An ambitious new study has added considerable weight to the claim that exercise can lower the risk for colon cancer. Researchers at Washington University School of Medicine in St. Louis and Harvard University combined and analyzed several decades worth of data from past studies on how exercise affects colon cancer risk. They found that people who exercised the most were 24 percent less likely to develop the disease than those who exercised the least.
"What's really compelling is that we see the association between exercise and lower colon cancer risk regardless of how physical activity was measured in the studies," says lead study author Kathleen Y. Wolin, Sc.D., a cancer prevention and control expert with the Siteman Cancer Center at Barnes-Jewish Hospital and Washington University. "That indicates that this is a robust association and gives all the more evidence that physical activity is truly protective against colon cancer."
Colorectal cancer is the third most common type of cancer. Each year more than 100,000 people in the United States are diagnosed with colon cancer and about 40,000 are diagnosed with rectal cancer. The study suggests that if the American population became significantly more physically active, up to 24 percent, or more than 24,000, fewer cases of colon cancer would occur each year.
Wolin's report was published Feb. 10, 2009 through advance online publication in the British Journal of Cancer. In the study, she and her colleagues gathered the results from all relevant studies published in English on the effect of physical activity on colon cancer risk.
They eliminated from consideration any studies that combined both colon and rectal cancer because exercise has not been shown to affect rectal cancer risk — including such studies would have led to an underestimation of the effect of exercise on colon cancer risk. In all, they analyzed 52 studies going back as far as 1984, making their analysis the most comprehensive to date.
They found that the protective effect of exercise held for all types of physical activity, whether that activity was recreational, such as jogging, biking or swimming, or job related, such as walking, lifting or digging.
"The beneficial effect of exercise holds across all sorts of activities," says Wolin, also assistant professor of surgery. "And it holds for both men and women. There is an ever-growing body of evidence that the behavior choices we make affect our cancer risk. Physical activity is at the top of the list of ways that you can reduce your risk of colon cancer."
The difference between people who were the most physically active and those who were the least varied from study to study in Wolin's analysis. As an example, in a 2007 study by Wolin and colleagues, women who walked the most realized a 23 percent reduction in their risk of colon cancer. Those highly active women walked briskly for five to six hours each week. By comparison, the women in that study who walked the least walked only a half hour each week.
Tuesday, June 30, 2009
Monday, June 29, 2009
Vigorous Exercise May Help Prevent Vision Loss
There's another reason to dust off those running shoes. Vigorous exercise may help prevent vision loss, according to a pair of studies from the U.S. Department of Energy's Lawrence Berkeley National Laboratory. The studies tracked approximately 31,000 runners for more than seven years, and found that running reduced the risk of both cataracts and age-related macular degeneration.
The research, which is among the first to suggest that vigorous exercise may help prevent vision loss, offers hope for people seeking to fend off the onset of eye disease.
"In addition to obtaining regular eye exams, people can take a more active role in preserving their vision," says Paul Williams, an epidemiologist in Berkeley Lab's Life Sciences Division who conducted the research. "The studies suggest that people can perhaps lessen their risk for these diseases by taking part in a fitness regimen that includes vigorous exercise."
A cataract, which is a cloudy opacity of the eye lens, is the leading cause of blindness. More than one-half of people in the U.S. over the age of 65 suffer from some form of cataracts. Age-related macular degeneration, which is damage to the retina, is the leading cause of irreversible vision loss in older white Americans, affecting 28 percent of people aged 75 and older.
The diseases have several known risk factors, such as sunlight exposure and diabetes in the case of cataracts, but few interventions. Now, it appears that vigorous cardiovascular exercise may be one way to derail the diseases.
To conduct the research, Williams analyzed data collected in the National Runners' Health Study, which he established in 1991 to determine the health benefits of running.
In this case, he followed approximately 29,000 male runners and 12,000 female runners for more than seven years. Of these people, 733 men reported being diagnosed with cataracts on a questionnaire filled out at the end of the study. Too few women reported cataracts to track.
Men who ran more than 5.7 miles per day had a 35 percent lower risk of developing cataracts than men who ran less than 1.4 miles per day. The study also analyzed men's 10-kilometer race performances, which is a good indicator of overall fitness. The fittest men boasted one-half the risk of developing cataracts compared to the least-fit men.
A second study found that running appeared to reduce the risk of age-related macular degeneration. In the study, 152 men and women reported being diagnosed with the disease. Compared to people who ran less than 1.2 miles per day, people who averaged between 1.2 and 2.4 miles per day had a 19 percent lower risk for the disease, and people who ran more than 2.4 miles per day had between 42 percent and 54 percent lower risk of the disease.
"These findings are compelling because of the large size of the study, and the fact that we are looking at something that is fairly well defined: vigorous exercise, as opposed to more moderate exercise," says Williams.
Most of the runners in the study exceeded the current public health recommendations for physical activity, which is at least 30 minutes of moderate-intensity activities such as brisk walking five days a week, or smaller doses of more vigorous exercise such as running. It is unclear whether people might also lower their risk for cataracts and age-related macular degeneration by walking.
"We know there are important health benefits to walking, including lowering heart disease risk," says Williams. "It is quite likely that the studies' results might apply to a lesser extent to smaller doses of more moderate exercise."
Williams also adds that further research is needed to explore why there is a link between vigorous exercise and a decreased risk for eye disease.
"We know some of the physiological benefits of exercise, and we know about the physiological background of these diseases, so we need to better understand where there's an overlap," says Williams.
The studies are published in the January 2009 issue of Investigative Ophthalmology and Visual Science. They were supported in part by grants from the National Heart Lung and Blood Institute.
The research, which is among the first to suggest that vigorous exercise may help prevent vision loss, offers hope for people seeking to fend off the onset of eye disease.
"In addition to obtaining regular eye exams, people can take a more active role in preserving their vision," says Paul Williams, an epidemiologist in Berkeley Lab's Life Sciences Division who conducted the research. "The studies suggest that people can perhaps lessen their risk for these diseases by taking part in a fitness regimen that includes vigorous exercise."
A cataract, which is a cloudy opacity of the eye lens, is the leading cause of blindness. More than one-half of people in the U.S. over the age of 65 suffer from some form of cataracts. Age-related macular degeneration, which is damage to the retina, is the leading cause of irreversible vision loss in older white Americans, affecting 28 percent of people aged 75 and older.
The diseases have several known risk factors, such as sunlight exposure and diabetes in the case of cataracts, but few interventions. Now, it appears that vigorous cardiovascular exercise may be one way to derail the diseases.
To conduct the research, Williams analyzed data collected in the National Runners' Health Study, which he established in 1991 to determine the health benefits of running.
In this case, he followed approximately 29,000 male runners and 12,000 female runners for more than seven years. Of these people, 733 men reported being diagnosed with cataracts on a questionnaire filled out at the end of the study. Too few women reported cataracts to track.
Men who ran more than 5.7 miles per day had a 35 percent lower risk of developing cataracts than men who ran less than 1.4 miles per day. The study also analyzed men's 10-kilometer race performances, which is a good indicator of overall fitness. The fittest men boasted one-half the risk of developing cataracts compared to the least-fit men.
A second study found that running appeared to reduce the risk of age-related macular degeneration. In the study, 152 men and women reported being diagnosed with the disease. Compared to people who ran less than 1.2 miles per day, people who averaged between 1.2 and 2.4 miles per day had a 19 percent lower risk for the disease, and people who ran more than 2.4 miles per day had between 42 percent and 54 percent lower risk of the disease.
"These findings are compelling because of the large size of the study, and the fact that we are looking at something that is fairly well defined: vigorous exercise, as opposed to more moderate exercise," says Williams.
Most of the runners in the study exceeded the current public health recommendations for physical activity, which is at least 30 minutes of moderate-intensity activities such as brisk walking five days a week, or smaller doses of more vigorous exercise such as running. It is unclear whether people might also lower their risk for cataracts and age-related macular degeneration by walking.
"We know there are important health benefits to walking, including lowering heart disease risk," says Williams. "It is quite likely that the studies' results might apply to a lesser extent to smaller doses of more moderate exercise."
Williams also adds that further research is needed to explore why there is a link between vigorous exercise and a decreased risk for eye disease.
"We know some of the physiological benefits of exercise, and we know about the physiological background of these diseases, so we need to better understand where there's an overlap," says Williams.
The studies are published in the January 2009 issue of Investigative Ophthalmology and Visual Science. They were supported in part by grants from the National Heart Lung and Blood Institute.
Prostate cancer screening has yet to prove its worth
The recent release of two large randomized trials suggests that if there is a benefit of screening, it is, at best, small, says a new report in CA: A Cancer Journal for Clinicians. Authored by Otis W. Brawley, M.D. of the American Cancer Society and Donna Ankerst, Ph.D. and Ian M. Thompson, M.D. of the University of Texas Health Science Center at San Antonio, the review says because prostate cancer is virtually ubiquitous in men as they age, it is clear that a goal of "finding more cancers" is not acceptable. Instead, public health principles demand that screening must reduce the risk of death from prostate cancer, reduce the suffering from prostate cancer, or reduce health care costs when compared with a non-screening scenario. The authors suggest prostate cancer screening has yet to reach one of these standards to date.
No major medical group, including the American Cancer Society, currently recommends routine prostate cancer screening for men at average risk. In the United States, prostate cancer will affect one man in six men during his lifetime. Since the mid-1980s, screening with the prostate–specific antigen (PSA) blood test has more than doubled the risk of a prostate cancer diagnosis. The review says a decrease in prostate cancer death rates has been observed since that time, but the relative contribution of PSA testing as opposed to other factors, such as improved treatment, has been uncertain.
The report says a computer modeling study using National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) registries estimated that more than one in four cancers detected in whites (29 percent) and nearly half of cancers detected in blacks (44 percent) were overdiagnosed cancers. A similar model using data from Europe estimated a 50 percent overdiagnosis rate. The authors say patients who are diagnosed with clinically insignificant tumors are subject to unnecessary diagnostic tests and unneeded treatment and suffer psychosocial harms. They are also labeled "a cancer patient," which can have negative economic consequences. Also, say the authors, overdiagnosis significantly affects 5–year survival statistics, making them uninformative in demonstrating progress in cancer control.
The report says the future of prostate cancer will include better screening tests, better methods to assess a man's risk of prostate cancer, and prevention strategies, including the use of finasteride, a drug currently used for the treatment of urinary symptoms related to prostate enlargement.
In a separate but related editorial, Peter Boyle, Ph.D., D.Sc., of the International Prevention Research Institute, Lyon, France and report co-author Dr. Brawley say "the real impact and tragedy of prostate cancer screening is the doubling of the lifetime risk of a diagnosis of prostate cancer with little if any decrease in the risk of dying from this disease." They say in 1985, before PSA screening was available, an American man had an 8.7 percent lifetime risk of being diagnosed with prostate cancer and a 2.5 percent lifetime risk of dying from the disease. Twenty years later, in 2005, an American man had a 17 percent lifetime risk of being diagnosed with prostate cancer and a 3 percent risk of dying from the disease. They add that even in the best case scenario, applying the findings of a European trial that found PSA led to a 20 percent reduction in the risk of death, the average man who chooses screening decreases his risk of prostate cancer death from a lifetime risk of 3 percent to a lifetime risk of 2.4 percent. In exchange, he doubles the chances of becoming a prostate cancer patient, his risk of diagnosis rising from about nine percent to at least 17 percent.
They conclude that "men should discuss the now quantifiable risks and benefits of having a PSA test with their physician and then share in making an informed decision," and that "the weight of the decision should not be thrown into the patient's lap."
No major medical group, including the American Cancer Society, currently recommends routine prostate cancer screening for men at average risk. In the United States, prostate cancer will affect one man in six men during his lifetime. Since the mid-1980s, screening with the prostate–specific antigen (PSA) blood test has more than doubled the risk of a prostate cancer diagnosis. The review says a decrease in prostate cancer death rates has been observed since that time, but the relative contribution of PSA testing as opposed to other factors, such as improved treatment, has been uncertain.
The report says a computer modeling study using National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) registries estimated that more than one in four cancers detected in whites (29 percent) and nearly half of cancers detected in blacks (44 percent) were overdiagnosed cancers. A similar model using data from Europe estimated a 50 percent overdiagnosis rate. The authors say patients who are diagnosed with clinically insignificant tumors are subject to unnecessary diagnostic tests and unneeded treatment and suffer psychosocial harms. They are also labeled "a cancer patient," which can have negative economic consequences. Also, say the authors, overdiagnosis significantly affects 5–year survival statistics, making them uninformative in demonstrating progress in cancer control.
The report says the future of prostate cancer will include better screening tests, better methods to assess a man's risk of prostate cancer, and prevention strategies, including the use of finasteride, a drug currently used for the treatment of urinary symptoms related to prostate enlargement.
In a separate but related editorial, Peter Boyle, Ph.D., D.Sc., of the International Prevention Research Institute, Lyon, France and report co-author Dr. Brawley say "the real impact and tragedy of prostate cancer screening is the doubling of the lifetime risk of a diagnosis of prostate cancer with little if any decrease in the risk of dying from this disease." They say in 1985, before PSA screening was available, an American man had an 8.7 percent lifetime risk of being diagnosed with prostate cancer and a 2.5 percent lifetime risk of dying from the disease. Twenty years later, in 2005, an American man had a 17 percent lifetime risk of being diagnosed with prostate cancer and a 3 percent risk of dying from the disease. They add that even in the best case scenario, applying the findings of a European trial that found PSA led to a 20 percent reduction in the risk of death, the average man who chooses screening decreases his risk of prostate cancer death from a lifetime risk of 3 percent to a lifetime risk of 2.4 percent. In exchange, he doubles the chances of becoming a prostate cancer patient, his risk of diagnosis rising from about nine percent to at least 17 percent.
They conclude that "men should discuss the now quantifiable risks and benefits of having a PSA test with their physician and then share in making an informed decision," and that "the weight of the decision should not be thrown into the patient's lap."
Exercise Fights Breast Cancer: 2 Studies
Physically Fit Women Less Likely to Die from Breast Cancer
Physically fit women are less likely to die from breast cancer, according to a study by researchers at the University of South Carolina Arnold School of Public Health.
The findings are published in the April issue of Medicine & Science in Sports & Exercise®, the official scientific journal of the American College of Sports Medicine.
The study of more than 14,000 women found that those with moderate or high aerobic fitness levels were much less likely to die from breast cancer, said Dr. Steve Blair, an Arnold School researcher and a past president of the American College of Sports Medicine.
“Women in the study’s lowest fitness category were nearly three times more likely to die from breast cancer than women in the most fit group,” he said.
“We believe this is the first study to evaluate the association of objectively measured fitness and risk of dying from breast cancer,” he said. “The results suggest a stronger protective effect than has been seen in most studies on self-reported physical activity and breast cancer, probably because the objective laboratory test of fitness is more accurate that self-reports of activity.”
Blair and his research team studied women from 20 to 83 years of age who had no previous history of breast cancer. The study participants received an initial medical examination that included a maximal exercise test on a treadmill, between 1973 and 2001, and were monitored for breast cancer mortality through 2003.
“The good news is that women who do at least 150 minutes of moderate-intensity activity, like walking, per week will escape the low fitness category,” he said. “Even better for some women, this activity can be accumulated in 10-minute bouts.”
This level of exercise meets the federal “Physical Activity Guidelines for Americans” recommendations, and can be easily achieved in 30 minutes of exercise five days/week.
To develop the highest fitness category in this study, Blair said, women should aim for the “high activity” level recommended by federal guidelines, which includes 300 minutes of moderate-intensity activity, such as walking, over the course of the week. This can be achieved through 150 minutes/week of more vigorous activity, such as jogging or taking an aerobics class.
