was associated with slower decline in some measures of cognitive function.
Details here:
Mediterranean diet, exercise fight Alzheimer disease
Elderly individuals who had a diet that included higher consumption of fruits, vegetables, legumes, cereal and fish and was low in red meat and poultry and who were physically active had an associated lower risk of Alzheimer disease
Details here:
A summary of earlier, but still relatively recent food research can be found here:
Meanwhile, from the last two weeks:
Healthy lifestyle = reduced risk of chronic disease
Four healthy lifestyle factors—never smoking, maintaining a healthy weight, exercising regularly and following a healthy diet—together appear to be associated with as much as an 80 percent reduction in the risk of developing the most common and deadly chronic diseases.
Details here:
But:
Physical inactivity poses greatest health risk
And something else to worry about:
Stress and Worry Can Be Hazardous to Your Health
But
Optimism=lower women’s risk of death/heart disease
And two of my old favorites re-appear, aspirin:
Aspirin fights colorectal cancer
Numerous studies demonstrate that regular aspirin use is associated with a lower risk of colorectal adenoma (a benign tumor) or cancer. According to a study in the August 12 issue of J o u r n a l o f t h e A m e r i c a n Medical Association..men and women who were diagnosed with colorectal cancer and began regular use of aspirin had a lower risk of overall and colorectal cancer death compared to patients not using aspirin.
Details here:
and red wine:
Drink Red Wine Daily For Best Results
Drinking Wine Protects Skin From Radiation
And lastly:
Danger in Herbal Supplements
Thursday, August 20, 2009
Oxycholesterol may pose greatest heart disease risk
Health-conscious people know that high levels of total cholesterol and LDL cholesterol (the so-called "bad" cholesterol) can increase the risk of heart attacks. Now scientists are reporting that another form of cholesterol called oxycholesterol — virtually unknown to the public — may be the most serious cardiovascular health threat of all. Scientists from China presented one of the first studies on the cholesterol-boosting effects of oxycholesterol here today at the 238th National Meeting of the American Chemical Society. The researchers hope their findings raise public awareness about oxycholesterol, including foods with the highest levels of the substance and other foods that can combat oxycholesterol's effects.
"Total cholesterol, low-density lipoprotein cholesterol (LDL), and the heart-healthy high-density lipoprotein cholesterol (HDL) are still important health issues," says study leader Zhen-Yu Chen, Ph.D., of Chinese University of Hong Kong. "But the public should recognize that oxycholesterol is also important and cannot be ignored. Our work demonstrated that oxycholesterol boosts total cholesterol levels and promotes atherosclerosis ["hardening of the arteries"] more than non-oxidized cholesterol."
Fried and processed food, particularly fast-food, contains high amounts of oxycholesterol. Avoiding these foods and eating a diet that is rich in antioxidants, such as fresh fruits and vegetables, may help reduce its levels in the body, the researchers note.
Scientists have known for years that a reaction between fats and oxygen, a process termed oxidation, produces oxycholesterol in the body. Oxidation occurs, for instance, when fat-containing foods are heated, as in frying chicken or grilling burgers or steaks. Food manufacturers produce oxycholesterol intentionally in the form of oxidized oils such as trans-fatty acids and partially-hydrogenated vegetable oils. When added to processed foods, those substances improve texture, taste and stability. Until now, however, much of the research focused on oxycholesterol's effects in damaging cells, DNA, and its biochemical effects in contributing to atherosclerosis. Chen believes this is one of the first studies on oxycholesterol's effects in raising blood cholesterol levels compared to non-oxidized cholesterol.
In the new study, Chen's group measured the effects of a diet high in oxycholesterol on hamsters, often used as surrogates for humans in such research. Blood cholesterol in hamsters fed oxycholesterol rose up to 22 percent more than hamsters eating non-oxidized cholesterol. The oxycholesterol group showed greater deposition of cholesterol in the lining of their arteries and a tendency to develop larger deposits of cholesterol. These fatty deposits, called atherosclerotic plaques, increase the risk for heart attack and stroke.
Most importantly, according to Chen, oxycholesterol had undesirable effects on "artery function." Oxycholesterol reduced the elasticity of arteries, impairing their ability to expand and carry more blood. That expansion can allow more blood to flow through arteries that are partially blocked by plaques, potentially reducing the risk that a clot will form and cause a heart attack or stroke.
But a healthy diet rich in antioxidants can counter these effects, Chen said, noting that these substances may block the oxidation process that forms oxycholesterol. Good sources of antioxidants include fruits, veggies, beans, and certain herbs and spices. Healthy alternatives to fast-food, which also boosts oxycholesterol, include whole grains, fresh fruits and vegetables, seeds, and nuts.
Scientists do not know whether the popular anti-cholesterol drugs called statins lower oxycholesterol, Chen said.
Tuesday, August 18, 2009
Whole grain cereals, popcorn rich in antioxidants
In a first-of-its kind study, scientists reported today at the 238th National Meeting of the American Chemical Society (ACS) that snack foods like popcorn and many popular breakfast cereals contain "surprisingly large" amounts of healthful antioxidant substances called "polyphenols."
Polyphenols are a major reason why fruits and vegetables — and foods like chocolate, wine, coffee, and tea — have become renowned for their potential role in reducing the risk of heart disease, cancer, and other diseases.
Until now, however, no one knew that commercial hot and cold whole grain cereals — regarded as healthful for their fiber content — and snack foods also were a source of polyphenols.
"Early researchers thought the fiber was the active ingredient for these benefits in whole grains, the reason why they may reduce the risk of cancer and coronary heart disease," said Joe Vinson, Ph.D., who headed the new study. "But recently, polyphenols emerged as potentially more important. Breakfast cereals, pasta, crackers, and salty snacks constitute over 66 percent of whole grain intake in the U.S. diet."
Vinson, a chemist at the University of Scranton in Pennsylvania, said "We found that, in fact, whole grain products have comparable antioxidants per gram to fruits and vegetables. This is the first study to examine total phenol antioxidants in breakfast cereals and snacks, whereas previous studies have measured free antioxidants in the products."
Polyphenols are a group of chemicals found in many fruits, vegetables, and other plants, such as berries, walnuts, olives, tea leaves and grapes. Known as antioxidants, they remove free radicals from the body. Free radicals are chemicals that have the potential to cause damage to cells and tissues in the body.
The whole grain cereal with the most antioxidants are made with wheat, with corn, oats and rice cereals following in descending order, according to Vinson. He also noted that raisin bran has the highest amount of antioxidants per serving, primarily due to the raisins.
Bran cereals made from wheat overall do not have more antioxidants than wheat cereals, though they do have more fiber, he said. In other findings, he said that whole grain flours are very high in antioxidants; whole grain snacks have slightly lower levels of antioxidants than cereals; of snacks, popcorn has the highest level of antioxidants; and there is a wide variation in the amount of antioxidants in each class of cold cereal.
Stress and Worry Can Be Hazardous to Your Health
Study: Personality Traits Associated With Stress and Worry Can Be Hazardous to Your Health
Personality traits associated with chronic worrying can lead to earlier death, at least in part because these people are more likely to engage in unhealthy behaviors, such as smoking, according to research from Purdue University.
"Research shows that higher levels of neuroticism can lead to earlier mortality, and we wanted to know why," said Daniel K. Mroczek, (pronounced Mro-ZAK) a professor of child development and family studies. "We found that having worrying tendencies or being the kind of person who stresses easily is likely to lead to bad behaviors like smoking and, therefore, raise the mortality rate."
"This work is a reminder that high levels of some personality traits can be hazardous to one's physical health."
Chronic worrying, anxiety and being prone to depression are key aspects of the personality trait of neuroticism. In this study, the researchers looked at how smoking and heavy drinking are associated with the trait. A person with high neuroticism is likely to experience anxiety or depression and may self-medicate with tobacco, alcohol or drugs as a coping mechanism.
They found that smoking accounted for about 25 percent to 40 percent of the association between high neuroticism and mortality. The other 60 percent is unexplained, but possibly attributed to biological factors or other environmental issues that neurotic individuals experience, Mroczek said.
The researchers analyzed data of 1,788 men and their smoking behavior and personality traits over a 30-year period from 1975 to 2005. The data was part of the VA Normative Aging Study, which is a long-term study of aging men based at the Boston VA Outpatient Clinic.
Mroczek and his co-authors, Avron Spiro III and Nicholas A. Turiano, published their findings in this month's Journal of Research in Personality.
A better understanding of the bridge between personality traits and physical health can perhaps help clinicians improve intervention and prevention programs, Mroczek said.
"For example, programs that target people high in neuroticism may get bigger bang for the buck than more widespread outreach efforts," he said. "It also may be possible to use personality traits to identify people who, because of their predispositions, are at risk for engaging in poor health behaviors such as smoking or excessive drinking."
Personality traits associated with chronic worrying can lead to earlier death, at least in part because these people are more likely to engage in unhealthy behaviors, such as smoking, according to research from Purdue University.
"Research shows that higher levels of neuroticism can lead to earlier mortality, and we wanted to know why," said Daniel K. Mroczek, (pronounced Mro-ZAK) a professor of child development and family studies. "We found that having worrying tendencies or being the kind of person who stresses easily is likely to lead to bad behaviors like smoking and, therefore, raise the mortality rate."
"This work is a reminder that high levels of some personality traits can be hazardous to one's physical health."
Chronic worrying, anxiety and being prone to depression are key aspects of the personality trait of neuroticism. In this study, the researchers looked at how smoking and heavy drinking are associated with the trait. A person with high neuroticism is likely to experience anxiety or depression and may self-medicate with tobacco, alcohol or drugs as a coping mechanism.
They found that smoking accounted for about 25 percent to 40 percent of the association between high neuroticism and mortality. The other 60 percent is unexplained, but possibly attributed to biological factors or other environmental issues that neurotic individuals experience, Mroczek said.
The researchers analyzed data of 1,788 men and their smoking behavior and personality traits over a 30-year period from 1975 to 2005. The data was part of the VA Normative Aging Study, which is a long-term study of aging men based at the Boston VA Outpatient Clinic.
Mroczek and his co-authors, Avron Spiro III and Nicholas A. Turiano, published their findings in this month's Journal of Research in Personality.
A better understanding of the bridge between personality traits and physical health can perhaps help clinicians improve intervention and prevention programs, Mroczek said.
"For example, programs that target people high in neuroticism may get bigger bang for the buck than more widespread outreach efforts," he said. "It also may be possible to use personality traits to identify people who, because of their predispositions, are at risk for engaging in poor health behaviors such as smoking or excessive drinking."
Monday, August 17, 2009
Eating animal foods does not cause breast cancer
Studies do not support unhealthful relation between animal foods and breast cancer
Breast cancer is the 7th leading cause of mortality in the United States and results in approximately 41,000 deaths each year. Although genetic factors are important, there is considerable evidence that breast cancer risk is related to modifiable lifestyle factors, such as physical activity, body weight, alcohol intake, and dietary choices. The September 2009 issue of The American Journal of Clinical Nutrition reports the results of 3 human studies designed to better delineate the relation between animal foods and breast cancer risk.
