Thursday, May 31, 2007

CPR: Push Harder!

New findings show that the majority of people untrained in how to perform cardiopulmonary resuscitation, and even many trained emergency personnel, do not push with enough force to properly administer CPR.

The research tested 104 adults untrained in CPR and 83 firefighters, trained in the procedure. The findings, to be published in the June issue of the journal Cardiovascular Engineering¹, showed that most of the untrained people simply do not apply enough force, said Leslie Geddes of Purdue University, one of the authors of the study.

The success rate for CPR ranges from 5 percent to 10 percent, depending on how quickly it is administered after a person's heart stops. "This is important because every minute lost in applying CPR results in a 10 percent decrease in successful resuscitation," Geddes said. "Time is the enemy. After 10 minutes, very few are resuscitated. The American Heart Association recommends pushing with enough force to compress the chest 1.5 to 2 inches, which requires 100 to 125 pounds of force.”

The research represents the first time such measurements have been recorded to quantify just how hard people push in a simulated CPR test. The findings showed that 60 percent of the CPR-trained rescue personnel pushed with more than 125 pounds, whereas more than 60 percent of those not trained in CPR failed to push with more than 125 pounds of force.

The people in the study were asked to push on a bathroom scale as though they were performing CPR, and their force was recorded by the scale. "All we are trying to establish is how hard people are able to push in a simulated CPR situation," Geddes said. "You can't tell from the data how successful they would have been at resuscitation in a real-life situation."

Pushing with more than 125 pounds increases the potential for rib fractures. Nevertheless, the chances of survival increase enormously. New guidelines from the American Hearth Association recommend that rescuers performing CPR should "push harder and faster," Geddes said. "As a result of this recommendation, it's likely that the resuscitation rate will increase, but it's equally likely that the fracture rate will increase."

Use Caution with All Pain Medications

Not long ago, choosing a pain reliever meant finding one that eased your pain without being too hard on the stomach. Now, research suggests that some commonly used pain medications—not just the now-banned Vioxx—can raise the risk of having a heart attack or stroke. New step-by-step recommendations from the American Heart Association (AHA) can help you choose a pain reliever that's good for both the heart and stomach, reports the June 2007 issue of the Harvard Heart Letter.

The AHA suggests starting with aspirin or acetaminophen (Tylenol) to quell muscle or joint pain. Aspirin is good for the heart, and acetaminophen doesn’t affect blood clotting. If they don't work, the next step for most people would be a nonsteroidal anti-inflammatory drug (NSAID). Try naproxen (Aleve) first, then ibuprofen (Advil). Next is diclofenac, but more caution is needed with this drug (which is available only by prescription). Celebrex, the only drug in the class known as COX-2 inhibitors that remains on the market, should be the last resort for managing pain. In addition to the side effect of increasing the risk of clots in the bloodstream, COX-2 inhibitors can also reduce blood flow through the kidneys and raise blood pressure. For short-term pain in some people, a narcotic pain reliever such as tramadol (Ultram), codeine, or fentanyl (Actiq, Duragesic) may be an option.

The Harvard Heart Letter notes that you shouldn’t be afraid to take aspirin, Tylenol, Advil, or Aleve for occasional aches and pains. But if you need a pain reliever several times a week, pay closer attention to your choices and talk with your doctor.

Also in this issue:
• Angioplasty vs. medical therapy
• Using CT scans to diagnose heart disease
• Spinal alignment and blood pressure
• More evidence against trans fats
• Can I stop taking my blood pressure medicine? And, can I take nitroglycerine during exercise?

The Harvard Heart Letter is available from Harvard Health Publications, the publishing division of Harvard Medical School, for $28 per year. Subscribe at http://www.health.harvard.edu/heart

Wednesday, May 30, 2007

Flavonol in tea, cocoa, etc. & exercise = memory+

A natural compound found in blueberries, tea, grapes, and cocoa enhances memory in mice, according to newly published research. This effect increased further when mice also exercised regularly.

"This finding is an important advance because it identifies a single natural chemical with memory-enhancing effects, suggesting that it may be possible to optimize brain function by combining exercise and dietary supplementation," says Mark Mattson, PhD, at the National Institute on Aging.

The compound, epicatechin, is one of a group of chemicals known as flavonols and has been shown previously to improve cardiovascular function in people and increase blood flow in the brain. Flavonols are found in some chocolate. Henriette van Praag, PhD, of the Salk Institute, and colleagues there and at Mars, Inc., showed that the combination of exercise and a diet with epicatechin also promoted structural and functional changes in the dentate gyrus, a part of the brain involved in the formation of learning and memory. The findings, published in the May 30 issue of The Journal of Neuroscience, suggest that a diet rich in flavonols may help reduce the incidence or severity of neurodegenerative disease or cognitive disorders related to aging.

Van Praag and her team compared mice fed a typical diet with those fed a diet supplemented with epicatechin. Half the mice in each group were allowed to run on a wheel for two hours each day. After a month, the mice were trained to find a platform hidden in a pool of water. Those that both exercised and ate the epicatechin diet remembered the location of the platform longer than the other mice.

When studying their brains, van Praag and her colleagues found that these mice had greater blood vessel growth in the dentate gyrus and had developed more mature nerve cells, suggesting an enhanced ability of the cells to communicate. Further analysis showed that the epicatechin and exercise combination had a beneficial effect on the expression of genes important for learning and memory, and decreased the activity of genes playing a role in inflammation and neurodegeneration.

The researchers found that sedentary mice fed epicatechin showed enhanced memory, blood vessel growth, and gene activity, but these benefits were even more evident in mice that also exercised.

"A logical next step will be to study the effects of epicatechin on memory and brain blood flow in aged animals," says van Praag, "and then humans, combined with mild exercise."

Aerobic exercise helps maintain muscle in elderly

Why do older people tend to lose muscle mass and grow frail? One important factor identified by medical science is the reduced ability of the elderly to respond to the muscle-building stimulus of the hormone insulin.

Insulin is best known for its link to diabetes — a condition in which either a complete lack of insulin or systemic resistance to the hormone's activity (as in type 2 diabetes) causes blood sugar levels to soar out of control. Recent studies have shown, however, that insulin also provides crucial assistance in building muscle, and that its ability to do so drops off dramatically in the elderly.

Now, a small but provocative study by medical researchers in Texas and California suggests that a simple, cost-free therapy appears to largely overcome that drop-off in insulin response: moderate aerobic exercise such as walking.

Experiments at the University of Texas Medical Branch at Galveston (UTMB) and the University of Southern California, Los Angeles conducted on 13 healthy volunteers in their late 60s showed that 45 minutes of walking 20 hours before exposure to insulin restored the muscle-growth-stimulating effects of the hormone to levels comparable to those seen in normal young adults.

Prior research had suggested that a large part of the problem older people experience lies in the tiny blood vessels that feed the muscles protein-building amino acids, glucose and insulin (which itself also works within muscle cells as a powerful protein growth factor). In young adults, these normally closed vessels open wide in response to the insulin increase generated by a meal, providing clear passage for muscle-making materials. In elderly people, however, this process, known as "vasodilation," is much less pronounced.

"We thought, let's see what happens if we use aerobic exercise, one of the interventions that has been shown in the past to improve vasodilation, to find out whether we can get insulin to stimulate muscle synthesis in older people," said UTMB professor Elena Volpi, senior author of a paper on the experiments appearing in the June issue of the journal Diabetes. "It turned out that a fast walk restored the insulin response quite well."

To test their hypothesis, the researchers first required six of their 13 subjects to walk for 45 minutes on a treadmill quickly enough to keep their hearts beating at 70 percent of their maximum rate —the same aerobic intensity level recommended to maintain cardiovascular fitness. The other seven subjects simply rested.

On the following morning, the researchers sampled the blood going into and coming out of thigh muscle in each of the volunteers, while supplying via the femoral artery a concentration of insulin similar to that released after a typical meal. They also took three small muscle tissue samples from each subject.

Tracer techniques enabled the scientists to track amino acids (the building blocks of muscle proteins) and determine muscle-protein synthesis and breakdown rates from the blood and muscle samples, while measuring blood flow at the same time. These revealed that the volunteers who exercised had both higher blood flow and net muscle protein growth. In addition, the researchers screened the muscle biopsy samples for signals associated with insulin's ability to stimulate the assembly of muscle protein from amino acids. This test also showed that exercise boosted insulin's role as a muscle protein growth factor.

"We already know that moderate aerobic exercise reduces cardiovascular disease, improves glucose uptake, and improves endurance," Volpi said. "Now it looks like it may also slow the rate of muscle loss in aging. We need to test this hypothesis further with larger trials, but still, it's one more reason why elderly people ought to be regularly walking, swimming or cycling."

Tuesday, May 29, 2007

Can You Exercise Too Much?

You run in the morning, train for your next marathon at night despite a nagging injury, and head to the gym to weight train in your free time. Missing a workout is not an option.

Are you exercised obsessed, or just an avid exercise enthusiast?

That depends on your attitude, say mental health experts. If you exercise frequently because you enjoy it and you like the health benefits it provides, you have the right reasons in mind. If you exercise because you feel compelled to do so, and in spite of having injuries, you may be at risk for developing an exercise disorder.

“There is no set formula or standard that reveals how much exercising is too much,” says Theresa Fassihi, Ph.D., a psychologist with the Eating Disorders Program at The Menninger Clinic. “But if exercising is interfering in a person’s life, and it is compulsory, then it may be a problem.”

Dr. Fassihi treats patients in the Eating Disorders Program who over exercise in an attempt to burn off calories, build muscle or attain physical perfection. It is common for patients with exercise disorders to also have an eating disorder, Fassihi says. Problems occur when body perception doesn’t match reality.

As with eating disorders, persons involved in activities or professions that require physical beauty or high levels of physical performance—such as athletes and dancers—are particularly vulnerable to developing exercise disorders. High achievers with perfectionist personalities are also vulnerable. Both men and women can have an exercising disorder, but they often have different goals for their exercise regimens. Women seek the “lean look” and typically exercise aerobically to become thin. Men want to bulk up and lift weights to increase muscle mass.