“With more than 40,000 women dying each year from this disease, finding a strong association between fitness, which can be improved by the relatively inexpensive lifestyle intervention of regular physical activity, such as walking, is exciting,” Blair said.
In addition, the study found that women with high aerobic fitness had lower body mass index, better cholesterol levels, lower blood pressure, and fewer chronic conditions such as diabetes and cardiovascular disease.
“This study is more evidence that physical activity is critical to health across our lifespan,” Blair said.
The study’s findings correlate with the message of ACSM’s Exercise is Medicine™ program, which calls for physical activity to be a standard part of health care and preventive treatment.
Study Examines Power of Exercise to Prevent Breast Cancer
Women With Family History May Cut Their Risk Through Regular Workouts
A new federally funded University of Pennsylvania School of Medicine study aims to learn whether women at high risk of breast cancer can use exercise to meaningfully reduce their risk of getting the disease. Building on evidence that reducing estrogen in the body reduces cancer risk, and that elite female athletes experience a drop in estrogen levels that often cause them to stop ovulating and menstruating, the WISER Sister trial will investigate two different levels of regular treadmill exercise as a possible intervention for breast cancer risk reduction.
The stakes for women who carry BRCA genetic mutations are high – as many as 80 percent of them will develop breast or ovarian cancer during their lives – but options for risk reduction are drastic and few, and the choices may be unacceptable to some women. Previous Penn research shows that prophylactic mastectomy slashes carriers’ breast cancer risk by 90 percent, while prophylactic oophorectomy, or ovary removal, halves their breast cancer risk and reduces their chances of getting of ovarian cancer by about 85 to 90 percent. Though the surgeries are highly effective, they usher in quality of life concerns – particularly with regard to body image and sexuality – and the early menopause that results from ovary removal brings a woman’s childbearing years to an end. And the procedures aren’t recommended for women who have a family history of breast cancer but don’t carry the mutated genes.
“The decision to have these surgeries is so difficult that many women delay them, sometimes with terrible consequences. We would like to find out if exercise could buy high-risk women time they need to more safely think through their options,” says Kathryn Schmitz, PhD, MPH, an assistant professor in the Center for Clinical Epidemiology and Biostatistics who is leading the new study, in partnership with Susan Domchek, MD, director of the Abramson Cancer Center’s Cancer Risk Evaluation Program. “Exercise also has a number of health and stress reduction benefits that make it even more attractive for this population.”
Over the next three years, Schmitz's team will enroll 160 women ages 18 to 40, who must have an elevated risk of getting breast cancer based on her family history of the disease. BRCA carriers will be included among eligible women. However, participants will not be required to undergo genetic testing.
Previous research on estrogen exposure strongly suggests that reducing estrogens will result in reduced breast cancer risk in this population. The investigators plan to use their findings to offer effective exercise guidelines for high-risk women. Unlike surgery, exercise is a low-cost intervention with few side effects, so Schmitz is hopeful that the study results will offer risk-reduction tools to a larger swath of high-risk women, including minorities and other groups that may be underserved or lack access to genetic testing or proper early screening.
“We are interested in rigorously investigating all potential options to decrease cancer risk,” says Domchek, an associate professor of Medicine in the division of Hematology/Oncology. “Exercise is a wonderful intervention due to its numerous health benefits. However, it is important for us to quantify the amount of exercise needed and the potential benefits such exercise might provide.”
Although it is unknown how much the exercise interventions tested in the trial will reduce estrogen exposure, Schmitz says even evidence of marginal risk reduction -- that exercise may help delay breast cancer onset, decrease breast density to improve the accuracy of early screening tests, or result in smaller tumors -- could be of help to women planning risk reduction strategies during their 20s and 30s.
Trial participants will be placed into three randomized groups who will be followed for seven months. Each participant will receive a treadmill to use at home, which she will get to keep after the study is over. A “low dose” group will complete 150 minutes of exercise each week, the same amount recommended for general health and fitness, while a “high dose” group will do 300 minutes of exercise each week, similar to the workouts recommended for weight control. A third group, serving as the control, will continue doing their usual activities for the duration of the study and will receive the treadmill at the end of study completion.
Each woman will give daily urine samples at points during the trial, which will allow investigators to measure their levels of estrogen, progesterone and other sex hormones. The women’s body composition will also be measured, and they will receive breast MRIs at no cost to them before and after the study to examine changes in the density of their breast tissue.
“It is frightening to face high risk for breast cancer at a young age. Most of us think of cancer as something that happens later in life. Young women may not even want to approach the issue of getting genetic testing yet, but may want to do something. The WISER Sister study offers those women an option,” Schmitz says. “The benefits of the study will have a ripple effect to other good health habits, too, by helping women adopt a regular exercise regimen.”
Physically fit women are less likely to die from breast cancer, according to a study by researchers at the University of South Carolina Arnold School of Public Health.
The findings are published in the April issue of Medicine & Science in Sports & Exercise®, the official scientific journal of the American College of Sports Medicine.
The study of more than 14,000 women found that those with moderate or high aerobic fitness levels were much less likely to die from breast cancer, said Dr. Steve Blair, an Arnold School researcher and a past president of the American College of Sports Medicine.
“Women in the study’s lowest fitness category were nearly three times more likely to die from breast cancer than women in the most fit group,” he said.
“We believe this is the first study to evaluate the association of objectively measured fitness and risk of dying from breast cancer,” he said. “The results suggest a stronger protective effect than has been seen in most studies on self-reported physical activity and breast cancer, probably because the objective laboratory test of fitness is more accurate that self-reports of activity.”
Blair and his research team studied women from 20 to 83 years of age who had no previous history of breast cancer. The study participants received an initial medical examination that included a maximal exercise test on a treadmill, between 1973 and 2001, and were monitored for breast cancer mortality through 2003.
“The good news is that women who do at least 150 minutes of moderate-intensity activity, like walking, per week will escape the low fitness category,” he said. “Even better for some women, this activity can be accumulated in 10-minute bouts.”
This level of exercise meets the federal “Physical Activity Guidelines for Americans” recommendations, and can be easily achieved in 30 minutes of exercise five days/week.
To develop the highest fitness category in this study, Blair said, women should aim for the “high activity” level recommended by federal guidelines, which includes 300 minutes of moderate-intensity activity, such as walking, over the course of the week. This can be achieved through 150 minutes/week of more vigorous activity, such as jogging or taking an aerobics class.
“With more than 40,000 women dying each year from this disease, finding a strong association between fitness, which can be improved by the relatively inexpensive lifestyle intervention of regular physical activity, such as walking, is exciting,” Blair said.
In addition, the study found that women with high aerobic fitness had lower body mass index, better cholesterol levels, lower blood pressure, and fewer chronic conditions such as diabetes and cardiovascular disease.
“This study is more evidence that physical activity is critical to health across our lifespan,” Blair said.
The study’s findings correlate with the message of ACSM’s Exercise is Medicine™ program, which calls for physical activity to be a standard part of health care and preventive treatment.
Study Examines Power of Exercise to Prevent Breast Cancer
Women With Family History May Cut Their Risk Through Regular Workouts
A new federally funded University of Pennsylvania School of Medicine study aims to learn whether women at high risk of breast cancer can use exercise to meaningfully reduce their risk of getting the disease. Building on evidence that reducing estrogen in the body reduces cancer risk, and that elite female athletes experience a drop in estrogen levels that often cause them to stop ovulating and menstruating, the WISER Sister trial will investigate two different levels of regular treadmill exercise as a possible intervention for breast cancer risk reduction.
The stakes for women who carry BRCA genetic mutations are high – as many as 80 percent of them will develop breast or ovarian cancer during their lives – but options for risk reduction are drastic and few, and the choices may be unacceptable to some women. Previous Penn research shows that prophylactic mastectomy slashes carriers’ breast cancer risk by 90 percent, while prophylactic oophorectomy, or ovary removal, halves their breast cancer risk and reduces their chances of getting of ovarian cancer by about 85 to 90 percent. Though the surgeries are highly effective, they usher in quality of life concerns – particularly with regard to body image and sexuality – and the early menopause that results from ovary removal brings a woman’s childbearing years to an end. And the procedures aren’t recommended for women who have a family history of breast cancer but don’t carry the mutated genes.
“The decision to have these surgeries is so difficult that many women delay them, sometimes with terrible consequences. We would like to find out if exercise could buy high-risk women time they need to more safely think through their options,” says Kathryn Schmitz, PhD, MPH, an assistant professor in the Center for Clinical Epidemiology and Biostatistics who is leading the new study, in partnership with Susan Domchek, MD, director of the Abramson Cancer Center’s Cancer Risk Evaluation Program. “Exercise also has a number of health and stress reduction benefits that make it even more attractive for this population.”
Over the next three years, Schmitz's team will enroll 160 women ages 18 to 40, who must have an elevated risk of getting breast cancer based on her family history of the disease. BRCA carriers will be included among eligible women. However, participants will not be required to undergo genetic testing.
Previous research on estrogen exposure strongly suggests that reducing estrogens will result in reduced breast cancer risk in this population. The investigators plan to use their findings to offer effective exercise guidelines for high-risk women. Unlike surgery, exercise is a low-cost intervention with few side effects, so Schmitz is hopeful that the study results will offer risk-reduction tools to a larger swath of high-risk women, including minorities and other groups that may be underserved or lack access to genetic testing or proper early screening.
“We are interested in rigorously investigating all potential options to decrease cancer risk,” says Domchek, an associate professor of Medicine in the division of Hematology/Oncology. “Exercise is a wonderful intervention due to its numerous health benefits. However, it is important for us to quantify the amount of exercise needed and the potential benefits such exercise might provide.”
Although it is unknown how much the exercise interventions tested in the trial will reduce estrogen exposure, Schmitz says even evidence of marginal risk reduction -- that exercise may help delay breast cancer onset, decrease breast density to improve the accuracy of early screening tests, or result in smaller tumors -- could be of help to women planning risk reduction strategies during their 20s and 30s.
Trial participants will be placed into three randomized groups who will be followed for seven months. Each participant will receive a treadmill to use at home, which she will get to keep after the study is over. A “low dose” group will complete 150 minutes of exercise each week, the same amount recommended for general health and fitness, while a “high dose” group will do 300 minutes of exercise each week, similar to the workouts recommended for weight control. A third group, serving as the control, will continue doing their usual activities for the duration of the study and will receive the treadmill at the end of study completion.
Each woman will give daily urine samples at points during the trial, which will allow investigators to measure their levels of estrogen, progesterone and other sex hormones. The women’s body composition will also be measured, and they will receive breast MRIs at no cost to them before and after the study to examine changes in the density of their breast tissue.
“It is frightening to face high risk for breast cancer at a young age. Most of us think of cancer as something that happens later in life. Young women may not even want to approach the issue of getting genetic testing yet, but may want to do something. The WISER Sister study offers those women an option,” Schmitz says. “The benefits of the study will have a ripple effect to other good health habits, too, by helping women adopt a regular exercise regimen.”
Exercise Reduces Migraine Suffering
While physical exercise has been shown to trigger migraine headaches among sufferers, a new study describes an exercise program that is well tolerated by patients. The findings show that the program decreased the frequency of headaches and improved quality of life. The study is published in Headache: The Journal of Head and Face Pain.
The study used a sample of migraine sufferers who were examined before, during and after an aerobic exercise intervention. The program was based on indoor cycling (for continuous aerobic exercise) and was designed to improve maximal oxygen uptake without worsening the patients’ migraines.
After the treatment period, patients’ maximum oxygen uptake increased significantly. There was no worsening of migraine status at any time during the study period and, during the last month of treatment, there was a significant decrease in the number of migraine attacks, the number of days with migraine per month, headache intensity and amount of headache medication used.
Individuals with headache and migraine typically are less physically active than those without headache. Patients with migraine often avoid exercise, resulting in less aerobic endurance and flexibility. Therefore, well designed studies of exercise in patients with migraine are imperative.
“While the optimal amount of exercise for patients with migraine remains unknown, our evaluated program can now be tested further and compared to pharmacological and non-pharmacological treatments to see if exercise can prevent migraine,” says Dr. Emma Varkey, co-author of the study.
The study used a sample of migraine sufferers who were examined before, during and after an aerobic exercise intervention. The program was based on indoor cycling (for continuous aerobic exercise) and was designed to improve maximal oxygen uptake without worsening the patients’ migraines.
After the treatment period, patients’ maximum oxygen uptake increased significantly. There was no worsening of migraine status at any time during the study period and, during the last month of treatment, there was a significant decrease in the number of migraine attacks, the number of days with migraine per month, headache intensity and amount of headache medication used.
Individuals with headache and migraine typically are less physically active than those without headache. Patients with migraine often avoid exercise, resulting in less aerobic endurance and flexibility. Therefore, well designed studies of exercise in patients with migraine are imperative.
“While the optimal amount of exercise for patients with migraine remains unknown, our evaluated program can now be tested further and compared to pharmacological and non-pharmacological treatments to see if exercise can prevent migraine,” says Dr. Emma Varkey, co-author of the study.
Exercise keeps the brain young
New research from the University of North Carolina at Chapel Hill School of Medicine finds that aerobic activity may keep the brain young.
In the study published July 9 in the American Journal of Neuroradiology, physically active elderly people showed healthier cerebral blood vessels.
Researchers led by Elizabeth Bullitt, M.D., Van L. Weatherspoon Distinguished Professor of neurosurgery, used non-invasive magnetic resonance (MR) angiography to examine the number and shape of blood vessels in the brains of physically active elderly people, 7 men and 7 women, ages 60 to 80.
The study subjects were equally divided into 2 groups. The high activity group reported participating in an aerobic activity for a minimum of 180 minutes per week for the past 10 consecutive years, and the low activity group told investigators they had no history of regular exercise and currently spent less than 90 minutes a week in any physical activity. (The researchers did not know into which group participants were placed.)
This is the first study to compare brain images of elderly subjects who exercise with those that do not.
Aerobically active subjects exhibited more small-diameter vessels with less tortuosity, or twisting, than the less active group, exhibiting a vessel pattern similar to younger adults.
The authors, who were sponsored in part by the National Institutes of Health’s National Institute of Biomedical Imaging and Bioengineering, identified significant differences in the left and right middle cerebral artery regions confirmed by more than one statistical analysis.
The brain’s blood vessels naturally narrow and become more tortuous with advancing age, but the study showed the cerebrovascular patterns of active patients appeared “younger” than those of relatively inactive subjects. The brains of these less active patients had increased tortuosity produced by vessel elongation and wider expansion curves.
The pilot study lays the foundation for future research to determine whether aerobic activity improves anatomy, if older patients with “younger” brains are more likely to engage in physical activity, and whether elderly adults who begin a program of aerobic activity can reverse the cerebrovascular, anatomic and functional changes associated with advancing age.
In the study published July 9 in the American Journal of Neuroradiology, physically active elderly people showed healthier cerebral blood vessels.
Researchers led by Elizabeth Bullitt, M.D., Van L. Weatherspoon Distinguished Professor of neurosurgery, used non-invasive magnetic resonance (MR) angiography to examine the number and shape of blood vessels in the brains of physically active elderly people, 7 men and 7 women, ages 60 to 80.
The study subjects were equally divided into 2 groups. The high activity group reported participating in an aerobic activity for a minimum of 180 minutes per week for the past 10 consecutive years, and the low activity group told investigators they had no history of regular exercise and currently spent less than 90 minutes a week in any physical activity. (The researchers did not know into which group participants were placed.)
This is the first study to compare brain images of elderly subjects who exercise with those that do not.