"These studies highlight two very important points," said American Society for Nutrition Spokesperson Shelley McGuire, PhD. "First we all need to remember that there are really no such things as 'bad' foods. Second, observational studies that show associations between diet and health need to be considered with a proverbial grain of salt. These studies clearly provide additional and strong evidence that consumption of meat and dairy products by women does not, by itself, increase breast cancer risk. Further, moderate and mindful consumption of these foods can be very important in attaining optimal nutrition for most women who often do not consume sufficient iron and calcium."
In the first study, which was a controlled dietary intervention trial conducted in the United States, 35 obese postmenopausal women with type 2 diabetes received conjugated linoleic acid (CLA) supplements or a control supplement (safflower oil) each for 36 wk; adiposity was assessed. In another study, researchers examined the association between CLA intake from natural sources and breast cancer incidence in a large cohort of initially cancer-free Swedish women for 17.4 y. The third study assessed whether the consumption of meat, eggs, and dairy products was associated with breast cancer risk in a very large group of healthy European women followed for 8.8 y.
These studies provide no evidence that animal-food consumption increases (or decreases) risk of breast cancer, although CLA supplementation may decrease adiposity (a major risk factor for this disease). In an editorial, Linos and Willett remind us that these studies did not assess the relation between animal-food intake during early life and later breast cancer, a likely important piece of the puzzle. Nonetheless, they conclude, "These data are sufficient to exclude any major effect of consuming these foods during midlife or later on risk of breast cancer." Perhaps we finally have the answer to this long-standing question.
###
To access full text versions of the studies visit:
http://www.nutrition.org/media/publications/ajcnSept309.pdf
http://www.nutrition.org/media/publications/ajcnSept409.pdf
http://www.nutrition.org/media/publications/ajcnSept509.pdf
http://www.nutrition.org/media/publications/ajcnSept609.pdf
Breast cancer is the 7th leading cause of mortality in the United States and results in approximately 41,000 deaths each year. Although genetic factors are important, there is considerable evidence that breast cancer risk is related to modifiable lifestyle factors, such as physical activity, body weight, alcohol intake, and dietary choices. The September 2009 issue of The American Journal of Clinical Nutrition reports the results of 3 human studies designed to better delineate the relation between animal foods and breast cancer risk.
"These studies highlight two very important points," said American Society for Nutrition Spokesperson Shelley McGuire, PhD. "First we all need to remember that there are really no such things as 'bad' foods. Second, observational studies that show associations between diet and health need to be considered with a proverbial grain of salt. These studies clearly provide additional and strong evidence that consumption of meat and dairy products by women does not, by itself, increase breast cancer risk. Further, moderate and mindful consumption of these foods can be very important in attaining optimal nutrition for most women who often do not consume sufficient iron and calcium."
In the first study, which was a controlled dietary intervention trial conducted in the United States, 35 obese postmenopausal women with type 2 diabetes received conjugated linoleic acid (CLA) supplements or a control supplement (safflower oil) each for 36 wk; adiposity was assessed. In another study, researchers examined the association between CLA intake from natural sources and breast cancer incidence in a large cohort of initially cancer-free Swedish women for 17.4 y. The third study assessed whether the consumption of meat, eggs, and dairy products was associated with breast cancer risk in a very large group of healthy European women followed for 8.8 y.
These studies provide no evidence that animal-food consumption increases (or decreases) risk of breast cancer, although CLA supplementation may decrease adiposity (a major risk factor for this disease). In an editorial, Linos and Willett remind us that these studies did not assess the relation between animal-food intake during early life and later breast cancer, a likely important piece of the puzzle. Nonetheless, they conclude, "These data are sufficient to exclude any major effect of consuming these foods during midlife or later on risk of breast cancer." Perhaps we finally have the answer to this long-standing question.
###
To access full text versions of the studies visit:
http://www.nutrition.org/media/publications/ajcnSept309.pdf
http://www.nutrition.org/media/publications/ajcnSept409.pdf
http://www.nutrition.org/media/publications/ajcnSept509.pdf
http://www.nutrition.org/media/publications/ajcnSept609.pdf
Antioxidants do not increase melanoma risk
Antioxidant supplements do not appear to be associated with an increased risk of melanoma, according to a report in the August issue of Archives of Dermatology, one of the JAMA/Archives journals.
A recent randomized trial of antioxidants for cancer prevention found that daily supplementation with nutritionally appropriate doses of vitamins C and E, beta carotene, selenium and zinc appeared to increase the risk of melanoma in women four-fold, according to background information in the article. Because an estimated 48 percent to 55 percent of U.S. adults use vitamin or mineral supplements regularly, the potential harmful effects of these nutrients is alarming, the authors note.
Maryam M. Asgari, M.D., M.P.H., of Kaiser Permanente Northern California, Oakland, and colleagues examined the association between antioxidants and melanoma among 69,671 women and men who were participating in the Vitamins and Lifestyle (VITAL) study, designed to examine supplement use and cancer risk. At the beginning of the study, between 2000 and 2002, participants completed a 24-page questionnaire about lifestyle factors, health history, diet, supplement use and other cancer risk factors.
Intake of multivitamins and supplements during the previous 10 years, including selenium and beta carotene, was not associated with melanoma risk in either women or men. The researchers also examined the risk of melanoma associated with long-term use of supplemental beta carotene and selenium at doses comparable to the previous study and found no association.
"Consistent with the present results, case-control studies examining serologic [blood] levels of beta carotene, vitamin E and selenium did not find any association with subsequent risk of melanoma," the authors write. "Moreover, the Nurses' Health Study reported no association between intake of vitamins A, C and E and melanoma risk in 162,000 women during more than 1.6 million person-years of follow-up."
A recent randomized trial of antioxidants for cancer prevention found that daily supplementation with nutritionally appropriate doses of vitamins C and E, beta carotene, selenium and zinc appeared to increase the risk of melanoma in women four-fold, according to background information in the article. Because an estimated 48 percent to 55 percent of U.S. adults use vitamin or mineral supplements regularly, the potential harmful effects of these nutrients is alarming, the authors note.
Maryam M. Asgari, M.D., M.P.H., of Kaiser Permanente Northern California, Oakland, and colleagues examined the association between antioxidants and melanoma among 69,671 women and men who were participating in the Vitamins and Lifestyle (VITAL) study, designed to examine supplement use and cancer risk. At the beginning of the study, between 2000 and 2002, participants completed a 24-page questionnaire about lifestyle factors, health history, diet, supplement use and other cancer risk factors.
Intake of multivitamins and supplements during the previous 10 years, including selenium and beta carotene, was not associated with melanoma risk in either women or men. The researchers also examined the risk of melanoma associated with long-term use of supplemental beta carotene and selenium at doses comparable to the previous study and found no association.
"Consistent with the present results, case-control studies examining serologic [blood] levels of beta carotene, vitamin E and selenium did not find any association with subsequent risk of melanoma," the authors write. "Moreover, the Nurses' Health Study reported no association between intake of vitamins A, C and E and melanoma risk in 162,000 women during more than 1.6 million person-years of follow-up."
Drink Red Wine Daily For Best Results
The polyphenols found in red wine are thought to help prevent Alzheimer's disease, and new research from Purdue University and Mount Sinai School of Medicine has shown that some of those compounds in fact reach the brain.
Mario Ferruzzi, a Purdue associate professor of food science; Connie Weaver, Purdue's head of foods and nutrition; and Elsa Janle, a Purdue associate professor of foods and nutrition, found that the amount of polyphenols from grapeseed extract that can reach a rat's brain is as much as 200 percent higher on the 10th consecutive day of feeding as compared to the first. Many previous experiments, in which absorption was measured after single or sporadic doses, often found very little, if any, of the bioactive polyphenols reaching brain tissues. However, more chronic exposure appears to improve absorption.
"This shows that reasonable and chronic consumption of these products may be the way to go, rather than single, high doses, similar to drugs," said Ferruzzi, who collaborated on the research with Mount Sinai's Dr. Giulio Pasinetti. "It's like eating an apple a day, not a case of apples over two days every month."
A paper detailing the findings was published in the early online version of the September issue of the Journal of Alzheimer's Disease.
Polyphenols, compounds found in the skins and seeds of grapes, are thought to prevent the formation of beta-amyloid protein, which creates the plaque in the brain that causes Alzheimer's disease. Alzheimer's is a progressive brain disease that destroys memory and cognitive skills and affects as many as 4.5 million Americans, according to the National Institute on Aging.
Pasinetti, the Aidekman Family Professor in Neurology and director of the Center of Excellence for Novel Approaches to Neurotherapeutics, said discovering how polyphenols are absorbed and distributed to the brain can impact researchers' understanding of the amount of grape products or red wine a person would need to consume to most effectively combat Alzheimer's disease.
"The most important thing is that when we follow the repetitive administration of this compound, we were able to observe the transfer of the compound to the brain," Pasinetti said. "This may help us figure out the proper concentration necessary to get these chemicals to the brain."
Ferruzzi said the study dealt with polyphenols, but also could be important for determining proper doses of other compounds or drugs for patients. Testing of a pharmaceutical, for example, could show that the drug is too potent when given repetitively; whereas that might not be apparent if the drug is administered on non-consecutive days or weeks.
"It could become important in terms of side effects," Ferruzzi said. "You could be overdosing because the body is adapting and absorbing or metabolizing these compounds differently over time."
Mario Ferruzzi, a Purdue associate professor of food science; Connie Weaver, Purdue's head of foods and nutrition; and Elsa Janle, a Purdue associate professor of foods and nutrition, found that the amount of polyphenols from grapeseed extract that can reach a rat's brain is as much as 200 percent higher on the 10th consecutive day of feeding as compared to the first. Many previous experiments, in which absorption was measured after single or sporadic doses, often found very little, if any, of the bioactive polyphenols reaching brain tissues. However, more chronic exposure appears to improve absorption.
"This shows that reasonable and chronic consumption of these products may be the way to go, rather than single, high doses, similar to drugs," said Ferruzzi, who collaborated on the research with Mount Sinai's Dr. Giulio Pasinetti. "It's like eating an apple a day, not a case of apples over two days every month."
A paper detailing the findings was published in the early online version of the September issue of the Journal of Alzheimer's Disease.
Polyphenols, compounds found in the skins and seeds of grapes, are thought to prevent the formation of beta-amyloid protein, which creates the plaque in the brain that causes Alzheimer's disease. Alzheimer's is a progressive brain disease that destroys memory and cognitive skills and affects as many as 4.5 million Americans, according to the National Institute on Aging.
Pasinetti, the Aidekman Family Professor in Neurology and director of the Center of Excellence for Novel Approaches to Neurotherapeutics, said discovering how polyphenols are absorbed and distributed to the brain can impact researchers' understanding of the amount of grape products or red wine a person would need to consume to most effectively combat Alzheimer's disease.
"The most important thing is that when we follow the repetitive administration of this compound, we were able to observe the transfer of the compound to the brain," Pasinetti said. "This may help us figure out the proper concentration necessary to get these chemicals to the brain."
Ferruzzi said the study dealt with polyphenols, but also could be important for determining proper doses of other compounds or drugs for patients. Testing of a pharmaceutical, for example, could show that the drug is too potent when given repetitively; whereas that might not be apparent if the drug is administered on non-consecutive days or weeks.