“If you have an exercising disorder, you also may be very preoccupied about your body’s appearance, weight and muscle mass.” Dr. Fassihi says. “You spend a lot of time looking at yourself, scrutinizing yourself, measuring yourself and constantly working out to create the muscle mass or lean body that you want.”

Distorted body image, also called body dysmorphia, is a common component of an exercising disorder. Persons with body dysmorphia have a distorted view and exaggerated vision of their appearance—thin women may think they are too big, and muscular men may think they are too puny or scrawny. The obsession with being too small or frail is a subtype of body dysmorphia called muscle dysmorphia, nicknamed bigorexia, which is most common in men. Men with muscle dysmorphia constantly weight train and exercise to achieve a more muscular or perceived “manly” body.

To achieve their ideal body or fitness goals, many persons with exercise disorders also restrict their calories, based on the mistaken belief that they will build a higher proportion of muscle if they restrict their food intake while exercising, Dr. Fassihi says. Instead, they lose both muscle and fat, putting their health at risk.

“Over exercising can cause significant damage to the body,” Dr. Fassihi adds. “It can increase the risk of injuries for both men and women. Women may be more at risk for osteoporosis if they are over exercising and restricting their food intake, and they may stop menstruating completely. Men may use steroids and protein powders to help them achieve their goals, leading to other health problems.”

Over exercising can also cause stress fractures, which can impede walking. Constant repetitive exercise can cause wear and tear on the body’s muscle, bones and joints--in severe cases making joint replacement surgery necessary at a young age.

Despite their health problems, many persons who over exercise are reluctant to admit their behavior is problematic, Dr. Fasshi says. Exercise provides them with a sense of control, power, and in some cases, superiority. Exercise also relieves anxiety and releases endorphins, which provide a sense of euphoria. Because of the positive aspects of exercise, and its value in our achievement and appearance oriented-society, treatment for exercise disorders can be difficult.

“If you give up an addiction that is bad for you, you give it up cold turkey. However, you can’t give up exercise completely, because it is healthy,” Dr. Fassihi says. “You want to learn how to exercise moderately in a healthy way. That’s very tough without help from a professional.”

Staff members with the Eating Disorders Program at Menninger work with patients who over exercise to help them recognize normal levels of exercise. At the beginning of treatment, patients are limited to the mildest physical activity, such as walking, in an attempt to increase their body weight to normal levels. As treatment progresses, patients may increase their amount of exercise. By the time they leave Menninger, patients are exercising moderately every other day, for about four hours a week.

Men and women also learn to confront their anxiety about not exercising, and learn other methods to help them relieve their anxiety—such as relaxation and breathing exercises. They may also participate in a body image group to identify negative beliefs they have about their bodies and how to dispute those beliefs.

With treatment, patients realize the toll that over exercising has taken on their lives.

“Over exercising interferes with their quality of life because they devote so much of their time to exercise to the exclusion of anything else,” Dr. Fassihi says. “Their time is not available for socializing, relationships or work. It is all consuming.”

Sidebar:

Am I exercising too much?

Dr. Fassihi says your attitude toward exercising provides important clues about whether you have a problem with over exercising. You may be exercising too much if you:

* Feel you absolutely cannot miss your workout. If you do miss a workout, you feel extremely guilty and uneasy.

* Feel you have to exercise even if you notice that instead of helping your body; you are damaging your body.

* Are getting more injuries.

* Hear family and friends expressing concern about your exercise regimen or appearance, yet don’t stop exercising.

* Feel like you can’t stop exercising. “It can feel like an addiction for some people,” Dr. Fassihi says. “They feel like they are powerless to stop.”

If you believe you have an over exercising disorder or at risk for developing an over exercising disorder, seek help from a trusted advisor, such as a coach or teacher, or a doctor or mental health professional.

Carb, Protein Supps Can Reduce Muscle Damage

A new study in The Journal of Strength and Conditioning Research suggests that drinking a carbohydrate and protein supplement prior to and during exercise does not improve exercise performance. However, subjects who consumed the supplement did experience significantly reduced muscle damage compared to control subjects.

The study examined the effects of consuming a carbohydrate and protein supplement prior to, during, and following an intense resistance exercise workout. The results indicate that a carbohydrate and protein supplement can significantly reduce muscle damage during acute bouts of resistance exercise, potentially allowing athletes to participate in their next high-intensity exercise bout in a shorter period of time. This finding can also apply to novice lifters and other individuals who regularly engage in resistance training.

The study authors are careful to note that although the supplement did not appear to influence exercise performance, previous studies were based on exercise programs targeting one main group of muscles, while the exercise program in this study incorporated the entire body.

To read the entire study, please click here: http://www.allenpress.com/pdf/scre_21_284_321_329.pdf.

The Journal of Strength and Conditioning Research, the official peer-reviewed research journal of the National Strength and Conditioning Association (NSCA), provides the reader with a better understanding of conditioning and sport by publishing premier scientific papers on exercise, sport, and conditioning practices. The journal provides important insights relating to training, nutritional, and biological factors that affect physical performance. Please visit the journal online at http://nsca.allenpress.com.

The NSCA brings is the worldwide authority on strength and conditioning, and supports and disseminates research-based knowledge and its practical application to improve athletic performance and fitness. For more information about the NSCA, please visit http://www.nsca-lift.org.

Soy Nuts May Improve Blood Pressure

Substituting soy nuts for other protein sources in a healthy diet appears to lower blood pressure in postmenopausal women, and also may reduce cholesterol levels in women with high blood pressure, according to a report in the May 28 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

The American Heart Association estimates that high blood pressure (hypertension) affects approximately 50 million Americans and 1 billion individuals worldwide. The most common-and deadly-result is coronary heart disease, according to background information in the article. Women with high blood pressure have four times the risk of heart disease as women with normal blood pressure.

Francine K. Welty, M.D., Ph.D., and colleagues at Beth Israel Deaconess Medical Center, Boston, assigned 60 healthy post-menopausal women to eat two diets for eight weeks each in random order. The first diet, the Therapeutic Lifestyle Changes (TLC) diet, consisted of 30 percent of calories from fat (with 7 percent or less from saturated fat), 15 percent from protein and 55 percent from carbohydrates; 1,200 milligrams of calcium per day; two meals of fatty fish (such as salmon or tuna) per week; and less than 200 milligrams of cholesterol per day. The other diet had the same calorie, fat and protein content, but the women were instructed to replace 25 grams of protein with one-half cup of unsalted soy nuts. Blood pressure and blood samples for cholesterol testing were taken at the beginning and end of each eight-week period.

At the beginning of the study, 12 women had high blood pressure (140/90 milligrams of mercury or higher) and 48 had normal blood pressure. "Soy nut supplementation significantly reduced systolic [top number] and diastolic [bottom number] blood pressure in all 12 hypertensive women and in 40 of the 48 normotensive women," the authors write. "Compared with the TLC diet alone, the TLC diet plus soy nuts lowered systolic and diastolic blood pressure 9.9 percent and 6.8 percent, respectively, in hypertensive women and 5.2 percent and 2.9 percent, respectively, in normotensive women."

In women with high blood pressure, the soy diet also decreased levels of low-density lipoprotein ("bad") cholesterol by an average of 11 percent and levels of apoliprotein B (a particle that carries bad cholesterol) by an average of 8 percent. Cholesterol levels remained the same in women with normal blood pressure.

"A 12-millimeter of mercury decrease in systolic blood pressure for 10 years has been estimated to prevent one death for every 11 patients with stage one hypertension treated; therefore, the average reduction of 15 milligrams of mercury in systolic blood pressure in hypertensive women in the present study could have significant implications for reducing cardiovascular risk and death on a population basis," the authors write.

"This study was performed in the free-living state; therefore, dietary soy may be a practical, safe and inexpensive modality to reduce blood pressure. If the findings are repeated in a larger group they may have important implications for reducing cardiovascular risk in postmenopausal women on a population basis," they conclude.

Exercise May Boost "Good" Cholesterol Levels

Regular exercise appears to modestly increase levels of high-density lipoprotein, or "good," cholesterol, according to a meta-analysis study in the May 28 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

A low level of high-density lipoprotein cholesterol (HDL-C) is an independent risk factor for cardiovascular disease, the leading cause of death worldwide, according to background information in the article. There is strong evidence that individuals who are more physically active have higher HDL-C levels. "Thus, the value of regular aerobic exercise in increasing serum [blood] HDL-C level and in reducing the risk of cardiovascular disease has received widespread acceptance," the authors write. "In contrast, results of aerobic exercise studies vary considerably, depending on the exercise program (e.g., duration, intensity or frequency) and characteristics of subjects at baseline."

Satoru Kodama, M.D., of Ochanomizu University, Tokyo, and colleagues performed a meta-analysis of 25 articles reporting the results of randomized controlled trials that were published between 1966 and 2005 and assessed the effects of exercise on HDL-C. To be included in the analysis, the studies had to evaluate aerobic exercise in adults with an average age of 20 or older, specify HDL-C measurements at the beginning and end of the study, have a length of at least eight weeks, and randomly assign some participants to a group of exercisers and others to a control group of non-exercisers.

The 25 articles analyzed included a total of 1,404 participants with an average age range of 23 to 75 years and an average study period of 27.4 weeks. The exercise groups were told to exercise for an average of 3.7 sessions per week at an average of 40.5 minutes each, burning an average of 1,019 calories per week.

In all the studies combined, HDL-C increased by an average of 2.53 milligrams per deciliter in the exercise groups. The minimum amount of weekly exercise that appeared necessary to change HDL-C levels was 120 minutes or 900 calories burned. The effect of exercise was greater in those who had a higher total cholesterol level (220 milligrams per deciliter or greater) and in those with a body mass index of less than 28.

"In a previous observational study, every 1-milligram per deciliter increment in HDL-C level was reported to be associated with a 2 percent and 3 percent decreased risk of cardiovascular disease in men and women, respectively," the authors write. "If this observation were applied to our results, the increase in HDL-C level by exercise determined by this analysis would, by a rough estimate, result in a cardiovascular disease risk reduced by approximately 5.1 percent in men and 7.6 percent in women. This is potentially of substantial importance in public health, although the effect of reducing cardiovascular risk by increasing HDL-C level might be smaller than that by use of medications such as fibrates or niacin."