Aerobically active subjects exhibited more small-diameter vessels with less tortuosity, or twisting, than the less active group, exhibiting a vessel pattern similar to younger adults.
The authors, who were sponsored in part by the National Institutes of Health’s National Institute of Biomedical Imaging and Bioengineering, identified significant differences in the left and right middle cerebral artery regions confirmed by more than one statistical analysis.
The brain’s blood vessels naturally narrow and become more tortuous with advancing age, but the study showed the cerebrovascular patterns of active patients appeared “younger” than those of relatively inactive subjects. The brains of these less active patients had increased tortuosity produced by vessel elongation and wider expansion curves.
The pilot study lays the foundation for future research to determine whether aerobic activity improves anatomy, if older patients with “younger” brains are more likely to engage in physical activity, and whether elderly adults who begin a program of aerobic activity can reverse the cerebrovascular, anatomic and functional changes associated with advancing age.
Friday, June 26, 2009
Latest Health Research Summary
There's an awful lot of interesting new health research published this week –the most exciting to me was the news that Overweight People Live Longest! My weight has always been pointed out as an increased health risk, and is probably the reason I try to do everything possible to protect my health (except lose weight, which I simply cannot seem to do, and even if I could, I am convinced that I would gain it back soon anyhow.) It’s great to know that it’s not such a problem after all – now if I could only convince my life insurance company.
Other new, not such good news: eating white bread and other high glycemic products can give you a heart attack.
Selenium can prevent prostate cancer, or make it worse, confirming other research that has suggested that antioxidants could be protective if you don't have cancer, but once you do, then antioxidants may be a bad thing, but green tea fights prostate cancer.
Just when I thought I had found a viable alternative to statins more evidence comes to light about all the great things statins do, (in addition to their main function of reducing cholesterol and thus preventing heart attacks), like:
fighting liver cancer and gall bladder disease,
improving lung function
and urologic health
now we find that statins fight Alzeihemer’s.
I had previously written about the benefits of the Mediterranean diet here and here.
Now new research focuses in on what parts of the diet are actually beneficial:
“Eating more vegetables, fruits, nuts, pulses (beans, peas and lentils) and olive oil, and drinking moderate amounts of alcohol, while not consuming a lot of meat or excessive amounts of alcohol is linked to people living longer.
However, the study also claims, that following a Mediterranean diet high in fish, seafood and cereals and low in dairy products were not indicators of longevity.”
There’s a new wonder supplement that makes you more fit without exercise: Quercitin (but watch out, its an anti-oxidant)
I have written often about the benefits of Vitamin D, including here and here.
But here’s even more new research:
And last, and yes, least, in addition to its other health benefits, drinking black coffee fights bad breath.
Other new, not such good news: eating white bread and other high glycemic products can give you a heart attack.
Selenium can prevent prostate cancer, or make it worse, confirming other research that has suggested that antioxidants could be protective if you don't have cancer, but once you do, then antioxidants may be a bad thing, but green tea fights prostate cancer.
Just when I thought I had found a viable alternative to statins more evidence comes to light about all the great things statins do, (in addition to their main function of reducing cholesterol and thus preventing heart attacks), like:
fighting liver cancer and gall bladder disease,
improving lung function
and urologic health
now we find that statins fight Alzeihemer’s.
I had previously written about the benefits of the Mediterranean diet here and here.
Now new research focuses in on what parts of the diet are actually beneficial:
“Eating more vegetables, fruits, nuts, pulses (beans, peas and lentils) and olive oil, and drinking moderate amounts of alcohol, while not consuming a lot of meat or excessive amounts of alcohol is linked to people living longer.
However, the study also claims, that following a Mediterranean diet high in fish, seafood and cereals and low in dairy products were not indicators of longevity.”
There’s a new wonder supplement that makes you more fit without exercise: Quercitin (but watch out, its an anti-oxidant)
I have written often about the benefits of Vitamin D, including here and here.
But here’s even more new research:
Vitamin D may go beyond its traditionally known role in maintaining bone integrity. It may play a role in preventing autoimmune diseases such as multiple sclerosis and rheumatoid arthritis, , some types of cancer (breast, ovarian, colorectal and prostate), types I and II diabetes—possibly even schizophrenia...
Research also shows a correlation between high vitamin D status and improved lower body muscle function in men and women over 60 years old.”
And last, and yes, least, in addition to its other health benefits, drinking black coffee fights bad breath.
Vitamin D Is The New Wonder Supplement
Scientific evidence shows vitamin D may go beyond its traditionally known role in maintaining bone integrity, according to new research presented at the Institute of Food Technologists Annual Meeting and Food Expo® earlier this month. It may play a role in preventing autoimmune diseases such as multiple sclerosis and rheumatoid arthritis, some types of cancer (breast, ovarian, colorectal and prostate).
Advancing technologies to add vitamin D to natural cheese, fruit juice, and other beverages and foods create offerings that provide excellent sources of both vitamin D and calcium which can help consumers achieve dietary adequacy of these largely under-consumed nutrients.
Recent headlines tout vitamin D as the new wonder supplement, with claims ranging from its ability to reduce cancer risk to its link to cognitive function in older men. While studies show connections exist, experts debate the amount of vitamin D necessary for optimal health, however.
“Low vitamin D status is linked to a number of different conditions,” said James C. Fleet, Ph.D. professor in the department of foods and nutrition at Purdue University. “These include certain cancers, muscle weakness and types I and II diabetes—possibly even schizophrenia and multiple sclerosis.”
Muscle weakness in cases of low levels of vitamin D may be explained by muscle's low levels of vitamin D receptors. "Studies with mice show that without vitamin D receptors, cells can't absorb the vitamin," said Dr. Fleet. "Research also shows a correlation between high vitamin D status and improved lower body muscle function in men and women over 60 years old."
Studies also show a decrease in colon cancer with an increase in vitamin D status, and it seems protective against other cancer risks as well. "One theory is that vitamin D may indirectly inhibit pro-cancer pathways," said Fleet. "The question is finding the protective level, which remains under some debate."
Although it remains controversial, 30 nanograms/milliliter (ng/mL) of vitamin D is associated with fewer fractures and falls, according to Karen Hansen, assistant professor of medicine within the rheumatology section at the University of Wisconsin. "Vitamin D deficiency causes osteoporosis by triggering decreased calcium absorption, secondary hyperparathyroidism, increased bone resorption and decreased bone mineral density." Study variables and inconsistencies make further studies necessary. Currently, 700 to 800 International Units (IU) of vitamin D a day seems most effective. Recommendations for an "adequate intake" of vitamin D will likely be increased
Advancing technologies to add vitamin D to natural cheese, fruit juice, and other beverages and foods create offerings that provide excellent sources of both vitamin D and calcium which can help consumers achieve dietary adequacy of these largely under-consumed nutrients.
Recent headlines tout vitamin D as the new wonder supplement, with claims ranging from its ability to reduce cancer risk to its link to cognitive function in older men. While studies show connections exist, experts debate the amount of vitamin D necessary for optimal health, however.
“Low vitamin D status is linked to a number of different conditions,” said James C. Fleet, Ph.D. professor in the department of foods and nutrition at Purdue University. “These include certain cancers, muscle weakness and types I and II diabetes—possibly even schizophrenia and multiple sclerosis.”
Muscle weakness in cases of low levels of vitamin D may be explained by muscle's low levels of vitamin D receptors. "Studies with mice show that without vitamin D receptors, cells can't absorb the vitamin," said Dr. Fleet. "Research also shows a correlation between high vitamin D status and improved lower body muscle function in men and women over 60 years old."
Studies also show a decrease in colon cancer with an increase in vitamin D status, and it seems protective against other cancer risks as well. "One theory is that vitamin D may indirectly inhibit pro-cancer pathways," said Fleet. "The question is finding the protective level, which remains under some debate."
Although it remains controversial, 30 nanograms/milliliter (ng/mL) of vitamin D is associated with fewer fractures and falls, according to Karen Hansen, assistant professor of medicine within the rheumatology section at the University of Wisconsin. "Vitamin D deficiency causes osteoporosis by triggering decreased calcium absorption, secondary hyperparathyroidism, increased bone resorption and decreased bone mineral density." Study variables and inconsistencies make further studies necessary. Currently, 700 to 800 International Units (IU) of vitamin D a day seems most effective. Recommendations for an "adequate intake" of vitamin D will likely be increased
Selenium intake may worsen prostate cancer
Higher selenium levels in the blood may worsen prostate cancer in some men who already have the disease, according to a study by researchers at Dana-Farber Cancer Institute the University of California, San Francisco.
A higher risk of more-aggressive prostate cancer was seen in men with a certain genetic variant found in about 75 percent of the prostate cancer patients in the study. In those subjects, having a high level of selenium in the blood was associated with a two-fold greater risk of poorer outcomes than men with the lowest amounts of selenium. By contrast, the 25 percent of men with a different variant of the same gene and who had high selenium levels were at 40 percent lower risk of aggressive disease. The variants are slightly different forms of a gene that instructs cells to make manganese superoxide dismutase (SOD2), an enzyme that protects the body against harmful oxygen compounds.
The research findings suggest that "if you already have prostate cancer, it may be a bad thing to take selenium," says Philip Kantoff, MD, director of Dana-Farber's Lank Center for Genitourinary Oncology and senior author of the study that is published by the Journal of Clinical Oncology on its website now and later will be in a print journal. The lead author is June Chan, ScD, of the University of California, San Francisco.
The unexpected results are the first to raise concern about this potentially harmful consequence of taking supplemental selenium. Kantoff says, "These findings are interesting particularly in light of the recent negative results from the SELECT prevention study, which asked if selenium could protect against prostate cancer."
The new study reveals the strong interaction between selenium and SOD2 to influence the biology of prostate cancer, a finding that these investigators had shown in a previous study. The authors say the current research demonstrated that variations in the make up of the SOD2 gene dramatically alter the effects of selenium on the risk of aggressive prostate cancer.
Selenium is a mineral found widely in rocks and dirt. Small amounts of selenium are essential for health: 40 to 70 micrograms is the recommended daily intake. In recent years, supplemental selenium has been sold and promoted as a means of preventing prostate cancer, largely based on observational studies that found higher risk of prostate cancer incidence and mortality in areas of the country that are naturally low in selenium.
However, research aimed at confirming the benefits of selenium supplementation have been mixed. Recently, the SELECT study, which involved 35,000 men, was halted early when, after more than five years, it showed that the supplements didn't affect the incidence of prostate cancer.
Previous studies had found that the risk of developing prostate cancer was modified by a strong interaction between SOD2 and selenium. The new research was designed to look at the effect of this interaction on men already diagnosed with prostate cancer.
Scientists examined banked blood samples, DNA, and medical records of 489 male Dana-Farber patients diagnosed between 1994 and 2001 with localized or locally advanced prostate cancer. Their mean age was 62, and their mean PSA (prostate-specific antigen) measurement was 6.0 ng/mL. About half the men were assessed as having a good disease risk, one-third had an intermediate risk, and the remaining one-sixth were at poor risk. The researchers measured the level of selenium in the blood and, using the stored DNA, they determined the SOD2 genotype -- the specific form of the SOD2 gene carried by each patient.
Simply having a high level of selenium was associated with a slightly elevated risk of aggressive prostate cancer. But the risk was much more strongly affected by the interaction of selenium levels and whether the patient had a certain variant of the SOD2 gene. Men with the highest selenium levels and the "AA" form of the SOD2 gene were 40 percent less likely to have been diagnosed with aggressive prostate cancer than the men with same gene form but low levels of selenium.
But for men carrying the "V" form of the gene, selenium had the opposite effect. In these men, those with the highest levels of selenium in their blood were about twice as likely to have an aggressive type of prostate cancer as their counterparts with low selenium levels, says Kantoff, who is also a professor of medicine at Harvard Medical School.
The study couldn't determine whether any of the men had been taking selenium supplements or not. But the researchers noted that men in the large SELECT prevention trial had a much higher average selenium level than those in the current study.
"Among the 25 percent of men with the AA genotype, having greater selenium levels may protect against aggressive disease," the authors concluded. "However, for the 75 percent of men who carry a V allele, higher selenium levels might increase the likelihood of having worse characteristics."
Therefore, they add, it is important to know which type of SOD2 gene a man has when considering the risks and potential benefits of taking selenium supplements. Additionally, the authors say the effects of the interaction between the SOD2 genotype and selenium may help explain apparently conflicting results of previous studies.
The results may seem counterintuitive to the public, who have been told for years that antioxidants can help people live longer, healthier lives with a lowered risk of cancer. However, Kantoff says, "There is some precedent to this – research has suggested that antioxidants could be protective if you don't have cancer, but once you do, then antioxidants may be a bad thing."
A higher risk of more-aggressive prostate cancer was seen in men with a certain genetic variant found in about 75 percent of the prostate cancer patients in the study. In those subjects, having a high level of selenium in the blood was associated with a two-fold greater risk of poorer outcomes than men with the lowest amounts of selenium. By contrast, the 25 percent of men with a different variant of the same gene and who had high selenium levels were at 40 percent lower risk of aggressive disease. The variants are slightly different forms of a gene that instructs cells to make manganese superoxide dismutase (SOD2), an enzyme that protects the body against harmful oxygen compounds.
The research findings suggest that "if you already have prostate cancer, it may be a bad thing to take selenium," says Philip Kantoff, MD, director of Dana-Farber's Lank Center for Genitourinary Oncology and senior author of the study that is published by the Journal of Clinical Oncology on its website now and later will be in a print journal. The lead author is June Chan, ScD, of the University of California, San Francisco.
The unexpected results are the first to raise concern about this potentially harmful consequence of taking supplemental selenium. Kantoff says, "These findings are interesting particularly in light of the recent negative results from the SELECT prevention study, which asked if selenium could protect against prostate cancer."
The new study reveals the strong interaction between selenium and SOD2 to influence the biology of prostate cancer, a finding that these investigators had shown in a previous study. The authors say the current research demonstrated that variations in the make up of the SOD2 gene dramatically alter the effects of selenium on the risk of aggressive prostate cancer.
Selenium is a mineral found widely in rocks and dirt. Small amounts of selenium are essential for health: 40 to 70 micrograms is the recommended daily intake. In recent years, supplemental selenium has been sold and promoted as a means of preventing prostate cancer, largely based on observational studies that found higher risk of prostate cancer incidence and mortality in areas of the country that are naturally low in selenium.
However, research aimed at confirming the benefits of selenium supplementation have been mixed. Recently, the SELECT study, which involved 35,000 men, was halted early when, after more than five years, it showed that the supplements didn't affect the incidence of prostate cancer.
Previous studies had found that the risk of developing prostate cancer was modified by a strong interaction between SOD2 and selenium. The new research was designed to look at the effect of this interaction on men already diagnosed with prostate cancer.
Scientists examined banked blood samples, DNA, and medical records of 489 male Dana-Farber patients diagnosed between 1994 and 2001 with localized or locally advanced prostate cancer. Their mean age was 62, and their mean PSA (prostate-specific antigen) measurement was 6.0 ng/mL. About half the men were assessed as having a good disease risk, one-third had an intermediate risk, and the remaining one-sixth were at poor risk. The researchers measured the level of selenium in the blood and, using the stored DNA, they determined the SOD2 genotype -- the specific form of the SOD2 gene carried by each patient.
Simply having a high level of selenium was associated with a slightly elevated risk of aggressive prostate cancer. But the risk was much more strongly affected by the interaction of selenium levels and whether the patient had a certain variant of the SOD2 gene. Men with the highest selenium levels and the "AA" form of the SOD2 gene were 40 percent less likely to have been diagnosed with aggressive prostate cancer than the men with same gene form but low levels of selenium.
