Vitamin-fortified foods and dietary health supplements can ease health worries. But what kinds of vitamins are right for you? And how much of them should you take, and how often?
A research group from Tel Aviv University has done the most comprehensive and accurate study of clinical data on Vitamin E use and heart disease to date, and it warns that indiscriminate use of high-dose Vitamin E supplementation does more harm than good. Their results were recently reported in ATVB, a leading journal of cardiology, and discussed in the journal BioFactors.
"There were so many conflicting reports about Vitamin E and its effect on various diseases, particularly heart disease, that we wanted to set the record straight, says Prof. Dov Lichtenberg of TAU's Sackler School of Medicine.
"Our new study shows that some people may be harmed by the treatment, whereas others may benefit from it. Now we're trying to identify groups of people that are most likely to benefit from the effects of Vitamin E," adds study co-researcher Dr. Ilya Pinchuk. The TAU research team also included decision analyst Dr. Moshe Leshno of the Sackler Faculty of Medicine and the Leon Recanati Faculty of Management and Dr. Yedidya (Didi) Dotan, whose PhD thesis is the basis for this analysis.
A longer life without it?
Applying a very different approach than any previous study, the team of researchers put their heads together to draw definitive conclusions about Vitamin E. In their publication in ATVB the Tel Aviv University researchers evaluated the results of the prominent studies measuring the health benefits of Vitamin E but reached varying conclusions. There have been many previous publications on the subject. Analysis of the results of all these past publications together revealed that subjects who did not take a Vitamin E supplement enjoyed more quality-adjusted-life-years (QALY), a standard parameter used in medicine to assess the effect of medical interventions.
"To explain the meaning of this parameter," says Dr. Pinchuk, "consider a participant who was healthy during the first 10 out of 20 years of the study, but then suffered a stroke and became dependent on others throughout the following 10 years. The QALY during the first 10 years of healthy life is 10, but after the stroke the quality of life is only half of what this person had before. Therefore, the second decade is considered the equivalent of merely 5 years of healthy life and in sum a person's QALY is 15.
The researchers examined data from more than 300,000 subjects in the US, Europe and Israel. "Our major finding," says Dr. Pinchuk, "was that the average quality-adjusted life years (QALY) of Vitamin E-supplemented individuals was 0.30 less than that of untreated people. This, of course, does not mean that everybody consuming Vitamin E shortens their life by almost 4 months. But on average, the quality-adjusted longevity is lower for vitamin-treated people. This says something significant."
Overturning earlier studies
In the BioFactors article, the TAU researchers defined "the real challenge as being able to identify who is likely to benefit taking Vitamin E." They also explored the first hypothesis of the oxidative theory of atherosclerosis published more than 20 years ago, which was the basis for the widespread use of antioxidants today. At first, this hypothesis raised great enthusiasm that anti-oxidants like Vitamins E and C and flavonoids could be used to prevent disease or its progression. In this respect, the new findings are very disappointing.
"We've now concluded that going to the grocery or to a health food store to buy Vitamin E supplements, for the most part, won't do you good. In some cases it can do harm," says Dr. Pinchuk. "A doctor wouldn't prescribe anti-hypertension drugs to the whole population, only to those with low blood pressure. It seems this is true for antioxidants, too. When you give them to everybody, you may be doing more harm than good. Some people may benefit from it, but more may be harmed."
The researchers are now building sets of criteria that detail under what conditions Vitamin E supplements should be taken. They are also investigating the chemical mechanisms of antioxidants in general to better understand how they work.
Thursday, December 31, 2009
Thursday, December 24, 2009
Factors Associated With Skin Aging
Smoking, being heavier, not using sunscreen and having had skin cancer appear to be associated with sun damage and aging of skin on the face, according to report based on a study of twins in the December issue of Archives of Dermatology, one of the JAMA/Archives journals.
Long-term exposure to the sun causes physical and structural changes to the skin, resulting in photodamage, according to background information in the article. Unlike typical skin aging, which is characterized by the development of fine wrinkles and skin growths, photodamage includes characteristics such as coarsely wrinkled skin, spots of extra pigment or lost pigment and dilated blood vessels on the face. Sun damage also has been associated with the development of cancerous growths. Up to 40 percent of aging-related changes are due to non-genetic factors.
To identify some of these environmental factors, Kathryn J. Martires, B.A., of Case Western Reserve School of Medicine, Cleveland, and colleagues studied 65 pairs of twins attending the 2002 annual Twin Days Festival in Twinsburg, Ohio. A total of 130 individuals completed surveys collecting information about skin type, history of skin cancer, smoking and drinking habits and weight. Clinicians assigned each participant a photodamage score, graded by such characteristics as wrinkling and change in pigmentation.
Photodamage scores were highly correlated among both monozygotic (identical) and dizygotic (fraternal) twins. Other factors associated with higher levels of photodamage included a history of skin cancer, heavier weight and smoking, whereas alcohol consumption was associated with lower photodamage scores.
"The Twins Days Festival provides a rare opportunity to study a large number of twin pairs to control for genetic susceptibility. Among the most important results is that a history of skin cancer and photodamage are highly associated in a population that shares genetic commonalities," the authors conclude. "The relationships found between smoking, weight, sunscreen use, skin cancer and photodamage in these twin pairs may help to motivate the reduction of risky behaviors."
Long-term exposure to the sun causes physical and structural changes to the skin, resulting in photodamage, according to background information in the article. Unlike typical skin aging, which is characterized by the development of fine wrinkles and skin growths, photodamage includes characteristics such as coarsely wrinkled skin, spots of extra pigment or lost pigment and dilated blood vessels on the face. Sun damage also has been associated with the development of cancerous growths. Up to 40 percent of aging-related changes are due to non-genetic factors.
To identify some of these environmental factors, Kathryn J. Martires, B.A., of Case Western Reserve School of Medicine, Cleveland, and colleagues studied 65 pairs of twins attending the 2002 annual Twin Days Festival in Twinsburg, Ohio. A total of 130 individuals completed surveys collecting information about skin type, history of skin cancer, smoking and drinking habits and weight. Clinicians assigned each participant a photodamage score, graded by such characteristics as wrinkling and change in pigmentation.
Photodamage scores were highly correlated among both monozygotic (identical) and dizygotic (fraternal) twins. Other factors associated with higher levels of photodamage included a history of skin cancer, heavier weight and smoking, whereas alcohol consumption was associated with lower photodamage scores.
"The Twins Days Festival provides a rare opportunity to study a large number of twin pairs to control for genetic susceptibility. Among the most important results is that a history of skin cancer and photodamage are highly associated in a population that shares genetic commonalities," the authors conclude. "The relationships found between smoking, weight, sunscreen use, skin cancer and photodamage in these twin pairs may help to motivate the reduction of risky behaviors."
Saturday, December 19, 2009
Bourbon Hurts More the Next Day
Bourbon Versus Vodka: Bourbon Hurts More the Next Day, Due to Byproducts of Fermenting Process
Many alcoholic beverages contain byproducts of the materials used in the fermenting process. These byproducts are called "congeners," complex organic molecules with toxic effects including acetone, acetaldehyde, fusel oil, tannins, and furfural. Bourbon has 37 times the amount of congeners that vodka has. A new study has found that while drinking a lot of bourbon can cause a worse hangover than drinking a lot of vodka, impairment in people's next-day task performance is about the same for both beverages.
Results will be published in the March 2010 issue of Alcoholism: Clinical & Experimental Research.
"While the toxic chemicals called congeners could be poisonous in large amounts, they occur in very small amounts in alcoholic beverages," explained Damaris J. Rohsenow, professor of community health at the Center for Alcohol and Addiction Studies at Brown University. "There are far more of them in the darker distilled beverages and wines than in the lighter colored ones. While the alcohol alone is enough to make many people feel sick the next day, these toxic natural substances can add to the ill effects as our body reacts to them."
Rohsenow added that few studies have looked at the effects of high- versus low-congener beverages on next-day hangover or performance, and some of those early studies were not careful to wait until breath alcohol levels (BALs) were close to zero before measuring performance, so results may have included some of alcohol's direct effects.
"We wanted to investigate next-day effects of bourbon versus vodka while ensuring that BALs were zero or almost zero when we studied performance, and we used a variety of performance measures classified by their relevance to safety," said Rohsenow. "We wanted to use a new hangover questionnaire that included only the symptoms that had been found to be valid in laboratory studies of hangover. We wanted to find out if bourbon's effects the next day were due to different effects on sleep, so people's sleep patterns were recorded while they slept. Finally, we wanted to know if performance impairments the morning after drinking were associated with how hung-over the person felt."
Researchers recruited and paid 95 (58 women, 37 men) healthy, heavy drinkers to participate in one acclimatization night, followed by two drinking nights. The participants drank bourbon or vodka to an average of 0.11 g% BAL on one night, with a matched placebo on the other night, randomized for type and order. Polysomnography recordings were made overnight; self-report and neurocognitive measures were assessed the next morning.
"First, while alcohol in the beverage did increase how hung-over people reported feeling the next morning compared to drinking a placebo, bourbon made people feel even worse than vodka did," said Rohsenow. "Second, alcohol in the beverage did make people do worse when they needed to pay attention for a continuous period of time while making rapid accurate choices, but they did no worse after bourbon than after vodka on these tasks. Therefore, while people felt worse, they didn't perform worse after bourbon than after vodka. However, people were not aware that they were performing worse since they thought their driving ability was not impaired in the morning even though they could not react as well." She added that other studies have found that professional pilots do worse on aspects of flying that require continuous attention across tasks the morning after drinking to intoxication.
"A third finding was that while alcohol in the beverages made people sleep less well because they woke up more during the night, this was no worse after bourbon than it was after vodka," Rohsenow said. "This means that bourbon's greater effects on hangover are not due to it having greater effects on sleep. Fourth, people who reported more hangover symptoms also did worse in their ability to pay attention for a continuous period of time while making rapid accurate choices."
Regarding this last finding, that people with more hangover symptoms -- feelings of headache, nausea, general lousiness, thirst and fatigue -- also performed worse when required to pay continuous attention and make choices, Rohsenow said that feeling worse was perhaps distracting them, or that it just hurt more to use the extra energy needed to pay close attention. "A second possibility is that as alcohol was metabolized into other substances in the body before leaving, these substances had a direct effect on the nervous system in addition to increasing hangover so that these were two separate but related after-effects of drinking to intoxication," she said.
The bottom line, said Rohsenow, is that becoming intoxicated to a .11 g% BAL makes it less safe for a person to engage in behaviors required for safety-sensitive performance the next morning. "Many safety-sensitive occupations require that workers be able to pay close attention to a number of tasks over a period of time, and to respond quickly with the right choices, and drinking to excess was found to impair this performance just after alcohol had left people's bodies."
Many alcoholic beverages contain byproducts of the materials used in the fermenting process. These byproducts are called "congeners," complex organic molecules with toxic effects including acetone, acetaldehyde, fusel oil, tannins, and furfural. Bourbon has 37 times the amount of congeners that vodka has. A new study has found that while drinking a lot of bourbon can cause a worse hangover than drinking a lot of vodka, impairment in people's next-day task performance is about the same for both beverages.
Results will be published in the March 2010 issue of Alcoholism: Clinical & Experimental Research.
"While the toxic chemicals called congeners could be poisonous in large amounts, they occur in very small amounts in alcoholic beverages," explained Damaris J. Rohsenow, professor of community health at the Center for Alcohol and Addiction Studies at Brown University. "There are far more of them in the darker distilled beverages and wines than in the lighter colored ones. While the alcohol alone is enough to make many people feel sick the next day, these toxic natural substances can add to the ill effects as our body reacts to them."
Rohsenow added that few studies have looked at the effects of high- versus low-congener beverages on next-day hangover or performance, and some of those early studies were not careful to wait until breath alcohol levels (BALs) were close to zero before measuring performance, so results may have included some of alcohol's direct effects.
"We wanted to investigate next-day effects of bourbon versus vodka while ensuring that BALs were zero or almost zero when we studied performance, and we used a variety of performance measures classified by their relevance to safety," said Rohsenow. "We wanted to use a new hangover questionnaire that included only the symptoms that had been found to be valid in laboratory studies of hangover. We wanted to find out if bourbon's effects the next day were due to different effects on sleep, so people's sleep patterns were recorded while they slept. Finally, we wanted to know if performance impairments the morning after drinking were associated with how hung-over the person felt."
Researchers recruited and paid 95 (58 women, 37 men) healthy, heavy drinkers to participate in one acclimatization night, followed by two drinking nights. The participants drank bourbon or vodka to an average of 0.11 g% BAL on one night, with a matched placebo on the other night, randomized for type and order. Polysomnography recordings were made overnight; self-report and neurocognitive measures were assessed the next morning.
"First, while alcohol in the beverage did increase how hung-over people reported feeling the next morning compared to drinking a placebo, bourbon made people feel even worse than vodka did," said Rohsenow. "Second, alcohol in the beverage did make people do worse when they needed to pay attention for a continuous period of time while making rapid accurate choices, but they did no worse after bourbon than after vodka on these tasks. Therefore, while people felt worse, they didn't perform worse after bourbon than after vodka. However, people were not aware that they were performing worse since they thought their driving ability was not impaired in the morning even though they could not react as well." She added that other studies have found that professional pilots do worse on aspects of flying that require continuous attention across tasks the morning after drinking to intoxication.
"A third finding was that while alcohol in the beverages made people sleep less well because they woke up more during the night, this was no worse after bourbon than it was after vodka," Rohsenow said. "This means that bourbon's greater effects on hangover are not due to it having greater effects on sleep. Fourth, people who reported more hangover symptoms also did worse in their ability to pay attention for a continuous period of time while making rapid accurate choices."
Regarding this last finding, that people with more hangover symptoms -- feelings of headache, nausea, general lousiness, thirst and fatigue -- also performed worse when required to pay continuous attention and make choices, Rohsenow said that feeling worse was perhaps distracting them, or that it just hurt more to use the extra energy needed to pay close attention. "A second possibility is that as alcohol was metabolized into other substances in the body before leaving, these substances had a direct effect on the nervous system in addition to increasing hangover so that these were two separate but related after-effects of drinking to intoxication," she said.
The bottom line, said Rohsenow, is that becoming intoxicated to a .11 g% BAL makes it less safe for a person to engage in behaviors required for safety-sensitive performance the next morning. "Many safety-sensitive occupations require that workers be able to pay close attention to a number of tasks over a period of time, and to respond quickly with the right choices, and drinking to excess was found to impair this performance just after alcohol had left people's bodies."
Thursday, December 17, 2009
Moderate Fish Consumption May Lower heart Risk
Including fish in a balanced diet has long been associated with the prevention of heart disease, and scientists now believe that it can help preserve heart function in patients who have experienced heart failure. A new study in the Journal of Food Science reports that moderate fish consumption can help reduce the risk of left ventricular systolic dysfunction (LVSD) in post acute coronary syndrome (ACS) patients.
Researchers from the University of Athens in Greece focused on demographical, nutritional, lifestyle, and medical factors combined with the risk of developing left ventricular dysfunction after nonfatal heart failure. The study included nearly one thousand patients who were hospitalized after ACS.