Only exercise duration, and not frequency or intensity, was associated with a change in HDL-C levels in the analysis. When the participants exercised for 23 to 74 minutes per session, each 10-minute increase in exercise duration corresponded to a 1.4-milligram per deciliter increase in HDL-C level. "This suggests that in improving blood HDL-C values, increasing time per session is better than performing multiple brief exercise sessions when total time for exercise is limited, as is the case for many people," the authors write.

Vitamin D, Calcium = Lower Risk of Breast Cancer

Intake of Vitamin D, Calcium Associated With Lower Risk of Breast Cancer Before Menopause

Women who consume higher amounts of calcium and vitamin D may have a lower risk of developing premenopausal breast cancer, according to a report in the May 28 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

Data from animal studies have linked calcium and vitamin D to breast cancer prevention, according to background information in the article. However, epidemiologic studies on humans have been less conclusive.

Jennifer Lin, Ph.D., of Brigham and Women's Hospital and Harvard Medical School, Boston, and colleagues assessed 10,578 premenopausal and 20,909 postmenopausal women age 45 and older who were part of the Women's Health Study. At the beginning of the study (in 1993 or 1995), the women completed a questionnaire about their medical history and lifestyle, plus a food frequency questionnaire that detailed how often they consumed certain foods, beverages and supplements during the previous year. Every six months during the first year and then every year after that, participants returned follow-up questionnaires indicating whether they had been diagnosed with breast cancer.

Over an average of 10 years of follow-up, 276 premenopausal women and 743 postmenopausal women developed breast cancer. Calcium and vitamin D intake were moderately associated with a lower risk of breast cancer before but not after menopause. The inverse associated in premenopausal women appeared more pronounced for more aggressive breast tumors.

"A possible explanation for the evident difference by menopause status may be related to the joint relationship among calcium, vitamin D and insulinlike growth factors (IGFs)," they continue. "In vitro studies have suggested that calcium and vitamin D exert anticarcinogenic effects on breast cancer cells expressing high levels of IGF-1 and IGF binding protein 3. Calcium, vitamin D and IGF binding protein 3 have been shown in vitro to interact with each other in promoting growth inhibition in breast cancer cells." Since blood levels of these compounds decline with age, they would be more prevalent in younger, premenopausal women.

"Further investigation is warranted to study the potential utility of calcium and vitamin D intake in reducing the risk of breast cancer," the authors conclud

Friday, May 25, 2007

Eating apples/fish helps vs asthma/allergies

Women who eat apples and fish during pregnancy may reduce the risk of their children developing asthma or allergic disease, suggests a new study presented at the American Thoracic Society 2007 International Conference, on Sunday, May 20.

The SEATON study, conducted at the University of Aberdeen, UK, found that the children of mothers who ate the most apples were less likely to ever have wheezed or have doctor-confirmed asthma at the age of 5 years, compared to children of mothers who had the lowest apple consumption. Children of mothers who ate fish once or more a week were less likely to have had eczema than children of mothers who never ate fish.

The study did not find any protective effect against asthma or allergic diseases from many other foods, including vegetables, fruit juice, citrus or kiwi fruit, whole grain products, fat from dairy products or margarine or other low-fat spreads.

The researchers studied 1212 children born to women who had filled out food questionnaires during their pregnancy. When the children were 5 years old, the mothers filled out a questionnaire about the children’s respiratory symptoms and allergies, as well as a questionnaire about their child’s food consumption.

The children were also given lung function and allergy tests. Previous studies in the same children have found evidence for protective effects of vitamin E and D and zinc during pregnancy in reducing the risk of children’s wheeze and asthma, notes researcher Saskia Willers, M.Sc. of Utrecht University in the Netherlands. If the new results are confirmed, she says, "recommendations on dietary modification during pregnancy may help to prevent childhood asthma and allergy."

Willers concludes that at least until age 5, a mother’s diet during pregnancy might be more influential on a child’s respiratory health than the child’s own diet. She notes that further study of this group of children will be needed to see whether the association with the mothers’ diet declines in older children, and if mothers’ and their childrens’ diets interact in older children.

Willers suggests that the beneficial effect of apples may come from powerful antioxidants called flavonoids, while fish’s protective effect may come from omega-3 fatty acids, which other studies have suggested have a protective effect on the heart and may have a protective effect in asthma. "Other studies have looked at individual nutrients’ effect on asthma in pregnancy, but our study looked at specific foods during pregnancy and the subsequent development of childhood asthma and allergies, which is quite new," Willers says. "Foods contain mixtures of nutrients that may contribute more than the sum of their parts."

Sleep apnea increases risk of heart attack, death a lot

The nighttime breathing disorder known as obstructive sleep apnea increases a person’s risk of having a heart attack or dying by 30% over a period of four to five years, according to a study presented at the American Thoracic Society 2007 International Conference, on Monday, May 21.

The more severe the sleep apnea at the beginning of the study, the greater the risk of developing heart disease or dying, the study found.

“While previous studies have shown an association between sleep apnea and heart disease, ours is a large study that allowed us to not only follow patients for five years and look at the association between sleep apnea and the combined outcome of heart attack and death, but also adjust for other traditional risk factors for heart disease,” says researcher Neomi Shah, M.D., of Yale University.

“We recommend that patients who experience symptoms of obstructive sleep apnea—excessive daytime sleepiness, or snoring along with breathing pauses—consult their physician,” Dr. Shah says. “There is some evidence to make us believe that when sleep apnea is appropriately treated, the risk of heart disease can be lowered.”

In obstructive sleep apnea, the upper airway narrows, or collapses, during sleep. Periods of apnea end with a brief partial arousal that may disrupt sleep hundreds of times a night. Obesity is a major risk factor for sleep apnea.

The most effective treatment for sleep apnea is a technique called nasal CPAP, for continuous positive airway pressure, which delivers air through a mask while the patient sleeps, keeping the airway open. It has proved successful in many cases in providing a good night’s sleep, preventing daytime accidents due to sleepiness and improving quality of life.

The study included 1,123 patients referred for sleep apnea evaluation. They underwent an overnight sleep study to determine if they had sleep apnea. Over the next four to five years, they were followed to see how many had any heart disease events (heart attack, coronary angiography or bypass surgery) or died.

Sleep apnea triggers the body’s “fight or flight” mechanism, which decreases the amount of blood pumped to the heart. Repeated episodes every night for a few years can starve the heart of enough oxygen when it is combined with the body’s decreased oxygen intake due to the frequent breathing stoppages during the night, Dr. Shah says.

Green tea may protect from inflamed bladder

Herbal agents could be used to treat inflammatory bladder diseases, according to a preliminary study that looked at the ability of green tea to protect bladder cells from inflammation. The University of Pittsburgh School of Medicine study, being presented at the annual meeting of the American Urological Association (AUA) in Anaheim, Calif., found that components of green tea protected bladder cells from damage in culture. The study is Abstract 299 in the AUA proceedings.

Green tea, reported to have many health benefits, is rich in powerful antioxidants that make it a possible remedy for many medical conditions. It is comprised of catechins – plant metabolites that provide it with many anti-oxidative properties.

"We discovered that catechins found in green tea protected both normal and cancerous bladder cells from inflammation when we exposed the cells to hydrogen peroxide," said Michael B. Chancellor, M.D., professor of urology and gynecology at the University of Pittsburgh School of Medicine. "Although further studies are needed, these results indicate herbal supplements from green tea could be a treatment option for various bladder conditions that are caused by injury or inflammation."

In the study, normal and cancerous bladder cells were exposed to two major catechin components of green tea, epigallocatechin gallate (EGCG) and epicatechin gallate (ECG), for 23 hours. Both significantly protected cell lines from exposure to hydrogen peroxide, which damages or kills cells. The concentrations of EGCG and ECG used in the study were at levels that may be achieved through dietary intake.

###
Approximately ten million American adults have problems controlling their bladders. Bladder disease affects both men and women and can include incontinence or interstitial cystitis, a chronic inflammatory condition that causes frequent, urgent and painful urination and pelvic discomfort.

Vitamin supplements don't protect vs. lung cancer?

Some vitamin supplements don't protect against lung cancer

A study of more than 75,000 adults found that taking supplemental multivitamins, vitamin C and E and folate do not decrease the risk of lung cancer. The findings are being reported at the American Thoracic Society 2007 International Conference, on Monday, May 21.

The study, which also did not find any increased lung cancer risk from the supplements, is one of the most detailed, prospective observational studies to look at the effect of vitamin supplements instead of vitamins from foods on lung cancer risk.

“People are spending billions of dollars on supplements, and there is a general sense in the population that they prevent cancer,” said researcher Chris Slatore, M.D., of the University of Washington School of Medicine in Seattle. “We need to find out if they’re helpful or even harmful.”

The 77,738 men and women in the VITamins And Lifestyle (VITAL) study, ages 50-76, filled out an extensive questionnaire on vitamin intake over the previous 10 years, including how much of each supplement they took. The researchers then checked to see how many of the people in the study had lung cancer, using a government cancer registry. They found 393 cases of lung cancer. Adjusting for such risk factors as smoking, age, sex, cancer history, other lung disease and history of lung cancer, they found no statistically significant relationships between different types of supplements and lung cancer.

In 1996, a large study known as the CARET study which was looking into the effects of the dietary supplements beta-carotene and retinol (vitamin A), was halted after the supplements were found to increase lung cancer risk, particularly among smokers. That study, and others, encouraged researchers to look more deeply into the relationship between supplements and lung cancer, Dr. Slatore said.

The new lung cancer and supplements study is part of a larger study that is looking at supplements and various types of cancer, including prostate cancer and breast cancer, Dr. Slatore said.

Supplements have been getting a lot of attention this year. In February, the Journal of the American Medical Association published an overview of studies that found that supplements of beta-carotene, vitamin E, or vitamin A slightly increases a person's risk of death.

Retinol lotion reduces the fine wrinkles from aging

Retinol lotion reduces the fine wrinkles from natural aging of skin

Products previously were thought only to improve skin aged by sun

Lotions containing retinol improve the appearance of skin that has become wrinkled through the normal aging process, not just skin that has been damaged by exposure to the sun, according to a new study from the University of Michigan Health System.

