Thursday, January 28, 2010

Tea and Exercise May Affect Depression in Breast Cancer Patients

Breast cancer patients who exercise and drink tea on a regular basis may be less likely to suffer from depression than other patients, according to a new study led by Xiao Ou Shu, M.D., Ph.D., professor of Medicine, Vanderbilt-Ingram Cancer Center. Xiaoli Chen, M.D., a post-doctoral fellow, was first author of the study published in the January issue of the Journal of Clinical Oncology.

The study, conducted in collaboration with investigators from the Shanghai Institute of Preventive Medicine, examined 1,399 women enrolled in the Shanghai Breast Cancer Survival Study in China. Each woman was interviewed about her exercise and diet habits six months following a breast cancer diagnosis. The women were interviewed again approximately 18 months after diagnosis and they also reported on their depressive symptoms. Twenty-six percent of the women reported depression during the follow-up survey: 13.4 percent had mild depression and 12.6 percent had clinical depression.
Depression may reduce a patient’s quality of life, increase the length of hospital stays and affect compliance with cancer therapy.

“We found that all types of exercise decreased the risk for clinical depression,” said Shu. “Women who exercised for two or more hours per week, and those who expended more energy during exercise were less likely to have depression than women who did not exercise.”

Those patients who increased their exercise level during the follow-up period were 42 percent less likely to report overall depression. However, quitting exercise or reducing exercise was not related to increased depression.

Women also were questioned about their tea-drinking habits and investigators estimated the amount of tea consumed.

“Tea consumption after diagnosis was inversely associated with the risk for mild depression,” said Shu. “Lifetime tea consumption also was inversely related to depression. This is the first epidemiologic evidence that tea consumption may be associated with lower risk for depression among breast cancer survivors, although this was not a prespecified hypothesis. This inverse association was independent of other risk factors for depression.”

Since this study was conducted among Chinese women living in Shanghai, the type of tea most commonly consumed was green tea. Tea and its constituents contain high levels of caffeine and catechin polyphenols, which have demonstrated antioxidant, anticarcinogenic and anti-inflammatory properties.

The study is ongoing and will allow the investigators to evaluate how depression changes over time and to assess the long-term effects of exercise and tea consumption on depression among breast cancer survivors.

Alli Raises Blood Pressure, Weight, Low Carb Diet Better

A new review of existing research confirms that a weight-loss drug raises blood pressure, posing a risk to obese patients who hope to reduce hypertension by shedding pounds.

Many doctors assume that patients automatically lower their blood pressure when they become thinner, but that is not necessarily the case when they use drugs to lose weight, said review lead author Dr. Andrea Siebenhofer.

In the big picture, "anti-obesity drugs are no wonder pills and should be prescribed only if patients beg doctors for some tablets which help them to lose some weight," said Siebenhofer, a researcher at the Medical University of Graz in Austria.

The review authors examined research regarding three weight-loss drugs — orlistat, sibutramine and rimonabant. They looked for studies that lasted at least six months and compared patients with high blood pressure who took one of the drugs to those who took a placebo.

The analysis appears in the latest issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.

The researchers found no studies that met their criteria for patients who took rimonabant, known by the brand name Acomplia.

The drug is not available in the United States; in 2007, the Food and Drug Administration declined to approve its sale and asked its manufacturer to provide more information about its safety. In 2008, the manufacturer agreed to suspend its sale in Europe, amid reports that it heightened the risk of suicidal thoughts.

The review authors did find four studies examining each of the other two drugs, orlistat and sibutramine.

Orlistat, known by the brand names Xenical and Alli, is both an over-the-counter and a prescription drug in the United States. Sibutramine is a prescription drug sold under the brand name Meridia.

The researchers conducted a meta-analysis by combining the studies and adjusting the statistical results to account for their sizes.

In those treated with orlistat, blood pressure fell by an average of 2.5 mm Hg systolic and 1.9 mm Hg diastolic.

However, the diastolic blood pressure levels of patients who took sibutramine rose by 3.2 mm Hg, according to the meta-analysis.

Systolic blood pressure is the top number in a blood-pressure reading (like 120/80) while diastolic is the bottom number.

The review of sibutramine research had some limitations. The review authors only looked at two of the four studies into the drug because they believed the other two did not meet the criteria they had set for inclusion in the meta-analysis.

In addition, the researchers reported that the two studies they did include failed to provide enough information to allow them to calculate how the drug affected systolic blood pressure.

Carla Wolper, a member of the research faculty at New York Obesity Research Center at St. Luke's Hospital, said weight-loss drugs have a place in obesity treatment, but that it is important to prescribe them with care and use them in conjunction with other strategies.

A "smart dietician" is crucial to success, Wolper said, as long as he or she "helps people adjust their diet without making a 180-degree change and uses cognitive behavior therapy to challenge people's ideas" about eating.

Wolper acknowledged working on a drug company-funded study into orlistat.

Dr. Raj Padwal, an assistant professor at the University of Alberta in Canada, said the weight-loss drugs only result in modest amounts of weight loss — typically 6 to 11 pounds — but do improve cardiovascular health. Sibutramine is the exception because it raises blood pressure, he said, and a large study is underway to see if it affects death rates in patients.

Only about 2 percent of patients continue to use the drugs after two years and many find the amount of weight lost disappointing, Padwal said. Side effects are also a problem — orlistat can cause loose stools, for instance — and the drugs are expensive, he added.

"There are no magic pills," he said. "These pills may help a minority of people, and I've seen some people lose a lot of weight, but treatment must be supervised by a health-care provider with appropriate monitoring of parameters, such as blood pressure."


Siebenhofer A, et al. Long-term effects of weight-reducing drugs in hypertensive patients. Cochrane Database of Systematic Reviews 2009, Issue 3.

Low-carb diet effective at lowering blood pressure

In a head-to-head comparison, two popular weight loss methods proved equally effective at helping participants lose significant amounts of weight. But, in a surprising twist, a low-carbohydrate diet proved better at lowering blood pressure than the weight-loss drug orlistat, according to researchers at Veterans Affairs Medical Center and Duke University Medical Center.

The findings send an important message to hypertensive people trying to lose weight, says William S. Yancy, Jr., MD, lead author of the study in the Jan. 25 Archives of Internal Medicine, and an associate professor of medicine at Duke. "If people have high blood pressure and a weight problem, a low-carbohydrate diet might be a better option than a weight loss medication."

Yancy added, "It's important to know you can try a diet instead of medication and get the same weight loss results with fewer costs and potentially fewer side effects."

Studies had already indicated that a low-carbohydrate diet and prescription-strength orlistat combined with a low-fat diet are effective weight loss therapies. But the two common strategies had not been compared to each other, an important omission now that orlistat is available over-the-counter. In addition, few studies provide data on these treatments for overweight patients with chronic health issues.

That's what made these findings particularly interesting, says Yancy, a staff physician at the Durham VA where the research was conducted. The 146 overweight participants in the year-long study had a range of health problems typically associated with obesity -- diabetes, high blood pressure, high cholesterol and arthritis.

"Most participants in weight loss studies are healthy and don't have these problems," he said. "In fact they are often excluded if they do."

The average weight loss for both groups was nearly 10 percent of their body weight. "Not many studies are able to achieve that," says Yancy, who attributes the significant weight loss to the group counseling that was offered for 48 weeks. In fact, he says "people tolerated orlistat better than I expected. Orlistat use is often limited by gastro-intestinal side effects, but these can be avoided, or at least lessened, by following a low-fat diet closely. We counseled people on orlistat in our study fairly extensively about the low-fat diet."

In addition to achieving equal success at weight loss, the methods proved equally effective at improving cholesterol and glucose levels.

But Yancy said it was the difference in blood pressure results that was most surprising.

Nearly half (47%) of patients in the low-carbohydrate group had their blood pressure medication decreased or discontinued while only 21 percent of the orlistat plus low-fat diet group experienced a reduction in medication use. Systolic blood pressure dropped considerably in the low-carbohydrate group when compared to the orlistat plus low-fat diet group.

"I expected the weight loss to be considerable with both therapies but we were surprised to see blood pressure improve so much more with the low-carbohydrate diet than with orlistat," says Yancy, who says the mechanism is unclear. "While weight loss typically induces improvements in blood pressure, it may be that the low-carbohydrate diet has an additional effect." That physiologic effect may be the subject of future studies.

The bottom line, says Yancy, is that many diet options are proving effective at weight loss. But it's counseling patients on how to best follow the options that appears to be making the biggest impact. "It is clear now that several diet options can work, so people can be given a choice of different ways to lose weight. But more importantly, we need to find new ways to help people maintain their new lifestyle."



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alli Proven to Reduce Visceral Fat, a Dangerous Fat Linked to Many Life-Threatening Diseases

New studies show that overweight and obese people using alli® (orlistat 60 mg) with a reduced calorie, lower-fat diet can significantly reduce weight, visceral fat, and waist circumference and therefore may reduce their risk of type 2 diabetes, hypertension, heart disease and stroke.1,2 The studies were presented at the 1st International Congress on Abdominal Obesity in Hong Kong earlier today.

alli is the only FDA-approved OTC weight loss aid that is clinically proven to boost weight loss by 50 percent and significantly reduce excess visceral fat.3 Working in the digestive tract, alli prevents about 25 percent of the fat that a person eats from being absorbed.3

Visceral fat is a dangerous type of fat that surrounds the vital organs in the abdomen and when present in excess disrupts the normal functioning of organs, increasing the risk of life-threatening diseases.4-12 Even modest weight loss can result in significant reductions in visceral fat and substantially improve health.14-17 In fact, when losing weight, visceral fat is among the first fat lost, which is associated with noticeable health benefits such as reductions in total cholesterol and low-density lipoprotein (LDL).21 This helps reduce the risk of type 2 diabetes, hypertension, heart disease and stroke.4-9 It is these health complications that have a high personal and societal toll and impact in the global obesity epidemic.