But for men carrying the "V" form of the gene, selenium had the opposite effect. In these men, those with the highest levels of selenium in their blood were about twice as likely to have an aggressive type of prostate cancer as their counterparts with low selenium levels, says Kantoff, who is also a professor of medicine at Harvard Medical School.
The study couldn't determine whether any of the men had been taking selenium supplements or not. But the researchers noted that men in the large SELECT prevention trial had a much higher average selenium level than those in the current study.
"Among the 25 percent of men with the AA genotype, having greater selenium levels may protect against aggressive disease," the authors concluded. "However, for the 75 percent of men who carry a V allele, higher selenium levels might increase the likelihood of having worse characteristics."
Therefore, they add, it is important to know which type of SOD2 gene a man has when considering the risks and potential benefits of taking selenium supplements. Additionally, the authors say the effects of the interaction between the SOD2 genotype and selenium may help explain apparently conflicting results of previous studies.
The results may seem counterintuitive to the public, who have been told for years that antioxidants can help people live longer, healthier lives with a lowered risk of cancer. However, Kantoff says, "There is some precedent to this – research has suggested that antioxidants could be protective if you don't have cancer, but once you do, then antioxidants may be a bad thing."
Quercetin Increases Endurance w/o Exercise
Quercetin may not be a household word -- yet.
But a study by researchers at the University of South Carolina’s Arnold School of Public Health shows that the powerful antioxidant/anti-inflammatory compound found in fruits and vegetables significantly boosts endurance capacity and maximal oxygen capacity (VO2max) in healthy, active but untrained men and women.
The findings of the study – one of the first in humans to examine the energy-boosting effects of quercetin – are reported in the International Journal of Sports Nutrition and Exercise Metabolism, published online Wednesday (June 24).
Dr. Mark Davis, the study’s lead author and a professor of exercise science, said the fatigue-fighting and health properties of quercetin – found in the skins of red apples, red onions, berries and grapes – have implications not only for athletes and soldiers whose energy and performance are tested to the extreme, but also for average adults who battle fatigue and stress daily.
“The natural, biological properties of quercetin that include powerful antioxidant and anti-imflammatory activity, as well as the ability to boost the immune system and increase mitochondria (the powerhouse of the cell) in muscle and brain is great news for those who often think that they’re too tired to exercise,” Davis said.
“While there’s no magic pill to make people get up and move, or to take the place of regular exercise, quercetin may be important in relieving the fatigue that keeps them sedentary and in providing some of the benefits of exercise,” he said. “We believe that this could be a major breakthrough in nutrition.”
For the study, funded in part by the U.S. Department of Defense, 12 participants were randomly assigned to one of two treatments. Half were given 500 milligrams of quercetin twice a day in Tang for seven days. The other subjects drank Tang with placebos. After the seven days of treatment, during which the subjects were told not to alter their physical activity, the participants rode stationary bicycles to the point of fatigue.
Researchers also tested their additional VO2max, one of the most important measures of fitness. Then the participants received the opposite treatment for another seven days before riding the bicycle to the point of fatigue and VO2max tests. Neither the participants nor the research staff knew who received the quercetin Tang or the placebo Tang, and all subjects took part in the quercetin and placebo treatments.
“The participants were healthy, relatively active, college-age students, but they were not physically trained athletes, and they were not taking part in a regular exercise training program,” he said.
The results: After taking quercetin for only seven days, the participants had a 13.2 percent increase in endurance and a 3.9 percent increase in VO2max.
“These were statistically significant effects that indicate an important improvement in endurance capacity in a very short time,” Davis said. “Quercetin supplementation was able to mimic some of the effects of exercise training.
Although the study did not examine why the results were so dramatic, Davis said pre-clinical data suggest that quercetin may increase the mitochondria in brain and muscle cells. He likened the mitochondria to the “powerhouse of the cell,” producing most of its energy. Mitochondria in brain and muscle also are believed to be fundamentally important in battling age-related dementia, obesity, diabetes and cardiovascular dysfunction.
“One of the most important biological mechanisms for increasing endurance is increasing the mitochondria,” said Davis. “More mitochondria in the brain and muscle would enhance both mental and physical energy, as well as provide a better ability to fight other diseases in which mitochondrial dysfunction are hallmarks.”
Quercetin also appears to have valuable properties to fight inflammation, which has been linked to health problems such as colon cancer and heart disease. Davis’ research group has recently received a National Institutes of Health grant to study quercetin’s effects on colon cancer and others are pending that involve breast cancer.
“If the findings of this study and others on the biological mechanisms of quercetin are confirmed in future clinical studies, the implications go beyond improvements in endurance,” he said. “We may find that quercetin may work in conjunction with regular physical activity as an ally in preventing and treating diabetes, obesity and cardiovascular diseases and the degenerative diseases of aging.”
But a study by researchers at the University of South Carolina’s Arnold School of Public Health shows that the powerful antioxidant/anti-inflammatory compound found in fruits and vegetables significantly boosts endurance capacity and maximal oxygen capacity (VO2max) in healthy, active but untrained men and women.
The findings of the study – one of the first in humans to examine the energy-boosting effects of quercetin – are reported in the International Journal of Sports Nutrition and Exercise Metabolism, published online Wednesday (June 24).
Dr. Mark Davis, the study’s lead author and a professor of exercise science, said the fatigue-fighting and health properties of quercetin – found in the skins of red apples, red onions, berries and grapes – have implications not only for athletes and soldiers whose energy and performance are tested to the extreme, but also for average adults who battle fatigue and stress daily.
“The natural, biological properties of quercetin that include powerful antioxidant and anti-imflammatory activity, as well as the ability to boost the immune system and increase mitochondria (the powerhouse of the cell) in muscle and brain is great news for those who often think that they’re too tired to exercise,” Davis said.
“While there’s no magic pill to make people get up and move, or to take the place of regular exercise, quercetin may be important in relieving the fatigue that keeps them sedentary and in providing some of the benefits of exercise,” he said. “We believe that this could be a major breakthrough in nutrition.”
For the study, funded in part by the U.S. Department of Defense, 12 participants were randomly assigned to one of two treatments. Half were given 500 milligrams of quercetin twice a day in Tang for seven days. The other subjects drank Tang with placebos. After the seven days of treatment, during which the subjects were told not to alter their physical activity, the participants rode stationary bicycles to the point of fatigue.
Researchers also tested their additional VO2max, one of the most important measures of fitness. Then the participants received the opposite treatment for another seven days before riding the bicycle to the point of fatigue and VO2max tests. Neither the participants nor the research staff knew who received the quercetin Tang or the placebo Tang, and all subjects took part in the quercetin and placebo treatments.
“The participants were healthy, relatively active, college-age students, but they were not physically trained athletes, and they were not taking part in a regular exercise training program,” he said.
The results: After taking quercetin for only seven days, the participants had a 13.2 percent increase in endurance and a 3.9 percent increase in VO2max.
“These were statistically significant effects that indicate an important improvement in endurance capacity in a very short time,” Davis said. “Quercetin supplementation was able to mimic some of the effects of exercise training.
Although the study did not examine why the results were so dramatic, Davis said pre-clinical data suggest that quercetin may increase the mitochondria in brain and muscle cells. He likened the mitochondria to the “powerhouse of the cell,” producing most of its energy. Mitochondria in brain and muscle also are believed to be fundamentally important in battling age-related dementia, obesity, diabetes and cardiovascular dysfunction.
“One of the most important biological mechanisms for increasing endurance is increasing the mitochondria,” said Davis. “More mitochondria in the brain and muscle would enhance both mental and physical energy, as well as provide a better ability to fight other diseases in which mitochondrial dysfunction are hallmarks.”
Quercetin also appears to have valuable properties to fight inflammation, which has been linked to health problems such as colon cancer and heart disease. Davis’ research group has recently received a National Institutes of Health grant to study quercetin’s effects on colon cancer and others are pending that involve breast cancer.
“If the findings of this study and others on the biological mechanisms of quercetin are confirmed in future clinical studies, the implications go beyond improvements in endurance,” he said. “We may find that quercetin may work in conjunction with regular physical activity as an ally in preventing and treating diabetes, obesity and cardiovascular diseases and the degenerative diseases of aging.”
Green tea fights prostate cancer
According to results of a study published in Cancer Prevention Research, a journal of the American Association for Cancer Research, men with prostate cancer who consumed the active compounds in green tea demonstrated a significant reduction in serum markers predictive of prostate cancer progression.
"The investigational agent used in the trial, Polyphenon E (provided by Polyphenon Pharma) may have the potential to lower the incidence and slow the progression of prostate cancer," said James A. Cardelli, Ph.D., professor and director of basic and translational research in the Feist-Weiller Cancer Center, LSU Health Sciences Center-Shreveport.
Green tea is the second most popular drink in the world, and some epidemiological studies have shown health benefits with green tea, including a reduced incidence of prostate cancer, according to Cardelli. However, some human trials have found contradictory results. The few trials conducted to date have evaluated the clinical efficacy of green tea consumption and few studies have evaluated the change in biomarkers, which might predict disease progression.
Cardelli and colleagues conducted this open-label, single-arm, phase II clinical trial to determine the effects of short-term supplementation with green tea's active compounds on serum biomarkers in patients with prostate cancer. The biomarkers include hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF) and prostate specific antigen (PSA). HGF and VEGF are good prognostic indicators of metastatic disease.
The study included 26 men, aged 41 to 72 years, diagnosed with prostate cancer and scheduled for radical prostatectomy. Patients consumed four capsules containing Polyphenon E until the day before surgery — four capsules are equivalent to about 12 cups of normally brewed concentrated green tea, according to Cardelli. The time of study for 25 of the 26 patients ranged from 12 days to 73 days, with a median time of 34.5 days.
Findings showed a significant reduction in serum levels of HGF, VEGF and PSA after treatment, with some patients demonstrating reductions in levels of greater than 30 percent, according to the researchers.
Cardelli and colleagues found that other biomarkers were also positively affected. There were only a few reported side effects associated with this study, and liver function remained normal.
Results of a recent year-long clinical trial conduced by researchers in Italy demonstrated that consumption of green tea polyphenols reduced the risk of developing prostate cancer in men with high-grade prostate intraepithelial neoplasia (HGPIN).
"These studies are just the beginning and a lot of work remains to be done, however, we think that the use of tea polyphenols alone or in combination with other compounds currently used for cancer therapy should be explored as an approach to prevent cancer progression and recurrence," Cardelli said.
William G. Nelson, V., M.D., Ph.D., professor of oncology, urology and pharmacology at the Johns Hopkins Kimmel Cancer Center, believes the reduced serum biomarkers of prostate cancer may be attributable to some sort of benefit relating to green tea components.
"Unfortunately, this trial was not a randomized trial, which would have been needed to be more sure that the observed changes were truly attributable to the green tea components and not to some other lifestyle change (better diet, taking vitamins, etc.) men undertook in preparation for surgery," added Nelson, who is also a senior editor for Cancer Prevention Research. However, "this trial is provocative enough to consider a more substantial randomized trial."
In collaboration with Columbia University in New York City, the researchers are currently conducting a comparable trial among patients with breast cancer. They also plan to conduct further studies to identify the factors that could explain why some patients responded more dramatically to Polyphenon E than others. Cardelli suggested that additional controlled clinical trials should be done to see if combinations of different plant polyphenols were more effective than Polyphenon E alone.
"There is reasonably good evidence that many cancers are preventable, and our studies using plant-derived substances support the idea that plant compounds found in a healthy diet can play a role in preventing cancer development and progression," said Cardelli.
"The investigational agent used in the trial, Polyphenon E (provided by Polyphenon Pharma) may have the potential to lower the incidence and slow the progression of prostate cancer," said James A. Cardelli, Ph.D., professor and director of basic and translational research in the Feist-Weiller Cancer Center, LSU Health Sciences Center-Shreveport.
Green tea is the second most popular drink in the world, and some epidemiological studies have shown health benefits with green tea, including a reduced incidence of prostate cancer, according to Cardelli. However, some human trials have found contradictory results. The few trials conducted to date have evaluated the clinical efficacy of green tea consumption and few studies have evaluated the change in biomarkers, which might predict disease progression.
Cardelli and colleagues conducted this open-label, single-arm, phase II clinical trial to determine the effects of short-term supplementation with green tea's active compounds on serum biomarkers in patients with prostate cancer. The biomarkers include hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF) and prostate specific antigen (PSA). HGF and VEGF are good prognostic indicators of metastatic disease.
The study included 26 men, aged 41 to 72 years, diagnosed with prostate cancer and scheduled for radical prostatectomy. Patients consumed four capsules containing Polyphenon E until the day before surgery — four capsules are equivalent to about 12 cups of normally brewed concentrated green tea, according to Cardelli. The time of study for 25 of the 26 patients ranged from 12 days to 73 days, with a median time of 34.5 days.
Findings showed a significant reduction in serum levels of HGF, VEGF and PSA after treatment, with some patients demonstrating reductions in levels of greater than 30 percent, according to the researchers.
Cardelli and colleagues found that other biomarkers were also positively affected. There were only a few reported side effects associated with this study, and liver function remained normal.
Results of a recent year-long clinical trial conduced by researchers in Italy demonstrated that consumption of green tea polyphenols reduced the risk of developing prostate cancer in men with high-grade prostate intraepithelial neoplasia (HGPIN).
"These studies are just the beginning and a lot of work remains to be done, however, we think that the use of tea polyphenols alone or in combination with other compounds currently used for cancer therapy should be explored as an approach to prevent cancer progression and recurrence," Cardelli said.
William G. Nelson, V., M.D., Ph.D., professor of oncology, urology and pharmacology at the Johns Hopkins Kimmel Cancer Center, believes the reduced serum biomarkers of prostate cancer may be attributable to some sort of benefit relating to green tea components.
"Unfortunately, this trial was not a randomized trial, which would have been needed to be more sure that the observed changes were truly attributable to the green tea components and not to some other lifestyle change (better diet, taking vitamins, etc.) men undertook in preparation for surgery," added Nelson, who is also a senior editor for Cancer Prevention Research. However, "this trial is provocative enough to consider a more substantial randomized trial."
In collaboration with Columbia University in New York City, the researchers are currently conducting a comparable trial among patients with breast cancer. They also plan to conduct further studies to identify the factors that could explain why some patients responded more dramatically to Polyphenon E than others. Cardelli suggested that additional controlled clinical trials should be done to see if combinations of different plant polyphenols were more effective than Polyphenon E alone.
"There is reasonably good evidence that many cancers are preventable, and our studies using plant-derived substances support the idea that plant compounds found in a healthy diet can play a role in preventing cancer development and progression," said Cardelli.
Statins can protect against Alzheimer's disease
High cholesterol levels are considered to be a risk factor not only for cardiovascular disease including stroke, but also for the development of Alzheimer's disease. Therefore, many cholesterol lowering drugs, including statins, have been developed in recent years. In addition to the cholesterol reducing effect of statins Amalia Dolga, PhD, of the University of Groningen, The Netherlands, and her co-investigators have demonstrated that statins can protect nerve cells against damage which we know to occur in the brain of Alzheimer's disease patients. The results are published in the June issue of the Journal of Alzheimer's Disease.
How nerve cells die in Alzheimer's disease is complex but we know that nerve cells eventually die because they are strongly overstimulated, a process called excitotoxicity. In animal experiments conducted in the laboratory of Professor Ulrich Eisel, Department of Molecular Neurobiology, University of Groningen, Dolga and colleagues overstimulated such nerve cells. They clearly demonstrated that treatment with a statin called Lovastatin could prevent the death of nerve cells under these conditions. The statins not only prevented cells from dying but also prevented the loss of memory capacity that normally occurs after such cell death. In a previous study Dolga had showed that these statins stimulate the protective capacity of tumor necrosis factor, which is a key player in the brain's immune response.