At the study’s conclusion, researchers noted that consuming fish one to two times per week was independently associated with a considerable reduction of the odds of developing LVSD. However, a higher consumption of fish did not result in further protection from the occurrence of LVSD
Researchers from the University of Athens in Greece focused on demographical, nutritional, lifestyle, and medical factors combined with the risk of developing left ventricular dysfunction after nonfatal heart failure. The study included nearly one thousand patients who were hospitalized after ACS.
At the study’s conclusion, researchers noted that consuming fish one to two times per week was independently associated with a considerable reduction of the odds of developing LVSD. However, a higher consumption of fish did not result in further protection from the occurrence of LVSD
Eat Fruits and Vegetable for Better Vision
Carotenoids, found in green leafy vegetables and colored fruits, have been found to increase visual performance and may prevent age-related eye diseases, according to a study in the Journal of Food Science, published by the Institute of Food Technologists. Authors from the University of Georgia compiled the results of multiple studies on the effects of the carotenoids lutein and zeaxanthin on visual performance. These carotenoids play an important role in human vision, including a positive impact on the retina.
After reviewing the various studies, the authors concluded that macular pigments, such as lutein and zeaxanthin do have an effect on visual performance. Lutein and zeaxanthin can reduce disability and discomfort from glare, enhance contrast, and reduce photostress recovery times. They can also reduce glare from light absorption and increase the visual range.
Lead author Dr. Billy R. Hammond Jr. noted that the research of the effects of lutein and zeazanthin are important because “it is clear that they could potentially improve vision through biological means. For example, a study conducted in 2008 suggests that the pigments protect the retina and lens and perhaps even help prevent age-related eye diseases such as macular degeneration and cataract.”
After reviewing the various studies, the authors concluded that macular pigments, such as lutein and zeaxanthin do have an effect on visual performance. Lutein and zeaxanthin can reduce disability and discomfort from glare, enhance contrast, and reduce photostress recovery times. They can also reduce glare from light absorption and increase the visual range.
Lead author Dr. Billy R. Hammond Jr. noted that the research of the effects of lutein and zeazanthin are important because “it is clear that they could potentially improve vision through biological means. For example, a study conducted in 2008 suggests that the pigments protect the retina and lens and perhaps even help prevent age-related eye diseases such as macular degeneration and cataract.”
Wednesday, December 16, 2009
Don't Take Aspirin Or Advil Before Sports (I Do)
Athletes' superstitions and rituals can help them get psyched up for contests, but when these rituals involve non-steroidal anti-inflammatory drugs (NSAIDs), which many athletes gobble down before and during events, they could be causing more harm than good.
"These agents are treatments for the symptoms of an injury, not the injury itself," says Stuart Warden, whose research at Indiana University focuses on musculoskeletal health and sports medicine. "They may allow an athlete to exercise or train at a certain level, but pain occurs for a reason. It is basically the body's mechanism of saying, 'Hang on, you've got some sort of injury that should not be ignored.'"
NSAIDs are recommended for use after an injury to reduce swelling or pain. Studies have found that many elite athletes, however, take these over-the-counter drugs -- and often several different kinds -- before contests and challenging workouts because they think they will reduce anticipated inflammation and soreness that could occur after the event.
Warden says there is no scientific evidence for this prophylactic use of NSAIDs. Such misuse, however, can cause a range of problems, from interfering with healing and inhibiting the body's ability to adapt to challenging workouts, to the development of stomach ulcers and possibly an increased risk for cardiovascular problems, says Warden, assistant professor in the Department of Physical Therapy at Indiana University-Purdue University Indianapolis.
The larger the dose and the longer duration of NSAID use, the greater potential for these risks. Warden warned against the misuse of NSAIDs in an editorial published earlier this year in the "British Journal of Sports Medicine."
"I want people, including recreational athletes, to think about the perceived benefits versus potential risks of taking NSAIDs, and to ask themselves why they are taking these agents," said Warden. "They need to ask, 'Do the benefits outweigh the risks?"
Background. NSAIDs interact with the body's chemistry at a cellular level by inhibiting the cyclooxygenase (COX) isozymes. The COX isozymes are critical for the synthesis of prostaglandins, which have important functions in the gut and cardiovascular system, as well as during inflammation and the adaptive response of the musculoskeletal system to stress. NSAIDs may reduce pain and inflammation following injury by inhibiting COX isozyme-induced prostaglandin synthesis; however, as they circulate within the body indiscriminately, rather than localizing to the source of an athlete's specific aches and pains, they may produce undesirable side effects. With regular misuse, athletes face extreme and severe risks, such as the development of ulcers, potentially fatal problems with renal blood flow, and increased risks for cardiovascular problems. On a lesser scale, they could actually increase their risk for injuries because their bodies are less able to adapt to rigorous workouts -- and healing could take longer.
Warden said NSAIDs should be taken as directed -- in the recommended dosages and for no more than a week after an acute injury that involves swelling and pain.
"But to take the drugs before every run and throughout the year is a concern. You need to think of pain not as a hindrance, but as a signal that something is not quite right," he says, adding that, "NSAIDs should not be used at the expense of a thorough assessment of an injury by a trained professional, such as a physical therapist or physician."
"These agents are treatments for the symptoms of an injury, not the injury itself," says Stuart Warden, whose research at Indiana University focuses on musculoskeletal health and sports medicine. "They may allow an athlete to exercise or train at a certain level, but pain occurs for a reason. It is basically the body's mechanism of saying, 'Hang on, you've got some sort of injury that should not be ignored.'"
NSAIDs are recommended for use after an injury to reduce swelling or pain. Studies have found that many elite athletes, however, take these over-the-counter drugs -- and often several different kinds -- before contests and challenging workouts because they think they will reduce anticipated inflammation and soreness that could occur after the event.
Warden says there is no scientific evidence for this prophylactic use of NSAIDs. Such misuse, however, can cause a range of problems, from interfering with healing and inhibiting the body's ability to adapt to challenging workouts, to the development of stomach ulcers and possibly an increased risk for cardiovascular problems, says Warden, assistant professor in the Department of Physical Therapy at Indiana University-Purdue University Indianapolis.
The larger the dose and the longer duration of NSAID use, the greater potential for these risks. Warden warned against the misuse of NSAIDs in an editorial published earlier this year in the "British Journal of Sports Medicine."
"I want people, including recreational athletes, to think about the perceived benefits versus potential risks of taking NSAIDs, and to ask themselves why they are taking these agents," said Warden. "They need to ask, 'Do the benefits outweigh the risks?"
Background. NSAIDs interact with the body's chemistry at a cellular level by inhibiting the cyclooxygenase (COX) isozymes. The COX isozymes are critical for the synthesis of prostaglandins, which have important functions in the gut and cardiovascular system, as well as during inflammation and the adaptive response of the musculoskeletal system to stress. NSAIDs may reduce pain and inflammation following injury by inhibiting COX isozyme-induced prostaglandin synthesis; however, as they circulate within the body indiscriminately, rather than localizing to the source of an athlete's specific aches and pains, they may produce undesirable side effects. With regular misuse, athletes face extreme and severe risks, such as the development of ulcers, potentially fatal problems with renal blood flow, and increased risks for cardiovascular problems. On a lesser scale, they could actually increase their risk for injuries because their bodies are less able to adapt to rigorous workouts -- and healing could take longer.
Warden said NSAIDs should be taken as directed -- in the recommended dosages and for no more than a week after an acute injury that involves swelling and pain.
"But to take the drugs before every run and throughout the year is a concern. You need to think of pain not as a hindrance, but as a signal that something is not quite right," he says, adding that, "NSAIDs should not be used at the expense of a thorough assessment of an injury by a trained professional, such as a physical therapist or physician."
Methionine could increase risk of Alzheimer’s
A diet rich in methionine, an amino acid typically found in red meats, fish, beans, eggs, garlic, lentils, onions, yogurt and seeds, can possibly increase the risk of developing Alzheimer’s disease, according to a study by Temple researchers.
The researchers published their findings, titled “Diet-induced hyperhomocysteinemia increases Amyloid-β formation and deposition in a mouse model of Alzheimer’s disease,” in the journal Current Alzheimer Research.
“When methionine reaches too high a level, our body tries to protect itself by transforming it into a particular amino acid called homocysteine,” said lead researcher Domenico Praticò, an associate professor of pharmacology in the School of Medicine. “The data from previous studies show — even in humans — when the level of homocysteine in the blood is high, there is a higher risk of developing dementia. We hypothesized that high levels of homocysteine in an animal model of Alzheimer’s would accelerate the disease.”
A brain sample taken from mice used in the study shows dark spots consistent with amyloid plaque, indicative of the progression of Alzheimer’s disease. Mice fed diets rich in methionine had an increased level of homocysteine and up to 40 percent more amyloid plaque in their brains.
Using a seven-month old mouse model of the disease, they fed one group an eight-month diet of regular food and another group a diet high in methionine. The mice were then tested at 15 months of age — the equivalent of a 70-year-old human.
“We found that the mice with the normal diet had normal homocysteine levels, but the mice with the high methionine diet had significantly increased levels of homocysteine, very similar to human subjects with hyperhomocysteinemia,” said Praticò. “The group with the high methionine diet also had up to 40 percent more amyloid plaque in their brains, which is a measurement of how much Alzheimer’s disease has developed.
The researchers also examined capacity to learn a new task and found it diminished in the group with the diet high in methionine.
Still, Praticò emphasized, methionine is an essential amino acid for the human body and “stopping one’s intake of methionine won’t prevent Alzheimer’s. But people who have a diet high in red meat, for instance, could be more at risk because they are more likely to develop this high level of circulating homocysteine,” he said.
The researchers published their findings, titled “Diet-induced hyperhomocysteinemia increases Amyloid-β formation and deposition in a mouse model of Alzheimer’s disease,” in the journal Current Alzheimer Research.
“When methionine reaches too high a level, our body tries to protect itself by transforming it into a particular amino acid called homocysteine,” said lead researcher Domenico Praticò, an associate professor of pharmacology in the School of Medicine. “The data from previous studies show — even in humans — when the level of homocysteine in the blood is high, there is a higher risk of developing dementia. We hypothesized that high levels of homocysteine in an animal model of Alzheimer’s would accelerate the disease.”
A brain sample taken from mice used in the study shows dark spots consistent with amyloid plaque, indicative of the progression of Alzheimer’s disease. Mice fed diets rich in methionine had an increased level of homocysteine and up to 40 percent more amyloid plaque in their brains.
Using a seven-month old mouse model of the disease, they fed one group an eight-month diet of regular food and another group a diet high in methionine. The mice were then tested at 15 months of age — the equivalent of a 70-year-old human.
“We found that the mice with the normal diet had normal homocysteine levels, but the mice with the high methionine diet had significantly increased levels of homocysteine, very similar to human subjects with hyperhomocysteinemia,” said Praticò. “The group with the high methionine diet also had up to 40 percent more amyloid plaque in their brains, which is a measurement of how much Alzheimer’s disease has developed.
The researchers also examined capacity to learn a new task and found it diminished in the group with the diet high in methionine.
Still, Praticò emphasized, methionine is an essential amino acid for the human body and “stopping one’s intake of methionine won’t prevent Alzheimer’s. But people who have a diet high in red meat, for instance, could be more at risk because they are more likely to develop this high level of circulating homocysteine,” he said.
Omega-3 = better nervous-system function
The omega-3 essential fatty acids commonly found in fatty fish and algae help animals avoid sensory overload, according to research published by the American Psychological Association. The finding connects low omega-3s to the information-processing problems found in people with schizophrenia; bipolar, obsessive-compulsive, and attention-deficit hyperactivity disorders; Huntington's disease; and other afflictions of the nervous system.
The study, reported in the journal Behavioral Neuroscience, provides more evidence that fish is brain food. The key finding was that two omega-3 fatty acids – docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) – appear to be most useful in the nervous system, maybe by maintaining nerve-cell membranes.
"It is an uphill battle now to reverse the message that 'fats are bad,' and to increase omega-3 fats in our diet," said Norman Salem Jr., PhD, who led this study at the Laboratory of Membrane Biochemistry and Biophysics at the National Institute on Alcohol Abuse and Alcoholism.
The body cannot make these essential nutrients from scratch. It gets them by metabolizing their precursor, α-linolenic acid (LNA), or from foods or dietary supplements with DHA and EPA in a readily usable form. "Humans can convert less than one percent of the precursor into DHA, making DHA an essential nutrient in the human diet," added Irina Fedorova, PhD, one of the paper's co-authors. EPA is already known for its anti-inflammatory and cardiovascular effects, but DHA makes up more than 90 percent of the omega-3s in the brain (which has no EPA), retina and nervous system in general.
In the study, the researchers fed four different diets with no or varying types and amounts of omega-3s to four groups of pregnant mice and then their offspring. They measured how the offspring, once grown, responded to a classic test of nervous-system function in which healthy animals are exposed to a sudden loud noise. Normally, animals flinch. However, when they hear a softer tone in advance, they flinch much less. It appears that normal nervous systems use that gentle warning to prepare instinctively for future stimuli, an adaptive process called sensorimotor gating.
Only the mice raised on DHA and EPA, but not their precursor of LNA, showed normal, adaptive sensorimotor gating by responding in a significantly calmer way to the loud noises that followed soft tones. The mice in all other groups, when warned, were startled nearly as much by the loud sound. When DHA was deficient, the nervous system most obviously did not downshift. That resulted in an abnormal state that could leave animals perpetually startled and easily overwhelmed by sensory stimuli.
The authors concluded that not enough DHA in the diet may reduce the ability to handle sensory input. "It only takes a small decrement in brain DHA to produce losses in brain function," said Salem.
In humans, weak sensorimotor gating is a hallmark of many nervous-system disorders such as schizophrenia or ADHD. Given mounting evidence of the role omega-3s play in the nervous system, there is intense interest in their therapeutic potential, perhaps as a supplement to medicines. For example, people with schizophrenia have lower levels of essential fatty acids, possibly from a genetic variation that results in poor metabolism of these nutrients.
More broadly, the typical American diet is much lower in all types of omega-3 than in omega-6 essential fatty acids, according to Salem. High intake of omega-6, or linoleic acid, reduces the body's ability to incorporate omega-3s. As a result, "we have the double whammy of low omega-3 intake and high omega-6 intake," he said.
The study, reported in the journal Behavioral Neuroscience, provides more evidence that fish is brain food. The key finding was that two omega-3 fatty acids – docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) – appear to be most useful in the nervous system, maybe by maintaining nerve-cell membranes.
"It is an uphill battle now to reverse the message that 'fats are bad,' and to increase omega-3 fats in our diet," said Norman Salem Jr., PhD, who led this study at the Laboratory of Membrane Biochemistry and Biophysics at the National Institute on Alcohol Abuse and Alcoholism.
The body cannot make these essential nutrients from scratch. It gets them by metabolizing their precursor, α-linolenic acid (LNA), or from foods or dietary supplements with DHA and EPA in a readily usable form. "Humans can convert less than one percent of the precursor into DHA, making DHA an essential nutrient in the human diet," added Irina Fedorova, PhD, one of the paper's co-authors. EPA is already known for its anti-inflammatory and cardiovascular effects, but DHA makes up more than 90 percent of the omega-3s in the brain (which has no EPA), retina and nervous system in general.