"Although most individuals try to lose weight to improve their appearance, it's important to help them understand that losing excess fat reduces their risks of life-threatening diseases,” said Jeanine Albu, M.D., Senior Attending in Medicine, Associate Chief of the Division of Endocrinology, Diabetes and Nutrition and the Chief of the Metabolism and Diabetes Clinic at the St. Luke’s-Roosevelt Hospital Center in New York.

“We need to raise awareness of the direct link between visceral fat on the inside and heart disease and diabetes,” said Dr. Albu. “Through healthy eating, keeping active and treatments such as alli, people can lose 5 to 10 percent of total body weight – including visceral fat – and achieve and maintain their healthy weight."

In two of the studies presented at the congress, alli was evaluated to determine its effect on excess visceral fat. This new body of evidence proves that alli significantly reduces weight and dangerous visceral fat to help people improve their health.1,2

The Visceral Fat Imaging Study_The three-month Visceral Fat Imaging Study demonstrated that alli reduced total body weight by 5.6 percent and visceral fat by 10.6 percent versus amounts at the start of the study in overweight and obese adults on a reduced calorie, lower-fat diet (P<0.0225).1 Carried out at Europe’s largest imaging center, the Clinical Imaging Centre in Hammersmith Hospital, UK, the study used MRI technology that showed changes taking place inside people’s bodies as they lost weight in a unique way.

Twenty-six study participants were counseled to follow a reduced calorie, lower-fat diet, and then took alli three times per day for 12 weeks. Results also showed that at week 12 alli significantly reduced waist circumference (the measurement around the waistline), the best practical way to assess visceral fat, by 5 cm (2 inches).1,18-20

The Visceral Fat Multi-Center Study_In the six-month Visceral Fat Multi-Center Study, overweight and obese adults receiving alli while on a reduced calorie, lower-fat diet had significantly greater improvements in visceral fat than those treated with diet alone. 2

In this study, 123 participants were randomly assigned to receive either alli three times per day or a placebo, along with recommendations to follow a reduced calorie, lower-fat diet, for 24 weeks. At week 24, statistically significant reductions in visceral fat and body weight were observed in both groups; however, the reduction was significantly higher among patients taking alli. Mean reductions in visceral fat were 15.66 percent for alli versus 9.39 percent for placebo (P<0.0001); mean reductions in body weight were 5.96 kg versus 3.91 kg, respectively (P<0.05).2

Overweight and obese people enrolled in the Visceral Fat Imaging Study and Visceral Fat Multi-Center Study had a body mass index (BMI) of 25-35 kg/m2, with a waist circumference greater than 88 cm (34.64 inches) for women or 102 cm (40.16 inches) for men at the start of the studies.1,2 Use of alli in both studies was shown to be generally well tolerated and consistent with the known safety profile.1,2

alli is marketed by GlaxoSmithKline Consumer Healthcare for use by overweight adults along with a reduced calorie, lower-fat diet. People interested in losing weight can access interactive tools, lower-fat recipes, physical activity tips and other useful information for leading a healthy life at www.myalli.com.

*Note to editors

For European interest, since overweight and obese is defined as BMI ≥28 kg/m2, post-hoc analysis for BMI ≥28 kg/m2 also found reductions in body weight and waist circumference (N=22, P<0.0001 for both) and VAT (N=19, P=0.0336).2

About alli®_alli is the only FDA-approved weight-loss product available to overweight adults, 18 years or older, without a prescription. alli is a clinically-proven product used with a comprehensive individualized action plan. People who use alli can lose 50 percent more weight than diet alone. The alli program encourages gradual weight loss, known by experts as the best way to lose weight. alli (60 mg orlistat capsules) is safe and effective when used as directed.

The alli plan was developed by nutritional and weight management experts who understand the struggle to lose weight. The alli program, which includes a healthy, balanced diet, regular physical activity and alli capsules available in 60-capsule and 90-capsule educational starter packs. alli works by blocking about 25 percent of fat in the foods eaten to reduce the amount of fat and calories absorbed. alli is non-systemic and well-tolerated.

www.myalli.com

About GlaxoSmithKline Consumer Healthcare_GlaxoSmithKline Consumer Healthcare is one of the world's largest over-the-counter consumer healthcare products companies. Its more than 30 well-known brands include the leading smoking cessation products, Nicorette®, NicoDerm® CQ and Commit® as well as many medicine cabinet staples, including Aquafresh®, Sensodyne®, Tums® and Breathe Right®.

About GlaxoSmithKline_GlaxoSmithKline -- one of the world's leading research-based pharmaceutical and healthcare companies -- is committed to improving the quality of human life by enabling people to do more, feel better and live longer. For company information visit: http://www.gsk.com.

Cautionary statement regarding forward-looking statements_Under the safe harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995, GSK cautions investors that any forward-looking statements or projections made by GSK, including those made in this announcement, are subject to risks and uncertainties that may cause actual results to differ materially from those projected. Factors that may affect GSK' s operations are described under 'Risk Factors' in the 'Business Review' in the company' s Annual Report on Form 20-F for 2008.

References:

1.Beaver J, Bell JD, Thomas EL et al. Orlistat 60 mg in conjunction with diet provides significant reduction in visceral adipose tissue. Poster presented at: 1st International Congress on Abdominal Obesity, 2009, Hong Kong._2.Greenway F, Smith SR, Murray K et al. Orlistat 60 mg demonstrates a significant reduction in visceral adipose tissue at 24 weeks compared with placebo. Poster presented at: 1st International Congress on Abdominal Obesity, 2009, Hong Kong._3.alli Product Label. GlaxoSmithKline Consumer Health._4. Wang Y et al. Comparison of abdominal adiposity and overall obesity in predicting risk of type 2 diabetes among men. Am J Clin Nutr. 2005, 81: 555-63._5. Chan J et al. Obesity, fat distribution, and weight gain as risk factors for clinical diabetes in men. Diabetes Care 1994;17(9): 961-969._6. Larsson B et al. Abdominal adipose tissue distribution, obesity, and risk of cardiovascular disease and death: 13 year follow-up of participants in the study of men born in 1913. Br Med J. 1984; 288: 1401-4._7. Sironi AM et al. Visceral Fat in Hypertension: Influence on Insulin Resistance and ß-Cell function. Hypertension 2004 ;44;127–133._8. Lapidus L et al. Distribution of adipose tissue and risk of cardiovascular disease and death: a 12-year follow-up of participants in the population study of women In Gothenburg, Sweden. Br Med J. 1984; 289: 1257-61._9. Yusuf S et al. Effect of potentially modifiable risk factors associated with myocardial infarction in 52 countries (the INTERHEART study): case-control study. Lancet 2004, 364: 937-952._10. Pouliot MC et al. Visceral obesity in men. Associations with glucose tolerance, plasma insulin, and lipoprotein levels. Diabetes 1992, 41: 826-34._11. Lean ME. Impairment of health and quality of life in people with large waist circumference. Lancet 1998; 351(9106): 853-6._12. Mathieu P et al. Visceral Obesity: The Link Among Inflammation, Hypertension, and Cardiovascular Disease. Hypertension 2009; 53:577-584_13. Purnell J et al. Effect of Weight Loss with Reduction of Intra-Abdominal Fat on Lipid Metabolism in Older Men. J Clin Endocrinol Metab. 2000; 85: 977–82._14. Rice B et al. Effects of Aerobic or Resistance Exercise and/or Diet on Glucose Tolerance and Plasma Insulin Levels in Obese Men. Diabetes Care 1999; 22(5): 684-91._15. Goodpaster B et al. Effects of weight loss on regional fat distribution and insulin sensitivity in obesity. Diabetes 1999; 48: 839-47._16. Ross R et al. Reduction in Obesity and Related Comorbid Conditions after Diet-Induced Weight Loss or Exercise-Induced Weight Loss in Men A Randomized, Controlled Trial. Ann Intern Med. 2000; 133: 92-103._17. Ross A et al. Exercise-Induced Reduction in Obesity and Insulin Resistance in Women: a Randomized Controlled Trial. Obesity Research 2004;12: 789–798._18. Lean ME, et al. Waist circumference as a measure for indicating need for weight management. British Med J. 1995;311:158-61._19. Pouliot MC, et al. Waist circumference and abdominal sagittal diameter: best simple anthropometric indexes of abdominal visceral adipose tissue accumulation and related cardiovascular risk in men and women. Am J Cardiol. 1994;73(7):460-8._20. NHLBI Obesity Education Initiative. The Practical Guide Identification, Evaluation, and Treatment of Overweight and Obesity in Adults. http://www.nhlbi.nih.gov/guidelines/obesity/prctgd_c.pdf. Accessed 02/11/2009._21. Weight Control Information Network. Statistics Related to Overweight and Obesity. http://www.win.niddk.nih.gov/statistics/index.htm. Accessed 8 January 2010

It's Better to Eat a Low Carb Meal After Exercise

Many of the health benefits of aerobic exercise are due to the most recent exercise session (rather than weeks, months and even years of exercise training), and the nature of these benefits can be greatly affected by the food we eat afterwards, according to a study published in the Journal of Applied Physiology.

“Differences in what you eat after exercise produce different effects on the body’s metabolism,” said the study’s senior author, Jeffrey F. Horowitz of the University of Michigan. This study follows up on several previous studies that demonstrate that many health benefits of exercise are transient: one exercise session produces benefits to the body that taper off, generally within hours or a few days.