"It could become important in terms of side effects," Ferruzzi said. "You could be overdosing because the body is adapting and absorbing or metabolizing these compounds differently over time."
Thursday, August 13, 2009
Danger in Herbal Supplements
St. John’s wort: This supplement can greatly increase or decrease the potency of many medications and cause serious side effects. Patients who take antidepressants, anti-blood-clotting drugs, certain asthma drugs, immune-suppressing medications or steroids should probably avoid St. John’s wort.
S-adenosylmethionine (SAM-e): This can cause serious side effects when taken with antidepressant medications that affect serotonin.
Garlic, ginseng, ginger and feverfew: Patients who take anti-clotting medications such as aspirin, warfarin (Coumadin) and clopidogrel (Plavix) should avoid these supplements. They may increase the risk of bleeding. Supplements chondroitin and glucosamine also may interfere with warfarin.
Ginkgo: Ginkgo may increase the risk of bleeding in patients taking anti-clotting medications. Ginkgo can counteract the blood pressure-lowering benefits of thiazide diuretic drugs. It also can interfere with anti-seizure medications.
Kava: Kava is a sedative herb and is associated with serious liver problems, even when taken for a short time. Many medications, such as cholesterol-lowering drugs, pose a risk of liver damage. Taking kava may increase the risk of liver problems even more.
S-adenosylmethionine (SAM-e): This can cause serious side effects when taken with antidepressant medications that affect serotonin.
Garlic, ginseng, ginger and feverfew: Patients who take anti-clotting medications such as aspirin, warfarin (Coumadin) and clopidogrel (Plavix) should avoid these supplements. They may increase the risk of bleeding. Supplements chondroitin and glucosamine also may interfere with warfarin.
Ginkgo: Ginkgo may increase the risk of bleeding in patients taking anti-clotting medications. Ginkgo can counteract the blood pressure-lowering benefits of thiazide diuretic drugs. It also can interfere with anti-seizure medications.
Kava: Kava is a sedative herb and is associated with serious liver problems, even when taken for a short time. Many medications, such as cholesterol-lowering drugs, pose a risk of liver damage. Taking kava may increase the risk of liver problems even more.
Drinking Wine Protects Skin From Radiation
Drinking wine while undergoing radiation treatment for breast carcinoma may reduce the incidence of skin toxicity in breast cancer patients, according to a study in the August issue of the International Journal of Radiation Oncology*Biology*Physics, the official journal of the American Society for Radiation Oncology (ASTRO).
Preventing radiation therapy-induced side effects is an important part of a patient’s cancer treatment management. Several medications are available to help protect healthy organs from the effects of radiation, but they are often expensive, have side effects themselves and can provide protection to tumor cells as well as healthy cells.
Researchers at the Department of Oncology and the Center for High Technology Research and Education in Biomedical Sciences at Catholic University in Campobasso, Italy, the Catholic University Department of Radiotherapy in Rome, Italy, and at the National Research Council’s BioMatLab in Rome, Italy, conducted this study to determine if the natural antioxidants in wine would provide a radioprotective effect in preventing acute skin toxicity in patients undergoing radiation therapy after conservative surgery for breast carcinoma.
The study consisted of 348 patients divided into three groups based on the dose/fractionation scheme used. Patients consuming wine had a lower incidence of Grade 2 or higher acute toxicity than those who did not consume alcohol. Patients who drank one glass of wine per day had a 13.6 percent incidence of skin toxicity versus a 38.4 percent incidence in patients who did not drink wine. “If wine can prevent radiotherapy-induced toxicity without affecting antitumor efficacy, as we observed, it also has the potential to enhance the therapeutic benefit in cancer patients without increasing their risk of serious adverse effects,” Vincenzo Valentini, M.D., a radiation oncologist at Catholic University in Rome, Italy, one of the study authors, said. “The possibility that particular dietary practices or interventions can reduce radiation-induced toxicity is very intriguing.”
Preventing radiation therapy-induced side effects is an important part of a patient’s cancer treatment management. Several medications are available to help protect healthy organs from the effects of radiation, but they are often expensive, have side effects themselves and can provide protection to tumor cells as well as healthy cells.
Researchers at the Department of Oncology and the Center for High Technology Research and Education in Biomedical Sciences at Catholic University in Campobasso, Italy, the Catholic University Department of Radiotherapy in Rome, Italy, and at the National Research Council’s BioMatLab in Rome, Italy, conducted this study to determine if the natural antioxidants in wine would provide a radioprotective effect in preventing acute skin toxicity in patients undergoing radiation therapy after conservative surgery for breast carcinoma.
The study consisted of 348 patients divided into three groups based on the dose/fractionation scheme used. Patients consuming wine had a lower incidence of Grade 2 or higher acute toxicity than those who did not consume alcohol. Patients who drank one glass of wine per day had a 13.6 percent incidence of skin toxicity versus a 38.4 percent incidence in patients who did not drink wine. “If wine can prevent radiotherapy-induced toxicity without affecting antitumor efficacy, as we observed, it also has the potential to enhance the therapeutic benefit in cancer patients without increasing their risk of serious adverse effects,” Vincenzo Valentini, M.D., a radiation oncologist at Catholic University in Rome, Italy, one of the study authors, said. “The possibility that particular dietary practices or interventions can reduce radiation-induced toxicity is very intriguing.”
Asparagus Good For Hangovers, Livers
The amino acids and minerals found in asparagus extract may alleviate alcohol hangover and protect liver cells against toxins, according to a study in the Journal of Food Science, published by the Institute of Food Technologists.
Asparagus officinalis is a common vegetable that is widely consumed worldwide and has long been used as an herbal medicine due to its anticancer effects. It also has antifungal, anti-inflammatory and diuretic properties.
Researchers at the Institute of Medical Science and Jeju National University in Korea analyzed the components of young asparagus shoots and leaves to compare their biochemical effects on human and rat liver cells. “The amino acid and mineral contents were found to be much higher in the leaves than the shoots,” says lead researcher B.Y. Kim.
Chronic alcohol use causes oxidative stress on the liver as well as unpleasant physical effects associated with a hangover. “Cellular toxicities were significantly alleviated in response to treatment with the extracts of asparagus leaves and shoots,” says Kim. “These results provide evidence of how the biological functions of asparagus can help alleviate alcohol hangover and protect liver cells.”
Asparagus officinalis is a common vegetable that is widely consumed worldwide and has long been used as an herbal medicine due to its anticancer effects. It also has antifungal, anti-inflammatory and diuretic properties.
Researchers at the Institute of Medical Science and Jeju National University in Korea analyzed the components of young asparagus shoots and leaves to compare their biochemical effects on human and rat liver cells. “The amino acid and mineral contents were found to be much higher in the leaves than the shoots,” says lead researcher B.Y. Kim.
Chronic alcohol use causes oxidative stress on the liver as well as unpleasant physical effects associated with a hangover. “Cellular toxicities were significantly alleviated in response to treatment with the extracts of asparagus leaves and shoots,” says Kim. “These results provide evidence of how the biological functions of asparagus can help alleviate alcohol hangover and protect liver cells.”
Healthy Diet = No Kidney Stones
Researchers have found another reason to eat well: a healthy diet helps prevent kidney stones. Loading up on fruits, vegetables, nuts, low-fat dairy products, and whole grains, while limiting salt, red and processed meats, and sweetened beverages is an effective way to ward off kidney stones, according to a study appearing in an upcoming issue of the Journal of the American Society Nephrology (JASN). Because kidney stones are linked to higher rates of hypertension, diabetes, increased body weight, and other risk factors for heart disease, the findings have considerable health implications.
Eric Taylor, MD (Maine Medical Center) and his colleagues at Brigham and Women’s Hospital conducted a large study to determine the effects of healthy eating habits on the formation of kidney stones. The investigators collected information from individuals enrolled in three clinical studies: the Health Professionals Follow-up Study (45,821 men followed for 18 years), the Nurses’ Health Study I (94,108 older women followed for 18 years), and the Nurses’ Health Study II (101,837 younger women followed for 14 years).
Dr. Taylor’s team assigned a score to each participant based on eight components of a DASH (Dietary Approaches to Stop Hypertension) style diet: high intake of fruits, vegetables, nuts and legumes, low-fat dairy products, and whole grains and low intake of salt, sweetened beverages, and red and processed meats. Individuals with higher DASH scores consumed diets that were higher in calcium, potassium, magnesium, oxalate, and vitamin C and lower in sodium.
A total of 5,645 incident kidney stones developed in the participants in the three studies. In each study, participants with the highest DASH scores were between 40% and 45% less likely to develop kidney stones than participants with the lowest DASH scores. The reductions in kidney stone risk were independent of age, body size, fluid intake, and other factors.
Because a DASH-style diet may affect the development of hypertension, diabetes, and other chronic diseases associated with kidney stones, the researchers also performed an analysis limited to study participants without hypertension or diabetes. Even among those individuals the DASH diet reduced the risk of kidney stones.
Many of the medications used to treat kidney stones have unpleasant side effects. This study indicates that adopting a DASH-style diet may be an effective alternative.
Eric Taylor, MD (Maine Medical Center) and his colleagues at Brigham and Women’s Hospital conducted a large study to determine the effects of healthy eating habits on the formation of kidney stones. The investigators collected information from individuals enrolled in three clinical studies: the Health Professionals Follow-up Study (45,821 men followed for 18 years), the Nurses’ Health Study I (94,108 older women followed for 18 years), and the Nurses’ Health Study II (101,837 younger women followed for 14 years).
Dr. Taylor’s team assigned a score to each participant based on eight components of a DASH (Dietary Approaches to Stop Hypertension) style diet: high intake of fruits, vegetables, nuts and legumes, low-fat dairy products, and whole grains and low intake of salt, sweetened beverages, and red and processed meats. Individuals with higher DASH scores consumed diets that were higher in calcium, potassium, magnesium, oxalate, and vitamin C and lower in sodium.
A total of 5,645 incident kidney stones developed in the participants in the three studies. In each study, participants with the highest DASH scores were between 40% and 45% less likely to develop kidney stones than participants with the lowest DASH scores. The reductions in kidney stone risk were independent of age, body size, fluid intake, and other factors.
Because a DASH-style diet may affect the development of hypertension, diabetes, and other chronic diseases associated with kidney stones, the researchers also performed an analysis limited to study participants without hypertension or diabetes. Even among those individuals the DASH diet reduced the risk of kidney stones.
Many of the medications used to treat kidney stones have unpleasant side effects. This study indicates that adopting a DASH-style diet may be an effective alternative.
High-fat diets make us stupid and lazy
New research in the FASEB Journal shows that high-fat diets are just as unhealthful in the short term as they are in the long term
New research published online in The FASEB Journal (http://www.fasebj.org) showed that in less than 10 days of eating a high-fat diet, rats had a decreased ability to exercise and experienced significant short-term memory loss. These results show an important link between what we eat, how we think, and how our bodies perform.
"Western diets are typically high in fat and are associated with long-term complications, such as obesity, diabetes, and heart failure, yet the short-term consequences of such diets have been given relatively little attention," said Andrew Murray, co-author of the study and currently at the University of Cambridge in the United Kingdom. "We hope that the findings of our study will help people to think seriously about reducing the fat content of their daily food intake to the immediate benefit of their general health, well-being, and alertness."