In the study, the researchers fed four different diets with no or varying types and amounts of omega-3s to four groups of pregnant mice and then their offspring. They measured how the offspring, once grown, responded to a classic test of nervous-system function in which healthy animals are exposed to a sudden loud noise. Normally, animals flinch. However, when they hear a softer tone in advance, they flinch much less. It appears that normal nervous systems use that gentle warning to prepare instinctively for future stimuli, an adaptive process called sensorimotor gating.
Only the mice raised on DHA and EPA, but not their precursor of LNA, showed normal, adaptive sensorimotor gating by responding in a significantly calmer way to the loud noises that followed soft tones. The mice in all other groups, when warned, were startled nearly as much by the loud sound. When DHA was deficient, the nervous system most obviously did not downshift. That resulted in an abnormal state that could leave animals perpetually startled and easily overwhelmed by sensory stimuli.
The authors concluded that not enough DHA in the diet may reduce the ability to handle sensory input. "It only takes a small decrement in brain DHA to produce losses in brain function," said Salem.
In humans, weak sensorimotor gating is a hallmark of many nervous-system disorders such as schizophrenia or ADHD. Given mounting evidence of the role omega-3s play in the nervous system, there is intense interest in their therapeutic potential, perhaps as a supplement to medicines. For example, people with schizophrenia have lower levels of essential fatty acids, possibly from a genetic variation that results in poor metabolism of these nutrients.
More broadly, the typical American diet is much lower in all types of omega-3 than in omega-6 essential fatty acids, according to Salem. High intake of omega-6, or linoleic acid, reduces the body's ability to incorporate omega-3s. As a result, "we have the double whammy of low omega-3 intake and high omega-6 intake," he said.
Statin Recommended For Prevention Of Heart Disease
AN FDA advisory panel has voted 10 - 4 to recommend Crestor for patients without high cholesterol but with the following characteristics: Low or normal levels of the variety of cholesterol known as low-density lipoprotein, or LDL; elevated levels of C-reactive protein (hsCRP), a marker of inflammation in the body, and at least one of the conventional risk factors for cardiovascular disease. (The “conventional risk factors” are smoking, age, high blood pressure, low levels of the good cholesterol, HDL, and a family history of heart disease).
More info here.
More info here.
Monday, December 14, 2009
Coffee, Tea = Reduced Risk of Diabetes
Drinking more coffee (regular or decaffeinated) or tea appears to lower the risk of developing type 2 diabetes, according to an analysis of previous studies reported in the December 14/28 issue of Archives of Internal Medicine, JAMA (1).
By the year 2025, approximately 380 million individuals worldwide will be affected by type 2 diabetes (1).
Despite considerable research attention, the role of specific dietary and lifestyle factors remains uncertain, although obesity and physical inactivity have consistently been reported to raise the risk of diabetes mellitus. A previously published meta-analysis suggested drinking more coffee may be linked with a reduced risk, but the amount of available information has more than doubled since.
Rachel Huxley, D.Phil, of The George Institute for International Health, University of Sydney, Australia, and colleagues identified 18 studies involving 457,922 participants and assessing the association between coffee consumption and diabetes risk published between 1966 and 2009.
Six studies involving 225,516 individuals also included information about decaffeinated coffee, whereas seven studies with 286,701 participants reported on tea consumption.
When the authors combined and analyzed the data, they found that each additional cup of coffee consumed in a day was associated with a 7 percent reduction in the excess risk of diabetes.
Individuals who drank three to four cups per day had an approximately 25 percent lower risk than those who drank between zero and two cups per day.
In addition, in the studies that assessed decaffeinated coffee consumption, those who drank more than three to four cups per day had about a one-third lower risk of diabetes than those who drank none. Those who drank more than three to four cups of tea had a one-fifth lower risk than those who drank no tea.
That the apparent protective effect of tea and coffee consumption appears to be independent of a number of potential confounding variables raises the possibility of direct biological effects, the authors write. Because of the association between decaffeinated coffee and diabetes risk, the association is unlikely to be solely related to caffeine. Other compounds in coffee and tea including magnesium, antioxidants known as lignans or chlorogenic acids may be involved, the authors note.
If such beneficial effects were observed in interventional trials to be real, the implications for the millions of individuals who have diabetes mellitus, or who are at future risk of developing it, would be substantial, they conclude. For example, the identification of the active components of these beverages could open up new therapeutic options for the primary prevention of diabetes mellitus. The findings also pose the question of whether patients most at risk for diabetes mellitus may in the future be advised to increase their consumption of tea and coffee in addition to increasing their levels of physical activity.
Spokesperson for the European Society of Cardiology, Professor Lars Rydén (Sweden), who is a diabetes specialist had the following advice: "This is a cautiously and carefully conducted meta-analysis which means authors have carefully conducted studies although each are too small to give an answer to the question although they indicate a positive correlation between the consumption of coffee and a decreasing occurrence of diabetes. So the principle is that if you drink coffee whether it is decaffeinated or not, you have less chance of developing diabetes. The data has been strengthened by bringing several studies together.
There are sometimes claims that coffee may do harm, that it may increase the propensity to Cardiovascular disease, but there is no evidence for this. The message is that people may drink coffee safely. Coffee from this point of view may actually be of benefit, as well as reducing the risk of getting diabetes – although the reduction is small (around 7%)."
However Prof Rydén warns that lifestyle changes far outweigh a regular coffee intake.
"Coffee helps, but other things are even more important. Those who are overweight should reduce their bodyweight by 5-10% - not too much - and include physical activity such as a brisk walk for 30 minutes a day. Then those people who are at risk of developing diabetes will reduce this risk by 40-50%.
It is interesting to consider why a beverage like coffee has a beneficial effect. It is obviously not the caffeine as decaffeinated coffee has the same efficiency as caffeinated coffee. Coffee may contain antioxidants but the studies have not measured the number of chemicals in the blood which is important."
By the year 2025, approximately 380 million individuals worldwide will be affected by type 2 diabetes (1).
Despite considerable research attention, the role of specific dietary and lifestyle factors remains uncertain, although obesity and physical inactivity have consistently been reported to raise the risk of diabetes mellitus. A previously published meta-analysis suggested drinking more coffee may be linked with a reduced risk, but the amount of available information has more than doubled since.
Rachel Huxley, D.Phil, of The George Institute for International Health, University of Sydney, Australia, and colleagues identified 18 studies involving 457,922 participants and assessing the association between coffee consumption and diabetes risk published between 1966 and 2009.
Six studies involving 225,516 individuals also included information about decaffeinated coffee, whereas seven studies with 286,701 participants reported on tea consumption.
When the authors combined and analyzed the data, they found that each additional cup of coffee consumed in a day was associated with a 7 percent reduction in the excess risk of diabetes.
Individuals who drank three to four cups per day had an approximately 25 percent lower risk than those who drank between zero and two cups per day.
In addition, in the studies that assessed decaffeinated coffee consumption, those who drank more than three to four cups per day had about a one-third lower risk of diabetes than those who drank none. Those who drank more than three to four cups of tea had a one-fifth lower risk than those who drank no tea.
That the apparent protective effect of tea and coffee consumption appears to be independent of a number of potential confounding variables raises the possibility of direct biological effects, the authors write. Because of the association between decaffeinated coffee and diabetes risk, the association is unlikely to be solely related to caffeine. Other compounds in coffee and tea including magnesium, antioxidants known as lignans or chlorogenic acids may be involved, the authors note.
If such beneficial effects were observed in interventional trials to be real, the implications for the millions of individuals who have diabetes mellitus, or who are at future risk of developing it, would be substantial, they conclude. For example, the identification of the active components of these beverages could open up new therapeutic options for the primary prevention of diabetes mellitus. The findings also pose the question of whether patients most at risk for diabetes mellitus may in the future be advised to increase their consumption of tea and coffee in addition to increasing their levels of physical activity.
Spokesperson for the European Society of Cardiology, Professor Lars Rydén (Sweden), who is a diabetes specialist had the following advice: "This is a cautiously and carefully conducted meta-analysis which means authors have carefully conducted studies although each are too small to give an answer to the question although they indicate a positive correlation between the consumption of coffee and a decreasing occurrence of diabetes. So the principle is that if you drink coffee whether it is decaffeinated or not, you have less chance of developing diabetes. The data has been strengthened by bringing several studies together.
There are sometimes claims that coffee may do harm, that it may increase the propensity to Cardiovascular disease, but there is no evidence for this. The message is that people may drink coffee safely. Coffee from this point of view may actually be of benefit, as well as reducing the risk of getting diabetes – although the reduction is small (around 7%)."
However Prof Rydén warns that lifestyle changes far outweigh a regular coffee intake.
"Coffee helps, but other things are even more important. Those who are overweight should reduce their bodyweight by 5-10% - not too much - and include physical activity such as a brisk walk for 30 minutes a day. Then those people who are at risk of developing diabetes will reduce this risk by 40-50%.
It is interesting to consider why a beverage like coffee has a beneficial effect. It is obviously not the caffeine as decaffeinated coffee has the same efficiency as caffeinated coffee. Coffee may contain antioxidants but the studies have not measured the number of chemicals in the blood which is important."
Exercise improves survival from colorectal cancer
Men who have been treated for colorectal cancer can reduce their risk of dying from the disease by engaging in regular exercise, according to a new study by researchers at Dana-Farber Cancer Institute. The findings are published in the December 14 issue of the Archives of Internal Medicine.
"Previous research has shown regular physical activity reduces the risk of developing colon cancer," says the study's lead author, Jeffrey A. Meyerhardt, MD, MPH, of Dana-Farber. "This current study confirms two other studies from our group that shows physical activity by colorectal cancer survivors helps them live longer than those survivors who are not physically active."
Meyerhardt and his team studied 668 men with colorectal cancer. More than 50 percent of the men exercised the equivalent of one hour of walking, at least six days per week, although the men engaged in a variety of different recreational exercises. Researchers found patients who engaged in moderate physical activity were 53 percent more likely to be alive and free of the disease than those who were less physically active. The benefit of exercise was seen regardless of age, how advanced the cancer, weight and any history of previous physical activity.
"Moderate exercise has now been incorporated in some guidelines for colorectal cancer survivors and this new research should further reinforce to oncologists that they should discuss this in their survivorship plan," says Meyerhardt. "However, while our work found a significant benefit for patients who exercise, it's important that exercise still be seen as a supplement to, not a replacement for, standard therapies."
More than 148,000 people in the United States are diagnosed with colorectal cancer each year and, despite advances in screening and treatment, the disease causes almost 50,000 deaths annually.
"Previous research has shown regular physical activity reduces the risk of developing colon cancer," says the study's lead author, Jeffrey A. Meyerhardt, MD, MPH, of Dana-Farber. "This current study confirms two other studies from our group that shows physical activity by colorectal cancer survivors helps them live longer than those survivors who are not physically active."
Meyerhardt and his team studied 668 men with colorectal cancer. More than 50 percent of the men exercised the equivalent of one hour of walking, at least six days per week, although the men engaged in a variety of different recreational exercises. Researchers found patients who engaged in moderate physical activity were 53 percent more likely to be alive and free of the disease than those who were less physically active. The benefit of exercise was seen regardless of age, how advanced the cancer, weight and any history of previous physical activity.
"Moderate exercise has now been incorporated in some guidelines for colorectal cancer survivors and this new research should further reinforce to oncologists that they should discuss this in their survivorship plan," says Meyerhardt. "However, while our work found a significant benefit for patients who exercise, it's important that exercise still be seen as a supplement to, not a replacement for, standard therapies."
More than 148,000 people in the United States are diagnosed with colorectal cancer each year and, despite advances in screening and treatment, the disease causes almost 50,000 deaths annually.
Consumer Reports: BPA in Most Canned Foods
Consumer Reports’ latest tests of canned foods, including soups, juice, tuna, and green beans, have found that almost all of the 19 name-brand foods tested contain measurable levels of Bisphenol A (BPA). The new findings show that BPA can be found in a diverse assortment of canned foods including those labeled “organic,” and even in some foods packaged in “BPA-free” cans. Consumer Reports’ tests of a few comparable products in alternative types of packaging showed lower levels of BPA in most, but not all cases. The results are reported in the December 2009 issue.
“The findings are noteworthy because they indicate the extent of potential exposure,” said Dr. Urvashi Rangan, Director of Technical Policy, at Consumers Union, nonprofit publisher of Consumer Reports. “Children eating multiple servings per day of canned foods with BPA levels comparable to the ones we found in some tested products could get a dose of BPA near levels that have caused adverse effects in several animal studies. The lack of any safety margin between the levels that cause harm in animals and those that people could potentially ingest from canned foods has been inadequately addressed by the FDA to date.”
The Food and Drug Administration (FDA) is soon expected to announce the findings of its most recent reassessment of the safety of BPA. Consumers Union hopes it will remedy some of the deficiencies of its previous analysis. BPA has been linked to a wide array of health effects including reproductive abnormalities, heightened risk of breast and prostate cancers, diabetes, and heart disease.
Consumers Union has previously called on manufacturers and government agencies to act to eliminate the use of BPA in all materials that come in contact with food and beverages. Given Consumer Reports’ new finding, Consumers Union sent a letter to FDA Commissioner Margaret Hamburg reiterating its request that the agency act this year to ban the use of BPA in food- and beverage-contact materials.
BPA, which has been used for years in clear plastic bottles and food-can liners, has been restricted in Canada and some U.S. states and municipalities because of potential health effects. But, there are no federal restrictions on BPA in food packaging. Federal guidelines currently put the daily upper limit of safe exposure at 50 micrograms of BPA per kilogram of body weight. But that level is based on experiments done in the 1980s rather than hundreds of more recent animal and laboratory studies indicating that serious health risks could result from much lower doses of BPA. Several animal studies show adverse effects, such as abnormal reproductive development, at exposures of 2.4 micrograms of BPA per kilogram of body weight per day, a dose that could be reached from a person eating one or a few servings daily or an adult daily diet that includes multiple servings of canned foods containing BPA levels comparable to some of the foods Consumer Reports tested.
In keeping with established practices that ensure an adequate margin of safety for human exposure, Consumer Reports’ food-safety scientists recommend limiting daily exposure to BPA to one-thousandth of that level, or 0.0024 micrograms per kilogram of body weight, significantly lower than FDA’s current safety limit.
An FDA special scientific advisory panel reported in late 2008 that the agency’s basis for setting safety standards to protect consumers was inadequate and should be reevaluated. A congressional subcommittee determined in 2009 that the agency relied too heavily on studies sponsored by the American Plastics Council. The FDA, now under the leadership of Dr. Margaret Hamburg, is expected to announce soon its reassessment of BPA safety. Bills are currently pending in Congress that would ban the use of BPA in all food and beverage containers. Industry has been waging a fight against new regulations.
Almost a decade ago, Consumers Union was one of the first consumer groups to test BPA in baby bottles, and to warn consumers about its potential dangers. Consumers Union calls on manufacturers and government agencies to act to eliminate the use of BPA in all materials that come into contact with food. Consumers who are concerned might be able to reduce, though not necessarily eliminate, their dietary exposure to BPA by taking the following steps:
• Choose fresh food whenever possible.
• Consider alternatives to canned food, beverages, juices, and infant formula.
• Use glass containers when heating food in microwave ovens.
“The findings are noteworthy because they indicate the extent of potential exposure,” said Dr. Urvashi Rangan, Director of Technical Policy, at Consumers Union, nonprofit publisher of Consumer Reports. “Children eating multiple servings per day of canned foods with BPA levels comparable to the ones we found in some tested products could get a dose of BPA near levels that have caused adverse effects in several animal studies. The lack of any safety margin between the levels that cause harm in animals and those that people could potentially ingest from canned foods has been inadequately addressed by the FDA to date.”