“Many of the improvements in metabolic health associated with exercise stem largely from the most recent session of exercise, rather than from an increase in ‘fitness’ per se,” Dr. Horowitz said. “But exercise doesn’t occur in a vacuum, and it is very important to look at both the effects of exercise and what you’re eating after exercise.”

Specifically, the study found that exercise enhanced insulin sensitivity, particularly when meals eaten after the exercise session contained relatively low carbohydrate content. Enhanced insulin sensitivity means that it is easier for the body to take up sugar from the blood stream into tissues like muscles, where it can be stored or used as fuel. Impaired insulin sensitivity (i.e., “insulin resistance”) is a hallmark of Type II diabetes, as well as being a major risk factor for other chronic diseases, such as heart disease.

Interestingly, when the research subjects in this study ate relatively low-calorie meals after exercise, this did not improve insulin sensitivity any more than when they ate enough calories to match what they expended during exercise. This suggests that you don’t have to starve yourself after exercise to still reap some of the important health benefits.

The paper, “Energy deficit after exercise augments lipid mobilization but does not contribute to the exercise-induced increase in insulin sensitivity,” appears in the online edition of the journal.

Study Design

The study included nine healthy sedentary men, all around 28-30 years old. They spent four separate sessions in the Michigan Clinical Research Unit in the University of Michigan Hospital. Each session lasted for approximately 29 hours. They fasted overnight before attending each session, which began in the morning.

The four hospital visits differed primarily by the meals eaten after exercise. The following describes the four different visits:

1. They did not exercise and ate meals to match their daily calorie expenditure. This was the control trial.

2. They exercised for approximately 90 min at moderate intensity, and then ate meals that matched their caloric expenditure. The carbohydrate, fat, and protein content of these meals were also appropriately balanced to match their expenditure.

3. They exercised for approximately 90 min at moderate intensity and then ate meals with relatively low carbohydrate content, but they ate enough total calories to match their calorie expenditure. This reduced-carbohydrate meal contained about 200 grams of carbohydrate, less than half the carbohydrate content of the balanced meal.

4. They exercised for approximately 90 min at moderate intensity and then ate relatively low-calorie meals, that is, meals that provided less energy than was expended (about one-third fewer calories than the meals in the other two exercise trials). These meals contained a relatively high carbohydrate content to replace the carbohydrate “burned” during exercise.

The exercise was performed on a stationary bicycle and a treadmill. The order in which the participants did the trials was randomized.

In the three exercise trials, there was a trend for an increase in insulin sensitivity. However, when participants ate less carbohydrate after exercise, this enhanced insulin sensitivity significantly more. Although weight loss is important for improving metabolic health in overweight and obese people, these results suggests that people can still reap some important health benefits from exercise without undereating or losing weight, Dr. Horowitz said.

The study also reinforces the growing body of evidence that each exercise session can affect the body’s physiology and also that differences in what you eat after exercise can produce different physiological changes.

Women's Health Alert: Fighting Heart Disease in Your 40s

The risk for heart-related death is increasing in young adults ages 35 to 54, and the numbers are even more alarming for younger women. It is the number-one cause of death for both men and women in the United States, yet every year since 1984 more women have died of cardiovascular health problems than men, according to the American Heart Association.

"Although there has been a general decline in deaths caused by heart disease, the last decade has seen a steady increase among younger women ages 35 to 44. Women account for more than 50 percent of deaths due to heart disease," says Dr. Holly Andersen, the director of education and outreach for the Ronald O. Perelman Heart Institute at NewYork-Presbyterian Hospital/Weill Cornell Medical Center.

Dr. Andersen offers the following advice to women the following advice on how to stay healthy, know their risk factors, and get the best medical treatments to take better care of their hearts.

* Enjoy yourself. Eat right, attempt to get a good night's sleep, practice stress reduction, and have some fun -- all have been shown to lower the risk of heart disease.

* Know the warning signs of an attack. Women may not always experience the typical crushing chest pain that is associated with a heart attack. Many women have symptoms that include neck, shoulder and abdominal pain; some may also have nausea, vomiting, fatigue and shortness of breath, along with chest pain.

* Test for the silent attack. Some women feel no pain at all and experience what is known as a "silent heart attack." Silent heart attacks lead to long-term shortage of blood and oxygen flow to the heart. If you are a post-menopausal woman and have at least three risk factors for heart disease you should ask your doctor for a cardiac stress test to determine if you have experienced this type of attack and permanent damage.

* Know your risk factors. Your risk of having a heart attack greatly increases if you are obese/overweight, a smoker, have high cholesterol and/or diabetes. There are also several risk factors that are of particular importance to women:

o Smoking greatly increases the risk of heart attack for women under the age of 45. The combination of smoking and birth control pills increases a woman's risk by at least 20-fold.

o High C-Reactive Protein (CRP) levels are a marker of inflammation that has been shown to be an independent risk factor for cardiovascular risk. Ask your doctor to check your level with a simple blood test.

o Experiencing complications during pregnancy can be an indicator of future cardiovascular disease for moms. Women who have had preeclampsia, gestational diabetes or delivered low-birth-weight babies should aggressively manage all risk factors for heart disease.

o According to the American Heart Association, low-levels of good cholesterol (HDL) are a stronger predictor of heart disease death in women than in men over 65.

* Call 911. Anyone who thinks they are having a heart attack should dial 911 immediately. Emergency medical teams can begin to treat patients before they arrive at the hospital and save precious time that is often lost when patients try to drive themselves to the emergency room.

* Get an EKG. Once a woman does arrive in the emergency room it is important to ask for an EKG test or an enzyme blood test to check for a heart attack, since medical professionals may attribute a woman's symptoms to other health conditions such as indigestion.

Magnesium enhances learning and memory

New research finds that an increase in brain magnesium improves learning and memory in young and old rats. The study, published by Cell Press in the January 28th issue of the journal Neuron, suggests that increasing magnesium intake may be a valid strategy to enhance cognitive abilities and supports speculation that inadequate levels of magnesium impair cognitive function, leading to faster deterioration of memory in aging humans.

Diet can have a significant impact on cognitive capacity. Identification of dietary factors which have a positive influence on synapses, the sites of communication between neurons, might help to enhance learning and memory and prevent their decline with age and disease. Professor Guosong Liu, Director of the Center for Learning and Memory at Tsinghua University in Beijing, China, led a study examining whether increased levels of one such dietary supplement, magnesium, boosts brain power.

Magnesium, an essential element, is found in dark, leafy vegetables such as spinach and in some fruits. Those who get less than 400 milligrams daily are at risk for allergies, asthma and heart disease, among other conditions. In 2004, Guosong Liu and colleagues at MIT discovered that magnesium might have a positive influence on learning and memory. They followed up by developing a new magnesium compound — magnesium-L-threonate (MgT) —that is more effective than conventional oral supplements at boosting magnesium in the brain, and tested it on rats.

"We found that elevation of brain magnesium led to significant enhancement of spatial and associative memory in both young and aged rats," said Liu, now director of the Center for Learning and Memory at Tsinghua University. "If MgT is shown to be safe and effective in humans, these results may have a significant impact on public health." Liu is cofounder of Magceutics, a California-based company developing drugs for prevention and treatment of age-dependent memory decline and Alzheimer's disease.

"Half the population of the industrialized countries has a magnesium deficit, which increases with aging. If normal or even higher levels of magnesium can be maintained, we may be able to significantly slow age-related loss of cognitive function and perhaps prevent or treat diseases that affect cognitive function," Liu said.

HOW THEY DID IT: To understand the molecular mechanisms underlying this MgT-induced memory enhancement, the researchers studied the changes induced in functional and structural properties of synapses. They found that in young and aged rats, MgT increased plasticity among synapses, the connections among neurons, and boosted the density of synapses in the hippocampus, a critical brain region for learning and memory.

Susumu Tonegawa at MIT's Picower Institute for Learning and Memory helped carry out the initial behavioral experiments that showed that magnesium boosted memory in aged rats. Min Zhou's laboratory at the University of Toronto helped demonstrate the enhancement of synaptic plasticity in magnesium-treated rats.

"Magnesium is essential for the proper functioning of many tissues in the body, including the brain and, in an earlier study, we demonstrated that magnesium promoted synaptic plasticity in cultured brain cells," explains Dr. Liu. "Therefore it was tempting to take our studies a step further and investigate whether an increase in brain magnesium levels enhanced cognitive function in animals."

Because it is difficult to boost brain magnesium levels with traditional oral supplements, Dr. Liu and colleagues developed a new magnesium compound, magnesium-L-threonate (MgT) that could significantly increase magnesium in the brain via dietary supplementation. They used MgT to increase magnesium in rats of different ages and then looked for behavioral and cellular changes associated with memory.

"We found that increased brain magnesium enhanced many different forms of learning and memory in both young and aged rats," says Dr. Liu. A close examination of cellular changes associated with memory revealed an increase in the number of functional synapses, activation of key signaling molecules and an enhancement of short- and long-term synaptic processes that are crucial for learning and memory.

The authors note that the control rats in this study had a normal diet which is widely accepted to contain a sufficient amount of magnesium, and that the observed effects were due to elevation of magnesium to levels higher than provided by a normal diet.

"Our findings suggest that elevating brain magnesium content via increasing magnesium intake might be a useful new strategy to enhance cognitive abilities," explains Dr. Liu. "Moreover, half the population of industrialized countries has a magnesium deficit, which increases with aging. This may very well contribute to age-dependent memory decline; increasing magnesium intake might prevent or reduce such decline."


NEXT STEPS: This study not only highlights the importance of a diet with sufficient daily magnesium, but also suggests the usefulness of magnesium-based treatments for aging-associated memory decline, Tonegawa said. Clinical studies in Beijing are now investigating the relationship between body magnesium status and cognitive functions in older humans and Alzheimer's patients.