Murray and colleagues studied rats fed a low-fat diet (7.5 percent of calories as fat) and rats fed a high-fat diet (55 percent of calories as fat). The researchers discovered that the muscles of the rats eating the high-fat diet for four days were less able to use oxygen to make the energy needed to exercise, causing their hearts to worker harder—and increase in size. After nine days on a high-fat diet, the rats took longer to complete a maze and made more mistakes in the process than their low-fat-diet counterparts. Researchers then investigated the cellular causes of these problems, particularly in the mitochondria of muscle cells. They found increased levels of a protein called uncoupling protein 3, which made them less efficient at using oxygen needed to make the energy required for running.
"It's nothing short of a high-fat hangover," said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. "A long weekend spent eating hotdogs, French fries, and pizza in Orlando might be a great treat for our taste buds, but they might send our muscles and brains out to lunch."
New research published online in The FASEB Journal (http://www.fasebj.org) showed that in less than 10 days of eating a high-fat diet, rats had a decreased ability to exercise and experienced significant short-term memory loss. These results show an important link between what we eat, how we think, and how our bodies perform.
"Western diets are typically high in fat and are associated with long-term complications, such as obesity, diabetes, and heart failure, yet the short-term consequences of such diets have been given relatively little attention," said Andrew Murray, co-author of the study and currently at the University of Cambridge in the United Kingdom. "We hope that the findings of our study will help people to think seriously about reducing the fat content of their daily food intake to the immediate benefit of their general health, well-being, and alertness."
Murray and colleagues studied rats fed a low-fat diet (7.5 percent of calories as fat) and rats fed a high-fat diet (55 percent of calories as fat). The researchers discovered that the muscles of the rats eating the high-fat diet for four days were less able to use oxygen to make the energy needed to exercise, causing their hearts to worker harder—and increase in size. After nine days on a high-fat diet, the rats took longer to complete a maze and made more mistakes in the process than their low-fat-diet counterparts. Researchers then investigated the cellular causes of these problems, particularly in the mitochondria of muscle cells. They found increased levels of a protein called uncoupling protein 3, which made them less efficient at using oxygen needed to make the energy required for running.
"It's nothing short of a high-fat hangover," said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. "A long weekend spent eating hotdogs, French fries, and pizza in Orlando might be a great treat for our taste buds, but they might send our muscles and brains out to lunch."
Tuesday, August 11, 2009
Mediterranean Diet = Slower Cognitive Decline
In an examination of the association between adherence to a Mediterranean-type diet and cognitive performance and risk of dementia, researchers found that high adherence to the diet was associated with slower decline in some measures of cognitive function but was not associated with decreased risk for dementia, according to a study in the August 12 issue of JAMA.
Higher adherence to a Mediterranean-type diet is linked to lower risk for mortality and chronic diseases, and "might also have protective effects against cognitive decline in older individuals, because it combines several foods and nutrients potentially protective against cognitive dysfunction or dementia, such as fish, monounsaturated fatty acids, vitamins B12 and folate, antioxidants (vitamin E, carotenoids, flavonoids), and moderate amounts of alcohol," the authors write. But its association with cognitive decline has been unclear.
Catherine Féart, Ph.D., of the Université Victor Ségalen Bordeaux 2, Bordeaux, France, and colleagues examined whether adherence to a Mediterranean diet was associated with change in cognitive performance and with lower risk of all-cause dementia or Alzheimer disease. The study included 1,410 individuals (age 65 years or older) from Bordeaux, France, who were part of the Three-City cohort in 2001-2002 (a study of vascular risk factors of dementia) and were re-examined at least once over 5 years. Adherence to a Mediterranean diet (scored as 0 to 9) was computed from a food frequency questionnaire and 24-hour recall.
Cognitive performance was assessed on 4 neuropsychological tests: the Mini-Mental State Examination (MMSE), Isaacs Set Test (IST), Benton Visual Retention Test (BVRT), and Free and Cued Selective Reminding Test (FCSRT). New cases of dementia (n = 99) were validated by an independent expert committee of neurologists.
After adjusting for age, sex, education, marital status, energy intake, physical activity, depressive symptomatology, taking 5 medications/day or more, apolipoprotein E genotype, cardiovascular risk factors, and stroke, the researchers found that higher Mediterranean diet score was associated with fewer MMSE errors. But performance on the IST, BVRT, or FCSRT over time was not significantly associated with Mediterranean diet adherence, especially in those who remained free from dementia over 5 years. Mediterranean diet adherence was not associated with the risk for incident dementia, although the statistical strength of the data to detect a difference was limited.
"The Mediterranean diet pattern probably does not fully explain the better health of persons who adhere to it, but it may contribute directly. A Mediterranean diet also may indirectly constitute an indicator of a complex set of favorable social and lifestyle factors that contribute to better health. Further research is needed to allow the generalization of these results to other populations and to establish whether a Mediterranean diet slows cognitive decline or reduces incident dementia in addition to its cardiovascular benefits," the authors conclude.
Higher adherence to a Mediterranean-type diet is linked to lower risk for mortality and chronic diseases, and "might also have protective effects against cognitive decline in older individuals, because it combines several foods and nutrients potentially protective against cognitive dysfunction or dementia, such as fish, monounsaturated fatty acids, vitamins B12 and folate, antioxidants (vitamin E, carotenoids, flavonoids), and moderate amounts of alcohol," the authors write. But its association with cognitive decline has been unclear.
Catherine Féart, Ph.D., of the Université Victor Ségalen Bordeaux 2, Bordeaux, France, and colleagues examined whether adherence to a Mediterranean diet was associated with change in cognitive performance and with lower risk of all-cause dementia or Alzheimer disease. The study included 1,410 individuals (age 65 years or older) from Bordeaux, France, who were part of the Three-City cohort in 2001-2002 (a study of vascular risk factors of dementia) and were re-examined at least once over 5 years. Adherence to a Mediterranean diet (scored as 0 to 9) was computed from a food frequency questionnaire and 24-hour recall.
Cognitive performance was assessed on 4 neuropsychological tests: the Mini-Mental State Examination (MMSE), Isaacs Set Test (IST), Benton Visual Retention Test (BVRT), and Free and Cued Selective Reminding Test (FCSRT). New cases of dementia (n = 99) were validated by an independent expert committee of neurologists.
After adjusting for age, sex, education, marital status, energy intake, physical activity, depressive symptomatology, taking 5 medications/day or more, apolipoprotein E genotype, cardiovascular risk factors, and stroke, the researchers found that higher Mediterranean diet score was associated with fewer MMSE errors. But performance on the IST, BVRT, or FCSRT over time was not significantly associated with Mediterranean diet adherence, especially in those who remained free from dementia over 5 years. Mediterranean diet adherence was not associated with the risk for incident dementia, although the statistical strength of the data to detect a difference was limited.
"The Mediterranean diet pattern probably does not fully explain the better health of persons who adhere to it, but it may contribute directly. A Mediterranean diet also may indirectly constitute an indicator of a complex set of favorable social and lifestyle factors that contribute to better health. Further research is needed to allow the generalization of these results to other populations and to establish whether a Mediterranean diet slows cognitive decline or reduces incident dementia in addition to its cardiovascular benefits," the authors conclude.
Mediterranean diet, exercise fight Alzheimer disease
Elderly individuals who had a diet that included higher consumption of fruits, vegetables, legumes, cereal and fish and was low in red meat and poultry and who were physically active had an associated lower risk of Alzheimer disease, according to a study in the August 12 issue of JAMA.
Research regarding the effect physical activity can have on the risk of Alzheimer disease (AD) or dementia has shown mixed results, as has the effect of dietary habits. Their combined association has not been investigated, according to background information in the article.
Nikolaos Scarmeas, M.D., of Columbia University Medical Center, New York, and colleagues examined the association between physical activity and risk of AD and also the effect of physical activity and adherence to a Mediterranean-type diet on AD risk. The study included 2 groups that consisted of 1,880 community-dwelling elderly residents of New York city without dementia at the start of the study, for whom there was both diet and physical activity information available. Standardized neurological and neuropsychological measures were administered approximately every 1.5 years from 1992 through 2006.
The participants received measurements of their adherence to a Mediterranean-type diet (scale of 0-9; categorized as low, middle, or high) and their physical activity (sum of weekly participation in various physical activities, weighted by the type of physical activity [light, moderate, vigorous]; categorized into no physical activity, some, or much, also low or high), separately and combined. A higher score for diet was obtained with higher consumption of fruits, vegetables, legumes, cereals, and fish; lower consumption of meat and dairy products; a higher ratio of monounsaturated fats to saturated fats and mild to moderate alcohol consumption.
Individuals were followed up for an average of 5.4 years, during which a total of 282 developed AD. In considering only physical activity, the researchers found that more physical activity was associated with lower risk for developing AD. "Compared with physically inactive individuals, report of some physical activity was associated with a 29 percent to 41 percent lower risk of developing AD, while report of much physical activity was associated with a 37 percent to 50 percent lower risk," the authors write.
When considered simultaneously, both physical activity and Mediterranean diet adherence were significantly associated with AD incidence. According to the researchers, "Belonging to the middle diet adherence tertile was associated with a 2 percent to 14 percent risk reduction, while belonging to the highest diet adherence tertile was associated with a 32 percent to 40 percent reduced risk. Similarly, compared with individuals with no physical activity, individuals reporting some physical activity had a 25 percent to 38 percent lower risk for AD, while individuals reporting much physical activity had a 33 percent to 48 percent lower risk for AD."
The authors also write, "Compared with individuals with low physical activity plus low adherence to a diet (absolute AD risk, 19 percent), high physical activity plus high diet adherence was associated with a 35 percent to 44 percent relative risk reduction (absolute AD risk, 12 percent). … Absolute AD risks declined from 21 percent in the group with no physical activity plus low diet adherence to 9 percent in the group with much physical activity plus high diet adherence."
"In summary, our results support the potentially independent and important role of both physical activity and dietary habits in relation to AD risk. These findings should be further evaluated in other populations."
Research regarding the effect physical activity can have on the risk of Alzheimer disease (AD) or dementia has shown mixed results, as has the effect of dietary habits. Their combined association has not been investigated, according to background information in the article.
Nikolaos Scarmeas, M.D., of Columbia University Medical Center, New York, and colleagues examined the association between physical activity and risk of AD and also the effect of physical activity and adherence to a Mediterranean-type diet on AD risk. The study included 2 groups that consisted of 1,880 community-dwelling elderly residents of New York city without dementia at the start of the study, for whom there was both diet and physical activity information available. Standardized neurological and neuropsychological measures were administered approximately every 1.5 years from 1992 through 2006.
The participants received measurements of their adherence to a Mediterranean-type diet (scale of 0-9; categorized as low, middle, or high) and their physical activity (sum of weekly participation in various physical activities, weighted by the type of physical activity [light, moderate, vigorous]; categorized into no physical activity, some, or much, also low or high), separately and combined. A higher score for diet was obtained with higher consumption of fruits, vegetables, legumes, cereals, and fish; lower consumption of meat and dairy products; a higher ratio of monounsaturated fats to saturated fats and mild to moderate alcohol consumption.