Dolga has demonstrated in animal experiments that this tumor necrosis factor has a strong beneficial effect on nerve cells and can protect nerve cells against death. A widely prescribed drug like statins can activate this protective pathway revealing strong beneficial effect.
How nerve cells die in Alzheimer's disease is complex but we know that nerve cells eventually die because they are strongly overstimulated, a process called excitotoxicity. In animal experiments conducted in the laboratory of Professor Ulrich Eisel, Department of Molecular Neurobiology, University of Groningen, Dolga and colleagues overstimulated such nerve cells. They clearly demonstrated that treatment with a statin called Lovastatin could prevent the death of nerve cells under these conditions. The statins not only prevented cells from dying but also prevented the loss of memory capacity that normally occurs after such cell death. In a previous study Dolga had showed that these statins stimulate the protective capacity of tumor necrosis factor, which is a key player in the brain's immune response.
Dolga has demonstrated in animal experiments that this tumor necrosis factor has a strong beneficial effect on nerve cells and can protect nerve cells against death. A widely prescribed drug like statins can activate this protective pathway revealing strong beneficial effect.
Longer life = specific foods in Mediterranean diet
Some food groups in the Mediterranean diet are more important than others in promoting health and longer life according to new research published on bmj.com.
Eating more vegetables, fruits, nuts, pulses and olive oil, and drinking moderate amounts of alcohol, while not consuming a lot of meat or excessive amounts of alcohol is linked to people living longer.
However, the study also claims, that following a Mediterranean diet high in fish, seafood and cereals and low in dairy products were not indicators of longevity.
While several studies have concluded that the Mediterranean diet improves chances of living longer, most recently the study described here, this is the first to investigate the importance of individual components of the diet.
Professor Dimitrios Trichopoulos at the Harvard School of Public Health explains that they have surveyed over 23,000 men and women who were participants in the Greek segment of the European Prospective Investigation into Cancer and Nutrition (EPIC).
Participants were given dietary and lifestyle questionnaires when they enrolled onto the study and they were subsequently followed up for around 8.5 years with interviews. Their diets were rated from 0 to 10 based on the level of conformity to a traditional Mediterranean diet.
As part of the interview process, participants were also asked about their smoking status, levels of physical activity and whether they had ever been diagnosed with cancer, diabetes and heart disease.
The authors maintain that when high intake of vegetables, low intake of meat or moderate alcohol intake were excluded from the rating system, the benefits of following a Mediterranean diet were substantially reduced. They also note that there are clear benefits in combining several of the key components, for example high consumption of vegetables and olive oil.
Professor Trichopoulou, lead author of the study, concludes that the main reasons why the Mediterranean diet can lead to living longer are moderate consumption of ethanol (mostly in the form of wine during meals, as traditionally done in the Mediterranean countries), low consumption of meat and meat products, and high consumption of vegetables, fruits and nuts, olive oil and legumes.
Eating more vegetables, fruits, nuts, pulses and olive oil, and drinking moderate amounts of alcohol, while not consuming a lot of meat or excessive amounts of alcohol is linked to people living longer.
However, the study also claims, that following a Mediterranean diet high in fish, seafood and cereals and low in dairy products were not indicators of longevity.
While several studies have concluded that the Mediterranean diet improves chances of living longer, most recently the study described here, this is the first to investigate the importance of individual components of the diet.
Professor Dimitrios Trichopoulos at the Harvard School of Public Health explains that they have surveyed over 23,000 men and women who were participants in the Greek segment of the European Prospective Investigation into Cancer and Nutrition (EPIC).
Participants were given dietary and lifestyle questionnaires when they enrolled onto the study and they were subsequently followed up for around 8.5 years with interviews. Their diets were rated from 0 to 10 based on the level of conformity to a traditional Mediterranean diet.
As part of the interview process, participants were also asked about their smoking status, levels of physical activity and whether they had ever been diagnosed with cancer, diabetes and heart disease.
The authors maintain that when high intake of vegetables, low intake of meat or moderate alcohol intake were excluded from the rating system, the benefits of following a Mediterranean diet were substantially reduced. They also note that there are clear benefits in combining several of the key components, for example high consumption of vegetables and olive oil.
Professor Trichopoulou, lead author of the study, concludes that the main reasons why the Mediterranean diet can lead to living longer are moderate consumption of ethanol (mostly in the form of wine during meals, as traditionally done in the Mediterranean countries), low consumption of meat and meat products, and high consumption of vegetables, fruits and nuts, olive oil and legumes.
Thursday, June 25, 2009
Overweight People Live Longest!
Underweight people and those who are extremely obese die earlier than people of normal weight—but those who are overweight actually live longer than people of normal weight. Those are the findings of a new study published online in Obesity by researchers at Statistics Canada, Kaiser Permanente Center for Health Research, Portland State University, Oregon Health & Science University, and McGill University.
"It's not surprising that extreme underweight and extreme obesity increase the risk of dying, but it is surprising that carrying a little extra weight may give people a longevity advantage," said David Feeny, PhD, coauthor of the study and senior investigator for the Kaiser Permanente Center for Health Research.
"It may be that a few extra pounds actually protect older people as their health declines, but that doesn't mean that people in the normal weight range should try to put on a few pounds," said Mark Kaplan, DrPH, coauthor and Professor of Community Health at Portland State University. "Our study only looked at mortality, not at quality of life, and there are many negative health consequences associated with obesity, including high blood pressure, high cholesterol, and diabetes."
"Good health is more than a BMI or a number on a scale. We know that people who choose a healthy lifestyle enjoy better health: good food choices, being physically active everyday, managing stress, and keeping blood pressure, cholesterol, and blood sugar levels in check," said Keith Bachman MD, a weight management specialist with Kaiser Permanente's Care Management Institute.
The study examined the relationship between body mass index and death among 11,326 adults in Canada over a 12-year period. (BMI uses height and weight to estimate body fat.) Researchers found that underweight people had the highest risk of dying, and the extremely obese had the second highest risk. Overweight people had a lower risk of dying than those of normal weight.
This is the first large Canadian study to show that people who are overweight may actually live longer than those of normal weight. An earlier study, conducted in the United States and published in 2005 in the Journal of the American Medical Association, showed similar results.
For this study, researchers used data from the National Population Health Survey conducted by Statistics Canada every two years. During the study period, from 1994/1995 through 2006/2007, underweight people were 70 percent more likely than people of normal weight to die, and extremely obese people were 36 percent more likely to die. But overweight individuals were 17 percent less likely to die. The relative risk for obese people was nearly the same as for people of normal weight. The authors controlled for factors such as age, sex, physical activity, and smoking.
Coffee W/O Milk Fights Bad Breath
We all know why Starbucks puts boxes of breath mints close to the cash register. Your morning latte can create a startling aroma in your mouth, strong enough to startle your co-workers too.
But intriguing new research from Tel Aviv University by renowned breath specialist Prof. Mel Rosenberg of TAU's Sackler Faculty of Medicine finds that a coffee extract can inhibit the bacteria that lead to bad breath. New laboratory tests have shown that the extract prevents malodorous bacteria from making their presence felt — or smelt.
"Everybody thinks that coffee causes bad breath," says Prof. Rosenberg, "and it's often true, because coffee, which has a dehydrating effect in the mouth, becomes potent when mixed with milk, and can ferment into smelly substances."
But not always. "Contrary to our expectations, we found some components in coffee that actually inhibit bad breath," explains Prof. Rosenberg.
In the laboratory, the team monitored the bacterial odor production of coffee in saliva. In the study, three different brands of coffee were tested: the Israeli brand Elite coffee, Landwer Turkish coffee, and Taster's Choice. Prof. Rosenberg expected to demonstrate the malodor-causing effect of coffee in an in vitro saliva assay developed by Dr. Sarit Levitan in his laboratory. To his surprise, the extracts had the opposite effect.
"The lesson we learned here is one of humility," says Prof. Rosenberg. "We expected coffee would cause bad breath, but there is something inside this magic brew that has the opposite effect."
Prof. Rosenberg would love to isolate the bacterial-inhibiting molecule in order to reap the biggest anti-bacterial benefits from coffee. "It's not the raw extract we will use, he says, "but an active material within it." His latest discovery could be the foundation for an entirely new class of mouthwash, breath mints and gum. Purified coffee extract can be added to a breath mint to stop bacteria from forming, stopping bad breath at its source, instead of masking the smell with a mint flavor.
Prof. Rosenberg is a successful scientist and inventor who has already developed a popular mouthwash sold widely in Europe, a pocket-based breath test, and an anti-odor chewing gum.
High Glycemic (Like White Bread) Cause Heart Attacks
Doctors have known for decades that foods like white bread and corn flakes aren't good for cardiac health. In a landmark study, new research from Tel Aviv University now shows exactly how these high carb foods increase the risk for heart problems.
"Looking inside" the arteries of students eating a variety of foods, Dr. Michael Shechter of Tel Aviv University's Sackler School of Medicine and the Heart Institute of Sheba Medical Center — with collaboration of the Endocrinology Institute — visualized exactly what happens inside the body when the wrong foods for a healthy heart are eaten. He found that foods with a high glycemic index distended brachial arteries for several hours.
Elasticity of arteries anywhere in the body can be a measure of heart health. But when aggravated over time, a sudden expansion of the artery wall can cause a number of negative health effects, including reduced elasticity, which can cause heart disease or sudden death.
Using a clinical and research technique pioneered by his laboratory in Israel, Dr. Shechter was able to visualize what happens inside our arteries before, during and after eating high carb foods. It is a first in medical history. The results were published in the Journal of the American College of Cardiology.
"It's very hard to predict heart disease," says Dr. Shechter, a fellow of the American College of Cardiology and the American Heart Association. "But doctors know that high glycemic foods rapidly increase blood sugar. Those who binge on these foods have a greater chance of sudden death from heart attack. Our research connects the dots, showing the link between diet and what's happening in real time in the arteries."
Like the uncomfortable medical warnings on packets of cigarettes, this new research could lead to a whole new way to show patients the effects of a poor diet on our body.
Using 56 healthy volunteers, the researchers looked at four groups. One group ate a cornflake mush mixed with milk, a second a pure sugar mixture, the third bran flakes, while the last group was given a placebo (water). Over four weeks, Dr. Shechter applied his method of "brachial reactive testing" to each group. The test uses a cuff on the arm, like those used to measure blood pressure, which can visualize arterial function in real time.
The results were dramatic. Before any of the patients ate, arterial function was essentially the same. After eating, except for the placebo group, all had reduced functioning.
All roads lead to the endothelium
Enormous peaks indicating arterial stress were found in the high glycemic index groups: the cornflakes and sugar group. "We knew high glycemic foods were bad for the heart. Now we have a mechanism that shows how," says Dr. Shechter. "Foods like cornflakes, white bread, french fries, and sweetened soda all put undue stress on our arteries. We've explained for the first time how high glycemic carbs can affect the progression of heart disease." During the consumption of foods high in sugar, there appears to be a temporary and sudden dysfunction in the endothelial walls of the arteries.
Endothelial health can be traced back to almost every disorder and disease in the body. It is "the riskiest of the risk factors," says Dr. Shechter, who practices at the Chaim Sheba Medical Center — Tel Hashomer Hospital. There he offers a treatment that can show patients — in real time — if they have a high risk for heart attacks. "Medical tourists" from America regularly visit to take the heart test.
The take-away message? Dr. Shechter says to stick to foods like oatmeal, fruits and vegetables, legumes and nuts, which have a low glycemic index. Exercising every day for at least 30 minutes, he adds, is an extra heart-smart action to take.
Thursday, June 18, 2009
Omega-3 Supplements Protect Eyes
Omega-3 fatty acids found in fatty fish such as tuna and salmon may protect against progression of age-related macular degeneration (AMD), but the benefits appear to depend on the stage of disease and whether certain supplements are taken, report researchers at the Laboratory for Nutrition and Vision Research (LNVR), Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University.
The researchers calculated intakes of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) from dietary questionnaires administered to 2,924 men and women, aged 55 to 80 years, participating in an eight-year supplement trial, the Age-Related Eye Disease Study (AREDS) of the National Eye Institute (NEI). The AREDS trial results suggest taking supplements of antioxidants plus zinc prevents progression of late-stage AMD. AREDS study participants were randomly allocated to receive either a placebo or supplements containing the antioxidants vitamins C and E and beta carotene, the minerals zinc and copper, or a combination of both.
"In our study, we observed participants with early stages of AMD in the placebo group benefited from higher intake of DHA, but it appears that the high-dose supplements of the antioxidants and/or the minerals somehow interfered with the benefits of DHA against early AMD progression," says senior author Allen Taylor, PhD, director of the LNVR at the USDA HNRCA. Taylor is also a professor at the Friedman School of Nutrition Science and Policy at Tufts and Tufts University School of Medicine (TUSM).
The antioxidant supplements did not seem to interfere with the protective effects of DHA and EPA against progression to advanced stages of AMD. Participants who consumed higher amounts of DHA and EPA appeared to have lower risk of progression to both wet and dry forms of advanced AMD. The results are published on-line ahead of print in the British Journal of Ophthalmology.
"Data from the present study also shows the supplements and omega-3 fatty acids collaborate with low-dietary glycemic index (dGI) diets against progression to advanced AMD," says corresponding author Chung-Jung Chiu, DDS, PhD, a scientist in the LNVR and an assistant professor at TUSM. "Our previous research suggests a low-GI diet may prevent AMD from progressing to the advanced stage. We hypothesize that the rapid rise of blood glucose initiated by high-GI foods results in cellular damage that retinal cells cannot handle, thus damaging eye tissues."
dGI is a scale used to determine how quickly carbohydrates are broken down into blood sugar, also known as blood glucose. Foods such as sweetened drinks, sodas and white bread are high-GI because they trigger a sharp rise and fall of blood sugar. Low-GI foods, such as whole grain versions of pasta and bread, have a milder effect on blood sugar response. Earlier data published by Taylor and Chiu suggests that daily substitution of five slices of whole grain bread for white bread out of a total intake of 250 g of carbohydrate might cut out almost 8% of advanced AMD over five years. This is readily achievable with little diet behavior modification.
Eating two to three servings of fatty fish such as salmon, tuna, mackerel, shellfish, and herring every week would achieve the recommended daily intake of DHA and EPA. However, the majority of AREDS participants and Americans eat a much lower level than recommended. "If changing dietary habits is not easy, supplementation is an option," says Chiu.
The authors stress it is still premature to conclude dietary recommendations for people with AMD and more studies are warranted. "Taken together, these data indicate that consuming a diet with higher levels of omega-3 fatty acids, antioxidants and low-GI foods may delay compromised vision due to AMD," says Taylor. "The present study adds the possibility that the timing of a dietary intervention as well as the combination of nutrients recommended may be important."
AMD is a progressive disease that attacks central vision, resulting in a gradual loss of eyesight and, in some cases, blindness. The NEI reports that AMD is the most common causes of non-remediable vision loss in Americans over 60.
The researchers calculated intakes of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) from dietary questionnaires administered to 2,924 men and women, aged 55 to 80 years, participating in an eight-year supplement trial, the Age-Related Eye Disease Study (AREDS) of the National Eye Institute (NEI). The AREDS trial results suggest taking supplements of antioxidants plus zinc prevents progression of late-stage AMD. AREDS study participants were randomly allocated to receive either a placebo or supplements containing the antioxidants vitamins C and E and beta carotene, the minerals zinc and copper, or a combination of both.