Wednesday, January 27, 2010

Ginkgo herbal medicines may increase seizures in people with epilepsy

Restrictions should be placed on the use of Ginkgo biloba (G. biloba) — a top-selling herbal remedy — because of growing scientific evidence that Ginkgo may increase the risk of seizures in people with epilepsy and could reduce the effectiveness of anti-seizure drugs, a new report concludes. The article appears in ACS' monthly Journal of Natural Products. It also suggests that Ginkgo may have harmful effects in other people after eating raw or roasted Ginkgo seed or drinking tea prepared from Ginkgo leaves.




Eckhard Leistner and Christel Drewke note that consumers use pills, teas, and other products prepared from leaves of the Ginkgo tree to treat a wide array of health problems. Those include Alzheimer's disease and other memory loss, clinical depression, headache, irritable bladder, alcohol abuse, blockages in blood vessels, poor concentration, and dizziness. Scientific concern focuses mainly on one chemical compound in the herb. It is a potentially toxic material known as ginkgotoxin.

They reviewed scientific research on Ginkgo, and found 10 reports indicating that patients with epilepsy who take Ginkgo products face an increased risk of seizures. They note that laboratory studies explain how Ginkgo could have that unwanted effect. Ginkgotoxin seems to alter a chemical signaling pathway in ways that may trigger epileptic seizures. Further evidence showed that Ginkgo can interact with anti-seizure medications and reduce their effectiveness. "Contrary to our own previous assumption, we are now convinced, however, that G. biloba medications and other products can have a detrimental effect on a person's health condition," the report concludes. "It is therefore important that the large number of G. biloba product users and their health care providers be made aware of these risks, in order to enable them to make informed decisions about the use of these preparations."

Vitamin D Supplements Could Fight Crohn's Disease; Canadian Research Team Publishes Findings in Journal of Biological Chemistry

A new study has found that Vitamin D, readily available in supplements or cod liver oil, can counter the effects of Crohn's disease. John White, an endocrinologist at the Research Institute of the McGill University Health Centre, led a team of scientists from McGill University and the Universite de Montreal who present their findings about the inflammatory bowel disease in the latest Journal of Biological Chemistry.

"Our data suggests, for the first time, that Vitamin D deficiency can contribute to Crohn's disease," says Dr. White, a professor in McGill's Department of Physiology, noting that people from northern countries, which receive less sunlight that is necessary for the fabrication of Vitamin D by the human body, are particularly vulnerable to Crohn's disease.

Vitamin D, in its active form (1,25-dihydroxyvitamin D), is a hormone that binds to receptors in the body's cells. Dr. White's interest in Vitamin D was originally in its effects in mitigating cancer. Because his results kept pointing to Vitamin D's effects on the immune system, specifically the innate immune system that acts as the body's first defense against microbial invaders, he investigated Crohn's disease. "It's a defect in innate immune handling of intestinal bacteria that leads to an inflammatory response that may lead to an autoimmune condition," stresses Dr. White.

What Vitamin D does

Dr. White and his team found that Vitamin D acts directly on the beta defensin 2 gene, which encodes an antimicrobial peptide, and the NOD2 gene that alerts cells to the presence of invading microbes. Both Beta-defensin and NOD2 have been linked to Crohn's disease. If NOD2 is deficient or defective, it cannot combat invaders in the intestinal tract.

What's most promising about this genetic discovery, says Dr. White, is how it can be quickly put to the test. "Siblings of patients with Crohn's disease that haven't yet developed the disease might be well advised to make sure they're vitamin D sufficient. It's something that's easy to do, because they can simply go to a pharmacy and buy Vitamin D supplements. The vast majority of people would be candidates for Vitamin D treatment."

"This discovery is exciting, since it shows how an over-the-counter supplement such as Vitamin D could help people defend themselves against Crohn's disease," says Marc J. Servant, a professor at the Universite de Montreal's Faculty of Pharmacy and study collaborator. "We have identified a new treatment avenue for people with Crohn's disease or other inflammatory bowel diseases."

Tuesday, January 26, 2010

Antioxidants aren't always good for you and can impair muscle function

Antioxidants increasingly have been praised for their benefits against disease and aging, but recent studies at Kansas State University show that they also can cause harm.

Researchers in K-State's Cardiorespiratory Exercise Laboratory have been studying how to improve oxygen delivery to the skeletal muscle during physical activity by using antioxidants, which are nutrients in foods that can prevent or slow the oxidative damage to the body. Their findings show that sometimes antioxidants can impair muscle function.

"Antioxidant is one of those buzz words right now," said Steven Copp, a doctoral student in anatomy and physiology from Manhattan and a researcher in the lab. "Walking around grocery stores you see things advertised that are loaded with antioxidants. I think what a lot of people don't realize is that the antioxidant and pro-oxidant balance is really delicate. One of the things we've seen in our research is that you can't just give a larger dose of antioxidants and presume that there will be some sort of beneficial effect. In fact, you can actually make a problem worse."

David C. Poole and Timothy I. Musch, K-State professors from both the departments of kinesiology and anatomy and physiology, direct the Cardiorespiratory Exercise Laboratory, located in the College of Veterinary Medicine complex. Researchers in the lab study the physiology of physical activity in health and disease through animal models. Copp and Daniel Hirai, an anatomy and physiology doctoral student from Manhattan working in the lab, have conducted various studies associated with how muscles control blood flow and the effects of different doses and types of antioxidants.

Abnormalities in the circulatory system, such as those that result from aging or a disease like chronic heart failure, can impair oxygen delivery to the skeletal muscle and increase fatigability during physical activity, Copp said. The researchers are studying the effects antioxidants could have in the process.

"If you have a person trying to recover from a heart attack and you put them in cardiac rehab, when they walk on a treadmill they might say it's difficult," Poole said. "Their muscles get sore and stiff. We try to understand why the blood cells aren't flowing properly and why they can't get oxygen to the muscles, as happens in healthy individuals."

Copp said there is a potential for antioxidants to reverse or partially reverse some of those changes that result from aging or disease. However, K-State's studies have shown that some of the oxidants in our body, such as hydrogen peroxide, are helpful to increase blood flow.

"We're now learning that if antioxidant therapy takes away hydrogen peroxide – or other naturally occurring vasodilators, which are compounds that help open blood vessels – you impair the body's ability to deliver oxygen to the muscle so that it doesn't work properly," Poole said.

Poole said antioxidants are largely thought to produce better health, but their studies have shown that antioxidants can actually suppress key signaling mechanisms that are necessary for muscle to function effectively.

"It's really a cautionary note that before we start recommending people get more antioxidants, we need to understand more about how they function in physiological systems and circumstances like exercise," Poole said.

Hirai said the researchers will continue to explore antioxidants and the effects of exercise training. Their studies are looking at how these can help individuals combat the decreased mobility and muscle function that comes with advancing age and diseases like heart failure.

"The research we do here is very mechanistic in nature, and down the road our aim is to take our findings and make recommendations for diseased and aging populations," Copp said.

Monday, January 25, 2010

Leafy greens can prevent the ill-effects of toxins in foods like peanut butter

Not only are the vitamins and minerals good for you, but eating greens could also save your life, according to a recent study invoving scientists from Lawrence Livermore National Laboratory (LLNL).



Photo-illustration depicts the relationship between aflatoxin B1, and healthy greens.

LLNL researchers Graham Bench and Ken Turteltaub found that giving someone a small dose of chlorophyll (Chla) or chlorophyllin (CHL) — found in green leafy vegetables such as spinach, broccoli and kale — could reverse the effects of aflatoxin poisoning.

Aflatoxin is a potent, naturally occurring carcinogenic mycotoxin that is associated with the growth of two types of mold: Aspergillus flavus and Aspergillus parasiticus. Food and food crops most prone to aflatoxin contamination include corn and corn products, cottonseed, peanuts and peanut products, tree nuts and milk.

Bench and Turteltaub, working with colleagues from Oregon State University and an industry partner, Cephalon Inc., found that greens have chemopreventive potential.

Aflatoxins can invade the food supply at anytime during production, processing, transport and storage. Evidence of acute aflatoxicosis in humans has been reported primarily in developing countries lacking the resources to effectively screen aflatoxin contamination from the food supply. Because aflatoxins, particularly aflatoxin B1 (AFB1), are potent carcinogens in some animals, there is interest in the effects of long-term exposure to low levels of these important mycotoxins on humans.

The study used AMS to provide aflatoxin pharmacokinetic parameters previously unavailable for humans, and suggest that chlorophyll and chlorophyllin co-consumption may limit the bioavailability of ingested aflatoxin in humans, as they do in animal models, according to Bench.


View video of Ken Turteltaub describing the findings


View video of Graham Bench describing how the study was conducted

Exposure to environmental carcinogens has been estimated to contribute to a majority of human cancers, especially through lifestyle factors related to tobacco use and diet. Notable examples are the tobacco-related carcinogens; heterocyclic amines produced from sustained, high-temperature cooking of meats; and the fungal food contaminants aflatoxins.

The team initially gave each of three volunteers a small dose of carbon 14 labeled aflatoxin (less than the amount that would be found in a peanut butter sandwich.) In subsequent experiments the patients were given a small amount of Chla or CHL concomitantly with the same dose of carbon 14 labeled aflatoxin.

By using LLNL’s Center for Accelerator Mass Spectrometry, the team was able to measure the amount of aflatoxin in each volunteer after each dosing regimen and determine whether the Chla or CHL reduced the amount of aflatoxin absorbed into the volunteers.

“The Chla and CHL treatment each significantly reduced aflatoxin absorption and bioavailability,” Bench said.