The Food and Drug Administration (FDA) is soon expected to announce the findings of its most recent reassessment of the safety of BPA. Consumers Union hopes it will remedy some of the deficiencies of its previous analysis. BPA has been linked to a wide array of health effects including reproductive abnormalities, heightened risk of breast and prostate cancers, diabetes, and heart disease.
Consumers Union has previously called on manufacturers and government agencies to act to eliminate the use of BPA in all materials that come in contact with food and beverages. Given Consumer Reports’ new finding, Consumers Union sent a letter to FDA Commissioner Margaret Hamburg reiterating its request that the agency act this year to ban the use of BPA in food- and beverage-contact materials.
BPA, which has been used for years in clear plastic bottles and food-can liners, has been restricted in Canada and some U.S. states and municipalities because of potential health effects. But, there are no federal restrictions on BPA in food packaging. Federal guidelines currently put the daily upper limit of safe exposure at 50 micrograms of BPA per kilogram of body weight. But that level is based on experiments done in the 1980s rather than hundreds of more recent animal and laboratory studies indicating that serious health risks could result from much lower doses of BPA. Several animal studies show adverse effects, such as abnormal reproductive development, at exposures of 2.4 micrograms of BPA per kilogram of body weight per day, a dose that could be reached from a person eating one or a few servings daily or an adult daily diet that includes multiple servings of canned foods containing BPA levels comparable to some of the foods Consumer Reports tested.
In keeping with established practices that ensure an adequate margin of safety for human exposure, Consumer Reports’ food-safety scientists recommend limiting daily exposure to BPA to one-thousandth of that level, or 0.0024 micrograms per kilogram of body weight, significantly lower than FDA’s current safety limit.
An FDA special scientific advisory panel reported in late 2008 that the agency’s basis for setting safety standards to protect consumers was inadequate and should be reevaluated. A congressional subcommittee determined in 2009 that the agency relied too heavily on studies sponsored by the American Plastics Council. The FDA, now under the leadership of Dr. Margaret Hamburg, is expected to announce soon its reassessment of BPA safety. Bills are currently pending in Congress that would ban the use of BPA in all food and beverage containers. Industry has been waging a fight against new regulations.
Almost a decade ago, Consumers Union was one of the first consumer groups to test BPA in baby bottles, and to warn consumers about its potential dangers. Consumers Union calls on manufacturers and government agencies to act to eliminate the use of BPA in all materials that come into contact with food. Consumers who are concerned might be able to reduce, though not necessarily eliminate, their dietary exposure to BPA by taking the following steps:
• Choose fresh food whenever possible.
• Consider alternatives to canned food, beverages, juices, and infant formula.
• Use glass containers when heating food in microwave ovens.
Friday, December 11, 2009
High CRP = Heart Disease, Stroke and Death
Patients with High CRP and Normal LDL Have Long-Term Risk for Heart Disease, Stroke and Death
New research shows a long-term benefit in screening people for C Reactive Protein, CRP, a marker for inflammation, even if they have normal levels of bad cholesterol, because of increased long-term risk for heart attack, stroke and death.
These findings, which will be published online today in the Journal of the American College of Cardiology (JACC), demonstrate that a very simple screening, age plus CRP, can identify individuals who may benefit from statin therapy.
“This study builds on results from the landmark JUPITER trial, which showed that statins can prevent heart disease in people with normal LDL-c, or bad cholesterol, and an increased level of CRP,” said Dr. Christie Ballantyne, director of the Center for Cardiovascular Disease Prevention at the Methodist DeBakey Heart & Vascular Center and last author on the study. “We have demonstrated that the cardiovascular disease event rates persist over time, validating that the risks identified in the JUPITER trial persist for nearly seven years.”
Questions remained after the JUPITER results were announced in 2008, including whether the observed cardiovascular disease (CVD) event rates would persist with time, because JUPITER was stopped early at two years median follow-up.
“The new study analyzed patients’ risk over an average of seven years to determine that CRP is, in fact, a long-term indicator of cardiovascular risk,” said Ballantyne, who is also professor of medicine at Baylor College of Medicine. “This is important because approximately one in five men over 50 and women over 60 has a similar profile of increased CRP but normal LDL.”
About the study_Methods: After stratification into four groups based on LDL cholesterol (LDL-C) and high-sensitivity CRP (hs-CRP) levels, with cutoffs at 130 mg/dL and 2.0 mg/L respectively, incident CVD events were examined (mean follow-up 6.9 years) and compared.
Results: Of 8,907 age-eligible participants, 18.2 percent (n=1,621) were “JUPITER-eligible” (hs-CRP ≥2.0 mg/L, LDL-C <130 mg/dL) and had an absolute CVD risk of ~10.9 percent over a mean follow-up of 6.9 years (1.57 percent per year). If JUPITER hazard ratios were applied to this group, the number needed to treat to prevent one CVD event would be estimated at 38 over 5 years and 26 over 6.9 years.
Conclusion: ARIC participants with elevated hs-CRP and low LDL-C had a CVD event rate of 1.57 percent per year over 6.9 years, similar to the CVD event rate noted in the JUPITER placebo group (1.36 percent per year over 1.9 years). The association of hs-CRP ≥2.0 mg/L with increased CVD risk and mortality regardless of LDL-C provides us a simple method of using age and hs-CRP for identifying higher risk individuals.
New research shows a long-term benefit in screening people for C Reactive Protein, CRP, a marker for inflammation, even if they have normal levels of bad cholesterol, because of increased long-term risk for heart attack, stroke and death.
These findings, which will be published online today in the Journal of the American College of Cardiology (JACC), demonstrate that a very simple screening, age plus CRP, can identify individuals who may benefit from statin therapy.
“This study builds on results from the landmark JUPITER trial, which showed that statins can prevent heart disease in people with normal LDL-c, or bad cholesterol, and an increased level of CRP,” said Dr. Christie Ballantyne, director of the Center for Cardiovascular Disease Prevention at the Methodist DeBakey Heart & Vascular Center and last author on the study. “We have demonstrated that the cardiovascular disease event rates persist over time, validating that the risks identified in the JUPITER trial persist for nearly seven years.”
Questions remained after the JUPITER results were announced in 2008, including whether the observed cardiovascular disease (CVD) event rates would persist with time, because JUPITER was stopped early at two years median follow-up.
“The new study analyzed patients’ risk over an average of seven years to determine that CRP is, in fact, a long-term indicator of cardiovascular risk,” said Ballantyne, who is also professor of medicine at Baylor College of Medicine. “This is important because approximately one in five men over 50 and women over 60 has a similar profile of increased CRP but normal LDL.”
About the study_Methods: After stratification into four groups based on LDL cholesterol (LDL-C) and high-sensitivity CRP (hs-CRP) levels, with cutoffs at 130 mg/dL and 2.0 mg/L respectively, incident CVD events were examined (mean follow-up 6.9 years) and compared.
Results: Of 8,907 age-eligible participants, 18.2 percent (n=1,621) were “JUPITER-eligible” (hs-CRP ≥2.0 mg/L, LDL-C <130 mg/dL) and had an absolute CVD risk of ~10.9 percent over a mean follow-up of 6.9 years (1.57 percent per year). If JUPITER hazard ratios were applied to this group, the number needed to treat to prevent one CVD event would be estimated at 38 over 5 years and 26 over 6.9 years.
Conclusion: ARIC participants with elevated hs-CRP and low LDL-C had a CVD event rate of 1.57 percent per year over 6.9 years, similar to the CVD event rate noted in the JUPITER placebo group (1.36 percent per year over 1.9 years). The association of hs-CRP ≥2.0 mg/L with increased CVD risk and mortality regardless of LDL-C provides us a simple method of using age and hs-CRP for identifying higher risk individuals.
Thursday, December 10, 2009
Alcohol may increase breast cancer recurrence risk
Post-menopausal and overweight women may be most susceptible
Moderate consumption of alcoholic beverages (at least three to four drinks per week, no matter the type of alcohol) is associated with a 30 percent increased risk of breast cancer recurrence, according to a new Kaiser Permanente study. Post-menopausal or overweight women may be most susceptible to the effects of alcohol on recurrence, according to the researchers.
Detailed results of this study will be presented December 9-13 at the Cancer Therapy & Research Center - American Association for Cancer Research San Antonio Breast Cancer Symposium by Marilyn L. Kwan, Ph.D., staff scientist in the Kaiser Permanente Division of Research in Oakland, Calif.
"Women previously diagnosed with breast cancer should consider limiting their consumption of alcohol to less than three drinks per week, especially women who are postmenopausal and overweight or obese," Kwan said
While previous research has shown that consumption of alcohol is associated with an increased risk of breast cancer, there have been limited studies about alcohol's role in patient prognosis and survival among those already diagnosed with breast cancer.
Kwan and her colleagues examined the effects of alcohol on cancer recurrence and mortality in the Life After Cancer Epidemiology Study, a prospective cohort study of 1,897 breast cancer survivors diagnosed with early-stage invasive breast cancer between 1997 and 2000. The researchers recruited participants from the Kaiser Permanente Northern California Cancer Registry and compared breast cancer recurrence in women previously diagnosed with breast cancer who drank with a reference group of women previously diagnosed with breast cancer who did not drink.
Researchers used a questionnaire to document information on wine, beer and liquor consumption over the past year. Each year, participants also completed information on health outcomes, including recurrence of breast cancer, which was then verified by their medical records.
After eight years of follow-up, Kwan and colleagues found 349 breast cancer recurrences and 332 deaths from cancer and other causes. Among drinkers (50 percent of the study population), wine was the most popular choice of alcohol (90 percent), followed by liquor (43 percent) then beer (36 percent).
The increased risk of recurrence appeared to be greater among participants who were postmenopausal and overweight or obese, and was present regardless of type of alcohol. Alcohol consumption was not associated with overall mortality.
"These results can help women make more informed decisions about lifestyle choices after a diagnosis of breast cancer," Kwan said. She added that these findings should be confirmed with more research because few studies have addressed the influence of alcohol on breast cancer prognosis, and the increased risk of recurrence was observed in only some subgroups.
Moderate consumption of alcoholic beverages (at least three to four drinks per week, no matter the type of alcohol) is associated with a 30 percent increased risk of breast cancer recurrence, according to a new Kaiser Permanente study. Post-menopausal or overweight women may be most susceptible to the effects of alcohol on recurrence, according to the researchers.
Detailed results of this study will be presented December 9-13 at the Cancer Therapy & Research Center - American Association for Cancer Research San Antonio Breast Cancer Symposium by Marilyn L. Kwan, Ph.D., staff scientist in the Kaiser Permanente Division of Research in Oakland, Calif.
"Women previously diagnosed with breast cancer should consider limiting their consumption of alcohol to less than three drinks per week, especially women who are postmenopausal and overweight or obese," Kwan said
While previous research has shown that consumption of alcohol is associated with an increased risk of breast cancer, there have been limited studies about alcohol's role in patient prognosis and survival among those already diagnosed with breast cancer.
Kwan and her colleagues examined the effects of alcohol on cancer recurrence and mortality in the Life After Cancer Epidemiology Study, a prospective cohort study of 1,897 breast cancer survivors diagnosed with early-stage invasive breast cancer between 1997 and 2000. The researchers recruited participants from the Kaiser Permanente Northern California Cancer Registry and compared breast cancer recurrence in women previously diagnosed with breast cancer who drank with a reference group of women previously diagnosed with breast cancer who did not drink.
Researchers used a questionnaire to document information on wine, beer and liquor consumption over the past year. Each year, participants also completed information on health outcomes, including recurrence of breast cancer, which was then verified by their medical records.
After eight years of follow-up, Kwan and colleagues found 349 breast cancer recurrences and 332 deaths from cancer and other causes. Among drinkers (50 percent of the study population), wine was the most popular choice of alcohol (90 percent), followed by liquor (43 percent) then beer (36 percent).
The increased risk of recurrence appeared to be greater among participants who were postmenopausal and overweight or obese, and was present regardless of type of alcohol. Alcohol consumption was not associated with overall mortality.
"These results can help women make more informed decisions about lifestyle choices after a diagnosis of breast cancer," Kwan said. She added that these findings should be confirmed with more research because few studies have addressed the influence of alcohol on breast cancer prognosis, and the increased risk of recurrence was observed in only some subgroups.
Wednesday, December 9, 2009
Pistachios May Reduce Lung Cancer Risk
A diet that incorporates a daily dose of pistachios may help reduce the risk of lung and other cancers, according to data presented at the American Association for Cancer Research Frontiers in Cancer Prevention Research Conference, held Dec. 6-9.
“It is known that vitamin E provides a degree of protection against certain forms of cancer. Higher intakes of gamma-tocopherol, which is a form of vitamin E, may reduce the risk of lung cancer,” said Ladia M. Hernandez, M.S., R.D., L.D., senior research dietitian in the Department of Epidemiology at the University of Texas M. D. Anderson Cancer Center, and doctoral candidate at Texas Woman’s University - Houston Center.
“Pistachios are a good source of gamma-tocopherol. Eating them increases intake of gamma-tocopherol so pistachios may help to decrease lung cancer risk,” she said.
Pistachios are known to provide a heart-healthy benefit by producing a cholesterol-lowering effect and providing the antioxidants that are typically found in food products of plant origin. Hernandez and colleagues conducted a six-week, controlled clinical trial to evaluate if the consumption of pistachios would increase dietary intake and serum levels of gamma-tocopherol. A pistachio-rich diet could potentially help reduce the risk of other cancers from developing as well, according to Hernandez.
“Because epidemiologic studies suggest gamma-tocopherol is protective against prostate cancer, pistachio intake may help,” she said. “Other food sources that are a rich source of gamma-tocopherol include nuts such as peanuts, pecans, walnuts, soybean and corn oils.”
The study, conducted at Texas Woman’s University - Houston Center, included 36 healthy participants who were randomized into either a control group or the intervention group consisting of a pistachio diet. There were 18 participants in the control group and 18 in the intervention group._There was a two-week baseline period, followed by a four-week intervention period in which the intervention group was provided with 68 grams (about 2 ounces or 117 kernels) of pistachios per day; the control group continued with their normal diet.
The effect on the intake and serum cholesterol-adjusted gamma-tocopherol was investigated. Intake was calculated using the Nutrition Data System for Research Version 2007, and consumption was monitored using diet diaries and by measuring the weights of the returned pistachios.
Hernandez and colleagues found a significant increase in energy-adjusted dietary intake of gamma-tocopherol at weeks three and four in those on the pistachio diet compared with those on the control diet. The similar effect was seen at weeks five and six among those on the pistachio diet compared with those on the control diet. For those on the pistachio diet, cholesterol-adjusted serum gamma-tocopherol was significantly higher at the end of the intervention period compared to baseline.
“Pistachios are one of those ‘good-for-you’ nuts, and 2 ounces per day could be incorporated into dietary strategies designed to reduce the risk of lung cancer without significant changes in body mass index,” said Hernandez.