"In our study, we observed participants with early stages of AMD in the placebo group benefited from higher intake of DHA, but it appears that the high-dose supplements of the antioxidants and/or the minerals somehow interfered with the benefits of DHA against early AMD progression," says senior author Allen Taylor, PhD, director of the LNVR at the USDA HNRCA. Taylor is also a professor at the Friedman School of Nutrition Science and Policy at Tufts and Tufts University School of Medicine (TUSM).
The antioxidant supplements did not seem to interfere with the protective effects of DHA and EPA against progression to advanced stages of AMD. Participants who consumed higher amounts of DHA and EPA appeared to have lower risk of progression to both wet and dry forms of advanced AMD. The results are published on-line ahead of print in the British Journal of Ophthalmology.
"Data from the present study also shows the supplements and omega-3 fatty acids collaborate with low-dietary glycemic index (dGI) diets against progression to advanced AMD," says corresponding author Chung-Jung Chiu, DDS, PhD, a scientist in the LNVR and an assistant professor at TUSM. "Our previous research suggests a low-GI diet may prevent AMD from progressing to the advanced stage. We hypothesize that the rapid rise of blood glucose initiated by high-GI foods results in cellular damage that retinal cells cannot handle, thus damaging eye tissues."
dGI is a scale used to determine how quickly carbohydrates are broken down into blood sugar, also known as blood glucose. Foods such as sweetened drinks, sodas and white bread are high-GI because they trigger a sharp rise and fall of blood sugar. Low-GI foods, such as whole grain versions of pasta and bread, have a milder effect on blood sugar response. Earlier data published by Taylor and Chiu suggests that daily substitution of five slices of whole grain bread for white bread out of a total intake of 250 g of carbohydrate might cut out almost 8% of advanced AMD over five years. This is readily achievable with little diet behavior modification.
Eating two to three servings of fatty fish such as salmon, tuna, mackerel, shellfish, and herring every week would achieve the recommended daily intake of DHA and EPA. However, the majority of AREDS participants and Americans eat a much lower level than recommended. "If changing dietary habits is not easy, supplementation is an option," says Chiu.
The authors stress it is still premature to conclude dietary recommendations for people with AMD and more studies are warranted. "Taken together, these data indicate that consuming a diet with higher levels of omega-3 fatty acids, antioxidants and low-GI foods may delay compromised vision due to AMD," says Taylor. "The present study adds the possibility that the timing of a dietary intervention as well as the combination of nutrients recommended may be important."
AMD is a progressive disease that attacks central vision, resulting in a gradual loss of eyesight and, in some cases, blindness. The NEI reports that AMD is the most common causes of non-remediable vision loss in Americans over 60.
Wednesday, June 17, 2009
Jon's Health Tips - Red Yeast Rice
I wrote a while ago about my secret desire to take a statin so I could eat lot more Egg McMuffins. One of my correspondents replied with a warning about muscle pain from statins, which I was not aware was as much of a problem as it appears to be.(Taking CoEnzyme Q-10 may relieve these pains) But an alternative has just appeared - and I am seriously thinking of trying it - although Egg McMuffins won't become a regular thing even so.
Red Yeast Rice Helps Reduce Cholesterol
Red yeast rice -- it's been a staple of some Asian countries for more than 1,000 years. As food coloring, it gives Peking Duck its signature red glow. And as herbal medicine, it lowers cholesterol levels.
"It works much the way a statin would work, by reducing the amount of cholesterol that the liver makes, but in a much gentler level," said Dr. Christopher Cannon a cardiologist at Boston's Brigham and Women's Hospital.
This latest study published in the Annals of Internal Medicine followed 62 patients who had tried taking prescription statins, such as Lipitor or Zocor, but complained it left them with severe muscle pains.
In the study, all of the patients received counseling on nutrition and exercise. Additionally, half of the participants also took 1,800 mg of red yeast rice supplements every day. After 12 weeks, those taking the supplements saw LDL, the "bad cholesterol," drop by a remarkable 27 percent. Those who did not take the red yeast rice supplements saw their LDL drop by only 6 percent.
Only two patents on the supplements reported those persistent muscle pains.
"I was pleasantly surprised with the degree of LDL lowering," said Dr. Daniel Rader a lipid specialist at the University of Pennsylvania School of Medicine and an author of the study. "I have to confess, I did not expect this degree of LDL lowering. And there were many fewer side effects than expected."
Research published last year in the American Journal of Cardiology showed that heart attack patients in China who took a red yeast rice supplement daily were 45 percent less likely to have another attack within five years.
The problem with this approach, however, is that unlike statin drugs, red yeast rice is not regulated. So whether it's purchased as dried grains, ground powder or a pill from a health food store, it's difficult to be certain exactly how much of the active ingredient you're consuming or whether it's been contaminated in any way.
About red yeast rice
Red yeast rice comes from yeast (Monascus purpureus) that is grown on rice. This bright reddish purple fermented rice, which acquires its colour from being cultivated with the mold Monascus purpureus, is served as a dietary staple in some Asian countries.
There has been some question about red yeast rice supplements:
In 2007 the FDA warned physicians and consumers to steer clear of several cholesterol-lowering supplements that contain what the FDA terms "unauthorized" lovastatin.
FDA testing revealed that several brands of nonprescription "red yeast rice extract" supplements, marketed as Red Yeast Rice, Red Yeast Rice/Policosonal Complex, and Cholestrix, contained lovastatin, a regulated prescription drug. In a MedWatch safety alert, the FDA tells consumers to "avoid using" the products because they "may contain an unauthorized drug that could be harmful to their health." Not mentioned in the FDA alert is the fact that lovastatin, marketed as Mevacor, first isolated from a fungus, also occurs naturally in certain forms of red yeast rice that are made when rice is cultivated with the mold Monascus purpureus.
In the products that the FDA targeted, lovastatin is not named in the list of product ingredients. The products are manufactured by Nature's Value Inc, Kabco Inc, and Sunburst Biorganics, respectively, and sold over the internet by the manufacturers, or in the case of Red Yeast Rice, by Swanson Healthcare Products.
The FDA's Medwatch alert notes that lovastatin can cause severe muscle problems leading to kidney impairment. "The risk is greater in patients who take higher doses of lovastatin or who take lovastatin and other medicines that increase the risk of muscle adverse reactions such as nefazodone (an antidepressant), certain antibiotics, drugs used to treat fungal infections and HIV infections, and other cholesterol-lowering agents," an FDA press release states. "Consumers who use any red yeast rice products should consult their healthcare provider if they experience any problems that may be due to these products."
Here' another study:
Chinese Red Yeast Rice May Prevent Heart Attack
(published by the US Gov't)
People who have had a heart attack may be able to reduce the risk of another attack by 45 percent by taking a purified extract of Chinese red yeast rice, a new study suggests.
What's more, the need for bypass surgery or angioplasty was reduced by one third, and death from cancer was reduced by two-thirds among those taking the extract, called Xuezhikang (XZK).
"A purified form of Chinese red yeast rice significantly reduced the risk of having another heart attack," said lead researcher Dr. David M. Capuzzi, director of the Cardiovascular Disease Prevention Program at the Myrna Brind Center of Integrative Medicine at Thomas Jefferson University in Philadelphia.
Although the results of the study are encouraging, people shouldn't run out and start taking Chinese red yeast rice to prevent heart attacks, Capuzzi said. He noted that the Chinese red yeast rice in health-food stores isn't pure. "This particular preparation [used in the study] was made by a biotech company. So the purity of the components was assured," he said.
In the study, almost 5,000 people in China who'd had a heart attack were randomly selected to receive capsules containing XZK or a placebo. The XZK capsules contained a combination of lovastatin, lovastatin hydroxyl acid, ergosterol, and other components, the report said.
During five years of follow-up, the researchers found that 10.4 percent of those receiving a placebo had a second heart attack, compared with 5.7 percent of those receiving XZK.
Also, those treated with XZK were 30 percent less likely to die from a cardiovascular problem and 33 percent less likely to die from any cause. And the need heart surgery or angioplasty was reduced by one third, the researchers reported.
The findings are published in the June 15 issue of the American Journal of Cardiology.
Capuzzi said a drug that includes Chinese red yeast rice may soon be used much the same way as cholesterol-lowering drugs to prevent heart attacks.
One heart expert thinks this study shows that Chinese red yeast rice may be another way to lower cholesterol, thereby preventing heart attack.
"Numerous clinical trials have established that statin medications in conjunction with lifestyle modification reduce the risk of recurrent cardiovascular events and prolong life in patients with prior myocardial infarction [heart attack] and elevated, average, or below average cholesterol levels," said Dr. Gregg C. Fonarow, director of the Ahmanson-UCLA Cardiomyopathy Center at the University of California, Los Angeles.
This new study may extend these prior findings to the statin medication lovastatin, which is derived from Chinese red yeast, Fonarow said.
"However, it is very important to note, as the authors do in the paper, that the various components of the specific XZK preparation used in this trial have not been adequately studied for its consistency, stability, and individual pharmacologic properties. As such, further study is required," Fonarow said.
Another expert thinks that red yeast rice might confer an extra measure of protection against heart attack.
The extract of red yeast rice contains lovastatin, a drug that has been proven to improve cholesterol profiles and decrease risk of heart attack, said Dr. Byron Lee, an associate professor of cardiology at the University of California, San Francisco.
"However, the improvement in the patients on the extract is far beyond what you would expect with lovastatin alone, so maybe there is some other natural component in the extract that is conferring the extra benefit," Lee said. "That would be quite exciting."
Chinese red yeast rice is rice that has been fermented by red yeast. This rice has been used in China for many centuries as a food preservative, food coloring, spice, and in rice wine. Red yeast rice remains a staple in China, Japan and in Asian communities in the United States.
Red yeast rice also has been used as a medicine for more than 1,000 years. It has been used to improve blood circulation and treat indigestion and diarrhea, the study authors said.
More U.S. Gov't Info:
Red yeast rice is the product of yeast ( Monascus purpureus ) grown on rice, and is served as a dietary staple in some Asian countries. It contains several compounds collectively known as monacolins, substances known to inhibit cholesterol synthesis. One of these, "monacolin K," is a potent inhibitor of HMG-CoA reductase, and is also known as mevinolin or lovastatin (Mevacor®, a drug produced by Merck & Co., Inc).
Red yeast rice extract has been sold as a natural cholesterol-lowering agent in over the counter supplements, such as CholestinTM (Pharmanex, Inc). However, there has been legal and industrial dispute as to whether red yeast rice is a drug or a dietary supplement, involving the manufacturer, the U.S. Food and Drug Administration (FDA), and the pharmaceutical industry (particularly producers of HMG-CoA reductase inhibitor prescription drugs or "statins").
The use of red yeast rice in China was first documented in the Tang Dynasty in 800 A.D. A detailed description of its manufacture is found in the ancient Chinese pharmacopoeia, Ben Cao Gang Mu-Dan Shi Bu Yi, published during the Ming Dynasty (1368-1644). In this text, red yeast rice is proposed to be a mild aid for gastric problems (indigestion, diarrhea), blood circulation, and spleen and stomach health. Red yeast rice in a dried, powdered form is called Zhi Tai. When extracted with alcohol it is called Xue Zhi Kang.
Uses based on scientific evidence:
High cholesterol
Since the 1970s, human studies have reported that red yeast lowers blood levels of total cholesterol, low-density lipoprotein/LDL ("bad cholesterol"), and triglyceride levels. Other products containing red yeast rice extract can still be purchased, mostly over the Internet. However, these products may not be standardized and effects are not predictable. For lowering cholesterol, there is better evidence for using prescription drugs such as lovastatin. Grade A
Coronary heart disease
Preliminary evidence shows that taking Monascus purpureus by mouth may result in cardiovascular benefits and improve blood flow. Additional study is needed before a firm recommendation can be made. Grade C
Diabetes
Early human evidence suggests the potential for benefits in diabetics. Additional study is needed before a firm recommendation can be made. Grade C
*Key to grades
A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use;
F: Strong scientific evidence against this use.
Grading rationale
Uses based on tradition or theory
The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Acetaminophen toxicity, anthrax, anti-inflammatory, antimicrobial, antioxidant, blood circulation problems, bruised muscles, bruises, cancer, colic in children, cuts, diarrhea, digestion, dysentery (bloody diarrhea), exercise performance enhancement, food additive (coloring), food preservative, hangover, high blood pressure, HIV (associated hyperlipidemia), immunosuppression, indigestion, liver disorders, metabolic disorders, obesity, ovarian cancer, postpartum problems, spleen problems, stomach problems, weight loss, wounds.
The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.
Adults (18 years and older)
1,200 milligrams of concentrated red yeast powder capsules have been taken two times per day by mouth with food.
The average consumption of naturally occurring red yeast rice in Asia has been reported as 14-55 grams per day.
Children (younger than 18 years)
There is not enough scientific evidence to recommend red yeast for children.
The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.
Allergies
There is one report of anaphylaxis (a severe allergic reaction) in a butcher who touched meat containing red yeast.
Side Effects and Warnings
There is limited evidence on the side effects of red yeast. Mild headache and abdominal discomfort can occur. Side effects may be similar to those for the prescription drug lovastatin (Mevacor®). Heartburn, gas, bloating, muscle pain or damage, dizziness, asthma, and kidney problems are possible. People with liver disease should not use red yeast products.
In theory, red yeast may increase the risk of bleeding. Caution is advised in patients with bleeding disorders or taking drugs that may increase the risk of bleeding. Dosing adjustments may be necessary. A metabolite of Monascus called mycotoxin citrinin may be harmful.
Pregnancy and Breastfeeding
Prescription drugs with similar chemicals as red yeast cannot be used during pregnancy. Therefore, it is recommended that pregnant or breastfeeding women not take red yeast.
Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.
Interactions with Drugs
There are not many studies of the interactions of red yeast rice extract with drugs. However, because red yeast rice extract contains the same chemicals as the prescription drug lovastatin, the interactions may be the same. Fibrate drugs or other cholesterol-lowering medications may cause additive effects or side effects when taken with red yeast. Alcohol and other drugs that may be toxic to the liver should be avoided with red yeast rice extract. Taking cyclosporine, ranitidine (Zantac®), and certain antibiotics with red yeast rice extract may increase the risk of muscle breakdown or kidney damage.
Certain drugs may interfere with the way the body processes red yeast using the liver's "cytochrome P450" enzyme system. Inhibitors of cytochrome P450 may increase the chance of muscle and kidney damage if taken with red yeast.
In theory, red yeast may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants ("blood thinners") such as warfarin (Coumadin®) or heparin, anti-platelet drugs such as clopidogrel (Plavix®), and non-steroidal anti-inflammatory drugs such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®).
Red yeast may produce gamma-aminobutyric acid (GABA) and therefore can have additive effects when taken with drugs that affect GABA such as neurontin (Gabapentin®).
Red yeast may also interact with digoxin, niacin, thyroid medications, and blood pressure-lowering medications. Caution is advised.
Red yeast may alter blood sugar levels; patients with diabetes or taking insulin or blood sugar-lowering medications by mouth should consult with a qualified healthcare professional, including a pharmacist. Dosing adjustments may be necessary.
Interactions with Herbs and Dietary Supplements
Red yeast may interact with products that cause liver damage or are broken down in the liver. Grapefruit juice may increase blood levels of red yeast. Milk thistle, St. John's wort, niacin, and vitamin A may interact with red yeast rice extract. Coenzyme Q10 levels may be lowered by red yeast rice extract. Cholesterol-lowering herbs and supplements such as guggul or fish oils may have increased effects when taken with red rice yeast. Although not well studied, red yeast may also interact with astaxanthin and zinc. Caution is advised.
Certain herbs and supplements may interfere with the way the body processes red yeast using the liver's "cytochrome P450" enzyme system. Inhibitors of cytochrome P450 may increase the chance of muscle and kidney damage if taken with red yeast.