Individuals were followed up for an average of 5.4 years, during which a total of 282 developed AD. In considering only physical activity, the researchers found that more physical activity was associated with lower risk for developing AD. "Compared with physically inactive individuals, report of some physical activity was associated with a 29 percent to 41 percent lower risk of developing AD, while report of much physical activity was associated with a 37 percent to 50 percent lower risk," the authors write.
When considered simultaneously, both physical activity and Mediterranean diet adherence were significantly associated with AD incidence. According to the researchers, "Belonging to the middle diet adherence tertile was associated with a 2 percent to 14 percent risk reduction, while belonging to the highest diet adherence tertile was associated with a 32 percent to 40 percent reduced risk. Similarly, compared with individuals with no physical activity, individuals reporting some physical activity had a 25 percent to 38 percent lower risk for AD, while individuals reporting much physical activity had a 33 percent to 48 percent lower risk for AD."
The authors also write, "Compared with individuals with low physical activity plus low adherence to a diet (absolute AD risk, 19 percent), high physical activity plus high diet adherence was associated with a 35 percent to 44 percent relative risk reduction (absolute AD risk, 12 percent). … Absolute AD risks declined from 21 percent in the group with no physical activity plus low diet adherence to 9 percent in the group with much physical activity plus high diet adherence."
"In summary, our results support the potentially independent and important role of both physical activity and dietary habits in relation to AD risk. These findings should be further evaluated in other populations."
Aspirin fights colorectal cancer
Men and women who were diagnosed with colorectal cancer and began regular use of aspirin had a lower risk of overall and colorectal cancer death compared to patients not using aspirin, according to a study in the August 12 issue of JAMA.
Numerous prospective, observational studies demonstrate that regular aspirin use is associated with a lower risk of colorectal adenoma (a benign tumor) or cancer. Aspirin is likely, at least in part, to prevent colorectal neoplasia (tumor growth) through inhibition of cyclooxygenase-2 (COX-2; an enzyme), which promotes inflammation and cell proliferation, and is overexpressed in the majority of human colorectal cancers, according to background information in the article. However, the influence of aspirin on survival after diagnosis of colorectal cancer has been unknown.
Andrew T. Chan, M.D., M.P.H., of Massachusetts General Hospital and Harvard Medical School, Boston, and colleagues studied the association between aspirin use and survival among 1,279 men and women with nonmetastatic (stage I, II, and III) colorectal cancer who were participating in 2 large prospective cohort studies (Nurses' Health Study [NHS] and the Health Professionals Follow-up Study [HPFS]) that were initiated (in 1980 and 1986, respectively) prior to cancer diagnosis and followed up through June 1, 2008.
"Within these cohorts, we previously have demonstrated that regular aspirin use was associated with a reduction in the subsequent risk of developing an initial primary colorectal cancer, particularly tumors with COX-2 overexpression. Because these participants have provided biennially updated data on aspirin use, we had a unique opportunity to extend these findings by examining the influence of prediagnosis and postdiagnosis aspirin use on the survival of patients with established colorectal cancer," the authors write.
For participants who were alive through the end of follow-up, the median (midpoint) time of follow-up from date of diagnosis was 11.8 years. There were 193 total deaths (35 percent) and 81 colorectal cancer-specific deaths (15 percent) among 549 participants who regularly used aspirin after colorectal cancer diagnosis, compared with 287 (39 percent) total and 141 (19 percent) colorectal cancer-specific deaths among 730 participants who did not use aspirin. For the entire cohort, the overall 5-year survival was 88 percent for participants who used aspirin compared with 83 percent for those who did not. The corresponding 10-year survival rates were 74 percent and 69 percent.
Regular use of aspirin after diagnosis was associated with a significant reduction in risk of colorectal cancer-specific death and a reduction in overall mortality. Compared with nonusers, regular aspirin use after diagnosis was associated with a 29 percent lower risk for colorectal-specific mortality and a 21 percent lower risk for overall mortality. Because the prognosis among stage I participants is generally favorable, the researchers also examined the influence of aspirin use among those diagnosed with stage II or III disease and observed similar results.
Among the 719 participants who did not use aspirin before diagnosis, initiation of use postdiagnosis was associated with a 47 percent lower risk for colorectal cancer-specific mortality and a 32 percent lower risk of overall mortality. In contrast, among participants who were using aspirin before diagnosis, continuation of aspirin use postdiagnosis was not associated with a significant reduction in colorectal cancer-specific survival or overall survival.
Among participants with COX-2–positive tumors, regular aspirin use after diagnosis was associated with a 61 percent lower risk of colorectal cancer-specific death and 38 percent lower risk of overall mortality, whereas postdiagnosis aspirin use was not associated with lower risk of either colorectal cancer-specific or overall mortality for those with COX-2–negative tumors. "This supports the hypothesis that COX-2–positive tumors may be relatively sensitive to the anticancer effect of aspirin, whereas COX-2–negative tumors may be relatively aspirin-resistant. Moreover, it potentially explains the observation that the benefit of postdiagnosis aspirin use on patient survival was not apparent among patients who used aspirin prior to cancer diagnosis," the researchers note.
"These results suggest that aspirin may influence the biology of established colorectal tumors in addition to preventing their occurrence. Our data also highlight the potential for using COX-2 or related markers to tailor aspirin use among patients with newly diagnosed colorectal cancer. Nonetheless, because our data are observational, routine use of aspirin or related agents as cancer therapy cannot be recommended, especially in light of concerns over their related toxicities, such as gastrointestinal bleeding. Further studies among patients with colorectal cancer, including placebo-controlled trials of aspirin or related agents as adjuncts to other routine therapies, are required."
Numerous prospective, observational studies demonstrate that regular aspirin use is associated with a lower risk of colorectal adenoma (a benign tumor) or cancer. Aspirin is likely, at least in part, to prevent colorectal neoplasia (tumor growth) through inhibition of cyclooxygenase-2 (COX-2; an enzyme), which promotes inflammation and cell proliferation, and is overexpressed in the majority of human colorectal cancers, according to background information in the article. However, the influence of aspirin on survival after diagnosis of colorectal cancer has been unknown.
Andrew T. Chan, M.D., M.P.H., of Massachusetts General Hospital and Harvard Medical School, Boston, and colleagues studied the association between aspirin use and survival among 1,279 men and women with nonmetastatic (stage I, II, and III) colorectal cancer who were participating in 2 large prospective cohort studies (Nurses' Health Study [NHS] and the Health Professionals Follow-up Study [HPFS]) that were initiated (in 1980 and 1986, respectively) prior to cancer diagnosis and followed up through June 1, 2008.
"Within these cohorts, we previously have demonstrated that regular aspirin use was associated with a reduction in the subsequent risk of developing an initial primary colorectal cancer, particularly tumors with COX-2 overexpression. Because these participants have provided biennially updated data on aspirin use, we had a unique opportunity to extend these findings by examining the influence of prediagnosis and postdiagnosis aspirin use on the survival of patients with established colorectal cancer," the authors write.
For participants who were alive through the end of follow-up, the median (midpoint) time of follow-up from date of diagnosis was 11.8 years. There were 193 total deaths (35 percent) and 81 colorectal cancer-specific deaths (15 percent) among 549 participants who regularly used aspirin after colorectal cancer diagnosis, compared with 287 (39 percent) total and 141 (19 percent) colorectal cancer-specific deaths among 730 participants who did not use aspirin. For the entire cohort, the overall 5-year survival was 88 percent for participants who used aspirin compared with 83 percent for those who did not. The corresponding 10-year survival rates were 74 percent and 69 percent.
Regular use of aspirin after diagnosis was associated with a significant reduction in risk of colorectal cancer-specific death and a reduction in overall mortality. Compared with nonusers, regular aspirin use after diagnosis was associated with a 29 percent lower risk for colorectal-specific mortality and a 21 percent lower risk for overall mortality. Because the prognosis among stage I participants is generally favorable, the researchers also examined the influence of aspirin use among those diagnosed with stage II or III disease and observed similar results.
Among the 719 participants who did not use aspirin before diagnosis, initiation of use postdiagnosis was associated with a 47 percent lower risk for colorectal cancer-specific mortality and a 32 percent lower risk of overall mortality. In contrast, among participants who were using aspirin before diagnosis, continuation of aspirin use postdiagnosis was not associated with a significant reduction in colorectal cancer-specific survival or overall survival.
Among participants with COX-2–positive tumors, regular aspirin use after diagnosis was associated with a 61 percent lower risk of colorectal cancer-specific death and 38 percent lower risk of overall mortality, whereas postdiagnosis aspirin use was not associated with lower risk of either colorectal cancer-specific or overall mortality for those with COX-2–negative tumors. "This supports the hypothesis that COX-2–positive tumors may be relatively sensitive to the anticancer effect of aspirin, whereas COX-2–negative tumors may be relatively aspirin-resistant. Moreover, it potentially explains the observation that the benefit of postdiagnosis aspirin use on patient survival was not apparent among patients who used aspirin prior to cancer diagnosis," the researchers note.
"These results suggest that aspirin may influence the biology of established colorectal tumors in addition to preventing their occurrence. Our data also highlight the potential for using COX-2 or related markers to tailor aspirin use among patients with newly diagnosed colorectal cancer. Nonetheless, because our data are observational, routine use of aspirin or related agents as cancer therapy cannot be recommended, especially in light of concerns over their related toxicities, such as gastrointestinal bleeding. Further studies among patients with colorectal cancer, including placebo-controlled trials of aspirin or related agents as adjuncts to other routine therapies, are required."
Monday, August 10, 2009
Physical inactivity poses greatest health risk
As many as 50 million Americans are living sedentary lives, putting them at increased risk of health problems and even early death, a leading expert in exercise science told the American Psychological Association today.
Speaking at APA's 117th Annual Convention, Steven Blair, PED, called Americans' physical inactivity "the biggest public health problem of the 21st century."
Blair is a professor of exercise science and epidemiology at the University of South Carolina's Arnold School of Public Health. He is one of the world's premier experts on exercise and its health benefits and was the senior scientific editor of the 1996 U.S. Surgeon General's Report on Physical Activity and Health.
Research has shown approximately 25 percent to 35 percent of American adults are inactive, Blair said, meaning that they have sedentary jobs, no regular physical activity program and are generally inactive around the house or yard. "This amounts to 40 million to 50 million people exposed to the hazard of inactivity," Blair said in an interview. "Given that these individuals are doubling their risk of developing numerous health conditions compared with those who are even moderately active and fit, we're looking at a major public health problem."
Blair's extensive research comes primarily from the Aerobics Center Longitudinal Study, in which he found that fitness level was a significant predictor of mortality. The ongoing study began in 1970 and includes more than 80,000 patients. The researchers periodically measured the participants' body composition and body mass index, and each patient underwent a stress test. Researchers also looked at numerous other factors including the participants' medical histories.
One follow-up study of 40,842 longitudinal study participants showed poor fitness level accounted for about 16 percent of all deaths in both men and women. The percentage was calculated by estimating the number of deaths that would have been avoided if people had spent 30 minutes a day walking. This percentage was significantly higher than when other risk factors were considered, including obesity, smoking, high cholesterol and diabetes. The Aerobics Center Longitudinal Study also found that moderately fit men lived six years longer than unfit men.