“It is known that vitamin E provides a degree of protection against certain forms of cancer. Higher intakes of gamma-tocopherol, which is a form of vitamin E, may reduce the risk of lung cancer,” said Ladia M. Hernandez, M.S., R.D., L.D., senior research dietitian in the Department of Epidemiology at the University of Texas M. D. Anderson Cancer Center, and doctoral candidate at Texas Woman’s University - Houston Center.
“Pistachios are a good source of gamma-tocopherol. Eating them increases intake of gamma-tocopherol so pistachios may help to decrease lung cancer risk,” she said.
Pistachios are known to provide a heart-healthy benefit by producing a cholesterol-lowering effect and providing the antioxidants that are typically found in food products of plant origin. Hernandez and colleagues conducted a six-week, controlled clinical trial to evaluate if the consumption of pistachios would increase dietary intake and serum levels of gamma-tocopherol. A pistachio-rich diet could potentially help reduce the risk of other cancers from developing as well, according to Hernandez.
“Because epidemiologic studies suggest gamma-tocopherol is protective against prostate cancer, pistachio intake may help,” she said. “Other food sources that are a rich source of gamma-tocopherol include nuts such as peanuts, pecans, walnuts, soybean and corn oils.”
The study, conducted at Texas Woman’s University - Houston Center, included 36 healthy participants who were randomized into either a control group or the intervention group consisting of a pistachio diet. There were 18 participants in the control group and 18 in the intervention group._There was a two-week baseline period, followed by a four-week intervention period in which the intervention group was provided with 68 grams (about 2 ounces or 117 kernels) of pistachios per day; the control group continued with their normal diet.
The effect on the intake and serum cholesterol-adjusted gamma-tocopherol was investigated. Intake was calculated using the Nutrition Data System for Research Version 2007, and consumption was monitored using diet diaries and by measuring the weights of the returned pistachios.
Hernandez and colleagues found a significant increase in energy-adjusted dietary intake of gamma-tocopherol at weeks three and four in those on the pistachio diet compared with those on the control diet. The similar effect was seen at weeks five and six among those on the pistachio diet compared with those on the control diet. For those on the pistachio diet, cholesterol-adjusted serum gamma-tocopherol was significantly higher at the end of the intervention period compared to baseline.
“Pistachios are one of those ‘good-for-you’ nuts, and 2 ounces per day could be incorporated into dietary strategies designed to reduce the risk of lung cancer without significant changes in body mass index,” said Hernandez.
High-fat Low-carb Diets=Heart Risk
New scientific research has shown that low-carbohydrate high-fat diets, made popular by the likes of the Atkins diet, do not achieve more weight loss than low-fat high-carbohydrate diets. Worryingly, the research, lead by Dr Steven Hunter from the Royal Victoria Hospital, Belfast, also shows significantly increased risks of cardiovascular disease for people following low-carbohydrate high-fat diets.
The research shows that the risks of low-carbohydrate high-fat diets far outweigh the potential benefits gained by overweight and obese people through weight loss, including improvements in blood pressure and risk factors for coronary heart disease.
The research results, released hot on the heels of both National Obesity Week and World Diabetes Day, are particularly important for nearly a quarter (24%¹) of the UK adult population, and 16% of the child population, now classified as obese and at risk of Type 2 Diabetes – 80%² of all people diagnosed with Type 2 diabetes are overweight.
Type 2 Diabetes is the result of inadequate insulin production and/or insulin resistance, which means that the right levels of glucose (our main source of energy from food) are not maintained naturally by the body. There are 180 million people in the world with diabetes and the World Health Organisation predicts this number will double in the next 20 years.
Dr Hunter, Royal Victoria Hospital, Belfast, said: “The worldwide obesity pandemic is a major public health concern and strongly linked to rises in diabetes and cardiovascular disease. By advocating low-carbohydrate high-fat diets as a weapon against obesity and diabetes, health professionals could be contributing to a dangerous rise in cardiovascular disease”.
The research study, conducted among a group of obese pre-diabetic adults, compared the results of following a low-fat high-carbohydrate diet (20% fat, 60% carbohydrate) with a high-fat low-carbohydrate diet (60% fat, 20% carbohydrate). It showed that in all areas, other than the risk of cardiovascular disease, the diets have equal health benefits. The same amount of weight is lost; there is no significant difference in the body’s glucose uptake or production; and meal tolerance-related insulin secretion is comparable. However, the study revealed a significant difference in overall systemic arterial stiffness and pointed to increased cardiovascular risk factors from high-fat low-carbohydrate diets.
Dr Hunter continued: “High-fat diets have become popular because they seemingly promote more rapid weight loss and because of their palatability. However, we now have proof that they do not help people lose weight any faster than more conventional diets, and the potential negatives of increased cardiovascular risks far outweigh the potential positives of more easily sustained dieting/weight loss, especially when there is a proven and safe alternative in low-fat high-carbohydrate weight loss diets.”
According to Dr Hunter, the challenge now is to find ways to make low-fat high-carbohydrate diets more palatable and easier to maintain, so that a long-term positive outcome is achieved.
The Food Standards Agency says that saturated fat should account for less than 11% of the total diet for a normal person, and Dr. Hunter concludes: “If your New Year’s resolution is to lose weight, make sure you do it the right way and don’t burden your body with additional unnecessary health risks by falling for the lure of the seemingly easy and fast weight loss offered by high-fat diets. The best approach for your overall health is a low-fat high-carbohydrate diet, coupled with exercise.”
¹ NHS Statistics on obesity, physical activity and diet: England, January 2008, published 31 January 2008
² Diabetes UK
Reference
Bradley U et al. Low-fat versus low-carbohydrate weight reduction diets: effects on weight loss, insulin resistance and cardiovascular risk. A randomised trial. Diabetes. December 2009, vol.58, no. 12, 2741-2748
doi: 10.2337/db09-0098
Low-Fat versus Low-Carbohydrate Weight Reductions Diets: Effects on Weight Loss, Insulin Resistance and Cardiovascular Risk A Randomised Control Trial, is one of the first studies to determine augmentation index, by measuring arterial stiffness using pulse wave analysis, in relation to cardiovascular risk.
Research Design and Methods: the research investigated a low-fat (20% fat, 60% carbohydrate) versus a low-carbohydrate (60% fat, 20% carbohydrate) weight reduction diet in 24 overweight/obese subjects, BMI 33.6±3.7 kg/m², age 39±10 years (mean ± SD), in an 8 week randomised controlled trial. All food was weighed and distributed and intake calculated to produce a 500kcal/day energy deficit. Insulin action was assessed by the euglycaemic clamp and insulin secretion by meal tolerance test. Body composition, adipokine levels and vascular compliance by pulse-wave analysis were also measured.
The Low-Fat versus Low-Carbohydrate Weight Reductions Diets: Effects on Weight Loss, Insulin Resistance and Cardiovascular Risk A Randomised Control Trial study, by Dr Steven J Hunter, was supported by RRG 5.42 (PI SJH) from the Northern Ireland Department of Health and Social Services Research and Development Office and by an unrestricted research grant from The Sugar Bureau (UK).
Background information
Diabetes is a common health problem which affects around 3-4% of the UK population.
The majority of people with type 2 diabetes are overweight. Therefore, weight management is a crucial aspect in the prevention of type 2 diabetes and the management of diabetes in general.
The diet for people with diabetes is no longer a special one, but merely follows the basic principles of healthy eating, ie a low-fat, high-carbohydrate diet.
One of the prominent changes of the recent nutrition guidelines from Europe is the relaxation on dietary restriction of sugar and high-sugar content foods, providing blood glucose levels are kept in control. This is because sucrose (table sugar) does not increase blood glucose to a greater extent than similar amounts of starchy foods like bread, potatoes or rice.
FAQ on sugar and health
Links
Diabetes and Nutrition Study Group of the EASD. 2000. Recommendations for the nutritional management of patients with diabetes mellitus. European Journal of Clinical Nutrition, 54, pp353-355.
American Diabetes Association. 2008:
Nutrition recommendations and interventions for diabetes: a position statement of the ADA. Diabetes Care, 31suppl, pp61-78.
Black RN et al 2006.
http://diabetes.diabetesjournals.org/content/55/12/3566.full.pdf+html
Diabetes; 55: 3566-3572.
The research shows that the risks of low-carbohydrate high-fat diets far outweigh the potential benefits gained by overweight and obese people through weight loss, including improvements in blood pressure and risk factors for coronary heart disease.
The research results, released hot on the heels of both National Obesity Week and World Diabetes Day, are particularly important for nearly a quarter (24%¹) of the UK adult population, and 16% of the child population, now classified as obese and at risk of Type 2 Diabetes – 80%² of all people diagnosed with Type 2 diabetes are overweight.
Type 2 Diabetes is the result of inadequate insulin production and/or insulin resistance, which means that the right levels of glucose (our main source of energy from food) are not maintained naturally by the body. There are 180 million people in the world with diabetes and the World Health Organisation predicts this number will double in the next 20 years.
Dr Hunter, Royal Victoria Hospital, Belfast, said: “The worldwide obesity pandemic is a major public health concern and strongly linked to rises in diabetes and cardiovascular disease. By advocating low-carbohydrate high-fat diets as a weapon against obesity and diabetes, health professionals could be contributing to a dangerous rise in cardiovascular disease”.
The research study, conducted among a group of obese pre-diabetic adults, compared the results of following a low-fat high-carbohydrate diet (20% fat, 60% carbohydrate) with a high-fat low-carbohydrate diet (60% fat, 20% carbohydrate). It showed that in all areas, other than the risk of cardiovascular disease, the diets have equal health benefits. The same amount of weight is lost; there is no significant difference in the body’s glucose uptake or production; and meal tolerance-related insulin secretion is comparable. However, the study revealed a significant difference in overall systemic arterial stiffness and pointed to increased cardiovascular risk factors from high-fat low-carbohydrate diets.
Dr Hunter continued: “High-fat diets have become popular because they seemingly promote more rapid weight loss and because of their palatability. However, we now have proof that they do not help people lose weight any faster than more conventional diets, and the potential negatives of increased cardiovascular risks far outweigh the potential positives of more easily sustained dieting/weight loss, especially when there is a proven and safe alternative in low-fat high-carbohydrate weight loss diets.”
According to Dr Hunter, the challenge now is to find ways to make low-fat high-carbohydrate diets more palatable and easier to maintain, so that a long-term positive outcome is achieved.
The Food Standards Agency says that saturated fat should account for less than 11% of the total diet for a normal person, and Dr. Hunter concludes: “If your New Year’s resolution is to lose weight, make sure you do it the right way and don’t burden your body with additional unnecessary health risks by falling for the lure of the seemingly easy and fast weight loss offered by high-fat diets. The best approach for your overall health is a low-fat high-carbohydrate diet, coupled with exercise.”
¹ NHS Statistics on obesity, physical activity and diet: England, January 2008, published 31 January 2008
² Diabetes UK
Reference
Bradley U et al. Low-fat versus low-carbohydrate weight reduction diets: effects on weight loss, insulin resistance and cardiovascular risk. A randomised trial. Diabetes. December 2009, vol.58, no. 12, 2741-2748
doi: 10.2337/db09-0098
Low-Fat versus Low-Carbohydrate Weight Reductions Diets: Effects on Weight Loss, Insulin Resistance and Cardiovascular Risk A Randomised Control Trial, is one of the first studies to determine augmentation index, by measuring arterial stiffness using pulse wave analysis, in relation to cardiovascular risk.
Research Design and Methods: the research investigated a low-fat (20% fat, 60% carbohydrate) versus a low-carbohydrate (60% fat, 20% carbohydrate) weight reduction diet in 24 overweight/obese subjects, BMI 33.6±3.7 kg/m², age 39±10 years (mean ± SD), in an 8 week randomised controlled trial. All food was weighed and distributed and intake calculated to produce a 500kcal/day energy deficit. Insulin action was assessed by the euglycaemic clamp and insulin secretion by meal tolerance test. Body composition, adipokine levels and vascular compliance by pulse-wave analysis were also measured.
The Low-Fat versus Low-Carbohydrate Weight Reductions Diets: Effects on Weight Loss, Insulin Resistance and Cardiovascular Risk A Randomised Control Trial study, by Dr Steven J Hunter, was supported by RRG 5.42 (PI SJH) from the Northern Ireland Department of Health and Social Services Research and Development Office and by an unrestricted research grant from The Sugar Bureau (UK).
Background information
Diabetes is a common health problem which affects around 3-4% of the UK population.
The majority of people with type 2 diabetes are overweight. Therefore, weight management is a crucial aspect in the prevention of type 2 diabetes and the management of diabetes in general.
The diet for people with diabetes is no longer a special one, but merely follows the basic principles of healthy eating, ie a low-fat, high-carbohydrate diet.
One of the prominent changes of the recent nutrition guidelines from Europe is the relaxation on dietary restriction of sugar and high-sugar content foods, providing blood glucose levels are kept in control. This is because sucrose (table sugar) does not increase blood glucose to a greater extent than similar amounts of starchy foods like bread, potatoes or rice.
FAQ on sugar and health
Links
Diabetes and Nutrition Study Group of the EASD. 2000. Recommendations for the nutritional management of patients with diabetes mellitus. European Journal of Clinical Nutrition, 54, pp353-355.
American Diabetes Association. 2008:
Nutrition recommendations and interventions for diabetes: a position statement of the ADA. Diabetes Care, 31suppl, pp61-78.
Black RN et al 2006.
http://diabetes.diabetesjournals.org/content/55/12/3566.full.pdf+html
Diabetes; 55: 3566-3572.
Beer May Prevent Prostate Cancer
I love it:
The natural compound xanthohumol blocks the effects of the male hormone testosterone, therefore aiding in the prevention of prostate cancer.
“We hope that one day we can demonstrate that xanthohumol prevents prostate cancer development, first in animal models and then in humans, but we are just at the beginning,” said Clarissa Gerhauser, Ph.D., group leader of cancer chemoprevention in the Division of Epigenomics and Cancer Risk Factors at the German Cancer Research Center, in Heidelberg, Germany.
Gerhauser presented these findings at the American Association for Cancer Research Frontiers in Cancer Prevention Research Conference, held in Houston, Dec. 6-9, 2009.
Xanthohumol is derived from hops and belongs to the group of flavonoids that are found in many plants, fruit, vegetables and spices. Studies to date have shown that xanthohumol blocks the action of estrogen by binding to its receptor, which may lead to prevention of breast cancer.
Since testosterone receptors act similarly to that of estrogen — by binding, then stimulating hormone-dependent effects, such as gene expression and cell growth — the researchers examined whether xanthohumol might not only block the effects of estrogen, but also of the male hormone androgen.
Gerhauser and colleagues stimulated hormone-dependent prostate cancer cells with testosterone, which led to a massive secretion of prostate specific antigen (PSA). PSA is used for screening and early detection of prostate cancer in men. Cells were then treated with testosterone and xanthohumol and the effects were examined.
“Xanthohumol prevented the receptor from translocating to the cell nucleus, thus inhibiting its potential to stimulate the secretion of PSA and other hormone-dependent effects,” she said.
Molecular modeling results showed that xanthohumol directly binds to the androgen receptor structure.
The researchers suggest that this compound may have beneficial effects in animals — when they measured the anti-androgenic potential of xanthohumol in a rat model, they found that although xanthohumol was not able to prevent an increase in prostate weight after testosterone treatment, it could reduce testosterone-increased seminal vesicle weight.