Researchers tested lotions containing retinol – Vitamin A that is found in many skin-care products – on the skin of elderly patients. Lotion containing retinol was used on one arm of each participant, while a lotion without retinol was applied to the other arm.

Wrinkles, roughness and overall aging severity were all significantly reduced in the retinol-treated arm compared with the control arm, according to the study, which appears in the May issue of the journal Archives of Dermatology. The production of collagen, due to the retinol treatment, also makes it more likely that the skin can withstand injury and ulcer formation, researchers say.

“With the population aging so rapidly, it is important that we find ways of treating skin conditions of elderly people – not just for purposes of vanity, but also for the healing of wounds and the reduction of ulcers,” says senior author Sewon Kang, M.D., professor of dermatology at the U-M Medical School.

This research serves as an important step forward in the understanding of how aging skin can be improved, researchers say.

“In the past, it was everyone believed that retinoids would treat only photoaging, or damage from exposure to sun. This is the first systematic, double-blind study showing that it improves any kind of aging – photoaging as well as natural aging,” says co-author John J. Voorhees, M.D., the Duncan and Ella Poth Distinguished Professor and chair of the Department of Dermatology at the U-M Medical School. “You can rub it anywhere, and it will help to treat the signs of aging.”

The lotion was made at U-M, but U-M will not commercialize this lotion because it was designed only for experimental purposes and, therefore, is cosmetically undesirable. Many retinol containing cosmeceutical creams, however, are sold by various companies. Those specific products were not tested by the U-M team.

The reduction of wrinkles in the study’s participants was due to increased collagen production and a significant induction of glycosaminoglycans, which are known to retain large quantities of water. In general, aging skin tends to be thinner, laxer and more prone to fine wrinkles than young skin.

Exercise reverses aging in human skeletal muscle

Buck Institute faculty leads study showing 'genetic fingerprint' becoming younger in healthy seniors who did resistance training

Not only does exercise make most people feel better and perform physical tasks better, it now appears that exercise – specifically, resistance training -- actually rejuvenates muscle tissue in healthy senior citizens.

A recent study, co-led by Buck Institute faculty member Simon Melov, PhD, and Mark Tarnopolsky, MD, PhD, of McMaster University Medical Center in Hamilton, Ontario, involved before and after analysis of gene expression profiles in tissue samples taken from 25 healthy older men and women who underwent six months of twice weekly resistance training, compared to a similar analysis of tissue samples taken from younger healthy men and women. The results of the study appear in the May 23 edition of the on-line, open access journal PLoS One.

The gene expression profiles involved age-specific mitochondrial function; mitochondria act as the "powerhouse" of cells. Multiple studies have suggested that mitochondrial dysfunction is involved in the loss of muscle mass and functional impairment commonly seen in older people. The study was the first to examine the gene expression profile, or the molecular "fingerprint", of aging in healthy disease-free humans.

Results showed that in the older adults, there was a decline in mitochondrial function with age. However, exercise resulted in a remarkable reversal of the genetic fingerprint back to levels similar to those seen in the younger adults. The study also measured muscle strength. Before exercise training, the older adults were 59% weaker than the younger adults, but after the training the strength of the older adults improved by about 50%, such that they were only 38% weaker than the young adults.

"We were very surprised by the results of the study," said Melov. "We expected to see gene expressions that stayed fairly steady in the older adults. The fact that their 'genetic fingerprints' so dramatically reversed course gives credence to the value of exercise, not only as a means of improving health, but of reversing the aging process itself, which is an additional incentive to exercise as you get older."

The study participants were recruited at McMaster University. The younger (20 to 35 with an average age of 26) and older (older than 65 with an average age of 70) adults were matched in terms of diet and exercise; none of them took medication or had diseases that can alter mitochondrial function. Tissue samples were taken from the thigh muscle. The six month resistance training was done on standard gym equipment. The twice-weekly sessions ran an hour in length and involved 30 contractions of each muscle group involved, similar to training sessions available at most fitness centers. The strength test was based on knee flexion.

The older participants, while generally active, had never participated in formal weight training said co-first author Tarnopolsky, who directs the Neuromuscular and Neurometabolic Clinic at McMaster University. In a four month follow up after the study was complete, he said most of the older adults were no longer doing formal exercise in a gym, but most were doing resistance exercises at home, lifting soup cans or using elastic bands. "They were still as strong, they still had the same muscle mass," said Tarnopolsky. "This shows that it's never too late to start exercising and that you don't have to spend your life pumping iron in a gym to reap benefits."

Future studies are being designed to determine if resistance training has any genetic impact on other types of human tissue, such as those that comprise organs; researchers also want to determine whether endurance training (running, cycling) impacts mitochondrial function and the aging process. The most recent study also points to particular gene expressions that could be used as starting points for chemical screenings that could lead to drug therapies that would modulate the aging process.

"The vast majority of aging studies are done in worms, fruit flies and mice; this study was done in humans," said Melov. "It's particularly rewarding to be able to scientifically validate something practical that people can do now to improve their health and the quality of their lives, as well as knowing that they are doing something which is actually reversing aspects of the aging process."

Botox injections help men with enlarged prostate

Men with enlarged prostate can benefit from botox injections up to a year after treatment

Injecting botulinum toxin A, or Botox, into the prostate gland of men with enlarged prostate, eased symptoms and improved quality of life up to a year after the procedure, according to a study by researchers at the Chang Gung University Medical College, Taiwan, and the University of Pittsburgh School of Medicine. The study, based on 37 men with benign prostatic hyperplasia (BPH), will be presented at the annual meeting of the American Urological Association (AUA) in Anaheim, Calif. and published in Abstract 1837 in the AUA proceedings.

"Millions of men in the United States suffer from enlarged prostate," said Michael B. Chancellor, M.D., senior author of the study and professor of urology and gynecology at the University of Pittsburgh School of Medicine. "It's a challenging disease to live with because it causes frequent and difficult urination. Unfortunately, common treatments also are problematic because they carry some risk of serious side effects, such as impotence. Our results are encouraging because they indicate that Botox could represent a simple, safe and effective treatment for enlarged prostate that has long-term benefits."

The study participants, previously diagnosed with symptomatic BPH that did not respond to standard medical treatment, received injections of Botox directly into their prostate glands. Up to one year post injection, 27 of these patients, or 73 percent, experienced a 30 percent improvement in urinary tract symptoms and quality of life. Patients did not experience any significant side effects, including stress urinary incontinence or erectile dysfunction.

According to Yao-Chi Chuang, M.D., principal investigator of the study from Chang Gung University Medical College, Taiwan, Botox reduces the size of the prostate gland through a cellular process called apoptosis, in which the prostate cells die in a programmed manner. This reduction in size can improve urine flow and decrease residual urine left in the bladder.

BPH is one of the most common diseases affecting men as they age. More than half of all men over the age of 60 and 80 percent by age 80, will have enlarged prostates. Forty to 50 percent will develop symptoms, which include more frequent urination, urinary tract infections, the inability to completely empty the bladder and, in severe cases, eventual damage to the bladder and kidneys.

Benefits of aspirin to prevent colon cancer

A colon cancer researcher at the Ireland Cancer Center of University Hospitals Case Medical Center (UHCMC) has laid out the roadmap for how medical science should employ aspirin and new aspirin-like drugs for use in preventing colon cancer in certain high-risk individuals.

In today's New England Journal of Medicine, Sanford Markowitz, MD, PhD, writes an editorial accompanying research from Dr. Charles Fuchs' team at Harvard Medical School that lays out the hypothesized mechanism by which the use of aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs), also called COX-2 inhibitors, act to decrease the risk of developing colon cancer.

"The compelling evidence that chronic use of aspirin or certain NSAIDS can substantially lower the risk of colon cancer has important implications, especially because colon cancer is the second leading cause of cancer death," writes Dr. Markowitz, the Francis Wragg Ingalls Professor of Cancer Genetics at UHCMC and Case Western Reserve University School of Medicine.

In the Journal article, the Harvard researchers' findings demonstrated that two-thirds of colon cancers have high levels of expression of the COX-2 enzyme, which is blocked by aspirin. Individuals who regularly used aspirin over a course of several years demonstrated a 36% decrease in the risk of developing one of these high COX-2 expressing colon cancers. These results again demonstrated that drugs that block COX-2 can decrease the risk of colon cancer, and demonstrated that such drugs specifically target those individuals whose tumor development is encouraged by the action of the COX-2 enzyme.

Dr. Markowitz' accompanying editorial maps out those studies which will be required to determine the potential use of aspirin in prevention of colon cancer and to determine which individuals might benefit most from taking aspirin or aspirin-like drugs (NSAIDS) such as ibuprofen and Celebrex. Finally, the editorial outlines potential targets for development of drugs that might provide similar protection as aspirin or COX-2 inhibitor drugs for developing colon cancer but with a lesser risk of adverse side effects.

"Interventional trials have shown a decreased risk of the development of colon cancer in high-risk subjects who were given aspirin or COX-2 selective NSAID inhibitors and observational trials have associated a decreased risk of colon cancer with aspirin use," writes Dr. Markowitz in the editorial. "The researchers' findings provide powerful support for the role of COX-2 as a key mediator in the development of colon cancer and now pose questions about the biologic basis and clinical applications of discovering differences that express high or low levels of COX-2."

Dr. Markowitz has done seminal research in the field of colon cancer genetics and prevention. Among his numerous research articles, he published a study on the findings of a new "Celebrex-like" gene that suppresses the grown of colon cancer in the July 2006 issue of Proceedings of the National Academy of Sciences. Dr. Markowitz likens the gene, called 15-PGDH, to a naturally occurring Cox-2 inhibitor such as Celebrex. These findings may lead to the development of a new drug for colon cancer prevention.

"Sandy and his research team have made great strides in colon cancer prevention," says Stanton Gerson, MD, Director of the Ireland Cancer Center at University Hospitals Case Medical Center as well as the Case Comprehensive Cancer Center. "This editorial and all of his proceeding work may have great impact on individuals at high risk for developing this deadly disease."