More examination of 14,811 female patients in the ACLS showed that women who were very fit were 55 percent less likely to die from breast cancer than women who were not in good shape. This was after the researchers had controlled for BMI, smoking, family history of breast cancer and other possible risk factors.
Blair also highlighted the benefits of exercise on the mind, referring to recent emerging evidence that activity delays the mind's decline and is good for brain health overall. Blair said he thinks psychologists can be integral in helping patients understand the health hazards of being inactive and encouraging people to look for more ways to get moving. "Over the past few decades, we have largely engineered the need for physical activity out of the daily lives of most people in industrialized societies," said Blair.
The message should be simple, he said: Doing something is better than doing nothing, and doing more is better than doing less, at least up to a point. "We need numerous changes to promote more physical activity for all, including public policies, changes in the health care system, promoting activity in educational settings and worksites, and social and physical environmental changes. We need more communities where people feel comfortable walking. I believe psychologists can help develop better lifestyle change interventions to help people be more active via the Internet and other technological methods."
Speaking at APA's 117th Annual Convention, Steven Blair, PED, called Americans' physical inactivity "the biggest public health problem of the 21st century."
Blair is a professor of exercise science and epidemiology at the University of South Carolina's Arnold School of Public Health. He is one of the world's premier experts on exercise and its health benefits and was the senior scientific editor of the 1996 U.S. Surgeon General's Report on Physical Activity and Health.
Research has shown approximately 25 percent to 35 percent of American adults are inactive, Blair said, meaning that they have sedentary jobs, no regular physical activity program and are generally inactive around the house or yard. "This amounts to 40 million to 50 million people exposed to the hazard of inactivity," Blair said in an interview. "Given that these individuals are doubling their risk of developing numerous health conditions compared with those who are even moderately active and fit, we're looking at a major public health problem."
Blair's extensive research comes primarily from the Aerobics Center Longitudinal Study, in which he found that fitness level was a significant predictor of mortality. The ongoing study began in 1970 and includes more than 80,000 patients. The researchers periodically measured the participants' body composition and body mass index, and each patient underwent a stress test. Researchers also looked at numerous other factors including the participants' medical histories.
One follow-up study of 40,842 longitudinal study participants showed poor fitness level accounted for about 16 percent of all deaths in both men and women. The percentage was calculated by estimating the number of deaths that would have been avoided if people had spent 30 minutes a day walking. This percentage was significantly higher than when other risk factors were considered, including obesity, smoking, high cholesterol and diabetes. The Aerobics Center Longitudinal Study also found that moderately fit men lived six years longer than unfit men.
More examination of 14,811 female patients in the ACLS showed that women who were very fit were 55 percent less likely to die from breast cancer than women who were not in good shape. This was after the researchers had controlled for BMI, smoking, family history of breast cancer and other possible risk factors.
Blair also highlighted the benefits of exercise on the mind, referring to recent emerging evidence that activity delays the mind's decline and is good for brain health overall. Blair said he thinks psychologists can be integral in helping patients understand the health hazards of being inactive and encouraging people to look for more ways to get moving. "Over the past few decades, we have largely engineered the need for physical activity out of the daily lives of most people in industrialized societies," said Blair.
The message should be simple, he said: Doing something is better than doing nothing, and doing more is better than doing less, at least up to a point. "We need numerous changes to promote more physical activity for all, including public policies, changes in the health care system, promoting activity in educational settings and worksites, and social and physical environmental changes. We need more communities where people feel comfortable walking. I believe psychologists can help develop better lifestyle change interventions to help people be more active via the Internet and other technological methods."
Optimism=lower women’s risk of death/heart disease
Study highlights:
Optimistic women have a lower risk of developing heart disease or dying from any cause compared to pessimistic women, according to research reported in Circulation: Journal of the American Heart Association.
Researchers also reported that women with a high degree of cynical hostility — harboring hostile thoughts toward others or having a general mistrust of people — were at higher risk of dying; however, their risk of developing heart disease was not altered.
“As a physician, I’d like to see people try to reduce their negativity in general,” said Hilary A. Tindle, M.D., M.P.H., lead author of the study and assistant professor of medicine at the University of Pittsburgh. “The majority of evidence suggests that sustained, high degrees of negativity are hazardous to health.”
In the largest study to date to prospectively study the health effects of optimism and cynical hostility in post-menopausal women, researchers found that white and black American women’s attitudes are associated with health outcomes.
Optimistic women, compared to pessimistic women, had a 9 percent lower risk of developing heart disease and a 14 percent lower risk of dying from any cause after more than eight years of follow-up. Furthermore, women with a high degree of cynical hostility, compared to those with a low degree, were 16 percent more likely to die during eight years of follow-up.
“Prior to our work, the strongest evidence linking optimism and all-cause mortality was from a Dutch cohort, showing a more pronounced association in men,” Tindle said.
Tindle’s team studied 97,253 postmenopausal women (89,259 white, 7,994 black) ages 50 to 79 from the Women’s Health Initiative. The women were free of cancer and cardiovascular disease (CVD) at the start of the study.
Using the Life Orientation Test Revised Questionnaire to measure optimism and cynical hostility, researchers categorized scores into quartiles: high scores of 26 or more were considered optimists; scores of 24-25 were considered mid-high; scores of 22-23 were considered mid-low; and scores below 22 were considered pessimists.
Optimism was defined as answering “yes” to questions like, “In unclear times, I usually expect the best.” Pessimism was defined as answering “yes” to questions like, “If something can go wrong for me, it will.”
Race also appears to modify the relationship between optimism and death, with a stronger association seen in African-American women as compared to white women. Among African-American women, optimists (vs. pessimists) had a 33 percent lower risk of death across eight years of follow-up. Among white women, optimists (vs. pessimists) had a 13 percent lower risk of death. Researchers also found that optimists (as compared to pessimists) were more likely to be younger (especially in blacks); live in the Western United States; report higher education and income; be employed and have health insurance; and attend religious services at least once a week.
Optimists were less likely to have diabetes, high blood pressure, high cholesterol or depressive symptoms, smoke, be sedentary or have a high body mass index. However, the relationship between optimism and heart disease and death persisted even after considering all of these factors.
“This study is a very reasonable stepping stone to future research in this area — both on potential mechanisms of how attitudes may affect health, and for randomized controlled trials to examine if attitudes can be changed to improve health,” Tindle said.
Optimistic women have a lower risk of developing heart disease or dying from any cause compared to pessimistic women, according to research reported in Circulation: Journal of the American Heart Association.
Researchers also reported that women with a high degree of cynical hostility — harboring hostile thoughts toward others or having a general mistrust of people — were at higher risk of dying; however, their risk of developing heart disease was not altered.
“As a physician, I’d like to see people try to reduce their negativity in general,” said Hilary A. Tindle, M.D., M.P.H., lead author of the study and assistant professor of medicine at the University of Pittsburgh. “The majority of evidence suggests that sustained, high degrees of negativity are hazardous to health.”
In the largest study to date to prospectively study the health effects of optimism and cynical hostility in post-menopausal women, researchers found that white and black American women’s attitudes are associated with health outcomes.
Optimistic women, compared to pessimistic women, had a 9 percent lower risk of developing heart disease and a 14 percent lower risk of dying from any cause after more than eight years of follow-up. Furthermore, women with a high degree of cynical hostility, compared to those with a low degree, were 16 percent more likely to die during eight years of follow-up.
“Prior to our work, the strongest evidence linking optimism and all-cause mortality was from a Dutch cohort, showing a more pronounced association in men,” Tindle said.
Tindle’s team studied 97,253 postmenopausal women (89,259 white, 7,994 black) ages 50 to 79 from the Women’s Health Initiative. The women were free of cancer and cardiovascular disease (CVD) at the start of the study.
Using the Life Orientation Test Revised Questionnaire to measure optimism and cynical hostility, researchers categorized scores into quartiles: high scores of 26 or more were considered optimists; scores of 24-25 were considered mid-high; scores of 22-23 were considered mid-low; and scores below 22 were considered pessimists.
Optimism was defined as answering “yes” to questions like, “In unclear times, I usually expect the best.” Pessimism was defined as answering “yes” to questions like, “If something can go wrong for me, it will.”
Race also appears to modify the relationship between optimism and death, with a stronger association seen in African-American women as compared to white women. Among African-American women, optimists (vs. pessimists) had a 33 percent lower risk of death across eight years of follow-up. Among white women, optimists (vs. pessimists) had a 13 percent lower risk of death. Researchers also found that optimists (as compared to pessimists) were more likely to be younger (especially in blacks); live in the Western United States; report higher education and income; be employed and have health insurance; and attend religious services at least once a week.
Optimists were less likely to have diabetes, high blood pressure, high cholesterol or depressive symptoms, smoke, be sedentary or have a high body mass index. However, the relationship between optimism and heart disease and death persisted even after considering all of these factors.
“This study is a very reasonable stepping stone to future research in this area — both on potential mechanisms of how attitudes may affect health, and for randomized controlled trials to examine if attitudes can be changed to improve health,” Tindle said.
Healthy lifestyle = reduced risk of chronic disease
Four healthy lifestyle factors—never smoking, maintaining a healthy weight, exercising regularly and following a healthy diet—together appear to be associated with as much as an 80 percent reduction in the risk of developing the most common and deadly chronic diseases, according to a report in the August 10/24 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.
Cardiovascular disease, cancer and diabetes—chronic diseases that together account for most deaths—are largely preventable, according to background information in the article. "An impressive body of research has implicated modifiable lifestyle factors such as smoking, physical activity, diet and body weight in the causes of these diseases," the authors write.
To further describe the reduction in risk associated with these factors, Earl S. Ford, M.D., M.P.H., of the Centers for Disease Control and Prevention, Atlanta, and colleagues assessed data from 23,513 German adults age 35 to 65. At the beginning of the European Prospective Investigation Into Cancer and Nutrition–Potsdam (EPIC-Potsdam) study—between 1994 and 1998—participants completed an assessment of their body weight and height, a personal interview that included questions about diseases, a questionnaire on sociodemographic and lifestyle characteristics and a food frequency questionnaire.
Their responses were assessed for adherence to four healthy lifestyle factors: never smoking, having a body mass index lower than 30, exercising for at least three and a half hours per week and following healthy dietary principles (for example, having a diet with high consumption of fruits and vegetables while limiting meat consumption). Follow-up questionnaires were administered every two to three years.
Most participants had one to three of these health factors, fewer than 4 percent had zero healthy factors and 9 percent had all four factors. Over an average of 7.8 years of follow-up, 2,006 participants developed new cases of diabetes (3.7 percent), heart attack (0.9 percent), stroke (0.8 percent) or cancer (3.8 percent).
After adjusting for age, sex, education level and occupation, individuals with more healthy lifestyle factors were less likely to develop chronic diseases. Participants who had all four factors at the beginning of the study had a 78 percent lower risk of developing any of the chronic diseases during the follow-up period than those who had none of the healthy factors. The four factors were associated with a 93 percent reduced risk of diabetes, 81 percent reduced risk of heart attack, 50 percent reduced risk of stroke and 36 percent reduced risk of cancer.