“What makes this study unique among prevention trials is, that we were able to administer a microdose of radio-labeled aflatoxin to assess the actions of the carcinogen directly in people. There was no extrapolation from animal models which often are wrong,” Turteltaub said.

Low-carb diet effective at lowering blood pressure

In a head-to-head comparison, two popular weight loss methods proved equally effective at helping participants lose significant amounts of weight. But, in a surprising twist, a low-carbohydrate diet proved better at lowering blood pressure than the weight-loss drug orlistat, according to researchers at Veterans Affairs Medical Center and Duke University Medical Center.

The findings send an important message to hypertensive people trying to lose weight, says William S. Yancy, Jr., MD, lead author of the study in the Jan. 25 Archives of Internal Medicine, and an associate professor of medicine at Duke. "If people have high blood pressure and a weight problem, a low-carbohydrate diet might be a better option than a weight loss medication."

Yancy added, "It's important to know you can try a diet instead of medication and get the same weight loss results with fewer costs and potentially fewer side effects."

Studies had already indicated that a low-carbohydrate diet and prescription-strength orlistat combined with a low-fat diet are effective weight loss therapies. But the two common strategies had not been compared to each other, an important omission now that orlistat is available over-the-counter. In addition, few studies provide data on these treatments for overweight patients with chronic health issues.

That's what made these findings particularly interesting, says Yancy, a staff physician at the Durham VA where the research was conducted. The 146 overweight participants in the year-long study had a range of health problems typically associated with obesity -- diabetes, high blood pressure, high cholesterol and arthritis.

"Most participants in weight loss studies are healthy and don't have these problems," he said. "In fact they are often excluded if they do."

The average weight loss for both groups was nearly 10 percent of their body weight. "Not many studies are able to achieve that," says Yancy, who attributes the significant weight loss to the group counseling that was offered for 48 weeks. In fact, he says "people tolerated orlistat better than I expected. Orlistat use is often limited by gastro-intestinal side effects, but these can be avoided, or at least lessened, by following a low-fat diet closely. We counseled people on orlistat in our study fairly extensively about the low-fat diet."

In addition to achieving equal success at weight loss, the methods proved equally effective at improving cholesterol and glucose levels.

But Yancy said it was the difference in blood pressure results that was most surprising.

Nearly half (47%) of patients in the low-carbohydrate group had their blood pressure medication decreased or discontinued while only 21 percent of the orlistat plus low-fat diet group experienced a reduction in medication use. Systolic blood pressure dropped considerably in the low-carbohydrate group when compared to the orlistat plus low-fat diet group.

"I expected the weight loss to be considerable with both therapies but we were surprised to see blood pressure improve so much more with the low-carbohydrate diet than with orlistat," says Yancy, who says the mechanism is unclear. "While weight loss typically induces improvements in blood pressure, it may be that the low-carbohydrate diet has an additional effect." That physiologic effect may be the subject of future studies.

The bottom line, says Yancy, is that many diet options are proving effective at weight loss. But it's counseling patients on how to best follow the options that appears to be making the biggest impact. "It is clear now that several diet options can work, so people can be given a choice of different ways to lose weight. But more importantly, we need to find new ways to help people maintain their new lifestyle."

Midlife Exercise Associated With Better Health in Later Years

Among women who survive to age 70 or older, those who regularly participated in physical activity during middle age appear more likely to be in better overall health. Qi Sun, M.D., Sc.D., of the Harvard School of Public Health, Brigham and Women's Hospital and Harvard Medical School, Boston, and colleagues analyzed data from 13,535 participants in the Nurses' Health Study.

The women reported their physical activity levels in 1986, at an average age of 60. Among those who had survived to age 70 or older as of 1995 to 2001, those who had higher levels of physical activity at the beginning of the study were less likely to have chronic diseases, heart surgery or any physical, cognitive or mental impairments.

"Since the American population is aging rapidly and nearly a quarter of Americans do not engage in any leisure-time activity, our findings appear to support federal guidelines regarding physical activity to promote health among older people and further emphasize the potential of activity to enhance overall health and well-being with aging," the authors conclude. "The notion that physical activity can promote successful survival rather than simply extend the lifespan may provide particularly strong motivation for initiating activity."

Physical Activity = Reduced Cognitive Impairment In Elderly Population

Moderate or high physical activity appears to be associated with a lower the risk of developing cognitive impairment in older adults after a two-year period. Thorleif Etgen, M.D., of Technische Universität München, Munich, and Klinikum Traunstein, Germany, and colleagues examined physical activity and cognitive function in 3,903 participants (older than 55) from southern Bavaria, Germany between 2001 and 2003.

At the beginning of the study, 418 participants (10.7 percent) had cognitive impairment. After two years, 207 (5.9 percent) of the remaining 3,485 unimpaired study participants developed cognitive impairment. "The incidence of new cognitive impairment among participants with no, moderate and high activity at baseline was 13.9 percent, 6.7 percent and 5.1 percent, respectively," the authors write.

"Future large randomized controlled intervention trials assessing the quantity (e.g., no activity vs. moderate vs. high activity) and quality (aerobic exercise or any kind type of physical exercise, like balance and strength training or even integrated physical activities like dancing or games) of physical activity that is required to prevent or delay a decline in cognitive function are recommended," they conclude.

Exercise Program Associated With Denser Bones, Lower Fall Risk in Older Women

Women age 65 or older assigned to an exercise program for 18 months appeared to have denser bones and a reduced risk of falls, but not a reduced cardiovascular disease risk, compared with women in a control group. Wolfgang Kemmler, Ph.D., and colleagues at Freidrich-Alexander University of Erlangen-Nuremberg, Erlangen, Germany, studied a total of 246 older women. Half of the women exercised four days per week with special emphasis on intensity while the other half participated in a wellness program that focused on well-being.

Among the 227 women who completed the study, the 115 who exercised had higher bone density in their spine and hip, and also had a 66 percent reduced rate of falls. Fractures due to falls were twice as common in the controls vs. the exercise group (12 vs. six). However, the 10-year risk of cardiovascular disease—assessed using the Framingham Risk Calculator, which incorporates factors such as cholesterol level, blood pressure and presence of diabetes—decreased in both groups and did not differ between the two.

"Because this training regimen can be easily adopted by other institutions and health care providers, a broad implementation of this program is feasible," the authors conclude.

Weight training improves cognitive function in seniors

Weight-bearing exercises may help minimize cognitive decline and impaired mobility in seniors, according to a new study conducted by the Centre for Hip Health and Mobility at Vancouver Coastal Health and the University of British Columbia.

The study, published today in the Archives of Internal Medicine, is one of the first randomized controlled trials of progressively intensive resistance training in senior women. Led by Dr. Teresa Liu-Ambrose, researcher at the Centre and assistant professor in the Faculty of Medicine at UBC, the research team found that 12 months of once-weekly or twice-weekly resistance training improved executive cognitive function in senior women aged 65 to 75 years old. Executive cognitive functions are cognitive abilities necessary for independent living.

"We were able to demonstrate that simple training with weights that seniors can easily handle improved ability to make accurate decisions quickly," says Liu-Ambrose, who is also a researcher at the Brain Research Centre at UBC and Vancouver Coastal Health. "Additionally, we found that the exercises led to increased walking speed, a predictor of considerable reduction in mortality."

Previous studies have shown that aerobic exercise training, such as walking or swimming enhances brain and cognitive function. However, seniors with limited mobility are unable to benefit from this type of exercise.

Until now, the benefits of resistance training, which is an attractive alternative type of exercise for seniors with limited mobility, on cognitive function has received little investigation. Liu-Ambrose is one of few researchers in Canada investigating the role of targeted resistance training in promoting mobility and cognitive in seniors.

Cognitive decline among seniors is a pressing health care issue and it is a key risk factor for falls. Approximately 30 per cent of B.C. seniors experience a fall each year and fall-related hip fractures account for more than 4,000 injures each year at a cost of $75 Million to the health care system.

The number of seniors in B.C. is expected to increase by 220 per cent by 2031, representing 23.5 per cent of B.C. population. Effective strategies to prevent cognitive decline are essential to improving quality of life for older British Columbians and to save the health care system millions in associated costs.

"At the Centre for Hip Health and Mobility we focus on research that will have a positive impact on the health of people in B.C. and Canada," says Heather McKay, centre director and professor in the Faculty of Medicine at UBC. "Dr. Liu-Ambrose's research provides a clear illustration of relatively simple interventions with a profound and immediate impact on the mobility and quality of life of older adults."

Saturday, January 23, 2010

Fish Oil Reduces Hospital Stays

A randomised controlled trial of fish oil given intravenously to patients in intensive care has found that it improves gas exchange, reduces inflammatory chemicals and results in a shorter length of hospital stay.

Researchers writing in BioMed Central's open access journal Critical Care investigated the effects of including fish oil in the normal nutrient solution for patients with sepsis, finding a significant series of benefits.

Philip Calder, from the University of Southampton, UK, worked with a team of researchers to carry out the study in 23 patients with systemic inflammatory response syndrome or sepsis in the Hospital Padre Américo, Portugal. He said, "Recently there has been increased interest in the fat and oil component of vein-delivered nutrition, with the realization that it not only supplies energy and essential building blocks, but may also provide bioactive fatty acids. Traditional solutions use soybean oil, which does not contain the omega-3 fatty acids contained in fish oil that act to reduce inflammatory responses. In fact, soybean oil is rich in omega-6 acids that may actually promote inflammation in an excessive or unbalanced supply."

Calder and his colleagues found that the 13 patients in the fish oil group had lower levels of inflammatory agents in their blood, were able to achieve better lung function and left hospital earlier than the 10 patients who received traditional nutrition.