Moderate drinking lowers women's heart attack risk

Women who regularly enjoy an alcoholic drink or two have a significantly lower risk of having a non-fatal heart attack than women who are life-time abstainers, epidemiologists at the University at Buffalo have shown.

Moderation is the key, however. Women in the study who reported being intoxicated at least once a month were nearly three times more likely to suffer a heart attack than abstainers, results showed.

One difference in the protective pattern among drinkers involved those who drank primarily liquor. Women who preferred liquor to wine experienced a borderline increase in risk of heart attack, results showed.

The study is published in the May 2007 issue of the journal Addiction.

"These findings have important implications, because heart disease is the leading cause of death for women," said Joan M. Dorn, Ph.D., associate professor of social and preventive medicine in the UB School of Public Health and Health Professions and first author on the study.

Women seem to have a quicker reaction to a smaller amount of alcohol, she noted: "Overdoing it is harmful, and what is too much depends on each individual. In some women, one drink can cause intoxication."

Moderate alcohol consumption has been shown to lower the risk of heart attack, but most studies have been done with men. The current study compared alcohol drinking volume and drinking patterns of women who had been hospitalized due to a heart attack, with age-matched controls without heart problems.

Women who had a prior heart attack, coronary bypass surgery, angioplasty, angina or a previous diagnosis of cardiovascular disease were excluded from the study.

Participants -- 320 heart attack patients and 1,565 controls -- were enrolled between 1996 and 2001. Extensive information was collected on the type of beverage consumed, serving size for each beverage and number of drinks consumed during the two years prior to the heart attack, or for controls, two years prior to the interview.

The researchers computed several variables. Drinking status was categorized as lifetime abstainers (women who reported never having 12 or more drinks in their lifetime or in any 1-year period); non-current drinkers (those who didn't consume at least one drink per month during the reference period), and current drinkers.

Additional variables calculated were: total ounces of alcohol consumed; drinks per drinking day; drinking frequency; drinking primarily with food; beverage preference -- wine, beer, liquor, or some of each; and frequency of intoxication -- current drinkers who stated they drank enough to get drunk or very high, once or more a month, and less than once a month.

Results showed that in this population-based study, women who drank moderately had a significantly lower risk of heart attack than abstainers, and the benefits were greatest in women who had a drink daily. A lower risk for drinkers than abstainers also was evident in women who drank with food, as well as without, and in those who primarily drank wine or a variety of alcoholic beverages.

Similar, but weaker, associations were found when patterns and volume were analyzed among drinkers only. Among these women, drinking alcohol in moderation in general was more important than the actual amount consumed. However, getting drunk at least once a month puts women at a significantly increased risk of heart attack, negating any of alcohol's potential protective effect.

Dorn emphasized that no one should interpret these finding as a reason to begin consuming alcohol, because alcohol brings with it risks for other conditions, such as breast cancer.

"I certainly wouldn't recommend that women start drinking, but among those who do, if they are concerning about heart health, the message is that a small amount is OK."

Grim warning for America's fast food consumers

It's research that may have you thinking twice before upgrading to the large size at your favorite fast food joint. Saint Louis University research presented this week in Washington, D.C., shows the dangers of high-fat food combined with high fructose corn syrup and a sedentary lifestyle – in other words, what may be becoming commonplace among Americans.

Brent Tetri, M.D., associate professor of internal medicine at Saint Louis University Liver Center, and colleagues studied the effects of a diet that was 40 percent fat and replete with high fructose corn syrup, a sweetener common in soda and some fruit juices. The research is being presented at the Digestive Diseases Week meeting.

"We wanted to mirror the kind of diet many Americans subsist on, so the high fat content is about the same you'd find in a typical McDonald's meal, and the high fructose corn syrup translates to about eight cans of soda a day in a human diet, which is not far off with what some people consume," says Tetri, a leading researcher in nonalcoholic fatty liver disease, which can lead to cirrhosis and, ultimately, death. "But we were also keeping the mice sedentary, with a very limited amount of activity."

The study, which lasted for 16 weeks, had some curious results, says Tetri.

"We had a feeling we'd see evidence of fatty liver disease by the end of the study," he says. "But we were surprised to find how severe the damage was and how quickly it occurred. It took only four weeks for liver enzymes to increase and for glucose intolerance – the beginning of type II diabetes – to begin."

And unlike other studies, the mice were not forced to eat; rather, they were able to eat whenever they wanted – and eat they did. Tetri says there's evidence that suggests fructose actually suppresses your fullness, unlike fiber-rich foods, which make you feel full quickly.

The take-home message for humans is obvious, he says.

"A high-fat and sugar-sweetened diet compounded by a sedentary lifestyle will have severe repercussions for your liver and other vital organs," he says. "Fatty liver disease now affects about one of every eight children in this country. The good news is that it is somewhat reversible – but for some it will take major changes in diet and lifestyle."

People may need more dietary choline

New study indicates that people may need more dietary choline than previously thought

Eggs one of the best sources of the nutrient

A new study published in the May issue of the American Journal of Clinical Nutrition indicates that the current recommended Adequate Intake (AI) for choline may, in fact, be inadequate for some people. Choline is an essential nutrient for normal functioning of all cells, including those involved with liver metabolism, brain and nerve function, memory, and the transportation of nutrients throughout the body.

In this depletion-repletion study, 57 adult subjects (26 men, 16 premenopausal women and 15 postmenopausal women) were fed a diet containing 550 mg of choline for 10 days, then fed less than 50 mg a day of choline for up to 42 days.

When deprived of the nutrient, 77 percent of men, 80 percent of postmenopausal women and 44 percent of premenopausal women developed fatty liver or muscle damage.

Six men (23 percent) developed these signs while consuming the initial 550 mg of daily choline, even though 550 mg is the current AI for men.

Nineteen percent of the subjects required as high as 825 mg of daily choline to prevent or reverse the organ dysfunction associated with the low-choline diet, an amount significantly higher than the current AI.

For all participants, blood homocysteine levels increased during choline depletion. Other studies have associated high homocysteine levels with heart disease.

"These study results clearly indicate that some adults, notably men and post-menopausal women, need more choline than is recommended by the current AI," says study co-author Kerry-Ann da Costa, PhD, a research assistant professor at the University of North Carolina at Chapel Hill. "We hope these findings will aid the Institute of Medicine in refining the Dietary Reference Intake (DRI) of this nutrient."

This study is the most complete study of choline requirements to date and is the first to include women. Its division of participants into two groups – one receiving dietary supplementation of folic acid and one not – also determined that susceptibility to choline deficiency was not altered by folic acid supplementation.

Closing the Choline Gap

Additional research on the population demonstrated that choline intake is far below the current AI, a concern that intakes may be too low to meet the needs of many individuals.

Research conducted at Iowa State University found that only 10 percent or less of older children, men, women and pregnant women in America get the AI of choline each day.

A separate study presented this month at the National Nutrient Data Bank Conference found that choline intake decreases with age and that adults ages 71 and older consume an average of about 264 milligrams per day – roughly half of the AI for choline.

Eggs, beef liver, chicken liver and wheat germ are considered excellent sources of choline. Two eggs contain 280 milligrams of choline, half the recommended daily supply.

"Eggs are a practical food that can help people get the choline they need, along with several other nutrients, at just 75 calories an egg," says registered dietitian Maye Musk. "Choline is actually found in the yolk of the egg, so people who consistently only eat egg whites may be missing out on a key nutrient opportunity."

Why Choline Matters

The importance of dietary choline has been well-established.

A 2004 study in the American Journal of Epidemiology linked poor dietary choline to adverse outcomes during pregnancy, including a four-fold increased risk of having a baby with a neural tube defect.

A research review published in the Annual Reviews of Nutrition suggests that choline plays an important role in normal fetal development, particularly during the stages that involve knowledge acquirement and life-long memory function.

Binge drinking= deficits among college students

Binge drinking leads to neurocognitive deficits among college students


Alcoholics tend to have poorer neurocognitive functioning, including decision-making capabilities.

A new study has found that binge drinking, common among college students, is associated with impaired decision making.
The long-term neurocognitive effects of binge drinking during young adulthood are unclear.

Researchers know that alcoholics tend to have poorer neurocognitive functioning, including decision making, than non-alcoholics do. Less is known, however, about alcohol’s effects on decision-making capabilities among people who drink heavily but are not considered alcoholics. A new study has found that binge drinking can lead to poor decision making among college students, independent of impulsivity.

Results are published in the June issue of Alcoholism: Clinical & Experimental Research.

"Alcoholics tend to exhibit poorer decision making such as preferring short-term rewards, when these are coupled to long-term losses, instead of choosing options which go together with long-term rewards," said Anna E. Goudriaan, a postdoctoral researcher at the University of Amsterdam and corresponding author for the study.

These choices tend to reflect more serious problems with executive functioning, added Jenny Larkins, a graduate student in clinical psychology at the University of Missouri. "Executive functioning involves skills such as planning for the future, abstract reasoning, inhibiting or delaying responses, initiating behavior, doing two things at once, and shifting between two activities in a flexible way," she said.

"There are not a lot of studies that focus on the effects of heavy alcohol use in people who are not addicted to alcohol," said Goudriaan. "However, it seemed logical … that heavy alcohol would impact their decision making, and we targeted young adults since they tend to drink the most, and binge drink the most. We specifically targeted binge drinking, since some animal studies suggest that it is deleterious for brain functioning."

Researchers examined 200 participants in an ongoing student-health study at the University of Missouri-Columbia. They formed four subgroups (n=50, 50% male) according to estimated binge-drinking trajectories during pre-college through to second year: low-binge drinkers; stable moderate-binge drinkers; increasing binge drinkers; and stable high-binge drinkers. Study authors also gathered decision-making and impulsivity measures, Iowa Gambling Task (IGT) results, and multiple indicators of heavy alcohol use.

Note: The Iowa Gambling Task is a computer card game in which four decks of cards are presented on the screen. The participant must choose a card from one of the four decks: each time they choose a card they will "win" money, but every so often, choosing a card will cause them to "lose" money. The goal of the game is to win as much money as possible. Decks A and B have a total penalty of $1250 for every ten cards; C and D have a total penalty of $250 for every ten cards). Thus, A and B are "bad decks," and C and D are "good decks."