“Although the prostate weights were not changed, xanthohumol still reduced the effects of hormone signaling, such as gene expression, measured in the prostate tissue,” said Gerhauser.
The natural compound xanthohumol blocks the effects of the male hormone testosterone, therefore aiding in the prevention of prostate cancer.
“We hope that one day we can demonstrate that xanthohumol prevents prostate cancer development, first in animal models and then in humans, but we are just at the beginning,” said Clarissa Gerhauser, Ph.D., group leader of cancer chemoprevention in the Division of Epigenomics and Cancer Risk Factors at the German Cancer Research Center, in Heidelberg, Germany.
Gerhauser presented these findings at the American Association for Cancer Research Frontiers in Cancer Prevention Research Conference, held in Houston, Dec. 6-9, 2009.
Xanthohumol is derived from hops and belongs to the group of flavonoids that are found in many plants, fruit, vegetables and spices. Studies to date have shown that xanthohumol blocks the action of estrogen by binding to its receptor, which may lead to prevention of breast cancer.
Since testosterone receptors act similarly to that of estrogen — by binding, then stimulating hormone-dependent effects, such as gene expression and cell growth — the researchers examined whether xanthohumol might not only block the effects of estrogen, but also of the male hormone androgen.
Gerhauser and colleagues stimulated hormone-dependent prostate cancer cells with testosterone, which led to a massive secretion of prostate specific antigen (PSA). PSA is used for screening and early detection of prostate cancer in men. Cells were then treated with testosterone and xanthohumol and the effects were examined.
“Xanthohumol prevented the receptor from translocating to the cell nucleus, thus inhibiting its potential to stimulate the secretion of PSA and other hormone-dependent effects,” she said.
Molecular modeling results showed that xanthohumol directly binds to the androgen receptor structure.
The researchers suggest that this compound may have beneficial effects in animals — when they measured the anti-androgenic potential of xanthohumol in a rat model, they found that although xanthohumol was not able to prevent an increase in prostate weight after testosterone treatment, it could reduce testosterone-increased seminal vesicle weight.
“Although the prostate weights were not changed, xanthohumol still reduced the effects of hormone signaling, such as gene expression, measured in the prostate tissue,” said Gerhauser.
Tuesday, December 8, 2009
Selenium May Help Fight Colon Cancer
Supplementation with a selenium-based antioxidant compound decreased the risk of developing new polyps of the large bowel — called colorectal metachronous adenomas — in people who previously had colorectal polyps removed.
“Our study is the first intervention trial specifically designed to evaluate the efficacy of the selenium-based antioxidant compound on the risk of developing metachronous adenomas,” said Luigina Bonelli, M.D., head of the unit of secondary prevention and screening at the National Institute for Cancer Research, in Genoa, Italy.
Bonelli presented these findings at the American Association for Cancer Research Frontiers in Cancer Prevention Research Conference, held in Houston, Dec. 6-9, 2009.
Adenomatous polyps (or adenoma) are benign lesions of the large bowel that, in time, could progress to cancer. Even though only a small proportion of adenomas will develop into cancer, almost 70 percent to 80 percent of colorectal cancer stems from an adenoma.
Adenomas are common in people aged 60 years or older; one in four people will have at least one adenoma.
Participants in this study were aged 25 to 75 years and had already had one or more colorectal adenomas removed, but did not have any other diagnosis of colorectal diseases, cancer or life-threatening illnesses and did not use vitamins or calcium supplementations. The researchers randomized 411 participants to the placebo group or to receive an antioxidant compound — specifically selenomethionnine 200 μg, zinc 30 mg, vitamin A 6,000 IU, vitamin C 180 mg and vitamin E 30 mg.
“Our results indicated that individuals who consumed antioxidants had a 40 percent reduction in the incidence of metachronous adenomas of the large bowel,” Bonelli said. “It is noteworthy that the benefit observed after the conclusion of the trial persisted through 13 years of follow up.”
The researchers are currently conducting a study to evaluate the role of genetic alterations as predictors of metachronous adenomas in participants received the antioxidant compound compared with those in a placebo group.
“Our study is the first intervention trial specifically designed to evaluate the efficacy of the selenium-based antioxidant compound on the risk of developing metachronous adenomas,” said Luigina Bonelli, M.D., head of the unit of secondary prevention and screening at the National Institute for Cancer Research, in Genoa, Italy.
Bonelli presented these findings at the American Association for Cancer Research Frontiers in Cancer Prevention Research Conference, held in Houston, Dec. 6-9, 2009.
Adenomatous polyps (or adenoma) are benign lesions of the large bowel that, in time, could progress to cancer. Even though only a small proportion of adenomas will develop into cancer, almost 70 percent to 80 percent of colorectal cancer stems from an adenoma.
Adenomas are common in people aged 60 years or older; one in four people will have at least one adenoma.
Participants in this study were aged 25 to 75 years and had already had one or more colorectal adenomas removed, but did not have any other diagnosis of colorectal diseases, cancer or life-threatening illnesses and did not use vitamins or calcium supplementations. The researchers randomized 411 participants to the placebo group or to receive an antioxidant compound — specifically selenomethionnine 200 μg, zinc 30 mg, vitamin A 6,000 IU, vitamin C 180 mg and vitamin E 30 mg.
“Our results indicated that individuals who consumed antioxidants had a 40 percent reduction in the incidence of metachronous adenomas of the large bowel,” Bonelli said. “It is noteworthy that the benefit observed after the conclusion of the trial persisted through 13 years of follow up.”
The researchers are currently conducting a study to evaluate the role of genetic alterations as predictors of metachronous adenomas in participants received the antioxidant compound compared with those in a placebo group.
Omega-3 Fatty Acids=Reduced Risk of Colon Cance
Long-chain omega-3 fatty acids, primarily found in fish and seafood, may have a role in colorectal cancer prevention, according to results presented at the American Association for Cancer Research Frontiers in Cancer Prevention Research Conference
“Experimental data have shown benefits of long-chain omega-3 fatty acids in colorectal carcinogenesis, ranging from reduced tumor growth, suppression of angiogenesis and inhibition of metastasis,” said Sangmi Kim, Ph.D., a postdoctoral fellow at the National Institute of Environmental Health Sciences, Research Triangle Park, N.C. “Our finding of inverse association between dietary intakes of long-chain omega-3 fatty acids and distal large bowel cancer in white participants adds additional support to the hypothesis.”
Although experimental and clinical data suggest that long-chain omega-3 fatty acids possess anti-neoplastic properties in the colon, epidemiologic data to date has been inconclusive.
Kim and colleagues studied the link between polyunsaturated fatty acid intake and distal large bowel cancer using data from a population-based control study. They recruited 1,509 white participants (716 cancer cases and 787 controls) and 369 black participants (213 cancer cases and 156 controls) using the State Cancer Registry and Division of Motor Vehicles records.
Nineteen polyunsaturated fatty acids were assessed using a validated food frequency questionnaire, which included 124 questions on food items. The researchers used the questionnaire to collect information on the frequency and amount of foods typically consumed in the past 12 months.
Patients who consumed more long-chain omega-3 fatty acids had a reduced risk of distal large bowel cancer. Compared to the lowest quartile, fat intake in the highest quartile was linked with a 39 percent reduced risk of cancer.
The researchers detected these associations in white participants, but not in black participants.
“We were surprised that the association was not also observed among blacks,” Kim said. “We considered several possible explanations but were not able to account for this difference with the data we had. This finding warrants future study, but we should be careful about drawing conclusions about potential racial differences in the benefit from long-chain omega-3 fatty acids from this study.”
“An increase in dietary intake of long-chain omega-3 fatty acids, which mainly come from fish and seafood, may be beneficial in the prevention of distal large bowel cancer,” Kim said.
“Experimental data have shown benefits of long-chain omega-3 fatty acids in colorectal carcinogenesis, ranging from reduced tumor growth, suppression of angiogenesis and inhibition of metastasis,” said Sangmi Kim, Ph.D., a postdoctoral fellow at the National Institute of Environmental Health Sciences, Research Triangle Park, N.C. “Our finding of inverse association between dietary intakes of long-chain omega-3 fatty acids and distal large bowel cancer in white participants adds additional support to the hypothesis.”
Although experimental and clinical data suggest that long-chain omega-3 fatty acids possess anti-neoplastic properties in the colon, epidemiologic data to date has been inconclusive.
Kim and colleagues studied the link between polyunsaturated fatty acid intake and distal large bowel cancer using data from a population-based control study. They recruited 1,509 white participants (716 cancer cases and 787 controls) and 369 black participants (213 cancer cases and 156 controls) using the State Cancer Registry and Division of Motor Vehicles records.
Nineteen polyunsaturated fatty acids were assessed using a validated food frequency questionnaire, which included 124 questions on food items. The researchers used the questionnaire to collect information on the frequency and amount of foods typically consumed in the past 12 months.
Patients who consumed more long-chain omega-3 fatty acids had a reduced risk of distal large bowel cancer. Compared to the lowest quartile, fat intake in the highest quartile was linked with a 39 percent reduced risk of cancer.
The researchers detected these associations in white participants, but not in black participants.
“We were surprised that the association was not also observed among blacks,” Kim said. “We considered several possible explanations but were not able to account for this difference with the data we had. This finding warrants future study, but we should be careful about drawing conclusions about potential racial differences in the benefit from long-chain omega-3 fatty acids from this study.”
“An increase in dietary intake of long-chain omega-3 fatty acids, which mainly come from fish and seafood, may be beneficial in the prevention of distal large bowel cancer,” Kim said.
Coffee = Reduced Risk of Advanced Prostate Cancer
Coffee Consumption Associated with Reduced Risk of Advanced Prostate Cancer
While it is too early for physicians to start advising their male patients to take up the habit of regular coffee drinking, data presented at the American Association for Cancer Research Frontiers in Cancer Prevention Research Conference revealed a strong inverse association between coffee consumption and the risk of lethal and advanced prostate cancers.
“Coffee has effects on insulin and glucose metabolism as well as sex hormone levels, all of which play a role in prostate cancer. It was plausible that there may be an association between coffee and prostate cancer,” said Kathryn M. Wilson, Ph.D., a postdoctoral fellow at the Channing Laboratory, Harvard Medical School and the Harvard School of Public Health.
In a prospective investigation, Wilson and colleagues found that men who drank the most coffee had a 60 percent lower risk of aggressive prostate cancer than men who did not drink any coffee. This is the first study of its kind to look at both overall risk of prostate cancer and risk of localized, advanced and lethal disease.
“Few studies have looked prospectively at this association, and none have looked at coffee and specific prostate cancer outcomes,” said Wilson. “We specifically looked at different types of prostate cancer, such as advanced vs. localized cancers or high-grade vs. low-grade cancers.”
Caffeine is actually not the key factor in this association, according to Wilson. The researchers are unsure which components of the beverage are most important, as coffee contains many biologically active compounds like antioxidants and minerals.
Using the Health Professionals’ Follow-Up Study, the researchers documented the regular and decaffeinated coffee intake of nearly 50,000 men every four years from 1986 to 2006; 4,975 of these men developed prostate cancer over that time. They also examined the cross-sectional association between coffee consumption and levels of circulating hormones in blood samples collected from a subset of men in the cohort.
“Very few lifestyle factors have been consistently associated with prostate cancer risk, especially with risk of aggressive disease, so it would be very exciting if this association is confirmed in other studies,” said Wilson. “Our results do suggest there is no reason to stop drinking coffee out of any concern about prostate cancer.”
This association might also help understand the biology of prostate cancer and possible chemoprevention measures.
While it is too early for physicians to start advising their male patients to take up the habit of regular coffee drinking, data presented at the American Association for Cancer Research Frontiers in Cancer Prevention Research Conference revealed a strong inverse association between coffee consumption and the risk of lethal and advanced prostate cancers.
“Coffee has effects on insulin and glucose metabolism as well as sex hormone levels, all of which play a role in prostate cancer. It was plausible that there may be an association between coffee and prostate cancer,” said Kathryn M. Wilson, Ph.D., a postdoctoral fellow at the Channing Laboratory, Harvard Medical School and the Harvard School of Public Health.
In a prospective investigation, Wilson and colleagues found that men who drank the most coffee had a 60 percent lower risk of aggressive prostate cancer than men who did not drink any coffee. This is the first study of its kind to look at both overall risk of prostate cancer and risk of localized, advanced and lethal disease.
“Few studies have looked prospectively at this association, and none have looked at coffee and specific prostate cancer outcomes,” said Wilson. “We specifically looked at different types of prostate cancer, such as advanced vs. localized cancers or high-grade vs. low-grade cancers.”
Caffeine is actually not the key factor in this association, according to Wilson. The researchers are unsure which components of the beverage are most important, as coffee contains many biologically active compounds like antioxidants and minerals.
Using the Health Professionals’ Follow-Up Study, the researchers documented the regular and decaffeinated coffee intake of nearly 50,000 men every four years from 1986 to 2006; 4,975 of these men developed prostate cancer over that time. They also examined the cross-sectional association between coffee consumption and levels of circulating hormones in blood samples collected from a subset of men in the cohort.
“Very few lifestyle factors have been consistently associated with prostate cancer risk, especially with risk of aggressive disease, so it would be very exciting if this association is confirmed in other studies,” said Wilson. “Our results do suggest there is no reason to stop drinking coffee out of any concern about prostate cancer.”
This association might also help understand the biology of prostate cancer and possible chemoprevention measures.
Exercise Reduces Prostate Cancer Death Rate
As little as 15 minutes of exercise a day can reduce overall mortality rates in patients with prostate cancer, according to findings presented at the American Association for Cancer Research Frontiers in Cancer Prevention Research Conference.
“We saw benefits at very attainable levels of activity,” said Stacey A. Kenfield, Sc.D., epidemiology research associate at the Harvard School of Public Health and lead author of the study. “The results suggest that men with prostate cancer should do some physical activity for their overall health.”
Researchers assessed physical activity levels for 2,686 patients enrolled in the Health Professionals Follow-up Study, both before and after diagnosis (men with metastases at diagnosis were excluded).
Men who engaged in three or more hours of Metabolic Equivalent Tasks (MET) a week — equivalent to jogging, biking, swimming or playing tennis for about a half-hour per week — had a 35 percent lower risk of overall mortality.
Specific to walking, the researchers found that men who walked four or more hours a week had a 23 percent lower risk of all-cause mortality compared to men who walked less than 20 minutes per week. Men who walked 90 or more minutes at a normal to brisk pace had a 51 percent lower risk of death from any cause than men who walked less than 90 minutes at an easy walking pace.
Walking didn’t show any effect on prostate cancer specific mortality, but more strenuous exercising did. Men who engaged in five or more hours of vigorous physical activity a week were at a decreased risk of dying from their prostate cancer.
“This is the first large population study to examine exercise in relation to mortality in prostate cancer survivors,” said Kenfield. Previous studies focused on how exercise affects risk of developing prostate cancer.
Kenfield said that researchers aren’t sure of the exact molecular effects exercise has on prostate cancer, but exercise is known to influence a number of hormones hypothesized to stimulate prostate cancer, boost immune function and reduce inflammation.
“How these factors may work together to affect prostate cancer biologically is still being studied,” she said. “For now, our data indicate that for prostate cancer survivors, a moderate amount of regular exercise may improve overall survival, while five or more hours per week of vigorous exercise may decrease the death rate due to prostate cancer specifically.”