The largest reduction in risk was associated with having a BMI lower than 30, followed by never smoking, at least 3.5 hours of physical activity and then adhering to good dietary principles.
"Our results reinforce current public health recommendations to avoid smoking, to maintain a healthy weight, to engage in physical activity appropriately and to eat adequate amounts of fruits and vegetables and foods containing whole grains and to partake of red meat prudently," the authors write. "Because the roots of these factors often originate during the formative stages of life, it is especially important to start early in teaching the important lessons concerning healthy living."
Cardiovascular disease, cancer and diabetes—chronic diseases that together account for most deaths—are largely preventable, according to background information in the article. "An impressive body of research has implicated modifiable lifestyle factors such as smoking, physical activity, diet and body weight in the causes of these diseases," the authors write.
To further describe the reduction in risk associated with these factors, Earl S. Ford, M.D., M.P.H., of the Centers for Disease Control and Prevention, Atlanta, and colleagues assessed data from 23,513 German adults age 35 to 65. At the beginning of the European Prospective Investigation Into Cancer and Nutrition–Potsdam (EPIC-Potsdam) study—between 1994 and 1998—participants completed an assessment of their body weight and height, a personal interview that included questions about diseases, a questionnaire on sociodemographic and lifestyle characteristics and a food frequency questionnaire.
Their responses were assessed for adherence to four healthy lifestyle factors: never smoking, having a body mass index lower than 30, exercising for at least three and a half hours per week and following healthy dietary principles (for example, having a diet with high consumption of fruits and vegetables while limiting meat consumption). Follow-up questionnaires were administered every two to three years.
Most participants had one to three of these health factors, fewer than 4 percent had zero healthy factors and 9 percent had all four factors. Over an average of 7.8 years of follow-up, 2,006 participants developed new cases of diabetes (3.7 percent), heart attack (0.9 percent), stroke (0.8 percent) or cancer (3.8 percent).
After adjusting for age, sex, education level and occupation, individuals with more healthy lifestyle factors were less likely to develop chronic diseases. Participants who had all four factors at the beginning of the study had a 78 percent lower risk of developing any of the chronic diseases during the follow-up period than those who had none of the healthy factors. The four factors were associated with a 93 percent reduced risk of diabetes, 81 percent reduced risk of heart attack, 50 percent reduced risk of stroke and 36 percent reduced risk of cancer.
The largest reduction in risk was associated with having a BMI lower than 30, followed by never smoking, at least 3.5 hours of physical activity and then adhering to good dietary principles.
"Our results reinforce current public health recommendations to avoid smoking, to maintain a healthy weight, to engage in physical activity appropriately and to eat adequate amounts of fruits and vegetables and foods containing whole grains and to partake of red meat prudently," the authors write. "Because the roots of these factors often originate during the formative stages of life, it is especially important to start early in teaching the important lessons concerning healthy living."
Friday, August 7, 2009
Beetroot juice boosts stamina
Beetroot juice boosts stamina
Drinking beetroot juice boosts your stamina and could help you exercise for up to 16% longer. A University of Exeter led-study shows for the first time how the nitrate contained in beetroot juice leads to a reduction in oxygen uptake, making exercise less tiring.
The study reveals that drinking beetroot juice reduces oxygen uptake to an extent that cannot be achieved by any other known means, including training.
The research team believes that the findings could be of great interest to endurance athletes. They could also be relevant to elderly people or those with cardiovascular, respiratory or metabolic diseases.
The research team conducted their study with eight men aged between 19 and 38. They were given 500ml per day of organic beetroot juice for six consecutive days before completing a series of tests, involving cycling on an exercise bike. On another occasion, they were given a placebo of blackcurrant cordial for six consecutive days before completing the same cycling tests.
After drinking beetroot juice the group was able to cycle for an average of 11.25 minutes, which is 92 seconds longer than when they were given the placebo. This would translate into an approximate 2% reduction in the time taken to cover a set distance. The group that had consumed the beetroot juice also had lower resting blood pressure.
The researchers are not yet sure of the exact mechanism that causes the nitrate in the beetroot juice to boost stamina. However, they suspect it could be a result of the nitrate turning into nitric oxide in the body, reducing the oxygen cost of exercise.
The research was carried out by the University of Exeter and Peninsula Medical School and published in the Journal of Applied Physiology. The research team now hopes to conduct further studies to try to understand in more detail the effects of nitrate-rich foods on exercise physiology.
Corresponding author of the study, Professor Andy Jones of the University of Exeter's School of Sport and Health Sciences, said: "Our study is the first to show that nitrate-rich food can increase exercise endurance. We were amazed by the effects of beetroot juice on oxygen uptake because these effects cannot be achieved by any other known means, including training. I am sure professional and amateur athletes will be interested in the results of this research. I am also keen to explore the relevance of the findings to those people who suffer from poor fitness and may be able to use dietary supplements to help them go about their daily lives."
Drinking beetroot juice boosts your stamina and could help you exercise for up to 16% longer. A University of Exeter led-study shows for the first time how the nitrate contained in beetroot juice leads to a reduction in oxygen uptake, making exercise less tiring.
The study reveals that drinking beetroot juice reduces oxygen uptake to an extent that cannot be achieved by any other known means, including training.
The research team believes that the findings could be of great interest to endurance athletes. They could also be relevant to elderly people or those with cardiovascular, respiratory or metabolic diseases.
The research team conducted their study with eight men aged between 19 and 38. They were given 500ml per day of organic beetroot juice for six consecutive days before completing a series of tests, involving cycling on an exercise bike. On another occasion, they were given a placebo of blackcurrant cordial for six consecutive days before completing the same cycling tests.
After drinking beetroot juice the group was able to cycle for an average of 11.25 minutes, which is 92 seconds longer than when they were given the placebo. This would translate into an approximate 2% reduction in the time taken to cover a set distance. The group that had consumed the beetroot juice also had lower resting blood pressure.
The researchers are not yet sure of the exact mechanism that causes the nitrate in the beetroot juice to boost stamina. However, they suspect it could be a result of the nitrate turning into nitric oxide in the body, reducing the oxygen cost of exercise.
The research was carried out by the University of Exeter and Peninsula Medical School and published in the Journal of Applied Physiology. The research team now hopes to conduct further studies to try to understand in more detail the effects of nitrate-rich foods on exercise physiology.
Corresponding author of the study, Professor Andy Jones of the University of Exeter's School of Sport and Health Sciences, said: "Our study is the first to show that nitrate-rich food can increase exercise endurance. We were amazed by the effects of beetroot juice on oxygen uptake because these effects cannot be achieved by any other known means, including training. I am sure professional and amateur athletes will be interested in the results of this research. I am also keen to explore the relevance of the findings to those people who suffer from poor fitness and may be able to use dietary supplements to help them go about their daily lives."
Tuesday, August 4, 2009
Millions of US children low in vitamin D
Seven out of ten U.S. children have low levels of vitamin D, raising their risk of bone and heart disease, according to a study of over 6,000 children by researchers at Albert Einstein College of Medicine of Yeshiva University. The striking findings suggest that vitamin D deficiency could place millions of children at risk for high blood pressure and other risk factors for heart disease. The study is published today in the online version of Pediatrics.
Vitamin D deficiency was thought to be relatively rare in the U.S. However, recent studies have documented this growing problem in adults. With cases of rickets (a bone disease in infants caused by low vitamin D levels) on the rise, it became clear that many children were also not getting enough of this essential vitamin, which is needed for healthy bone growth, among other biological processes.
"Several small studies had found a high prevalence of vitamin D deficiency in specific populations of children, but no one had examined this issue nationwide," says study leader Michal L. Melamed, M.D., assistant professor of medicine and of epidemiology & population health at Einstein. Dr. Melamed has published extensively on the importance of vitamin D.
To learn more about the prevalence of vitamin D deficiency (defined as less than 15 ng/mL of blood) and vitamin D insufficiency (15 to 29 ng/mL), the researchers analyzed data on more than 6,000 children, ages one to 21, collected by the National Health and Nutrition Examination Survey (NHANES) 2001-2004.
The researchers found that 9 percent of the study sample, equivalent to 7.6 million children across the U.S., was vitamin D deficient, while another 61 percent, or 50.8 million, was vitamin D insufficient. Low vitamin D levels were especially common in children who were older, female, African-American, Mexican-American, obese, drank milk less than once a week, or spent more than four hours a day watching TV, playing videogames, or using computers.
The researchers also found that low levels of vitamin D deficiency were associated with higher parathyroid hormone levels, a marker of bone health, higher systolic blood pressure, and lower serum calcium and HDL (good) cholesterol levels, which are key risk factors for heart disease.
"We expected the prevalence of vitamin D deficiency would be high, but the magnitude of the problem nationwide was shocking," says lead author Juhi Kumar, M.D., M.P.H., a fellow in pediatrics at Children's Hospital at Montefiore Medical Center, The University Hospital and Academic Medical Center for Albert Einstein College of Medicine. Dr. Kumar will become an assistant professor of pediatrics at Weill Cornell Medical College in August, 2009.
"We know from earlier NHANES data that vitamin D levels have declined over the last 20 years," says Dr. Melamed. "Kids have more sedentary lifestyles today and are not spending as much time outdoors. The widespread use of sunscreens, which block UV-B rays, has only compounded the problem." The body uses UV-B sunlight to convert a form of cholesterol in the skin into vitamin D.
Dr. Melamed recommends that children should consume more foods rich in vitamin D, such as milk and fish. "But it's very hard to get enough vitamin D from dietary sources alone," she says.
Vitamin D supplementation can help. In the study, children who took vitamin D supplements (400 IU/day) were less likely to be deficient in the vitamin. However, only four percent of the study population actually used supplements. The American Academy of Pediatrics, which recently updated its vitamin D guidelines, now recommends that infants, children, and teens should take 400 IU per day in supplement form.
Supplements are especially important for those living in the country's northern regions where the sun may be too weak to maintain healthy vitamin D levels. Supplements are also critical for infants who are breast-fed, say the researchers. Breast milk contains relatively little vitamin D, while formula is fortified with the vitamin.
The authors recommend that pediatricians should routinely screen high-risk children for vitamin D deficiency, and that parents should ensure that their kids get adequate amounts of the vitamin through a combination of diet, supplements, and exposure to sunlight.
"The message for pediatricians is that vitamin D deficiency is a real problem with consequences not only for bone health but also potentially for long-term cardiovascular health. Pediatricians should be screening children for vitamin D levels, especially in the high-risk populations," says Dr. Kumar. A study co-led by Dr. Melamed and published in the Archives of Internal Medicine in August 2008 reported that individuals with low levels of vitamin D may have an increased risk of death from all causes.
As for parents, says Dr. Melamed, "It would good for them to turn off the TV and send their kids outside. Just 15 to 20 minutes a day should be enough. And unless they burn easily, don't put sunscreen on them until they've been out in the sun for 10 minutes, so they get the good stuff but not sun damage."
Vitamin D deficiency was thought to be relatively rare in the U.S. However, recent studies have documented this growing problem in adults. With cases of rickets (a bone disease in infants caused by low vitamin D levels) on the rise, it became clear that many children were also not getting enough of this essential vitamin, which is needed for healthy bone growth, among other biological processes.