"We found that stable high-binge drinking, starting at a pre-college age, is related to diminished decision-making abilities, as exemplified by preferring short-term rewards over long-term losses," said Goudriaan. "In other words, this study shows that even in a group of "healthy" college students who are not alcoholics, heavy alcohol use is related to diminished decision making abilities or disadvantageous cognitive functions."

"It is also interesting to note that neither externalizing psychopathology nor impulsivity as measured by questionnaires was associated with impaired IGT performance," observed Larkins. "However, this finding … should be tested in other college student samples as it could be due to the sampling strategy employed."

"Based on these results and those from several other studies," said Larkins, "adolescence appears to be a time of exquisite sensitivity to the effects of alcohol on the brain. For these reasons, parents and clinicians must be especially diligent in monitoring young people to prevent alcohol abuse, and further attention to treatment programs designed for adolescents is warranted."

Coffee consumption may lower blood uric acid levels

Coffee consumption may lower blood uric acid levels -- the precursor of gout

High uric acid levels in the blood are a precursor of gout, the most common inflammatory arthritis in adult men. It is believed that coffee and tea consumption may affect uric acid levels but only one study has been conducted to date. A new large-scale study published in the June 2007 issue of Arthritis Care & Research (http://www.interscience.wiley.com/journal/arthritiscare) examined the relationship between coffee, tea, caffeine intake, and uric acid levels and found that coffee consumption is associated with lower uric acid levels but that this appears to be due to components other than caffeine.

Coffee is one of the most widely consumed beverages in the world; more than 50 percent of Americans drink it at the average rate of 2 cups per day. Because of this widespread consumption, its potential effects have important implications for public and individual health. Led by Hyon K. Choi, of the University of British Columbia in Vancouver, Canada, the current study was based on the U.S. Third National Health and Nutrition Examination Survey, conducted between 1988 and 1994. It included over 14,000 men and women at least 20 years old who consented to a medical exam in which blood and urine specimens were obtained. Coffee and tea consumption were determined based on responses to a food questionnaire that assessed intake over the previous month. Researchers estimated the amount of caffeine per cup of coffee or tea using data from the U.S. Department of Agriculture.

The results showed that levels of uric acid in the blood significantly decreased with increasing coffee intake, but not with tea intake. In addition, there was no association between total caffeine intake from beverages and uric acid levels. These results were similar to those found in the only previous study on the topic, which was conducted in Japan. Interestingly, there was an association between decaffeinated coffee consumption and uric acid levels. "These findings suggest that components of coffee other than caffeine contribute to the observed inverse association between coffee intake and uric acid levels," the researchers state.

A recent study found that coffee was associated lower C peptide levels (a marker of insulin levels). The researchers in the current study suggest that because there is a strong relationship between insulin resistance and elevated uric acid levels, the decreased insulin levels associated with coffee consumption may lead to lower uric acid levels. Coffee is also a major source of chlorogenic acid, a strong antioxidant, which may improve insulin sensitivity. Chlorogenic acid also helps inhibit glucose absorption in the intestine; in another study decaffeinated coffee seemed to delay intestinal absorption of glucose and increase concentrations of glucagon-like peptide 1, which is well known for its beneficial effects on insulin secretion and action. The researchers note further that their results could be due to an effect of non-caffeine components found in coffee, which would also explain why coffee affected uric acid levels but tea did not.


To examine how coffee consumption might aggravate or protect against this common and excruciatingly painful condition, researchers at the Arthritis Research Centre of Canada, University of British Columbia in Canada, Brigham and Women’s Hospital, Harvard Medical School, and Harvard School of Public Health in Boston conducted a prospective study on 45,869 men over age 40 with no history of gout at baseline. Over 12 years of follow-up, Hyon K. Choi, MD, DrPH, and his associates evaluated the relationship between the intake of coffee and the incidence of gout in this high risk population. Their findings, featured in the June 2007 issue of Arthritis & Rheumatism (http://www.interscience.wiley.com/journal/arthritis), provide compelling evidence that drinking 4 or more cups of coffee a day dramatically reduces the risk of gout for men.

Subjects were drawn from an ongoing study of some 50,000 male health professionals, 91 percent white, who were between 40 and 75 years of age in 1986 when the project was initiated. To assess coffee and total caffeine intake, Dr. Choi and his team used a food-frequency questionnaire, updated every 4 years. Participants chose from 9 frequency responses – ranging from never to 2 to 4 cups per week to 6 or more per day – to record their average consumption of coffee, decaffeinated coffee, tea, and other caffeine-containing comestibles, such as cola and chocolate.

Through another questionnaire, the researchers documented 757 newly diagnosed cases meeting the American College of Rheumatology criteria for gout during the follow-up period. Then, they determined the relative risk of incident gout for long-term coffee drinkers divided into 4 groups – less than 1 cup per day, 1 to 3 cups per day, 4 to 5 cups per day, and 6 or more cups per day – as well as for regular drinkers of decaffeinated coffee, tea, and other caffeinated beverages. They also evaluated the impact of other risk factors for gout – body mass index, history of hypertension, alcohol use, and a diet high in red meat and high-fat dairy foods among them – on the association between coffee consumption and gout among the study participants.

Most significantly, the data revealed that the risk for developing gout decreased with increasing coffee consumption. The risk of gout was 40 percent lower for men who drank 4 to 5 cups a day and 59 percent lower for men who drank 6 or more cups a day than for men who never drank coffee. There was also a modest inverse association with decaffeinated coffee consumption. These findings were independent of all other risk factors for gout. Tea drinking and total caffeine intake were both shown to have no effect on the incidence of gout among the subjects. On the mechanism of these findings, Dr. Choi speculates that components of coffee other than caffeine may be responsible for the beverage’s gout-prevention benefits. Among the possibilities, coffee contains the phenol chlorogenic acid, a strong antioxidant.

While not prescribing 4 or more cups a day, this study can help individuals make an informed choice regarding coffee consumption. "Our findings are most directly generalizable to men age 40 years and older, the most gout-prevalent population, with no history of gout," Dr. Choi notes. "Given the potential influence of female hormones on the risk of gout in women and an increased role of dietary impact on uric acid levels among patients with existing gout, prospective studies of these populations would be valuable."

Friday, May 18, 2007

Prostate Cancer: Beta-carotene Makes Worse

No magic tomato? Study breaks link between lycopene and prostate cancer prevention

Tomatoes might be nutritious and tasty, but don’t count on them to prevent prostate cancer. In the May issue of Cancer Epidemiology, Biomarkers & Prevention, researchers based at the National Cancer Institute and Fred Hutchinson Cancer Research Center report that lycopene, an antioxidant predominately found in tomatoes, does not effectively prevent prostate cancer. In fact, the researchers noted an association between beta-carotene, an antioxidant related to lycopene, and an increased risk for aggressive prostate cancer.

According to the researchers, the study is one of the largest to evaluate the role of blood concentrations of lycopene and other carotenoid antioxidants in preventing prostate cancer. Study data were derived from over 28,000 men enrolled in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial, an ongoing, randomized National Cancer Institute trial to evaluate cancer screening methods and to investigate early markers of cancer.

"It is disappointing, since lycopene might have offered a simple and inexpensive way to lower prostate cancer risk for men concerned about this common disease," said Ulrike Peters, Ph.D., M.P.H., of the Fred Hutchinson Cancer Research Center. "Unfortunately, this easy answer just does not work."

Previous studies suggested that a diet rich in lycopene protected against prostate cancer, spurring commercial and public interest in the antioxidant. Antioxidants protect against free radicals, highly reactive atoms and molecules that can damage DNA and other important molecules in the cell. Since free radical damage increases with age, there has been a long-held suspicion in the scientific community that free radical damage could increase the risk of prostate cancer, a disease that has been clearly associated with age.

Subsequent studies of the potentially protective role of lycopene have been contradictory or inconclusive, according to Peters. In a 2006 study, she and her colleagues looked at the dietary intake of more than 25 tomato-based foods, also using data from the PLCO trial, and found no overall association between lycopene intake and prostate cancer.

In their current study, the researchers followed over 28,000 men between the ages of 55 and 74, enrolled in the PLCO Trial, with no history of prostate cancer. The men were initially screened through a PSA test and digital rectal exam, and were then followed through routine exams and screenings until first occurrence of prostate cancer, death or the end of the trial in 2001. At the beginning of the trial, the men gave a blood sample and completed a questionnaire related to their health, diet and lifestyle.

The researchers focused on non-Hispanic Caucasian men, as the small number of cases among other ethnic groups was statistically insignificant. They found no significant difference between those who had prostate cancer and those who did not in relation to the concentration of lycopene in their bloodstream. "Our results do not offer support for the benefits of lycopene against prostate cancer," Peters said.

Most surprisingly, says Peters, was the relationship between increased risk of aggressive prostate cancer – defined as disease that has spread beyond the prostate – and beta-carotene, another antioxidant found in many vegetables and commonly used as a dietary supplement.

This unexpected observation "may be due to chance, however beta carotene is already known to increase risk of lung cancer and cardiovascular disease in smokers," Peters said.

"While it would be counter-productive to advise people against eating carrots and leafy vegetables, I would say to be cautious about taking beta carotene supplements, particularly at high doses, and consult a physician," Peters said.

Lipoic acid explored as anti-aging compound

Researchers said today they have identified the mechanism of action of lipoic acid, a remarkable compound that in animal experiments appears to slow down the process of aging, improve blood flow, enhance immune function and perform many other functions.

The findings, discussed at the "Diet and Optimum Health" conference sponsored by the Linus Pauling Institute at Oregon State University, shed light on how this micronutrient might perform such a wide range of beneficial functions.

"The evidence suggests that lipoic acid is actually a low-level stressor that turns on the basic cellular defenses of the body, including some of those that naturally decline with age," said Tory Hagen, an LPI researcher and associate professor of biochemistry and biophysics at OSU. "In particular, it tends to restore levels of glutathione, a protective antioxidant and detoxification compound, to those of a young animal. It also acts as a strong anti-inflammatory agent, which is relevant to many degenerative diseases."