According to Calder, "This is the first study of this particular fish oil solution in septic patients in the ICU. The positive results are important since they indicate that the use of such an emulsion in this group of patients will improve clinical outcomes, in comparison with the standard mix."

Protein Supplements Don't Help

Protein Supplements Are Often Misused by Athletes, Study Finds

Protein supplements don't improve performance or recovery time and, according to a recent study, such supplements are inefficient for most athletes. "They are often poorly used or unnecessary by both high-level athletes and amateurs," says Martin Fréchette, a researcher and graduate of the Université de Montréal Department of Nutrition.

Fréchette submitted questionnaires to 42 athletes as part of his master's thesis. Sportsmen were asked about their use of supplements while keeping a journal of their eating habits for three days. They came from a variety of disciplines including biathlon, cycling, long-distance running, swimming, judo, skating and volleyball.

Nine athletes out of 10 reported food supplements on a regular basis. They consume an average of 3,35 products: energy drinks, multi-vitamins, minerals and powdered protein supplements. Fréchette found their knowledge of food supplements to be weak.

"The role of proteins is particularly misunderstood," he warns. "Only one out of four consumers could associate a valid reason, backed by scientific literature, for taking the product according."

Despite the widespread use of protein supplements, 70 percent of athletes in Fréchette's study didn't feel their performance would suffer if they stopped such consumption. "More than 66 percent of those who believed to have bad eating habits took supplements. For those who claimed to have 'good' or 'very good' eating habits that number climbs to 90 percent."

Fréchette stresses that supplements come with certain risks. "Their purity and preparation aren't as controlled as prescription medication," he says. "Sports supplements often contain other ingredients than those listed on the label. Some athletes consume prohibited drugs without knowing."

Other studies have shown that 12 to 20 percent of products regularly used by athletes contain prohibited substances. Fréchette observed a particular interest by the athletes on the efficiency, legality and safety of those drugs.

"No less than 81 percent of athletes taking supplements already had sufficient protein from their diet," says Fréchette. "The use of multivitamins and minerals can make up for an insufficient intake of calcium, folate yet not for lack of potassium."

What's more, consumers of supplements had levels of sodium, magnesium, niacin, folate, vitamin A and iron that exceeded the acceptable norms. "This makes them susceptible to health problems such as nausea, vision trouble, fatigue and liver anomalies," says Fréchette.

Omega-3 Fatty Acid May Protect Against Aging

Patients with coronary heart disease who had higher omega-3 fatty acid blood levels had an associated lower rate of shortening of telomere length, a chromosome marker of biological aging, raising the possibility that these fatty acids may protect against cellular aging, according to a study in the January 20 issue of JAMA.

Several studies have shown increased survival rates among individuals with high dietary intake of marine omega-3 fatty acids and established cardiovascular disease. The mechanisms underlying this protective effect are not well understood, according to background information in the article.

Telomeres are a structure at the end of a chromosome involved in the replication and stability of the chromosome. Genetic factors and environmental stressors can shorten the length of the telomere, with telomere length becoming an emerging marker of biological age.

Ramin Farzaneh-Far, M.D., of the University of California, San Francisco, and colleagues conducted a study to determine whether omega-3 fatty acid blood levels were associated with changes in leukocyte (a type of blood cell) telomere length in a study of 608 outpatients with stable coronary artery disease. The patients were recruited between September 2000 and December 2002 for the Heart and Soul Study, and followed up to January 2009 (median [midpoint], 6.0 years). The researchers measured leukocyte telomere length at the beginning of the study and again after 5 years of follow-up. Multivariable models were used to examine the association of baseline levels of omega-3 fatty acids (docosahexaenoic acid [DHA] and eicosapentaenoic acid [EPA]) with subsequent change in telomere length.

The researchers found that individuals in the lowest quartile of DHA+EPA experienced the most rapid rate of telomere shortening, whereas those in the highest quartile experienced the slowest rate of telomere shortening. "Levels of DHA+EPA were associated with less telomere shortening before and after sequential adjustment for established risk factors and potential confounders. Each 1-standard deviation increase in DHA+EPA levels was associated with a 32 percent reduction in the odds of telomere shortening," the authors write.

"In summary, among patients with stable coronary artery disease, there was an inverse relationship between baseline blood levels of marine omega-3 fatty acids and the rate of telomere shortening over 5 years."

"These findings raise the possibility that omega-3 fatty acids may protect against cellular aging in patients with coronary heart disease," the researchers write.

Friday, January 22, 2010

The “Chocolate Cure” for Emotional Stress

The “chocolate cure” for emotional stress is now getting new support from a clinical trial published online in ACS’ Journal of Proteome Research:
“Metabolic Effects of Dark Chocolate Consumption on Energy, Gut Microbiota, and Stress-Related Metabolism in Free-Living Subjects”


It found that eating about an ounce and a half of dark chocolate a day for two weeks reduced levels of stress hormones in the bodies of people feeling highly stressed. Everyone’s favorite treat also partially corrected other stress-related biochemical imbalances.

Sunil Kochhar and colleagues note growing scientific evidence that antioxidants and other beneficial substances in dark chocolate may reduce risk factors for heart disease and other physical conditions. Studies also suggest that chocolate may ease emotional stress. Until now, however, there was little evidence from research in humans on exactly how chocolate might have those stress-busting effects.

In the study, scientists identified reductions in stress hormones and other stress-related biochemical changes in volunteers who rated themselves as highly stressed and ate dark chocolate for two weeks. “The study provides strong evidence that a daily consumption of 40 grams [1.4 ounces] during a period of 2 weeks is sufficient to modify the metabolism of healthy human volunteers,” the scientists say.

Thursday, January 21, 2010

Over age 50 - cut copper and iron intake

With scientific evidence linking high levels of copper and iron to Alzheimer's disease, heart disease, and other age-related disorders, a new report in ACS' Chemical Research in Toxicology suggests specific steps that older consumers can take to avoid build up of unhealthy amounts of these metals in their bodies. "This story of copper and iron toxicity, which I think is reaching the level of public health significance, is virtually unknown to the general medical community, to say nothing of complete unawareness of the public," George Brewer states in the report.

The article points out that copper and iron are essential nutrients for life, with high levels actually beneficial to the reproductive health of younger people. After age 50, however, high levels of these metals can damage cells in ways that may contribute to a range of age-related diseases.

"It seems clear that large segments of the population are at risk for toxicities from free copper and free iron, and to me, it seems clear that preventive steps should begin now." The article details those steps for people over age 50, including avoiding vitamin and mineral pills that contain cooper and iron; lowering meat intake: avoiding drinking water from copper pipes; donating blood regularly to reduce iron levels; and taking zinc supplements to lower copper levels.

Blueberry juice improves memory in older adults





Scientists are reporting the first evidence from human research that blueberries — one of the richest sources of healthful antioxidants and other so-called phytochemicals — improve memory. They said the study establishes a basis for comprehensive human clinical trials to determine whether blueberries really deserve their growing reputation as a memory enhancer. A report on the study appears in ACS' Journal of Agricultural and Food Chemistry, a bi-weekly publication.

Robert Krikorian and colleagues point out that previous studies in laboratory animals suggest that eating blueberries may help boost memory in the aged. Until now, however, there had been little scientific work aimed at testing the effect of blueberry supplementation on memory in people.

In the study, one group of volunteers in their 70s with early memory decline drank the equivalent of 2-2 l/2 cups of a commercially available blueberry juice every day for two months. A control group drank a beverage without blueberry juice. The blueberry juice group showed significant improvement on learning and memory tests, the scientists say. "These preliminary memory findings are encouraging and suggest that consistent supplementation with blueberries may offer an approach to forestall or mitigate neurodegeneration," said the report. The research involved scientists from the University of Cincinnati, the U.S. Department of Agriculture, and the Canadian department of agriculture.

Reducing Salt = Fewer Heart Attacks, Strokes and Deaths

Findings Published in New England Journal of Medicine

Reducing salt in the American diet by as little as one-half teaspoon (or three grams) per day could prevent nearly 100,000 heart attacks and 92,000 deaths each year, according to a new study. Such benefits are on par with the benefits from reductions in smoking and could save the United States about $24 billion in healthcare costs, the researchers add.

A team from the University of California, San Francisco, Stanford University Medical Center and Columbia University Medical Center conducted the study. The findings appear January 20 in online publication by the New England Journal of Medicine and also will be reported in the February 18 print issue of the journal.

The team’s results were derived from the Coronary Heart Disease Policy Model, a computer simulation of heart disease among U.S. adults that has been used by researchers to project benefits from public health interventions.

“A very modest decrease in the amount of salt, hardly detectable in the taste of food, can have dramatic health benefits for the U.S.,” said Kirsten Bibbins-Domingo, PhD, MD, lead author of the study, UCSF associate professor of medicine and epidemiology and the co-director of the UCSF Center for Vulnerable Populations at San Francisco General Hospital.


Lee Goldman, M.D.
“It was a surprise to see the magnitude of the impact on the population, given the small reductions in salt that we were modeling,” Bibbins-Domingo added.

The CHD Policy Model found that reducing dietary salt by three grams per day (about 1200 mg of sodium) would result in 11 percent fewer cases of new heart disease, 13 percent fewer heart attacks, 8 percent fewer strokes, and 4 percent fewer deaths. For African Americans, who researchers believe are more likely to have high blood pressure and may be more sensitive to salt, this degree of salt reduction could reduce new cases of heart disease by 16 percent and heart attacks by 19 percent.