In theory, red yeast may increase the risk of bleeding when taken with herbs and supplements that are believed to increase the risk of bleeding. Multiple cases of bleeding have been reported with the use of Ginkgo biloba , and fewer cases with garlic and saw palmetto. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases.
Red yeast may also interact with digitalis (foxglove), or herbs and supplements that affect the thyroid or blood pressure. It may also have anti-inflammatory effects and should be used cautiously with other herbs or supplements that may have anti-inflammatory effects.
Red yeast may alter blood sugar levels in the blood, and patients with diabetes or taking herbs and supplement to control blood sugar should use with caution.
Monday, June 15, 2009
Young adults not drinking enough milk
Consumption of dairy products decreases as teens reach their 20s
Calcium and dairy products play major roles in health maintenance and the prevention of chronic disease. Because peak bone mass is not achieved until the third decade of life, it is particularly important for young adults to consume adequate amounts of calcium, protein and vitamin D found in dairy products to support health and prevent osteoporosis later in life. In a study in the July/August issue of the Journal of Nutrition Education and Behavior, researchers report that young people actually reduce their intake of calcium and dairy products as they enter their twenties.
Drawing data from Project EAT (Eating Among Teens), a prospective, population-based study designed to examine determinants of dietary intake and weight status, the responses of over 1,500 young adults (45% male) were analyzed by investigators from the University of Minnesota, Minneapolis. The mean age of participants was 15.9 years at baseline and 20.5 years at follow-up.
During the transition from middle adolescence (high school) to young adulthood (post-high school), females and males respectively reduced their daily calcium intakes by an average of 153 mg and 194 mg. Although 38% of females and 39% of males increased their intake of calcium over 5 years, the majority of the sample reduced their intake of calcium over 5 years. During middle adolescence, more than 72% of females and 55% of males had calcium intakes lower than the recommended level of 1,300 mg/day. Similarly, during young adulthood, 68% of females and 53% of males had calcium intakes lower than the recommended level of 1,000 mg/day.
The researchers found that reports of mealtime milk availability, positive health/nutrition attitudes, taste preference for milk, healthful weight control behaviors and peer support for healthful eating when the participants were teenagers were associated with higher calcium intake in young adulthood. Time spent watching television and lactose intolerance during middle adolescence were associated with lower calcium intake in young adulthood.
Writing in the article, Dr. Nicole I. Larson, Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, and colleagues state, "The findings of this study indicate that future interventions designed to promote improvements in calcium intake should encourage the families of adolescents to serve milk at meals. In addition, interventions targeted to female adolescents should build concern for healthful eating, develop confidence in skills for healthful eating and reduce exposure to television advertisements. Interventions targeted to male adolescents should emphasize opportunities to taste calcium-rich food, the promotion of healthful weight management behaviors and supporting peers to engage in healthful eating behaviors."
Thursday, June 11, 2009
Jon's Health Tips - Red Wine Update
A red-wine polyphenol called resveratrol demonstrates significant health benefits
• Resveratrol shows therapeutic potential for cancer chemoprevention as well as cardioprotection.
•
• Resveratrol may aid in the prevention of age-related disorders, such as neurodegenerative diseases, inflammation, diabetes, and cardiovascular disease.
•
The benefits of alcohol are all about moderation. Low to moderate drinking – especially of red wine – appears to reduce all causes of mortality, while too much drinking causes multiple organ damage. A mini-review of recent findings on red wine's polyphenols, particularly one called resveratrol, will be published in the September issue of Alcoholism: Clinical & Experimental Research.
"Reports on the benefits of red wine are almost two centuries old," said Lindsay Brown, associate professor in the School of Biomedical Sciences at The University of Queensland and corresponding author for the study. "The media developed the more recent story of the French paradox in the early 1990s. However, studies on the actions of resveratrol, one of the active non-alcoholic ingredients, were uncommon until research around 1997 showed prevention of cancers. This led to a dramatic interest in this compound."
Red wine contains a complex mixture of bioactive compounds, including flavonols, monomeric and polymeric flavan-3-ols, highly colored anthocyanins, as well as phenolic acids and the stilbene polyphenol, resveratrol. Brown said that some of these compounds, particularly resveratrol, appear to have health benefits.
"The breadth of benefits is remarkable – cancer prevention, protection of the heart and brain from damage, reducing age-related diseases such as inflammation, reversing diabetes and obesity, and many more," said Brown. "It has long been a question as to how such a simple compound could have these effects but now the puzzle is becoming clearer with the discovery of the pathways, especially the sirtuins, a family of enzymes that regulate the production of cellular components by the nucleus. 'Is resveratrol the only compound with these properties?' This would seem unlikely, with similar effects reported for other components of wine and for other natural products such as curcumin. However, we know much more about resveratrol relative to these other compounds."
Stephen Taylor, professor of pharmacology at the University of Queensland, agreed that resveratrol is the "compound du jour."
"I think that red wine has both some mystique and some historical symbolism in the west," said Taylor, "and of course, some various pleasures attached to its ingestion, all of which give it a psychological advantage edge, food-wise. Not many of us can or will eat a couple of cups of blueberries a day for years on end, but if we could do a population study for a decade or so on such a group, you might actually see similar results."
Key points of the review include:
• Resveratrol exhibits therapeutic potential for cancer chemoprevention as well as cardioprotection.
•
"It sounds contradictory that a single compound can benefit the heart by preventing damage to cells, yet prevent cancer by causing cell death, said Brown. "The most likely explanation for this, still to be rigorously proved in many organs, is that low concentrations activate survival mechanisms of cells while high concentrations turn on the in-built death signals in these cells."
• Resveratrol may aid in the prevention of age-related disorders, such as neurodegenerative diseases, inflammation, diabetes, and cardiovascular disease.
•
"The simplest explanation is that resveratrol turns on the cell's own survival pathways, preventing damage to individual cells," said Brown. "Further mechanisms help, including removing very reactive oxidants in the body and improving blood supply to cells."
• Low doses of resveratrol improve cell survival as a mechanism of cardio- and neuro-protection, while high doses increase cell death
•
"The key difference is probably the result of activation of the sirtuins in the nucleus," said Brown. "Low activation reverses age-associated changes, while high activation increases the process of apoptosis or programmed cell death to remove cellular debris. Similar changes are seen with low-dose versus high-dose resveratrol: low-dose resveratrol produces cellular protection and reduces damage, while high-dose resveratrol prevents cancers."
In summary, noted Brown, current scientific research is starting to explain reports from the last 200 years that drinking red wine improves health. "It is a cliché that 'nature is a treasure trove of compounds,' but studies with resveratrol show that this is correct! We need to understand better the vast array of compounds that exist in nature, and determine their potential benefits to health."
"There is one particular point that deserves fleshing out," added Taylor. "Resveratrol is largely inactivated by the gut or liver before it reaches the blood stream, where it exerts its effects – whatever they may be – good, bad, or indifferent. Thus, most of the reseveratrol in imbibed red wine does not reach the circulation. Interestingly, absorption via the mucous membanes in the mouth can result in up to around 100 times the blood levels, if done slowly rather than simply gulping it down. Of course, we don't know if these things matter yet, but issues like this are real and generally ignored by all."
• Resveratrol shows therapeutic potential for cancer chemoprevention as well as cardioprotection.
•
• Resveratrol may aid in the prevention of age-related disorders, such as neurodegenerative diseases, inflammation, diabetes, and cardiovascular disease.
•
The benefits of alcohol are all about moderation. Low to moderate drinking – especially of red wine – appears to reduce all causes of mortality, while too much drinking causes multiple organ damage. A mini-review of recent findings on red wine's polyphenols, particularly one called resveratrol, will be published in the September issue of Alcoholism: Clinical & Experimental Research.
"Reports on the benefits of red wine are almost two centuries old," said Lindsay Brown, associate professor in the School of Biomedical Sciences at The University of Queensland and corresponding author for the study. "The media developed the more recent story of the French paradox in the early 1990s. However, studies on the actions of resveratrol, one of the active non-alcoholic ingredients, were uncommon until research around 1997 showed prevention of cancers. This led to a dramatic interest in this compound."
Red wine contains a complex mixture of bioactive compounds, including flavonols, monomeric and polymeric flavan-3-ols, highly colored anthocyanins, as well as phenolic acids and the stilbene polyphenol, resveratrol. Brown said that some of these compounds, particularly resveratrol, appear to have health benefits.
"The breadth of benefits is remarkable – cancer prevention, protection of the heart and brain from damage, reducing age-related diseases such as inflammation, reversing diabetes and obesity, and many more," said Brown. "It has long been a question as to how such a simple compound could have these effects but now the puzzle is becoming clearer with the discovery of the pathways, especially the sirtuins, a family of enzymes that regulate the production of cellular components by the nucleus. 'Is resveratrol the only compound with these properties?' This would seem unlikely, with similar effects reported for other components of wine and for other natural products such as curcumin. However, we know much more about resveratrol relative to these other compounds."
Stephen Taylor, professor of pharmacology at the University of Queensland, agreed that resveratrol is the "compound du jour."
"I think that red wine has both some mystique and some historical symbolism in the west," said Taylor, "and of course, some various pleasures attached to its ingestion, all of which give it a psychological advantage edge, food-wise. Not many of us can or will eat a couple of cups of blueberries a day for years on end, but if we could do a population study for a decade or so on such a group, you might actually see similar results."
Key points of the review include:
• Resveratrol exhibits therapeutic potential for cancer chemoprevention as well as cardioprotection.
•
"It sounds contradictory that a single compound can benefit the heart by preventing damage to cells, yet prevent cancer by causing cell death, said Brown. "The most likely explanation for this, still to be rigorously proved in many organs, is that low concentrations activate survival mechanisms of cells while high concentrations turn on the in-built death signals in these cells."
• Resveratrol may aid in the prevention of age-related disorders, such as neurodegenerative diseases, inflammation, diabetes, and cardiovascular disease.
•
"The simplest explanation is that resveratrol turns on the cell's own survival pathways, preventing damage to individual cells," said Brown. "Further mechanisms help, including removing very reactive oxidants in the body and improving blood supply to cells."
• Low doses of resveratrol improve cell survival as a mechanism of cardio- and neuro-protection, while high doses increase cell death
•
"The key difference is probably the result of activation of the sirtuins in the nucleus," said Brown. "Low activation reverses age-associated changes, while high activation increases the process of apoptosis or programmed cell death to remove cellular debris. Similar changes are seen with low-dose versus high-dose resveratrol: low-dose resveratrol produces cellular protection and reduces damage, while high-dose resveratrol prevents cancers."
In summary, noted Brown, current scientific research is starting to explain reports from the last 200 years that drinking red wine improves health. "It is a cliché that 'nature is a treasure trove of compounds,' but studies with resveratrol show that this is correct! We need to understand better the vast array of compounds that exist in nature, and determine their potential benefits to health."
"There is one particular point that deserves fleshing out," added Taylor. "Resveratrol is largely inactivated by the gut or liver before it reaches the blood stream, where it exerts its effects – whatever they may be – good, bad, or indifferent. Thus, most of the reseveratrol in imbibed red wine does not reach the circulation. Interestingly, absorption via the mucous membanes in the mouth can result in up to around 100 times the blood levels, if done slowly rather than simply gulping it down. Of course, we don't know if these things matter yet, but issues like this are real and generally ignored by all."
Friday, June 5, 2009
Apples
An Apple Peel a Day Could Keep Cancer at Bay
An apple peel a day might help keep cancer at bay, according to Rui Hai Liu, Cornell associate professor of food science, who has identified a dozen compounds -- triterpenoids -- in apple peel that either inhibit or kill cancer cells in laboratory cultures. Three of the compounds have not previously been described in the literature.
"We found that several compounds have potent anti-proliferative activities against human liver, colon and breast cancer cells and may be partially responsible for the anti-cancer activities of whole apples," says Liu, who is affiliated with Cornell's Institute of Comparative and Environmental Toxicology and is senior author of the study, which is online and published in the Journal of Agricultural and Food Chemistry.
In previous Cornell studies, apples had been found not only to fight cancer cells in the laboratory but also to reduce the number and size of mammary tumors in rats. The Cornell researchers now think that the triterpenoids may be doing much of the anti-cancer work.
"Some compounds were more potent and acted differently against the various cancer cell lines, but they all show very potent anti-cancer activities and should be studied further," says Liu.
With co-author Xiangjiu He, a Cornell postdoctoral researcher, Liu analyzed the peel from 230 pounds of red delicious apples from the Cornell Orchard and isolated their individual compounds. After identifying the structures of the promising compounds in the peel, the researchers tested the pure compounds against cancer cell growth in the laboratory. In the past, Liu has also identified compounds called phytochemicals -- mainly flavonoids and phenolic acids -- in apples and other foods that appear to be have anti-cancer properties as well, including inhibiting tumor growth in human breast cancer cells.
"We believe that a recommendation that consumers to eat five to 12 servings of a wide variety of fruits and vegetables daily is appropriate to reduce the risks of chronic diseases, including cancer, and to meet nutrient requirements for optimum health," said Liu.
The study online: http://pubs.acs.org/cgi-bin/abstract.cgi/jafcau/2007/55/i11/abs/jf063563o.html
Adults who eat apples, drink apple juice have lower risk for metabolic syndrome
Apple product consumers likely to have lower blood pressure, trimmer waistlines, and more nutrient dense diets
Not eating your apple a day" Perhaps you should be. Adults who eat apples, apple juice and applesauce have a significantly reduced risk of metabolic syndrome, a cluster of health problems that are linked to numerous chronic diseases such as diabetes and cardiovascular disease.
The study results, presented at the Experimental Biology 2008 meeting this week, were derived from an analysis of adult food consumption data collected in the 1999-2004 National Health and Nutrition Examination Survey (NHANES), the government’s largest food consumption and health database.
Dr. Victor Fulgoni analyzed the data, specifically looking at the association between consumption of apples and apple products, nutrient intake and various physiological parameters related to metabolic syndrome. When compared to non-consumers, adult apple product consumers had a 27% decreased likelihood of being diagnosed with metabolic syndrome.
Fulgoni notes, “We found that adults who eat apples and apple products have smaller waistlines that indicate less abdominal fat, lower blood pressure and a reduced risk for developing what is known as the metabolic syndrome.”
In addition to having a 30% decreased likelihood for elevated diastolic blood pressure and a 36% decreased likelihood for elevated systolic blood pressure, apple product consumers also had a 21% reduced risk of increased waist circumference – all predictors of cardiovascular disease and an increased likelihood of metabolic syndrome. Additionally, adult apple product consumers had significantly reduced C-reactive protein levels, another measurable marker related to cardiovascular risk.
Furthermore, apple product consumers’ diets were healthier than non-consumers – they had an overall greater intake of fruit and key nutrients, including dietary fiber, vitamins A and C, calcium and potassium. These consumers also ate less total fat, saturated fat, discretionary fat and added sugars.
Apple pectin, apple juice extracts shown to have anticarcinogenic effects on colon
The apples and apple juice you consume may have positive effects in one of the most unlikely places in the body – in the colon. New research has demonstrated that both apple pectin and polyphenol-rich apple juice components actually enhance biological mechanisms that produce anticarcinogenic compounds during the fermentation process.
Using human fecal matter as the test substance, German researchers Dr. Dieter Schrenk, M.D. and his colleagues hypothesized that the compound butyrate could be increased in the presence of apple pectin and apple juice extracts.