“We saw benefits at very attainable levels of activity,” said Stacey A. Kenfield, Sc.D., epidemiology research associate at the Harvard School of Public Health and lead author of the study. “The results suggest that men with prostate cancer should do some physical activity for their overall health.”
Researchers assessed physical activity levels for 2,686 patients enrolled in the Health Professionals Follow-up Study, both before and after diagnosis (men with metastases at diagnosis were excluded).
Men who engaged in three or more hours of Metabolic Equivalent Tasks (MET) a week — equivalent to jogging, biking, swimming or playing tennis for about a half-hour per week — had a 35 percent lower risk of overall mortality.
Specific to walking, the researchers found that men who walked four or more hours a week had a 23 percent lower risk of all-cause mortality compared to men who walked less than 20 minutes per week. Men who walked 90 or more minutes at a normal to brisk pace had a 51 percent lower risk of death from any cause than men who walked less than 90 minutes at an easy walking pace.
Walking didn’t show any effect on prostate cancer specific mortality, but more strenuous exercising did. Men who engaged in five or more hours of vigorous physical activity a week were at a decreased risk of dying from their prostate cancer.
“This is the first large population study to examine exercise in relation to mortality in prostate cancer survivors,” said Kenfield. Previous studies focused on how exercise affects risk of developing prostate cancer.
Kenfield said that researchers aren’t sure of the exact molecular effects exercise has on prostate cancer, but exercise is known to influence a number of hormones hypothesized to stimulate prostate cancer, boost immune function and reduce inflammation.
“How these factors may work together to affect prostate cancer biologically is still being studied,” she said. “For now, our data indicate that for prostate cancer survivors, a moderate amount of regular exercise may improve overall survival, while five or more hours per week of vigorous exercise may decrease the death rate due to prostate cancer specifically.”
Soy Decreases Breast Cancer Recurrence and Death
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Researchers at Vanderbilt-Ingram Cancer Center, led by Xiao Ou Shu, M.D., Ph.D., professor of Medicine, have found that a higher intake of soy foods was associated with a lower risk of death and breast cancer recurrence among breast cancer patients in China. The study is published in the December 9 issue of JAMA.
There had been a concern that soy foods could have an adverse effect on outcomes among breast cancer patients.
“Soy foods are rich in isoflavones, a major group of phytoestrogens that have been hypothesized to reduce the risk of breast cancer. However, the estrogen-like effect of isoflavones and the potential interaction between isoflavones and tamoxifen have led to concern about soy food consumption among breast cancer patients,” the authors write.
Tamoxifen, which is designed to block estrogen, is a widely used treatment for breast cancer patients.
Shu and her colleagues analyzed data from the Shanghai Breast Cancer Survival Study, a large, population-based study of 5,042 female breast cancer survivors in China, which Vanderbilt University Medical Center and the Shanghai Institute of Preventive Medicine have carried out since 2001.
Women ages 20 to 75 years, diagnosed between March 2002 and April 2006, were studied through June 2009. Trained interviewers using structured questionnaires asked the women about demographic characteristics, reproductive and disease history, medication use, diet, lifestyle factors and use of complementary and alternative medicine.
Researchers used a food frequency questionnaire designed to measure soy foods commonly consumed in Shanghai, including tofu, soy milk, fresh soy beans and other soy products, as well as meat, fish and cruciferous vegetables.
After a median follow-up of 3.9 years, there were 444 total deaths and 534 breast cancer recurrences in the study group. Soy food consumption after cancer diagnosis, measured as soy protein intake, was inversely associated with mortality and recurrence. The associations of soy protein/isoflavones intake with mortality and recurrence appear to follow a dose-response pattern until soy protein intake reaches 11 grams per day or soy isoflavones intake reaches 40 mg/day. After these points, the association appears to level off or rebound.
“We found that women in the highest soy food intake groups had the lowest mortality and recurrence rates rate compared with women in the lowest soy food intake group, regardless of tamoxifen use status,” said Shu.
The associations of soy food intake with mortality and recurrence were observed for women with either ER-positive or ER-negative breast cancer. The association between soy food intake and overall mortality did not appear to vary by menopausal status.
“It is important to note that we studied soy food intake and not the use of soy capsule supplements,” explained Shu. “These capsules frequently contain only soy isoflavones, while soy foods contain other nutrients, as well. So we cannot infer that the isoflavones alone would provide the same protective benefits.”
Soy isoflavones compete with estrogens in the binding of estrogen receptors, reduce estrogen synthesis and help clear steroids from the body. These anti-estrogenic effects may be one of the underlying mechanisms through which soy foods are associated with better breast cancer outcomes. Other constituents of soy foods, such as folate, protein, protease inhibitors, calcium or fiber, also may be responsible for the survival benefits of soy food consumption.
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Researchers at Vanderbilt-Ingram Cancer Center, led by Xiao Ou Shu, M.D., Ph.D., professor of Medicine, have found that a higher intake of soy foods was associated with a lower risk of death and breast cancer recurrence among breast cancer patients in China. The study is published in the December 9 issue of JAMA.
There had been a concern that soy foods could have an adverse effect on outcomes among breast cancer patients.
“Soy foods are rich in isoflavones, a major group of phytoestrogens that have been hypothesized to reduce the risk of breast cancer. However, the estrogen-like effect of isoflavones and the potential interaction between isoflavones and tamoxifen have led to concern about soy food consumption among breast cancer patients,” the authors write.
Tamoxifen, which is designed to block estrogen, is a widely used treatment for breast cancer patients.
Shu and her colleagues analyzed data from the Shanghai Breast Cancer Survival Study, a large, population-based study of 5,042 female breast cancer survivors in China, which Vanderbilt University Medical Center and the Shanghai Institute of Preventive Medicine have carried out since 2001.
Women ages 20 to 75 years, diagnosed between March 2002 and April 2006, were studied through June 2009. Trained interviewers using structured questionnaires asked the women about demographic characteristics, reproductive and disease history, medication use, diet, lifestyle factors and use of complementary and alternative medicine.
Researchers used a food frequency questionnaire designed to measure soy foods commonly consumed in Shanghai, including tofu, soy milk, fresh soy beans and other soy products, as well as meat, fish and cruciferous vegetables.
After a median follow-up of 3.9 years, there were 444 total deaths and 534 breast cancer recurrences in the study group. Soy food consumption after cancer diagnosis, measured as soy protein intake, was inversely associated with mortality and recurrence. The associations of soy protein/isoflavones intake with mortality and recurrence appear to follow a dose-response pattern until soy protein intake reaches 11 grams per day or soy isoflavones intake reaches 40 mg/day. After these points, the association appears to level off or rebound.
“We found that women in the highest soy food intake groups had the lowest mortality and recurrence rates rate compared with women in the lowest soy food intake group, regardless of tamoxifen use status,” said Shu.
The associations of soy food intake with mortality and recurrence were observed for women with either ER-positive or ER-negative breast cancer. The association between soy food intake and overall mortality did not appear to vary by menopausal status.
“It is important to note that we studied soy food intake and not the use of soy capsule supplements,” explained Shu. “These capsules frequently contain only soy isoflavones, while soy foods contain other nutrients, as well. So we cannot infer that the isoflavones alone would provide the same protective benefits.”
Soy isoflavones compete with estrogens in the binding of estrogen receptors, reduce estrogen synthesis and help clear steroids from the body. These anti-estrogenic effects may be one of the underlying mechanisms through which soy foods are associated with better breast cancer outcomes. Other constituents of soy foods, such as folate, protein, protease inhibitors, calcium or fiber, also may be responsible for the survival benefits of soy food consumption.
Fatty food can weaken the immune system
Fresh evidence that fatty food is bad for our health has come to light: mice fed a lard-based diet over a long period got worse at fighting bacteria in the blood, reveals a thesis from the Sahlgrenska Academy.
The mice fed the lard-based diet derived 60 per cent of their total calories from fat. They were compared with mice fed a low-fat diet, where no more than ten per cent of their calories came from fat. As expected, the mice on the high-fat diet got fatter. A more surprising result was that their immune system was less active. The white blood cells got worse at dealing with bacteria in the blood, which could have contributed to many dying of sepsis.
"Obesity is usually associated with inflammation that does not result from an infection, which simply means that the immune defences are activated unnecessarily," says doctoral student Louise Strandberg who wrote the thesis. "Ironically, the mice on the high-fat diet seem to have a less active immune system when they really need it."
Fat people are also at a greater risk of aquiring infection, for example in connection with an operation. In mice, the thesis shows that it is fatty food rather than obesity in itself which affects the ability to fight off sepsis caused by bacteria.
Strandberg has also investigated different variants of three genes that are important for the immune system and noted that several of the gene variants that strengthen immunity also result in less obesity.
"So there are all kinds of links between the immune system on the one hand and obesity and diet on the other," says Strandberg.
The mice fed the lard-based diet derived 60 per cent of their total calories from fat. They were compared with mice fed a low-fat diet, where no more than ten per cent of their calories came from fat. As expected, the mice on the high-fat diet got fatter. A more surprising result was that their immune system was less active. The white blood cells got worse at dealing with bacteria in the blood, which could have contributed to many dying of sepsis.
"Obesity is usually associated with inflammation that does not result from an infection, which simply means that the immune defences are activated unnecessarily," says doctoral student Louise Strandberg who wrote the thesis. "Ironically, the mice on the high-fat diet seem to have a less active immune system when they really need it."
Fat people are also at a greater risk of aquiring infection, for example in connection with an operation. In mice, the thesis shows that it is fatty food rather than obesity in itself which affects the ability to fight off sepsis caused by bacteria.
Strandberg has also investigated different variants of three genes that are important for the immune system and noted that several of the gene variants that strengthen immunity also result in less obesity.
"So there are all kinds of links between the immune system on the one hand and obesity and diet on the other," says Strandberg.
Monday, December 7, 2009
Vitamin D levels = survival in lymphoma patients
A new study has found that the amount of vitamin D () in patients being treated for diffuse large B-cell lymphoma was strongly associated with cancer progression and overall survival. The results will be presented at the annual meeting of the American Society of Hematology ) in New Orleans.
"These are some of the strongest findings yet between vitamin D and cancer outcome," says the study's lead investigator, Matthew Drake, M.D., Ph.D., an endocrinologist at Mayo Clinic in Rochester. "While these findings are very provocative, they are preliminary and need to be validated in other studies. However, they raise the issue of whether vitamin D supplementation might aid in treatment for this malignancy, and thus should stimulate much more research."
The researchers' study of 374 newly diagnosed diffuse large B-cell lymphoma patients found that 50 percent had deficient vitamin D levels based on the commonly used clinical value of total serum 25(OH)D less than 25 ng/mL. Patients with deficient vitamin D levels had a 1.5-fold greater risk of disease progression and a twofold greater risk of dying, compared to patients with optimal vitamin D levels after accounting for other patient factors associated with worse outcomes.
The study was conducted by a team of researchers from Mayo Clinic and the University of Iowa. These researchers participate in the University of Iowa/Mayo Clinic Lymphoma Specialized Program of Research Excellence (SPORE), which is funded by the National Cancer Institute. The 374 patients were enrolled in an epidemiologic study designed to identify predictors of outcomes in lymphoma. Since this was not a clinical trial, patient management and treatments were not assigned, but rather followed standard of care for clinical practice.
The findings support the growing association between vitamin D and cancer risk and outcomes, and suggest that vitamin D supplements might help even those patients already diagnosed with some forms of cancer, says Dr. Drake. "The exact roles that vitamin D might play in the initiation or progression of cancer is unknown, but we do know that the vitamin plays a role in regulation of cell growth and death, among other processes important in limiting cancer," he says.
The findings also reinforce research in other fields that suggest vitamin D is important to general health, Dr. Drake says. "It is fairly easy to maintain vitamin D levels through inexpensive daily supplements or 15 minutes in the sun three times a week in the summer, so that levels can be stored inside body fat," he says. Many physicians recommend 800-1,200 International Units (IU) daily, he adds.
Vitamin D is a steroid hormone obtained from sunlight and converted by the skin into its active form. It also can come from food (naturally or fortified as in milk) or from supplements. It is known best for its role of increasing the flow of calcium into the blood. Because of that role, vitamin D deficiency has long been known to be a major risk factor for bone loss and bone fractures, particularly in elderly people whose skin is less efficient at converting sunlight into vitamin D. But recent research has found that many people suffer from the deficiency, and investigators are actively looking at whether low vitamin D promotes poorer health in general.
Cancer researchers have discovered that vitamin D regulates a number of genes in various cancers, including prostate, colon and breast cancers. Recent studies have suggested that vitamin D deficiency may play a role in causing certain cancers as well as impacting the outcome once someone is diagnosed with cancer.
Researchers looked at vitamin D levels in lymphoma patients because of the observation, culled from U.S. mortality maps issued by the National Cancer Institute, that both incidence and mortality rates of this cancer increase the farther north a person lives in the United States, where sunlight is limited in the winter. Also, several recent reports have concluded that vitamin D deficiency is associated with poor outcomes in other cancers, including breast, colon and head and neck cancer. This is the first study to look at lymphoma outcome.
"These are some of the strongest findings yet between vitamin D and cancer outcome," says the study's lead investigator, Matthew Drake, M.D., Ph.D., an endocrinologist at Mayo Clinic in Rochester. "While these findings are very provocative, they are preliminary and need to be validated in other studies. However, they raise the issue of whether vitamin D supplementation might aid in treatment for this malignancy, and thus should stimulate much more research."
The researchers' study of 374 newly diagnosed diffuse large B-cell lymphoma patients found that 50 percent had deficient vitamin D levels based on the commonly used clinical value of total serum 25(OH)D less than 25 ng/mL. Patients with deficient vitamin D levels had a 1.5-fold greater risk of disease progression and a twofold greater risk of dying, compared to patients with optimal vitamin D levels after accounting for other patient factors associated with worse outcomes.
The study was conducted by a team of researchers from Mayo Clinic and the University of Iowa. These researchers participate in the University of Iowa/Mayo Clinic Lymphoma Specialized Program of Research Excellence (SPORE), which is funded by the National Cancer Institute. The 374 patients were enrolled in an epidemiologic study designed to identify predictors of outcomes in lymphoma. Since this was not a clinical trial, patient management and treatments were not assigned, but rather followed standard of care for clinical practice.
The findings support the growing association between vitamin D and cancer risk and outcomes, and suggest that vitamin D supplements might help even those patients already diagnosed with some forms of cancer, says Dr. Drake. "The exact roles that vitamin D might play in the initiation or progression of cancer is unknown, but we do know that the vitamin plays a role in regulation of cell growth and death, among other processes important in limiting cancer," he says.
The findings also reinforce research in other fields that suggest vitamin D is important to general health, Dr. Drake says. "It is fairly easy to maintain vitamin D levels through inexpensive daily supplements or 15 minutes in the sun three times a week in the summer, so that levels can be stored inside body fat," he says. Many physicians recommend 800-1,200 International Units (IU) daily, he adds.
Vitamin D is a steroid hormone obtained from sunlight and converted by the skin into its active form. It also can come from food (naturally or fortified as in milk) or from supplements. It is known best for its role of increasing the flow of calcium into the blood. Because of that role, vitamin D deficiency has long been known to be a major risk factor for bone loss and bone fractures, particularly in elderly people whose skin is less efficient at converting sunlight into vitamin D. But recent research has found that many people suffer from the deficiency, and investigators are actively looking at whether low vitamin D promotes poorer health in general.