Researchers at LPI are studying vitamins, dietary approaches and micronutrients that may be implicated in the aging or degenerative disease process, and say that lipoic acid appears to be one of those with the most compelling promise. It's normally found at low levels in green leafy vegetables, but can also be taken as a supplement.

According to Hagen, research on the natural processes of aging, and steps that could slow it or improve health until near the end of life, are of growing importance.

"We're coming into the middle of an aging epidemic in the country," he said. "In a short time more than 70 million Americans will be over 65. This is partly because of the Baby Boom, but also people are living longer, being saved with antibiotics and other medical treatments. In any case, it will be an unprecedented number of elderly people in this nation."

The goal of LPI research, Hagen said, is to address issues of "healthspan," not just lifespan – meaning the ability to live a long life with comparatively good health and vigor, free of degenerative disease, until very near death. The best mechanisms to accomplish that, scientists say, have everything to do with diet, exercise, healthy lifestyle habits and micronutrient intake.

At the moment, Hagen said, that's not the way things appear to be headed – diabetes is skyrocketing, about 50 percent of people over 65 have high blood pressure, heart disease often leads to permanent disability, and almost half of the elderly people in America have malnutrition that is easily preventable.

No single intervention can address all of these issues, Hagen said, but one that scientists keep coming back to is lipoic acid.

"Our studies have shown that mice supplemented with lipoic acid have a cognitive ability, behavior, and genetic expression of almost 100 detoxification and antioxidant genes that are comparable to that of young animals," Hagen said. "They aren't just living longer, they are living better – and that's the goal we're after."

What the OSU researchers now believe is that the role of lipoic acid is not so much a direct one to benefit cells, but rather an indirect aid that "kick starts" declining function in cells and helps them recover the functions that came more easily and naturally in young animals.

In various effects, lipoic acid appears to help restore a cellular "signaling" process that tends to break down in older blood vessels. It reduces mitochondrial decay in cells, which is closely linked to the symptoms of aging. With age, glutathione levels naturally decline, making older animals more susceptible to both free radicals and other environmental toxins – but lipoic acid can restore glutathione function to near normal. And the expression and function of other genes seems to come back to life.

"We never really expected such a surprising range of benefits from one compound," Hagen said. "This is really unprecedented, and we're pretty excited about it."

Many other presentations have been made at this conference on the role of diet, lifestyle and micronutrients in health and degenerative disease, including cancer, heart disease, neurological diseases and aging.

The conference is organized every two years by OSU's Linus Pauling Institute, and attracts leading experts from around the world in these research fields.

'Five-Second Rule' for Dropped Food More Like 30

Two Connecticut College student researchers have found that the "five-second rule" - which stipulates that dropped food will be safe to eat if it stays on the floor for fewer than five seconds - might better be known as the "30-second rule."

Connecticut College seniors and cell and molecular biology majors Molly Goettsche and Nicole Moin took two food samples - apple slices and Skittles candies - to the Connecticut College dining hall and snack bar. They dropped the foods onto the floors in both locations for five, 10, 30 and 60 second intervals, and also tested them after allowing five minutes to elapse. They then looked for any rogue bacteria that might have attached to the foods.

The researchers found no bacteria were present on the foods that had remained on the floor for five, 10 or 30 seconds. The apple slices did pick up bacteria after one minute, however, and the Skittles showed a bacterial presence after remaining on the floor for five minutes.

The results prove, according Goettsche and Moin, that you can wait at least 30 seconds to pick up wet foods and more than a minute to pick up dry foods before they become contaminated with bacteria.

"The five-second rule should probably be renamed," Goettsche said. "You actually have a little more time."

The research was conducted under the supervision of Anne Bernhard, assistant professor of biology at Connecticut College. Previous research on the rule, Moin said, was conducted by a University of Illinois researcher in 2003 and involved dropping food items directly onto e-coli contaminated tiles.

"That is not what is representative of what actually happens," Goettsche said. "We wanted to apply this to everyday life."

Wednesday, May 16, 2007

Heavy multivitamin use = advanced prostate cancer?

While regular multivitamin use is not linked with early or localized prostate cancer, taking too many multivitamins may be associated with an increased risk for advanced or fatal prostate cancers, according to a study in the May 16 issue of the Journal of the National Cancer Institute.

Millions of Americans take multivitamins because of a belief in their potential health benefits, even though there is limited scientific evidence that they prevent chronic disease. Researchers have wondered what impact multivitamin use might have on cancer risk.

Karla Lawson, Ph.D., of the National Cancer Institute in Bethesda, Md., and colleagues followed 295,344 men enrolled in the National Institutes of Health-AARP Diet and Health Study to determine the association between multivitamin use and prostate cancer risk. After five years of follow-up, 10,241 men were diagnosed with prostate cancer, including 8,765 with localized cancers and 1,476 with advanced cancers.

The researchers found no association between multivitamin use and the risk of localized prostate cancer. But they did find an increased risk of advanced and fatal prostate cancer among men who used multivitamins more than seven times a week, compared with men who did not use multivitamins. The association was strongest in men with a family history of prostate cancer and men who also took selenium, beta-carotene, or zinc supplements.

“Because multivitamin supplements consist of a combination of several vitamins and men using high levels of multivitamins were also more likely to take a variety of individual supplements, we were unable to identify or quantify individual components responsible for the associations that we observed,” the authors write.

Tobacco, alcohol increase risk of head/ neck cancer

Tobacco and alcohol use independently increase risk of head and neck cancer

Cigarette smoking is more strongly associated with head and neck cancers than drinking alcohol, according to a study in the May 16 issue of the Journal of the National Cancer Institute. The study found that smoking is responsible for a quarter of head and neck cancers among individuals who do not drink alcohol.

At least 75 percent of head and neck cancers are caused by a combination of cigarette smoking and drinking alcohol, but researchers have not known the individual contributions of these risk factors because people who smoke are more likely to drink than the general population and vice versa. In a new study, researchers sought to tease out the independent effect of each risk factor on head and neck cancer development.

Mia Hashibe, Ph.D., of the International Agency for Cancer Research in Lyon, France, and colleagues examined head and neck cancer risk among smokers who never drank alcohol and people who drink but never used tobacco products. They pooled data from 15 case–control studies, which included 10,244 head and neck cancer patients and 15,227 controls. About 16 percent of the patients and 27 percent of the controls never drank, and about 11 percent of the patients and 38 percent of the controls never smoked.

Cigarette smoking was associated with an increased risk of head and neck cancer—especially cancer of the larynx—among patients who never drank alcohol. About 24 percent of head and neck cancers were due to smoking among patients who never drank.

Drinking alcohol was also associated with greater risk of head and neck cancers among never smokers, but mainly for patients who drank three or more drinks per day. They had twice the risk of head and neck cancers as people who never drink. Only seven percent of head and neck cancers were due to drinking among never smokers.

Boiling Broccoli Ruins Its Anti Cancer Properties

Researchers at the University of Warwick have found that the standard British cooking habit of boiling vegetables severely damages the anticancer properties of many Brassica vegetables such as broccoli, Brussel sprouts, cauliflower and green cabbage.

Past studies have shown that consumption of Brassica vegetables decreases the risk of cancer. This is because of the high concentration in Brassicas of substances known as glucosinolates which are metabolized to cancer preventive substances known as isothiocyanates. However before this research it was not known how the glucosinolates and isothiocyanates were influenced by storage and cooking of Brassica vegetables.

The researchers, Prof Paul Thornalley from Warwick Medical School at the University of Warwick and Dr Lijiang Song from the University of Warwick’s Department of Chemistry bought Brassica vegetables, (broccoli, Brussel sprouts, cauliflower and green cabbage) from a local store and transported them to the laboratory within 30 minutes of purchasing. The effect of cooking on the glucosinolate content of vegetables was then studied by investigating the effects of cooking by boiling, steaming, microwave cooking and stir-fry.

Boiling appeared to have a serious impact on the retention of those important glucosinolate within the vegetables. The loss of total glucosinolate content after boiling for 30 minutes was: broccoli 77%, Brussel sprouts 58%, cauliflower 75% and green cabbage 65%.

The effects of other cooking methods were investigated: steaming for 0–20 min, microwave cooking for 0–3 min and stir-fry cooking for 0–5 min. All three methods gave no significant loss of total glucosinolate analyte contents over these cooking periods.

Domestic storage of the vegetables at ambient temperature and in a domestic refrigerator showed no significant difference with only minor loss of glucosinolate levels over 7 days.

However the researchers found that storage of fresh vegetables at much lower temperatures such as −85 °C (much higher than for storage in a refrigerator at 4–8 °C) may cause significant loss of glucosinolates up to 33% by fracture of vegetable material during thawing.

The researchers found that preparation of Brassica vegetables had caused only minor reductions in glucosinolate except when they were shredded finely which showed a marked decline of glucosinolate levels with a loss of up to 75% over 6 hours after shredding.

Professor Thornalley said: "If you want to get the maximum benefit from your five portions-a-day vegetable consumption, if you are cooking your vegetables boiling is out. You need to consider stir frying steaming or micro-waving them."

Mediterranean Diet Halves Risk of Lung Disease

A Mediterranean diet halves the chances of developing progressive inflammatory lung disease (COPD), reveals a large study, published ahead of print in Thorax.

COPD (chronic obstructive pulmonary disease) is an umbrella term for chronic progressive lung disease, such as emphysema and bronchitis. It is expected to become the third leading cause of death worldwide by 2020, with cigarette smoking the primary factor in its development.

The researchers tracked the health of almost 43,000 men, who were already part of the US Health Professionals Follow up Study. This began in 1986 and involved more than 50,000 US health care professionals aged between 40 and 75, who were surveyed every two years.

They were asked questions about lifestyle, including smoking and exercise, diet and medical history. Dietary intake was assessed in detail every four years.

Eating patterns fell into two distinct categories: those who ate a diet rich in fruit, vegetables, whole grains and fish (Mediterranean diet); and those who ate a diet rich in processed foods, refined sugars, and cured and red meats (Western diet).

Between 1986 and 1998, 111 cases of COPD were newly diagnosed.