“Reducing dietary salt is one of those rare interventions that has a huge health benefit and actually saves large amounts of money. At a time when so much public debate has focused on the costs of health care for the sick, here is a simple remedy, already proven to be feasible in other countries,” said Lee Goldman, MD, MPH, senior author, executive vice president for health and biomedical sciences and dean of the faculties of health sciences and medicine at Columbia University.

The American Heart Association reports that salt consumption among Americans has risen by 50 percent and blood pressure has risen by nearly the same amount since the 1970s - despite evidence linking salt intake to high blood pressure and heart disease.

“In addition to its independent benefits on blood pressure, reducing salt intake can enhance the effects of most anti-hypertensive (blood pressure lowering) agents and reduce complications associated with diabetes, obesity and kidney disease,” said Glenn M. Chertow, MD, study co-author, professor of medicine and chief of the Division of Nephrology at Stanford University.

According to federal government data, the average American man consumes more than10 grams of salt (4000 mg sodium) daily. Most health organizations recommend far lower targets - no more than 5.8 grams of salt per day (2300 mg sodium) and less than 3.8 grams for those over 40. Each gram of salt contains 0.4 grams of sodium.

“It’s clear that we need to lower salt intake, but individuals find it hard to make substantial cuts because most salt comes from processed foods, not from the salt shaker,” Bibbins-Domingo said. “Our study suggests that the food industry and those who regulate it could contribute substantially to the health of the nation by achieving even small reductions in the amount of salt in these processed foods.”

The New York City Department of Public Health and other state and local municipalities nationally have seen salt as an important target for regulation. Mayor Michael Bloomberg has already made sweeping changes to the City’s health regulations, including cutting trans fats in eating places and requiring fast-food restaurant menus to list calories. Now the city is seeking to join a national movement in cutting salt intake by 25 percent, which he referenced in today’s State of the City address.

“Our projects suggest that these regulatory efforts could both improve health and save money because of the healthcare costs avoided,” said Bibbins-Domingo. “For every dollar spent in regulating salt, anywhere from seven to 76 healthcare dollars could be saved.”

Wednesday, January 20, 2010

Stretching Good For Your Heart Health?

From the NY Times:

What is surprising are some early indications that increasing your flexibility might somehow loosen up your arteries, too. That was the accidental and, as yet unreplicated finding of a small 2008 study at the University of Texas at Austin. The study was designed to examine whether weight lifting increased arterial stiffness. (It didn’t, at least on this occasion.) The control group consisted of people who stretched. They were not expected to show any change in cardiac function, but over the course of 13 weeks they in fact increased the pliability of their arteries by more than 20 percent.

Mr. Yamamoto and his colleagues are currently conducting an ambitious study to determine just how and whether stretching directly affects the arteries. The results won’t be available for some time. Until then, Mr. Yamamoto says, it’s best to consider your flexibility (or lack thereof) as a marker of your probable arterial elasticity. “If you can touch your toes in the sit-and-reach test, your flexibility is good,” he says. If you can’t, you might consider talking to your cardiologist — although, remember, as Mr. Yamamoto points out, that tight arteries are not necessarily diseased arteries. They’re just less than ideally fit.

Friday, January 15, 2010

Latest Health Research

Good and bad news in the latest health research reports.

I drink lots of green tea, which is good, and don’t smoke, which is even better:


Green tea fights lung cancer risk for smokers:



Among smokers and non-smokers, those who did not drink green tea had a 5.16-fold increased risk of lung cancer compared with those who drank at least one cup of green tea per day. Among smokers, those who did not drink green tea at all had a 12.71-fold increased risk of lung cancer compared with those who drank at least one cup of green tea per day.




I take Vitamin D which is good, but not calcium, which I guess I bad – I need to think about adding it to my regimen:

CALCIUM/VITAMIN D PREVENT FRACTURES:



Taking both calcium and vitamin D supplements on a daily basis reduces the risk of bone fractures, regardless of whether a person is young or old, male or female, or has had fractures in the past, a large study of nearly 70,000 patients from throughout the United States and Europe has found.




I am not particularly hairy which is good:

Wet and Hairy = Sunburn?



Water droplets held above human skin by body hair can cause sunburn This is because the hairs can hold the water droplets in focus above the surface, acting as a magnifying glass.




I don’t eat mangoes or pomegranates, which is too bad because they are both very good for you:

Mango fights colon, and breast cancer

Pomegranates fight breast cancer



Eating fruit, such as pomegranates, that contain anti-aromatase phytochemicals reduces the incidence of hormone-dependent breast cancer, according to results of a study published in the January issue of Cancer Prevention Research, a journal of the American Association for Cancer Research.




I don’t drink much champagne, which I guess is too bad, but do drink plenty of red wine, which is very good (not the wine, but the health benefit) :


Champagne Is Good for Your Heart:



Dr Jeremy Spencer, from the Department of Food and Nutritional Sciences said: "Our research has shown that drinking around two glasses of champagne can have beneficial effects on the way blood vessels function, in a similar way to that observed with red wine. We always encourage a responsible approach to alcohol consumption, but the fact that drinking champagne has the potential to reduce the risks of suffering from cardiovascular diseases such as heart disease and stroke, is very exciting news."




I don’t get much Vitamin C, which is too bad because it’s even better for you than we thought:

Vitamin C Is Good For You:



Famous for its antioxidant properties and role in tissue repair, vitamin C is touted as beneficial for illnesses ranging from the common cold to cancer and perhaps even for slowing the aging process. Now, a study uncovers an unexpected new role for this natural compound: facilitating the generation of embryonic-like stem cells from adult cells.



I don’t do yoga, which is bad, but my wife does, which is good:

YOGA REDUCES INFLAMMATION



Regularly practicing yoga exercises may lower a number of compounds in the blood and reduce the level of inflammation that normally rises because of both normal aging and stress, a new study has shown.




I’ve been cutting way back on my carbs, which has some benefit, although not what I hoped for, but I also kept fat consumption way down, so I’m not in as bad shape as some on low-carb diets:


Low Carb Diet Reduces Pain and Inflammation,

But Not Weight or Heart Risks:



Low-carb diets could be bad for the heart and are no more effective in weight loss than a diet that is high in carbs and low in fat, according to recent research. Some obese people may be considering taking on a low-carb lifestyle for the New Year, such as the popular Atkins diet. But recent research shows that a high-fat, low-carb way of eating could be bad for the heart – and, it is no more effective for losing weight than a diet low in fat and high in carbs.

A research team led by Dr. Steven Hunter of the Royal Victoria Hospital in Ireland examined a group of obese adults. Some of them were on a low-carb, high-fat diet and the others were eating a diet that was low in fat.

The average weight loss was the same for both groups, but over time, the people who ate a high-fat diet showed a clear increase in cardiovascular risk factors.

The Atkins diet allows high-fat meats, including bacon – and many people who try this diet will indulge in them. But Dr. Hunter explained that the risks outweigh the benefits. Patients don’t lose weight much faster than with other diets, and the high saturated fat content can put a toll on the heart. A better bet for the new year, says Dr. Hunter, is a diet low in fat, coupled with exercise.



I get plenty of exrercie, which is very good, but I also sit much too much, which is very, very bad:


Exercise = Reduced Cogntive Risk


Moderate physical activity performed in midlife or later appears to be associated with a reduced risk of mild cognitive impairment.


Exercise Is Good For You

Just three months of physical activity reaps heart health benefits for older adults with type 2 diabetes by improving the elasticity in their arteries -- reducing risk of heart disease and stroke.


Sedentary TV time may cut life short



Study highlights:
Australian researchersfound that each hour spent in front of the television daily was associated with:
" an 11 percent increased risk of death from all causes,
" a 9 percent increased risk of cancer death; and
" an 18 percent increased risk of cardiovascular disease (CVD)-related death.
Compared with people who watched less than two hours of television daily, those who watched more than four hours a day had a 46 percent higher risk of death from all causes and an 80 percent increased risk for CVD-related death. This association held regardless of other independent and common cardiovascular disease risk factors, including smoking, high blood pressure, high blood cholesterol, unhealthy diet, excessive waist circumference, and leisure-time exercises.
While the study focused specifically on television watching, the findings suggest that any prolonged sedentary behavior, such as sitting at a desk or in front of a computer, may pose a risk to one’s health. The human body was designed to move, not sit for extended periods of time, said David Dunstan, Ph.D., the study’s lead author and professor and Head of the Physical Activity Laboratory in the Division of Metabolism and Obesity at the Baker IDI Heart and Diabetes Institute in Victoria, Australia.

“What has happened is that a lot of the normal activities of daily living that involved standing up and moving the muscles in the body have been converted to sitting, “ Dunstan said. Technological, social, and economic changes mean that people dont move their muscles as much as they used to - consequently the levels of energy expenditure as people go about their lives continue to shrink. For many people, on a daily basis they simply shift from one chair to anotherfrom the chair in the car to the chair in the office to the chair in front of the television.

Dunstan said the findings apply not only to individuals who are overweight and obese, but also those who have a healthy weight. “Even if someone has a healthy body weight, sitting for long periods of time still has an unhealthy influence on their blood sugar and blood fats, “ he said.

Although the study was conducted in Australia, Dunstan said the findings are certainly applicable to Americans. Average daily television watching is approximately three hours in Australia and the United Kingdom, and up to eight hours in the United States, where two-thirds of all adults are either overweight or obese.


And finally, some notes that have nothing to do with my personal health:

Pregnant women should eat bacon and eggs:




If you're pregnant and looking for an excuse to eat bacon and eggs, now you've got one: a new research study shows that choline plays a critical role in helping fetal brains develop regions associated with memory. Choline is found in meats, including pork, as well as chicken eggs.


Raising kids lowers blood pressure



A new Brigham Young University study found that parenthood is associated with lower blood pressure, particularly so among women.