Cancer researchers have discovered that vitamin D regulates a number of genes in various cancers, including prostate, colon and breast cancers. Recent studies have suggested that vitamin D deficiency may play a role in causing certain cancers as well as impacting the outcome once someone is diagnosed with cancer.
Researchers looked at vitamin D levels in lymphoma patients because of the observation, culled from U.S. mortality maps issued by the National Cancer Institute, that both incidence and mortality rates of this cancer increase the farther north a person lives in the United States, where sunlight is limited in the winter. Also, several recent reports have concluded that vitamin D deficiency is associated with poor outcomes in other cancers, including breast, colon and head and neck cancer. This is the first study to look at lymphoma outcome.
Thursday, December 3, 2009
Methionine May Be Key To Longevity
Amino acids are the building blocks of life as they form the basis of proteins. Methionine is one of the most important amino acids at it is essential to the formation of all proteins. Whilst proteins are formed naturally in the body, we also consume proteins from many different food types, including meat and dairy products, soy-derived food such as tofu, and pulses. The relative abundance of methionine differs depending on the food type in question; it occurs in naturally high levels in foods such as sesame seeds, Brazil nuts, wheat germ, fish and meats.
Getting the correct balance of proteins in our diet may be more important for healthy ageing than reducing calories, new research funded by the Wellcome Trust and Research into Ageing suggests.
The research may help explain why 'dietary restriction' (also known as calorie restriction) – reducing food intake whilst maintaining sufficient quantities of vitamins, minerals and other important nutrients – appears to have health benefits. In many organisms, such as the fruit fly (drosophila), mice, rats and the Rhesus monkey, these benefits include living longer. Evidence suggests that dietary restriction can have health benefits for humans, too, though it is unclear whether it can increase longevity.
Dietary restriction can have a potentially negative side effect, however: diminished fertility. For example, the female fruit fly reproduces less frequently on a low calorie diet and its litter size is reduced, though its reproductive span lasts longer. This is believed to be an evolutionary trait: in times of famine, essential nutrients are diverted away from reproduction and towards survival.
To understand whether the health benefits of dietary restriction stem from a reduction in specific nutrients or in calorie intake in general, researchers at the Institute of Healthy Ageing, UCL (University College London), measured the effects of manipulating the diet of female fruit flies. The results of the study are published today in the journal Nature.
The fruit flies were fed a diet of yeast, sugar and water, but with differing amounts of key nutrients, such as vitamins, lipids and amino acids. The researchers found that varying the amount of amino acids in the mixture affected lifespan and fertility; varying the amount of the other nutrients had little or no effect.
In fact, when the researchers studied the effect further, they found that levels of a particular amino acid known as methionine were crucial to maximising lifespan without decreasing fertility. Adding methionine to a low calorie diet boosted fertility without reducing lifespan; likewise, reducing methionine content in a high calorie diet prolonged lifespan. Previous studies have also shown that reducing the intake of methionine in rodents can help extend lifespan.
"By carefully manipulating the balance of amino acids in the diet, we have been able to maximise both lifespan and fertility," explains Dr Matthew Piper, one of the study authors. "This indicates that it is possible to extend lifespan without wholesale dietary restriction and without the unfortunate consequence of lowering reproductive capacity."
"In the past, we have tended to think that the amount of protein is what is important to our diet," says Dr Piper. "We've shown here that in flies – and this is likely to be the case for other organisms – the balance of amino acids in the diet can affect health later in life. If this is the case for humans, then the type of protein will be more important.
"It's not as simple as saying 'eat less nuts' or 'eat more nuts' to live longer – it's about getting the protein balance right, a factor that might be particularly important for high protein diets, such as the Atkins diet or body builders' protein supplements."
Because the effects of dietary restriction on lifespan appears to be evolutionarily conserved – occurring in organisms from yeast to monkeys – scientists believe that the mechanisms may also be conserved. This opens up the possibility of using these organisms as models to study how dietary restriction works.
Although the human genome has around four times the number of genes as the fruit fly genome, there is a close relationship between many of these genes. Since it is easy to create mutants and carry out experiments on fruit flies, the functions of many fly genes have been established and newly discovered human genes can often be matched against their fly counterparts. Therefore, even though the fruit fly does not on the surface resemble humans, many findings about its basic biology can be interpreted for human biology.
Getting the correct balance of proteins in our diet may be more important for healthy ageing than reducing calories, new research funded by the Wellcome Trust and Research into Ageing suggests.
The research may help explain why 'dietary restriction' (also known as calorie restriction) – reducing food intake whilst maintaining sufficient quantities of vitamins, minerals and other important nutrients – appears to have health benefits. In many organisms, such as the fruit fly (drosophila), mice, rats and the Rhesus monkey, these benefits include living longer. Evidence suggests that dietary restriction can have health benefits for humans, too, though it is unclear whether it can increase longevity.
Dietary restriction can have a potentially negative side effect, however: diminished fertility. For example, the female fruit fly reproduces less frequently on a low calorie diet and its litter size is reduced, though its reproductive span lasts longer. This is believed to be an evolutionary trait: in times of famine, essential nutrients are diverted away from reproduction and towards survival.
To understand whether the health benefits of dietary restriction stem from a reduction in specific nutrients or in calorie intake in general, researchers at the Institute of Healthy Ageing, UCL (University College London), measured the effects of manipulating the diet of female fruit flies. The results of the study are published today in the journal Nature.
The fruit flies were fed a diet of yeast, sugar and water, but with differing amounts of key nutrients, such as vitamins, lipids and amino acids. The researchers found that varying the amount of amino acids in the mixture affected lifespan and fertility; varying the amount of the other nutrients had little or no effect.
In fact, when the researchers studied the effect further, they found that levels of a particular amino acid known as methionine were crucial to maximising lifespan without decreasing fertility. Adding methionine to a low calorie diet boosted fertility without reducing lifespan; likewise, reducing methionine content in a high calorie diet prolonged lifespan. Previous studies have also shown that reducing the intake of methionine in rodents can help extend lifespan.
"By carefully manipulating the balance of amino acids in the diet, we have been able to maximise both lifespan and fertility," explains Dr Matthew Piper, one of the study authors. "This indicates that it is possible to extend lifespan without wholesale dietary restriction and without the unfortunate consequence of lowering reproductive capacity."
"In the past, we have tended to think that the amount of protein is what is important to our diet," says Dr Piper. "We've shown here that in flies – and this is likely to be the case for other organisms – the balance of amino acids in the diet can affect health later in life. If this is the case for humans, then the type of protein will be more important.
"It's not as simple as saying 'eat less nuts' or 'eat more nuts' to live longer – it's about getting the protein balance right, a factor that might be particularly important for high protein diets, such as the Atkins diet or body builders' protein supplements."
Because the effects of dietary restriction on lifespan appears to be evolutionarily conserved – occurring in organisms from yeast to monkeys – scientists believe that the mechanisms may also be conserved. This opens up the possibility of using these organisms as models to study how dietary restriction works.
Although the human genome has around four times the number of genes as the fruit fly genome, there is a close relationship between many of these genes. Since it is easy to create mutants and carry out experiments on fruit flies, the functions of many fly genes have been established and newly discovered human genes can often be matched against their fly counterparts. Therefore, even though the fruit fly does not on the surface resemble humans, many findings about its basic biology can be interpreted for human biology.
Statins Do Not Stop Advanced AMD
In the largest study of statin use by advanced AMD patients to date, researchers followed 744 patients enrolled in the Complications of Age-Related Macular Degeneration Prevention Trial (CAPT) for five or six years. Statin drugs are primarily used to lower cholesterol in CVD patients, but they also affect mechanisms thought to impact AMD, including reduction of the inflammatory marker C-reactive protein. Earlier studies on statins' effects had been inconclusive. All patients from the CAPT cohort study were at risk for advanced AMD, but none had developed advanced "wet" or "dry" AMD at baseline. The study was supported by the National Eye Institute.
"The CAPT data did not support a large effect for statins in decreasing advanced AMD risk in patients who already had large drusen in both eyes," said lead researcher Maureen G. Maguire, PhD, Department of Ophthalmology, University of Pennsylvania. Drusen are whitish deposits, common in the eyes of people older than 60, which may signal AMD. Statin users were at slightly higher risk than non-users for developing advanced AMD, she said.
Dr. Maguire said several factors may be masking a protective effect for statins, the most important being that most patients who take statins for CVD are also at high risk for AMD. Only a randomized controlled trial could reveal statins' impact on AMD in the wider population, but since so many elderly people take statins it could be difficult to recruit a control group. It is also possible that statins may need to be taken for longer than the CAPT study's timeframe to show a protective effect, she added.
"The CAPT data did not support a large effect for statins in decreasing advanced AMD risk in patients who already had large drusen in both eyes," said lead researcher Maureen G. Maguire, PhD, Department of Ophthalmology, University of Pennsylvania. Drusen are whitish deposits, common in the eyes of people older than 60, which may signal AMD. Statin users were at slightly higher risk than non-users for developing advanced AMD, she said.
Dr. Maguire said several factors may be masking a protective effect for statins, the most important being that most patients who take statins for CVD are also at high risk for AMD. Only a randomized controlled trial could reveal statins' impact on AMD in the wider population, but since so many elderly people take statins it could be difficult to recruit a control group. It is also possible that statins may need to be taken for longer than the CAPT study's timeframe to show a protective effect, she added.
Aspirin May Offer Mild Protection from AMD
Records for 39,421women enrolled in the 10-year Women's Health Study (WHS) were used to evaluate the impact of low-dose aspirin on AMD risk. None of the women had AMD at the study outset; they were randomly assigned to take low-dose aspirin (100 mg on alternate days) or a placebo. It is known that low-dose aspirin substantially reduces the risk of serious blood vessel blockage, so researchers reasoned it might affect blood vessels that may play a role in AMD. Aspirin's anti-inflammatory and anti-oxidant effects were also considered potentially relevant. The research was supported by the National Eye Institute.
"Although our study found no large benefit from low-dose aspirin, the possible modest protective effect we did find warrants further study," said lead researcher William G. Christen, ScD, of Brigham and Women's Hospital, Boston, MA. "If future studies confirm our findings, it could be important to make the public aware of this benefit," he added.
The risk of developing vision-impacting AMD was reduced by18 percent in women who took low-dose aspirin. During the 10 year study, 245 AMD cases developed, 111 in the aspirin group and 134 in the placebo group. "Vision impact" was defined as a reduction in visual acuity to 20/30 or worse due to AMD. Though not statistically significant, the WHS risk reduction is similar to the result of the only other large randomized trial on this question: the Physicians' Health Study I, which followed 22,071 men who took low-dose aspirin or a placebo for five years.
The primary aim of the WHS was to learn whether Vitamin E and low-dose aspirin would help prevent heart disease and cancer. The AMD study also found that women who were not taking multivitamins appeared to benefit more from low-dose aspirin than vitamin users.
"Although our study found no large benefit from low-dose aspirin, the possible modest protective effect we did find warrants further study," said lead researcher William G. Christen, ScD, of Brigham and Women's Hospital, Boston, MA. "If future studies confirm our findings, it could be important to make the public aware of this benefit," he added.
The risk of developing vision-impacting AMD was reduced by18 percent in women who took low-dose aspirin. During the 10 year study, 245 AMD cases developed, 111 in the aspirin group and 134 in the placebo group. "Vision impact" was defined as a reduction in visual acuity to 20/30 or worse due to AMD. Though not statistically significant, the WHS risk reduction is similar to the result of the only other large randomized trial on this question: the Physicians' Health Study I, which followed 22,071 men who took low-dose aspirin or a placebo for five years.
The primary aim of the WHS was to learn whether Vitamin E and low-dose aspirin would help prevent heart disease and cancer. The AMD study also found that women who were not taking multivitamins appeared to benefit more from low-dose aspirin than vitamin users.
Tuesday, December 1, 2009
Aspirin, Tylenol May Decrease Vaccines Effect
With flu season in full swing and the threat of H1N1 looming, demand for vaccines is at an all-time high. Although those vaccines are expected to be effective, University of Missouri researchers have found further evidence that some over-the-counter drugs, such as aspirin and Tylenol, that inhibit certain enzymes could impact the effectiveness of vaccines.
“If you’re taking aspirin regularly, which many people do for cardiovascular treatment, or acetaminophen (Tylenol) for pain and fever and get a flu shot, there is a good chance that you won’t have a good antibody response,” said Charles Brown. “These drugs block the enzyme COX-1, which works in tissues throughout the body. We have found that if you block COX-1, you might be decreasing the amount of antibodies your body is producing, and you need high amounts of antibodies to be protected.”
COX enzymes play important roles in the regulation of the immune system. The role of these enzymes is not yet understood completely, and medications that inhibit them may have adverse side effects. Recent research has discovered that drugs that inhibit COX enzymes, such as COX-2, have an impact on the effectiveness of vaccines. Brown’s research indicates that inhibiting COX-1, which is present in tissues throughout the body, such as the brain or kidneys, could also impact vaccines’ effectiveness.
These MU researchers also are studying the regulation of inflammation and how that leads to the development or prevention of disease. Many diseases, such as arthritis, cardiovascular disease and diabetes, are all chronic inflammatory diseases. Contrary to previous beliefs, inflammation is generally a good thing that helps protect individuals from infection. Many of the non-steroidal drugs that treat inflammatory conditions reduce antibody responses, which are necessary for treating infections.
“So far, we’ve tested this on an animal model and have found that these non-steroidal drugs do inhibit vaccines, but the next step is to test it on humans,” Brown said. “If our results show that COX-1 inhibitors affect vaccines, the takeaway might be to not take drugs, such as aspirin, Tylenol and ibuprofen, for a couple weeks before and after you get a vaccine.”
“If you’re taking aspirin regularly, which many people do for cardiovascular treatment, or acetaminophen (Tylenol) for pain and fever and get a flu shot, there is a good chance that you won’t have a good antibody response,” said Charles Brown. “These drugs block the enzyme COX-1, which works in tissues throughout the body. We have found that if you block COX-1, you might be decreasing the amount of antibodies your body is producing, and you need high amounts of antibodies to be protected.”
COX enzymes play important roles in the regulation of the immune system. The role of these enzymes is not yet understood completely, and medications that inhibit them may have adverse side effects. Recent research has discovered that drugs that inhibit COX enzymes, such as COX-2, have an impact on the effectiveness of vaccines. Brown’s research indicates that inhibiting COX-1, which is present in tissues throughout the body, such as the brain or kidneys, could also impact vaccines’ effectiveness.
These MU researchers also are studying the regulation of inflammation and how that leads to the development or prevention of disease. Many diseases, such as arthritis, cardiovascular disease and diabetes, are all chronic inflammatory diseases. Contrary to previous beliefs, inflammation is generally a good thing that helps protect individuals from infection. Many of the non-steroidal drugs that treat inflammatory conditions reduce antibody responses, which are necessary for treating infections.
“So far, we’ve tested this on an animal model and have found that these non-steroidal drugs do inhibit vaccines, but the next step is to test it on humans,” Brown said. “If our results show that COX-1 inhibitors affect vaccines, the takeaway might be to not take drugs, such as aspirin, Tylenol and ibuprofen, for a couple weeks before and after you get a vaccine.”
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