The Mediterranean diet was associated with a 50% lower risk of developing COPD than the Western diet, even after adjusting for age, smoking, and other risk factors.

And men who ate a predominantly Western diet were more than four times as likely to develop COPD, even after taking account of other influential factors.

The higher the compliance with a Mediterranean diet, the lower was the risk of developing COPD over the 12 year period.

Conversely, the higher the compliance with the Western diet, the higher was the risk of developing COPD.

To view the paper in full: http://press.psprings.co.uk/thx/may/tx74534.pdf

A Walk a Day Might Help Keep the Doctor Away

New research reported in the Journal of the American Medical Association shows daily, mild exercise - walking or bike riding - improves the fitness of post-menopausal women who are currently sedentary, overweight or obese.

Timothy Church, M.D., Ph.D., of the Pennington Biomedical Research Center, led a team of researchers who examined the effect of various amounts of walking on more than 460 women. The results showed that as little as 15 minutes a day, five days a week of walking on a treadmill or riding a stationary bike improved fitness.

"The level of walking we studied was so light most people would not consider it exercise," Church said, "The message for women here is just get up and walk. You don't need a gym, you don't need fancy clothes or a stop-watch. All you need is a pair of comfortable shoes that you can walk in."

The women were randomly placed into one of four groups: a control group that did not exercise and groups that exercised 72 minutes, 135 minutes, or 191 minutes of exercise per week. Church's team found that the more exercise performed the greater the increase in fitness, which was expected. However, the lowest exercise groups also saw improvements in fitness, which the team did not expect.

"The surprising news," Church said, "is that the lowest exercise group showed significant improvement. We continue to recommend 30 minutes a day of walking at least five days a week, but the data suggests just doing something - even 15 minutes a day - is better than nothing.

Monday, May 14, 2007

Calcium plus vitamin D may help prevent weight gain

Calcium plus vitamin D supplements may help prevent weight gain in postmenopausal women

Postmenopausal women who take calcium and vitamin D supplements may gain less weight than those who do not, although the overall effect is small, according to a report in the May 14 issue of Archives of Internal Medicine, one of the JAMA/Archives journals. The benefit is greater in those who had not previously been getting the daily recommended amount of calcium.

"Because weight loss or prevention of weight gain is likely to have significant health benefits for middle-aged women, early to middle menopause may be a critical period of life in which to slow the trajectory of weight gain," the authors note as background information in the article. Some evidence suggests that calcium and vitamin D may play a role in effective weight management. These nutrients may stimulate the breakdown of fat cells and suppress the development of new ones.

Bette Caan, Dr.P.H., of Kaiser Permanente Northern California, Oakland, and colleagues studied 36,282 postmenopausal women age 50 to 79 who were enrolled in the Women's Health Initiative clinical trial. The women were randomly assigned to receive a dose of 1,000 milligrams of calcium plus 400 international units of vitamin D (18,176 women) or placebo (18,106 women) daily. They were weighed each year for approximately seven years.

At the beginning of the study, 39.63 percent of the women met current recommended daily intake of 1,200 milligrams of calcium, 53.94 percent reported taking any calcium supplements and 28.95 percent reported taking supplements of 500 milligrams of calcium or more. At the end of the study, women who took the supplements weighed an average of 0.28 pounds less than those who did not.

Among women who were getting less than the recommended amount of calcium daily before the study, those who took the supplements weighed an average of 0.42 pounds less than those who did not. After three years, when compared to women taking placebo, these women had a lower risk of gaining weight in both small amounts (2.2 to 6.6 pounds) and moderate amounts (more than 6.6 pounds) and had a higher likelihood of maintaining a stable weight (within 2.2 pounds of starting weight) or losing weight (more than 2.2 pounds).

"Prevention of weight gain is an important public health goal, and caloric restriction and daily physical activity should still be considered the basic tenets of weight management," the authors conclude. "Further research should be undertaken to address the effect of calcium supplementation combined with caloric restriction and physical activity on weight gain prevention."

Grain fiber and magnesium = lower risk for diabetes

Grain fiber and magnesium intake associated with lower risk for diabetes

Higher dietary intake of fiber from grains and cereals and of magnesium may each be associated with a lower risk of type 2 diabetes, according to a report and meta-analysis in the May 14 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

Projections indicate that the number of people diagnosed with diabetes worldwide may increase from 171 million in 2000 to 370 million by 2030, according to background information in the article. The associated illness, death and health care costs emphasize the need for effective prevention, the authors write. Fiber may help reduce the risk of diabetes by increasing the amount of nutrients absorbed by the body and reducing blood sugar spikes after eating, among other mechanisms. Current American Diabetes Association guidelines include goals for total fiber intake, but research suggests that some types of fiber may be more beneficial than others. Findings regarding magnesium and diabetes risk remain unclear.

Matthias B. Schulze, Dr.P.H., and colleagues at the German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, conducted a study of 9,702 men and 15,365 women age 35 to 65 years. Participants completed a food questionnaire when they enrolled in the study between 1994 and 1998, then were followed up through 2005—an average of seven years—to see if they developed diabetes. In addition, the researchers performed a meta-analysis of previously published work related to intake of fiber or magnesium and risk of diabetes.

During the follow-up period, 844 individuals in the study developed type 2 diabetes. Those who consumed more fiber through cereal, bread and other grain products (cereal fiber) were less likely to develop diabetes than those who ate less fiber. When the participants were split into five groups based on cereal fiber intake, those who ate the most (an average of 17 grams per day) had a 27 percent lower risk of developing diabetes than those in the group that ate the least (an average of 7 grams per day). Eating more fiber overall or from fruits and vegetables was not associated with diabetes risk, nor was magnesium intake.

In the meta-analysis, the researchers identified nine studies of fiber and eight studies of magnesium intake. Based on the results of all the studies, in which participants were classified into either four or five groups according to their intake of fiber or magnesium, those who consumed the most cereal fiber had a 33 percent lower risk of developing diabetes than those who took in the least, while those who consumed the most magnesium had a 23 percent lower risk than those who consumed the least. There was no association between fruit or vegetable fiber and diabetes risk.

"In conclusion, the evidence from our study and previous studies, summarized by means of meta-analysis, strongly supports that higher cereal fiber and magnesium intake may decrease diabetes risk," the authors conclude. "Whole-grain foods are therefore important in diabetes prevention."

More fish and vitamin D = less macular disease

Higher intake of fish and vitamin D levels linked to lower risk of age-related macular disease

Individuals who have higher dietary intake of foods with omega-3 fatty acids and higher fish consumption have a reduced risk of advanced age-related macular degeneration, while those with higher serum levels of vitamin D may have a reduced risk of the early stages of the disease, according to two reports in the May issue of Archives of Ophthalmology, one of the JAMA/Archives journals.

Age-related macular degeneration (AMD) occurs when the macula, the area at the back of the retina that produces the sharpest vision, deteriorates over time. It is the most common cause of blindness among older adults in the United States, affecting more than 7 million individuals older than 40 years, according to background information in the articles. The prevalence of AMD is likely to increase as the population ages. There is currently no known way to prevent the condition, but research has begun to identify potentially modifiable risk factors and nutrient-based treatments.

The Age-Related Eye Disease Study Research Group assessed 4,519 individuals who were age 60 to 80 when they enrolled in 1992 through 1998. At that time, photographs were taken of their retinas to determine if they had AMD, and if so, to which of four stages the condition had progressed. The participants also completed a food frequency questionnaire that measured how often they consumed foods rich in certain vitamins, minerals and other nutrients, such as omega-3 fatty acids commonly found in tuna, salmon and other fish.

A total of 1,115 participants did not have any symptoms of AMD at the beginning of the study, and were compared with those who did, including 658 individuals with neovascular (severe) AMD. "Dietary total omega-3 long-chain polyunsaturated fatty acid intake was inversely associated with neovascular AMD, as was docosahexaenoic acid," or DHA, a fatty acid that previous evidence suggests affects the retina, the authors write. "Higher fish consumption, both total and broiled/baked, was also inversely associated with neovascular AMD." Eating more than two medium (4-ounce) servings of fish per week or more than one medium serving of broiled or baked fish was associated with the lowest risk for advanced AMD.

Omega-3 fatty acids may influence processes involved in the development of blood vessel– and nerve-related diseases of the retina, the authors write. For instance, DHA may protect the retina by influencing which genes turn on and off, while fatty acids overall may eventually form compounds that promote cell survival and proper blood vessel function, reduce inflammation and maintain energy balance.

"These results and those from other observational analytic investigations suggest that modifying diet to include more foods rich in omega-3 long-chain polyunsaturated fatty acids could result in a reduction in the risk of having neovascular AMD," the authors conclude. Clinical trials would provide further information about whether diet changes or supplements could prevent the development of advanced AMD.

In a related study, Niyati Parekh, Ph.D., R.D., of the University of the Medicine and Dentistry of New Jersey, New Brunswick, and the University of Wisconsin–Madison, and colleagues analyzed data from 7,752 individuals (including 11 percent with AMD) who were part of the National Health and Nutrition Examination Survey, a large study designed to represent the entire U.S. population. Participants were enrolled in the study between 1988 and 1994. They had physical examinations that included blood and urine samples, photographs of the retinas, and interviews and questionnaires regarding sociodemographics, lifestyle habits and food intake.

"Levels of serum vitamin D were inversely associated with early AMD but not advanced AMD," the authors write. When participants were split into five groups based on level of vitamin D in the blood, those in the highest group had a 40 percent lower risk of early AMD than those in the lowest group. "Milk intake was inversely associated with early AMD. Fish intake was inversely associated with advanced AMD."

Vitamin D may reduce the risk of AMD by reducing inflammation or by preventing the growth of new blood vessels in the retina, which contributes to some forms of AMD, the authors speculate. "This study provides evidence that vitamin D may protect against AMD," the authors conclude. "However, at this time there is insufficient epidemiologic evidence of the relationship between vitamin D level and AMD to make recommendations regarding optimum serum vitamin D levels or milk and fish intake to protect against AMD or its progression. The results of the present research warrant further investigation for confirmation of the vitamin D-AMD association in other population studies."