Thursday, January 14, 2010

Raising kids lowers blood pressure

They turn Dad’s hair gray, but children can now take partial credit for the health of Mom’s heart.

A new Brigham Young University study found that parenthood is associated with lower blood pressure, particularly so among women.

Julianne Holt-Lunstad, a BYU psychologist who studies relationships and health, reports her findings Jan. 14 in the peer-reviewed journal Annals of Behavioral Medicine.




Of course parenthood is not the only route to low blood pressure – daily exercise and a low-sodium diet also do the trick. The noteworthy aspect of the study is the idea that social factors may also protect physical health.

“While caring for children may include daily hassles, deriving a sense of meaning and purpose from life’s stress has been shown to be associated with better health outcomes,” Holt-Lunstad said.

The study involved 198 adults who wore portable blood pressure monitors, mostly concealed by their clothes, for 24 hours.

The monitors took measurements at random intervals throughout the day – even while participants slept. This method provides a better sense of a person’s true day-to-day blood pressure. Readings taken in a lab can be inflated by people who get the jitters in clinical settings. It’s a real phenomenon known as the “white coat” effect, and it can mess up the results of studies done without the portable monitors.

A statistical analysis allowed the researchers to account for other factors known to influence blood pressure – things like age, body mass, gender, exercise, employment and smoking – and zero in on the effect of parenthood. For parents overall, the 24-hour blood pressure readings averaged 116 / 71.

All other things being equal, parents scored 4.5 points lower than non-parents in systolic blood pressure (the top number) and 3 points lower than non-parents in diastolic blood pressure. Holt-Lunstad says the size of the difference is statistically significant, but she warns against hastily making major life changes based on this finding alone.

“This doesn’t mean the more kids you have, the better your blood pressure,” Holt-Lunstad said. “The findings are simply tied to parenthood, no matter the number of children or employment status.”

The effect was more pronounced among women, with motherhood corresponding to a 12-point difference in systolic blood pressure and a 7-point difference in diastolic blood pressure.

And if fulfilling relationships make your body feel better, it’s no surprise what stressful relationships can do. See this story on “frenemies” for more about that:
BYU study shows why 'frenemies' make blood pressure rise


About the study participants

All participants were married and considered to be in good health.

Age range: 20 to 68 years old

Parental status: 70 percent had children

Average number of children: 1.9

Ethnicity: 80.6 percent white

Average years of education: 16

CALCIUM/VITAMIN D PREVENT FRACTURES

Taking both calcium and vitamin D supplements on a daily basis reduces the risk of bone fractures, regardless of whether a person is young or old, male or female, or has had fractures in the past, a large study of nearly 70,000 patients from throughout the United States and Europe has found.

The study included data published in 2006 from clinical trials conducted at UC Davis in Sacramento as part of the Women’s Health Initiative (WHI). It appears online in this week’s edition of the British Medical Journal.

“What is important about this very large study is that goes a long way toward resolving conflicting evidence about the role of vitamin D, either alone or in combination with calcium, in reducing fractures,” said John Robbins, professor of internal medicine at UC Davis and a co-author of the journal article. “Our WHI research in Sacramento included more than 1,000 healthy, postmenopausal women and concluded that taking calcium and vitamin D together helped them preserve bone health and prevent fractures. This latest analysis, because it incorporates so many more people, really confirms our earlier conclusions.”

Led by researchers at Copenhagen University in Denmark, Robbins and an international team of colleagues analyzed the results of seven large clinical trials from around the world to assess the effectiveness of vitamin D alone or with calcium in reducing fractures among people averaging 70 years or older. The researchers could not identify any significant effects for people who only take vitamin D supplements.

Among the clinical trial results analyzed was Robbins’ WHI research, which was part of a 15-year, national program to address the most common causes of death, disability and poor quality of life in postmenopausal women such as cardiovascular disease, cancer and osteoporosis. Those trials were primarily designed to study the effect of calcium and vitamin D supplementation in preventing hip fractures, with a secondary objective of testing the supplements on spine and other types of fractures, as well as on colorectal cancer. The results were published in the Feb. 16, 2006 edition of the New England Journal of Medicine.

Fractures are a major cause of disability, loss of independence and death for older people. The injuries are often the result of osteoporosis, or porous bone, a disease characterized by low bone mass and bone fragility. The National Osteoporosis Foundation estimates that about 10 million Americans have osteoporosis; 80 percent of them are women. Four of 10 women over age 50 will experience a fracture of the hip, spine or wrist in their lifetime, and osteoporosis-related fractures were responsible for an estimated $19 billion in health-related costs in 2005.

“This study supports a growing consensus that combined calcium and vitamin D is more effective than vitamin D alone in reducing a variety of fractures,” said Robbins. “Interestingly, this combination of supplements benefits both women and men of all ages, which is not something we fully expected to find. We now need to investigate the best dosage, duration and optimal way for people to take it.”

Radon Gas Is America's Leading In-Home Killer

According to recent reports from the World Health Organization, radon gas is responsible for approximately 20,000 deaths in the U.S. and 100,000 deaths worldwide each year. This equates to about 15% of all lung cancer deaths. Statistically, radon is the leading cause of lung cancer for non-smokers and the second leading cause for smokers. Learn more about radon gas

Wednesday, January 13, 2010

Thyme oil fights inflammation

For those who do not drink, researchers have found that six essential oils –from thyme, clove, rose, eucalyptus, fennel and bergamot—can suppress the inflammatory COX-2 enzyme, in a manner similar to resveratrol, the chemical linked with the health benefits of red wine. They also identified that the chemical carvacrol was primarily responsible for this suppressive activity.

These findings, appearing in the January issue of Journal of Lipid Research, provide more understanding of the health benefits of many botanical oils and provide a new avenue for anti-inflammatory drugs.

Essential oils from plants have long been a component of home remedies, and even today are used for their aromatherapy, analgesic (e.g. cough drops), or antibacterial properties. Of course, the exact way they work is not completely understood. However, Hiroyasu Inoue and colleagues in Japan believed that many essential oils might target COX-2 much like compounds in wine and tea.

So, they screened a wide range of commercially available oils and identified six (thyme, clove, rose, eucalyptus, fennel and bergamot) that reduced COX-2 expression in cells by at least 25%. Of these, thyme oil proved the most active, reducing COX-2 levels by almost 75%.

When Inoue and colleagues analyzed thyme oil, they found that the major component –carvacrol– was the primary active agent; in fact when they use pure carvacrol extracts in their tests COX-2 levels decreased by over 80%.

Tuesday, January 12, 2010

Low-Carb Diet Bad for the Heart?

Low-carb diets could be bad for the heart and are no more effective in weight loss than a diet that is high in carbs and low in fat, according to recent research.

Some obese people may be considering taking on a low-carb lifestyle for the New Year, such as the popular Atkins diet. But recent research shows that a high-fat, low-carb way of eating could be bad for the heart – and, it is no more effective for losing weight than a diet low in fat and high in carbs.

A research team led by Dr. Steven Hunter of the Royal Victoria Hospital in Ireland examined a group of obese adults. Some of them were on a low-carb, high-fat diet and the others were eating a diet that was low in fat.

The average weight loss was the same for both groups, but over time, the people who ate a high-fat diet showed a clear increase in cardiovascular risk factors.

The Atkins diet allows high-fat meats, including bacon – and many people who try this diet will indulge in them. But Dr. Hunter explained that the risks outweigh the benefits. Patients don’t lose weight much faster than with other diets, and the high saturated fat content can put a toll on the heart. A better bet for the new year, says Dr. Hunter, is a diet low in fat, coupled with exercise.

Green tea fights lung cancer risk for smokers

Drinking green tea could modulate the effect of smoking on lung cancer. Results of this hospital-based, randomized study conducted in Taiwan were presented at the AACR-IASLC Joint Conference on Molecular Origins of Lung Cancer, held there from Jan. 11-14, 2010.

"Lung cancer is the leading cause of all cancer deaths in Taiwan," said I-Hsin Lin, M.S., a student at Chung Shan Medical University in Taiwan. "Tea, particularly green tea, has received a great deal of attention because tea polyphenols are strong antioxidants, and tea preparations have shown inhibitory activity against tumorigenesis."

However, previous studies of green tea have been inhibited by the flaws of the epidemiologic model with its inherent biases.

Lin and colleagues enrolled 170 patients with lung cancer and 340 healthy patients as controls. The researchers administered questionnaires to obtain demographic characteristics, cigarette smoking habits, green tea consumption, dietary intake of fruits and vegetables, cooking practices and family history of lung cancer. They also performed genotyping on insulin-like growth factors as polymorphisms on the following insulin-like growth factors: IGF1, IGF2 and IGFBP3, which have all been reported to be associated with cancer risk.

Among smokers and non-smokers, those who did not drink green tea had a 5.16-fold increased risk of lung cancer compared with those who drank at least one cup of green tea per day. Among smokers, those who did not drink green tea at all had a 12.71-fold increased risk of lung cancer compared with those who drank at least one cup of green tea per day.

Lin and colleagues suspect genetics may play a role in this risk differential. Green tea drinkers with non-susceptible IGF1 (CA)19/(CA)19 and (CA)19/X genotypes reported a 66 percent reduction in lung cancer risk as compared with green tea drinkers carrying the IGF1 X/X genotype.

Heavy smokers carrying susceptible IGF1, IGF2 and IGFBP3 genotypes also had a higher risk of lung cancer compared with nonsmokers carrying non-susceptible IGF1, IGF2 and IGFBP3 genotypes.

"Our study may represent a clue that in the case of lung cancer, smoking-induced carcinogenesis could be modulated by green tea consumption and the growth factor environment," said Lin.