Butyrate has been suggested to be a chemopreventative metabolite that might prevent the occurrence of colorectal cancer, which is very common in Western industrialized countries. It is a short chain fatty acid which is seen as a major factor contributing to healthy colon mucosa. The research notes, “Butyrate not only serves as a major nutrient for the colon epithelia but is also thought to play an important role in the protective effect of natural fiber against colorectal cancer.”
So how do apple pectin and apple juice extracts play a role in increasing amounts of butyrate? The laboratory tests performed by Schrenk found that by the increased production of butyrate via the addition of apple components, histone deacetlyases (HDAC) were inhibited. With slowed production of HDAC, there would be significantly less growth of precancerous and tumor cells.
The research, published in the April 2008 issue of Nutrition, notes, “apples are a major source of natural fiber and of low molecular weight plan polyphenols in the Western diet.” The researchers conclude, “Pectin-rich apple products can thus be expected to exert anticarginogenic effects in the colon.”
Apple consumers reap heart-health benefits
Apple consumers reap heart-health benefits thanks to flavonoid content, says new research
American Heart Association new recommendations support increased fruit, vegetable consumption
Apples may prove to be a winner when it comes to reducing the risk of heart disease, says a new study of more than 34,000 women. In this study, flavonoid-rich apples were found to be one of three foods (along with red wine and pears) that decrease the risk of mortality for both coronary heart disease (CHD) and cardiovascular disease (CVD) among post-menopausal women, The findings were published in the March 2007 American Journal of Clinical Nutrition.
Women of all ages are encouraged to consume more fruit and vegetables, including apples and apple products, for heart health. However, this study focused on postmenopausal woman, a group becoming more aware of the risk for heart disease. Using a government database that assesses the flavonoid-compound content of foods, the researchers hypothesized that flavonoid intake (in general and from specific foods), might be inversely associated with mortality from CVD and CHD among the women in the study groupSubjects selected for this research analysis were postmenopausal and part of the ongoing Iowa Women's Health Study, each of which has been monitored for dietary intake and various health outcomes for nearly 20 years.
As a result of the extensive analysis that considered what the women ate, the types of cardiovascular-related diseases they experienced, and the overall flavonoid content of an extensive list of foods, the researchers concluded that consumption of apples, pears and red wine were linked with the lowest risk for mortality related to both CHD and CVD (not just one or the other).
"Flavonoids are compounds found in small quantities in numerous plant foods, including fruits and vegetables, tea, wine, nuts and seeds, and herbs and spices," say the university researchers from the University of Minnesota and the University of Oslo (Norway) Earlier research has indicated that flavonoids also have antioxidant properties that are linked to the reduction of oxidation of the bad (LDL - low density lipoprotein) cholesterol which have been linked in various ways with the development of CVD. According to the government database cited in this paper, apples contain a wide variety of flavonoid compounds.
The researchers also believe this is the first prospective study of postmenopausal women to report on the intake and impact of total and specific flavonoid subclasses. They conclude, "Dietary intakes of flavanones, anthocyanins, and certain foods rich in flavonoids were associated with reduced risk of death due to CHD, CVD and all causes."_
The publication of this positive study for apples comes on the heels of updated heart disease prevention guidelines for women just released by the American Heart Association in the February 20 issue of Circulation. As part of their guidelines, AHA emphasizes that women increase their intake of fruits and vegetables to help prevent heart disease over their lifetime, not just to reduce short-term risk. Worldwide, cardiovascular disease is the largest single cause of mortality among women, accounting for one third of all deaths.
Can an apple a day keep asthma away?
Poor diets show increased respiratory symptoms in teens
Teenagers who forego a healthy and balanced diet may have a harder time catching their breath. A new study, published in the July issue of CHEST, the peer-reviewed journal of the American College of Chest Physicians (ACCP), shows that a low dietary intake of certain nutrients increases the likelihood of respiratory symptoms such as asthma, especially in teens who smoke. Furthermore, a lack of these nutrients may also lead to lower lung function.
“Our study, as well as other research, suggests that higher intakes of antioxidant and anti-inflammatory micronutrients are associated with lower reports of cough, respiratory infections, and less severe asthma-related symptoms,” said lead study author Jane Burns, ScD, Harvard School of Public Health. “Teenagers who have low dietary intakes of fruit, vitamin E, and omega-3 fatty acids are at greater risk of having asthma, emphasizing the importance of a balanced diet, composed of whole foods.”
While observing 12th-grade students from 12 communities around the US and Canada, Dr. Burns and her colleagues from the Harvard School of Public Health, Health Canada, Brigham and Women’s Hospital, and the Environmental Protection Agency (EPA), examined the associations of low dietary nutrient intake with low pulmonary function and respiratory symptoms. Over the period of one school year, 2,112 students completed a standardized respiratory questionnaire and a dietary questionnaire. They also answered questions about medication use, smoking habits, and recent exercise, before participating in lung function testing. Dr. Burns explained that the researchers focused on teens because it is the ideal age at which to test lung capacity and eating habits.
“During late adolescence, physical stature has, on average, been attained and lung growth closely parallels this growth. Therefore we were observing a time when lung function was close to its optimal capacity,” she said. “Also, although our diet survey targeted eating habits only during the past year, it did give us some idea of the teens’ general past diet. However, their current respiratory health may be a reflection of diet during childhood, as well as during the past year.”
The majority of adolescents in the study were white, one third was overweight, and 72% did not consume multivitamins. Also, nearly 25% reported smoking on a daily basis. Researchers also found that at least one third of the students’ diets were below the recommended levels of fruit, vegetable, vitamins A and E, beta-carotene, and omega-3 fatty acid intake.
“Vitamin supplements can help teens meet their daily recommended levels,” said Dr. Burns, “and surprisingly, even relatively low levels of omega-3 fatty acids appeared to protect teens from higher reported respiratory symptoms.”
Results showed that low dietary intakes of fruit, vitamins C and E, and omega-3 fatty acids were associated with decreased lung function and a greater risk of chronic bronchitic symptoms, wheeze, and asthma. These risks were further increased among students with the lowest intakes and who also smoked.
“I wish we could say that an apple a day can keep asthma away, but it’s a complex disease with a genetic component. However, it may be that certain foods can lessen or prevent asthma symptoms,” said Dr. Burns. “The most important thing to remember is that diet can have a significant impact on teens’ respiratory health. I would encourage them to make healthy eating a part of their daily routine, and stress to them that smoking is bad.” Researchers emphasized that fresh fruits make for convenient snacks. They also suggest preparing a simple, daily family meal, as a method to promote both communication and good nutrition.
“A balanced diet is not only good for lung health, but for general health,” said Mark J. Rosen, MD, FCCP, President of the American College of Chest Physicians. “Parents and physicians should work together to monitor and maintain healthy diets and lifestyles for children of all ages.”
Apples, apple juice shown to prevent early atherosclerosis
A new study shows that apples and apple juice are playing the same health league as the often-touted purple grapes and grape juice. The study was published in the April 2008 issue of Molecular Nutrition and Food Research.
Researcher Kelly Decorde from the Universite Montpelier in France was part of the European research team that found apples have similar cardiovascular protective properties to grapes. The researchers also observed that processing the fruit into juice has the potential to increase the bioavailability of the naturally-occurring compounds and antioxidants found in the whole fruit.
Using a variety of established analytical techniques, aortic plaque was evaluated to determine the effectiveness in decreasing plaque that is associated with atherosclerosis.
According to the research, “This study demonstrates that processing apples and purple grapes into juice modifies the protective effect of their phenolics against diet induced oxidative stress and early atherosclerosis in hypercholesterolemic hamsters.”
Researchers also noted, “These results show for the first time that long-term consumption of antioxidants supplied by apples and purple grapes, especially phenolic compounds, prevents the development of atherosclerosis in hamsters, and that the processing can have a major impact on the potential health effects of a product.”
In summary, the researchers stated that their work would help provide encouragement that fruit and fruit juices may have significant clinical and public health relevance.
Apples, Apple Juice Lower Wheezing and Asthma Risk in Children
Published in the September 2007 issue of Thorax, the latest study finds that when women ate apples during pregnancy, researchers found a significant decrease in asthma and wheezing among their children when the children were followed over five years and reached five years of age.
This unique longitudinal study tracked dietary intake by 1253 mother-child pairs. According to the researchers that conducted medical evaluations for asthma and related symptoms (i.e., wheezing) in the children, they found no other association with decreased risk other than for apple consumption. The only other positive association found between prenatal food intake and risk reduction in the children was with fish intake by the mothers, for which the researchers found that children of mothers who ate fish had a lowered incidence of doctor-confirmed eczema.
A similar but different study published June 2007 also showed a link between apple juice consumption and a reduction in wheezing among children. That study was published in June’s European Respiratory Journal.
Among children who experienced what was characterized as “current wheeze” (where the child had wheezing or whistling in the chest in the last 12 months), there was a significant, dose response association between consumption of apple juice and a reduced incidence of the wheezing. The researchers found that drinking apple juice made from concentrate and consumption of bananas one or more times a day (compared to drinking apple juice or eating bananas less than once a month) was directly associated with improvement of wheezing occurences.
According to the authors of the Thorax paper, the protective effect from apples is attributable to their powerful phytochemical content, which includes flavonoids, isoflavonoids, and phenolic acids. Apples and apple products combined are the largest source of free phenolics in people’s diet in the US and in Europe.
The American Lung Association states that asthma remains a major public health concern. In 2003, approximately 20 million Americans had asthma and the condition accounted for an estimated 12.8 million lost school days in children. Asthma ranks within the top ten prevalent conditions causing limitation of activity and costs our nation $16.1 billion in health care costs annually.
Apple's benefits reach into the womb to fight asthma
Eating apples while pregnant may give new meaning to an apple a day keeping the doctor away. Compelling new research has concluded that mothers who eat apples during pregnancy may protect their children from developing asthma later in life. The study was published in Thorax online.
This unique longitudinal study tracked dietary intake by nearly 2000 pregnant women, then examined the effects of the maternal diet on airway development in more than 1200 of their children five years later. Among a wide variety of foods consumed and recorded by the pregnant women, the researchers concluded that the children of mothers who ate apples had a significantly reduced risk for the development of asthma and childhood wheezing.
This study focuses on medical evaluations for asthma and related symptoms (i.e., wheezing) when the children were five years old. As a result of the evaluations cited in this research, other than apples, there were no consistent associations found between prenatal consumption of a range of healthful foods and asthma in the 1253 children who were evaluated.
Children of mothers who ate apples during pregnancy were much less likely to exhibit symptoms of asthma (including wheezing), say the researchers who hail from institutions in The Netherlands and Scotland. These same researchers previously reported positive associations between maternal consumption of vitamins A, E, D and zinc with reduced risk of asthma, wheeze and eczema in children.
The only other positive association found between prenatal food intake and risk reduction in the children was with fish, for which the researchers found that children of mothers who ate fish had a lowered incidence of doctor-confirmed eczema.
According to the research, "The present study suggests beneficial associations between maternal apple intake during pregnancy and wheeze and asthma at age five years." They add that their findings "suggest an apple specific effect, possibly because of its phytochemical content, such as flavonoids." The research paper cites other related studies on apples, including those which found that "intake of apples as a significant source of flavonoids and other polyphenols has been beneficially associated with asthma, bronchial hypersensitivity, and lung function in adults."
In 2004, the National Center for Health Statistics reported that nine million U.S. children have been diagnosed with asthma at one point in their lives and four million children suffered from asthma attacks that year. Others suffer from "hidden asthma" – undetected or undiagnosed asthma, according the American Lung Association. The cost of this disease is great – statistics show asthma to be the third-ranking cause of hospitalization among children under 15 and is among the leading causes of school absenteeism.
Eating apples/fish helps vs asthma/allergies
Women who eat apples and fish during pregnancy may reduce the risk of their children developing asthma or allergic disease, suggests a new study presented at the American Thoracic Society 2007 International Conference, on Sunday, May 20.
The SEATON study, conducted at the University of Aberdeen, UK, found that the children of mothers who ate the most apples were less likely to ever have wheezed or have doctor-confirmed asthma at the age of 5 years, compared to children of mothers who had the lowest apple consumption. Children of mothers who ate fish once or more a week were less likely to have had eczema than children of mothers who never ate fish.
The study did not find any protective effect against asthma or allergic diseases from many other foods, including vegetables, fruit juice, citrus or kiwi fruit, whole grain products, fat from dairy products or margarine or other low-fat spreads.
The researchers studied 1212 children born to women who had filled out food questionnaires during their pregnancy. When the children were 5 years old, the mothers filled out a questionnaire about the children’s respiratory symptoms and allergies, as well as a questionnaire about their child’s food consumption.
The children were also given lung function and allergy tests. Previous studies in the same children have found evidence for protective effects of vitamin E and D and zinc during pregnancy in reducing the risk of children’s wheeze and asthma, notes researcher Saskia Willers, M.Sc. of Utrecht University in the Netherlands. If the new results are confirmed, she says, "recommendations on dietary modification during pregnancy may help to prevent childhood asthma and allergy."
Willers concludes that at least until age 5, a mother’s diet during pregnancy might be more influential on a child’s respiratory health than the child’s own diet. She notes that further study of this group of children will be needed to see whether the association with the mothers’ diet declines in older children, and if mothers’ and their childrens’ diets interact in older children.
Willers suggests that the beneficial effect of apples may come from powerful antioxidants called flavonoids, while fish’s protective effect may come from omega-3 fatty acids, which other studies have suggested have a protective effect on the heart and may have a protective effect in asthma. "Other studies have looked at individual nutrients’ effect on asthma in pregnancy, but our study looked at specific foods during pregnancy and the subsequent development of childhood asthma and allergies, which is quite new," Willers says. "Foods contain mixtures of nutrients that may contribute more than the sum of their parts."
Naturally-occurring apple compounds reduce risk of pancreatic cancer
Smokers benefit most from intake of 'hidden' plant nutrients
Eating flavonol-rich foods like apples may help reduce the risk of pancreatic cancer, says a team of international researchers. Quercetin, which is found naturally in apples and onions, has been identified as one of the most beneficial flavonols in preventing and reducing the risk of pancreatic cancer. Although the overall risk was reduced among the study participants, smokers who consumed foods rich in flavonols had a significantly greater risk reduction.
This study, published in the October 15 issue of the American Journal of Epidemiology, is the first of its kind to evaluate the effect of flavonols – compounds found specifically in plants – on developing pancreatic cancer. According to the research paper, “only a few prospective studies have investigated flavonols as risk factors for cancer, none of which has included pancreatic cancer. “
Researchers from Germany, the Univ. of Hawaii and Univ. of Southern California tracked food intake and health outcomes of 183,518 participants in the Multiethnic Cohort Study for eight years. The study evaluated the participants’ food consumption and calculated the intake of the three flavonols quercetin, kaempferol, and myricetin. The analyses determined that flavonol intake does have an impact on the risk for developing pancreatic cancer.
The most significant finding was among smokers. Smokers with the lowest intake of flavonols presented with the most pancreatic cancer. Smoking is an established risk factor for the often fatal pancreatic cancer, notes the research.
Among the other findings were that women had the highest intake of total flavonols and seventy percent of the flavonol intake came from quercetin, linked to apple and onion consumption.
It is believed that these compounds may have anticancer effects due to their ability to reduce oxidative stress and alter other cellular functions related to cancer development.
“Unlike many of the dietary components, flavonols are concentrated in specific foods rather than in broader food groups, for example, in apples rather than in all fruit,” notes the research study. Previously, the most consistent inverse association was found between flavonols, especially quercetin in apples and lung cancer, as pointed out in this study. No other epidemiological flavonol studies have included evaluation of pancreatic cancer.
While found in many plants, flavonols are found in high concentrations in apples, onions, tea, berries, kale, and broccoli. Quercetin is most plentiful in apples and onions.
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