"Several small studies had found a high prevalence of vitamin D deficiency in specific populations of children, but no one had examined this issue nationwide," says study leader Michal L. Melamed, M.D., assistant professor of medicine and of epidemiology & population health at Einstein. Dr. Melamed has published extensively on the importance of vitamin D.
To learn more about the prevalence of vitamin D deficiency (defined as less than 15 ng/mL of blood) and vitamin D insufficiency (15 to 29 ng/mL), the researchers analyzed data on more than 6,000 children, ages one to 21, collected by the National Health and Nutrition Examination Survey (NHANES) 2001-2004.
The researchers found that 9 percent of the study sample, equivalent to 7.6 million children across the U.S., was vitamin D deficient, while another 61 percent, or 50.8 million, was vitamin D insufficient. Low vitamin D levels were especially common in children who were older, female, African-American, Mexican-American, obese, drank milk less than once a week, or spent more than four hours a day watching TV, playing videogames, or using computers.
The researchers also found that low levels of vitamin D deficiency were associated with higher parathyroid hormone levels, a marker of bone health, higher systolic blood pressure, and lower serum calcium and HDL (good) cholesterol levels, which are key risk factors for heart disease.
"We expected the prevalence of vitamin D deficiency would be high, but the magnitude of the problem nationwide was shocking," says lead author Juhi Kumar, M.D., M.P.H., a fellow in pediatrics at Children's Hospital at Montefiore Medical Center, The University Hospital and Academic Medical Center for Albert Einstein College of Medicine. Dr. Kumar will become an assistant professor of pediatrics at Weill Cornell Medical College in August, 2009.
"We know from earlier NHANES data that vitamin D levels have declined over the last 20 years," says Dr. Melamed. "Kids have more sedentary lifestyles today and are not spending as much time outdoors. The widespread use of sunscreens, which block UV-B rays, has only compounded the problem." The body uses UV-B sunlight to convert a form of cholesterol in the skin into vitamin D.
Dr. Melamed recommends that children should consume more foods rich in vitamin D, such as milk and fish. "But it's very hard to get enough vitamin D from dietary sources alone," she says.
Vitamin D supplementation can help. In the study, children who took vitamin D supplements (400 IU/day) were less likely to be deficient in the vitamin. However, only four percent of the study population actually used supplements. The American Academy of Pediatrics, which recently updated its vitamin D guidelines, now recommends that infants, children, and teens should take 400 IU per day in supplement form.
Supplements are especially important for those living in the country's northern regions where the sun may be too weak to maintain healthy vitamin D levels. Supplements are also critical for infants who are breast-fed, say the researchers. Breast milk contains relatively little vitamin D, while formula is fortified with the vitamin.
The authors recommend that pediatricians should routinely screen high-risk children for vitamin D deficiency, and that parents should ensure that their kids get adequate amounts of the vitamin through a combination of diet, supplements, and exposure to sunlight.
"The message for pediatricians is that vitamin D deficiency is a real problem with consequences not only for bone health but also potentially for long-term cardiovascular health. Pediatricians should be screening children for vitamin D levels, especially in the high-risk populations," says Dr. Kumar. A study co-led by Dr. Melamed and published in the Archives of Internal Medicine in August 2008 reported that individuals with low levels of vitamin D may have an increased risk of death from all causes.
As for parents, says Dr. Melamed, "It would good for them to turn off the TV and send their kids outside. Just 15 to 20 minutes a day should be enough. And unless they burn easily, don't put sunscreen on them until they've been out in the sun for 10 minutes, so they get the good stuff but not sun damage."
Mounting evidence of fish oil's heart health benefits
Researchers set forth recommendations for daily intake
There is mounting evidence that omega-3 fatty acids from fish or fish oil supplements not only help prevent cardiovascular diseases in healthy individuals, but also reduce the incidence of cardiac events and mortality in patients with existing heart disease. A new study, published in the August 11, 2009, issue of the Journal of the American College of Cardiology, extensively reviews data from a broad range of studies in tens of thousands of patients and sets forth suggested daily targets for omega-3 consumption.
"This isn't just hype; we now have tremendous and compelling evidence from very large studies, some dating back 20 and 30 years, that demonstrate the protective benefits of omega-3 fish oil in multiple aspects of preventive cardiology," said Carl Lavie, M.D., F.A.C.C., medical director of Cardiac Rehabilitation and Prevention, Ochsner Medical Center, New Orleans, LA, and lead author of the article. "The strongest evidence of a cardioprotective effect of omega-3s appears in patients with established cardiovascular disease and following a heart attack with up to a 30 percent reduction in CV-related death."
Dietary intake of fish oil can also decrease the risk of atherosclerosis, arrhythmias, heart attack, sudden cardiac death and even health failure. Dr. Lavie adds that although there is a smaller benefit in reducing heart failure death—9 percent mortality benefit in a major recent randomized controlled trial—this is still very impressive given patients' grave prognosis.
"If we translate this finding, it means that we only need to treat 56 patients for four years to prevent one death," he said. "And we are talking about a very safe and relatively inexpensive therapy."
Most of the evidence for the cardioprotective benefits supports the use of DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid), the long-chain fatty acids in the omega-3 family. According to Dr. Lavie, EPA and DHA work by getting into the membranes of cells and, in doing so, may help to improve the heart's electrical activity, vascular tone, plaque stabilization and blood pressure, among other benefits. Studies show that the reduction in CV events is inversely related to the tissue level EPA and, even more so, DHA.
Based on these findings, and because the body does not produce its own essential fatty acids, the authors recommend that healthy individuals should consume 500 mg daily of omega-3 fish oil containing EPA and DHA, and people with known heart disease or heart failure aim for at least 800 to 1,000 mg daily.
"There are clear health and heart benefits associated with increasing one's intake of foods that are rich in Omega-3s, including oily fish like salmon, sardines, trout, herring, and oysters" said Dr. Lavie "Patients should talk with their doctors about whether a fish oil supplement is needed to get the right amount and, in turn, benefit from the associated cardiovascular protection."
Dr. Lavie and his team came across only a few negative studies, including a recent one that showed no benefit in post-MI patients, but it has raised the possibility that omega-3 fatty acids may not provide as much additional protective benefits in low-risk patients already receiving extensive and rigorous post-MI therapies. "It was a one-year study that enrolled fewer than 4,000 patients and the majority were using aspirin, clopidogrel, statins, beta-blockers and ACE-inhibitors—the best of modern medicine," he said. "It may be that their risk was so low to start, that a larger study with longer follow-up would be required to better assess the true efficacy of omega-3 in such relatively low-risk patients."
Authors say further studies are needed to investigate and determine optimal dosages, as well as the relative ration of DHA and EPA that provides maximal heart protection in those at risk of cardiovascular disease, and in the treatment of atherosclerosis, arrhythmias and heart attacks.
Interestingly, culture has historically played a role; sometimes dubbed the "Eskimo factor," research shows cultures that have traditionally supported a diet rich in fish oil (Asian and Alaskan American populations) had a lower prevalence of cardiovascular disease and mortality, including a reduced prevalence of atherosclerosis and heart disease, compared to European and United States populations where consumption of fish is lower. Ironically, the introduction of Western dietary practices into Asian and Native American cultures may be diluting the cardioprotective benefits enjoyed by these populations by both reducing the overall intake of fish oils, as well as overwhelming its benefits with other deleterious dietary practices, including high intakes of saturated and trans fats and cholesterol.
There is mounting evidence that omega-3 fatty acids from fish or fish oil supplements not only help prevent cardiovascular diseases in healthy individuals, but also reduce the incidence of cardiac events and mortality in patients with existing heart disease. A new study, published in the August 11, 2009, issue of the Journal of the American College of Cardiology, extensively reviews data from a broad range of studies in tens of thousands of patients and sets forth suggested daily targets for omega-3 consumption.
"This isn't just hype; we now have tremendous and compelling evidence from very large studies, some dating back 20 and 30 years, that demonstrate the protective benefits of omega-3 fish oil in multiple aspects of preventive cardiology," said Carl Lavie, M.D., F.A.C.C., medical director of Cardiac Rehabilitation and Prevention, Ochsner Medical Center, New Orleans, LA, and lead author of the article. "The strongest evidence of a cardioprotective effect of omega-3s appears in patients with established cardiovascular disease and following a heart attack with up to a 30 percent reduction in CV-related death."
Dietary intake of fish oil can also decrease the risk of atherosclerosis, arrhythmias, heart attack, sudden cardiac death and even health failure. Dr. Lavie adds that although there is a smaller benefit in reducing heart failure death—9 percent mortality benefit in a major recent randomized controlled trial—this is still very impressive given patients' grave prognosis.
"If we translate this finding, it means that we only need to treat 56 patients for four years to prevent one death," he said. "And we are talking about a very safe and relatively inexpensive therapy."
Most of the evidence for the cardioprotective benefits supports the use of DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid), the long-chain fatty acids in the omega-3 family. According to Dr. Lavie, EPA and DHA work by getting into the membranes of cells and, in doing so, may help to improve the heart's electrical activity, vascular tone, plaque stabilization and blood pressure, among other benefits. Studies show that the reduction in CV events is inversely related to the tissue level EPA and, even more so, DHA.
Based on these findings, and because the body does not produce its own essential fatty acids, the authors recommend that healthy individuals should consume 500 mg daily of omega-3 fish oil containing EPA and DHA, and people with known heart disease or heart failure aim for at least 800 to 1,000 mg daily.
"There are clear health and heart benefits associated with increasing one's intake of foods that are rich in Omega-3s, including oily fish like salmon, sardines, trout, herring, and oysters" said Dr. Lavie "Patients should talk with their doctors about whether a fish oil supplement is needed to get the right amount and, in turn, benefit from the associated cardiovascular protection."
Dr. Lavie and his team came across only a few negative studies, including a recent one that showed no benefit in post-MI patients, but it has raised the possibility that omega-3 fatty acids may not provide as much additional protective benefits in low-risk patients already receiving extensive and rigorous post-MI therapies. "It was a one-year study that enrolled fewer than 4,000 patients and the majority were using aspirin, clopidogrel, statins, beta-blockers and ACE-inhibitors—the best of modern medicine," he said. "It may be that their risk was so low to start, that a larger study with longer follow-up would be required to better assess the true efficacy of omega-3 in such relatively low-risk patients."
Authors say further studies are needed to investigate and determine optimal dosages, as well as the relative ration of DHA and EPA that provides maximal heart protection in those at risk of cardiovascular disease, and in the treatment of atherosclerosis, arrhythmias and heart attacks.
Interestingly, culture has historically played a role; sometimes dubbed the "Eskimo factor," research shows cultures that have traditionally supported a diet rich in fish oil (Asian and Alaskan American populations) had a lower prevalence of cardiovascular disease and mortality, including a reduced prevalence of atherosclerosis and heart disease, compared to European and United States populations where consumption of fish is lower. Ironically, the introduction of Western dietary practices into Asian and Native American cultures may be diluting the cardioprotective benefits enjoyed by these populations by both reducing the overall intake of fish oils, as well as overwhelming its benefits with other deleterious dietary practices, including high intakes of saturated and trans fats and cholesterol.
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