Archive for the ‘Diet’ Category

Researchers from the Division of Health Promotion & Sports Medicine at Oregon Health & Science University have found steroid use among teen girls is not limited to athletes and often goes hand in hand with other unhealthy choices, including smoking and taking diet pills. The study was published in the Archives of Pediatrics & Adolescent Medicine, a JAMA/Archives journal.Diane Elliot, M.D., professor of medicine (health promotion and sports medicine), OHSU School of Medicine, and colleagues analyzed findings from the Center for Disease Control’s Youth Risk Behavior Survey of 7,544 ninth- through 12th-grade girls from around the country. The questionnaire asked about sports participation, anabolic steroid and drug use, and other illegal or unhealthy behaviors. Approximately 5 percent of participants reported prior or ongoing anabolic steroid use.

In addition to greater substance use, young female steroid users were more likely to have had sexual intercourse before age 13; have been pregnant; drink and drive or have ridden with a drinking driver; carry a weapon; have been in a fight on school property; have feelings of sadness or hopelessness almost every day for at least two weeks; and have attempted suicide. Those reporting anabolic steroid use were less likely to participate in team athletics.

Overall, more than two-thirds of those surveyed reported trying to change their weight. Girls who used steroids were more likely try extreme weight-loss techniques, such as vomiting and laxative use.

Adolescent girls reporting anabolic steroid use had significantly more other health-harming behaviors, Elliot explained, “They were much more likely to use other unhealthy substances, including cigarettes, alcohol, marijuana and cocaine.”

“Across all grades, these seem to be troubled adolescents with co-occurring health-compromising activities in the domains of substance use, sexual behavior, violence and mental health,” Elliot said. “Anabolic steroid use is a marker for high-risk girls. High-risk young women have received less attention than young men, perhaps reflecting that their actions are less socially, albeit more personally, destructive. Further study is needed to develop effective interventions for these young women.”

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Article adapted by MD Sports Weblog from original press release.
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Contact: Tamara Hargens
Oregon Health & Science University
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New research on the effects of the female sex hormone estrogen in the brain lend credence to what many women have suspected about the hormonal changes that accompany aging: Menopause can make you fat.Scientists long have sought to understand how changes in hormones during menopause could account for the increase in appetite and accompanying weight gain that often occurs among aging women.

In a series of animal experiments described today at the 234th national meeting of the American Chemical Society, the world’s largest scientific society, researchers showed how estrogen receptors located in the hypothalamus serve as a master switch to control food intake, energy expenditure and body fat distribution. When these receptors are destroyed, the animals immediately begin to eat more food, burn less energy and pack on pounds.

This research seems to support a link between estrogen and regulation of obesity, especially the dangerous accumulation of abdominal fat linked to heart disease, diabetes, and cancer, says Deborah J. Clegg, Ph. D., assistant professor of psychiatry at the University of Cincinnati Academic Health Center, who is directing the studies.

The findings may also help scientists develop more targeted hormone replacement therapies, capable of stimulating estrogen receptors in one part of the brain or body while dampening it in the next, Clegg says.

Estrogen receptors are located on cells throughout a woman’s body. Previous studies have shown that one type of estrogen receptor, known as estrogen receptor alpha or ER-alpha, plays a role in regulating food intake and energy expenditure. But scientists have been unable to pinpoint exactly where these fat-regulating receptors reside or how they work to govern these behaviors.

To determine the effect of dwindling estrogen levels in the brain, Clegg and her colleagues are focusing on two ER-alpha rich regions located in the hypothalamus, an area of the brain that controls body temperature, hunger and thirst. The first region, called the ventromedial nucleus or VMN, is a key center for energy regulation.

Using a relatively new gene-silencing technique called RNA interference, the researchers in earlier research deactivated the alpha-receptors in the VMN. The estrogen receptors in other regions of the brain maintained their normal capacity.

When estrogen levels in the VMN dipped, the animals’ metabolic rate and energy levels also plummeted. The findings show the animals quickly developed an impaired tolerance to glucose and a sizable weight gain, even when their caloric intake remained the same. What’s more, the excess weight went straight to their middle sections, creating an increase in visceral fat.

The findings suggested that the ER-alpha in this region plays an essential role in controlling energy balance, body fat distribution and normal body weight.

Clegg now plans to perform a similar experiment to deactivate ER-alpha in the arcuate nucleus region of the hypothalamus. This region contains two populations of neurons: one puts the brake on food intake and the other stimulates food intake. Clegg anticipates that a loss of estrogen in this region may create an increase in the animals’ appetites as well as their weight.

Clegg says her studies address an area that is sorely needed given the incidence and impact of gender differences in obesity and its complications.

“The accumulation of abdominal fat puts both men and women at a heightened risk of cardiovascular disease, diabetes, and insulin resistance,” she says. “Women are protected from these negative consequences as long as they carry their weight in their hips and saddlebags. But when they go through menopause and the body fat shifts to the abdomen, they have to start battling all of these medical complications.”

By identifying the critical brain regions that determine where body fat is distributed, Clegg says her findings may help scientists design hormone replacement therapies to better manage and manipulate estrogen levels.

“If we could target those critical regions and estrogen receptors associated with weight gain and energy expenditure, we could perhaps design therapies that help women sidestep many of the complications brought on by the onset of menopause,” she says.

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Article adapted by MD Sports Weblog from original press release.
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Contact: Charmayne Marsh
American Chemical Society

 The American Chemical Society — the world’s largest scientific society — is a nonprofit organization chartered by the U.S. Congress and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.

Deborah J. Clegg, Ph.D., is assistant professor of psychiatry at the University of Cincinnati Academic Health Center in Cincinnati, Ohio.

Female athletes often lose their menstrual cycle when training strenuously, but researchers have long speculated on whether this infertility was due to low body fat, low weight or exercise itself. Now, researchers have shown that the cause of athletic amenorrhea is more likely a negative energy balance caused by increasing exercise without increasing food intake.”A growing proportion of women are susceptible to losing their menstrual cycle when exercising strenuously,” says Dr. Nancy I. Williams, assistant professor of kineseology and physiology at Penn State. “If women go six to 12 months without having a menstrual cycle, they could show bone loss. Bone densities in some long distance runners who have gone for a prolonged time period without having normal menstrual cycles can be very low.”

In studies done with monkeys, which show menstrual cyclicity much like women, researchers showed that low energy availability associated with strenuous exercise training plays an important role in causing exercise-induced amenorrhea. These researchers, working at the University of Pittsburgh, published findings in the Journal of Clinical Endocrinology and Metabolism showing that exercise-induced amenorrhea was reversible in the monkeys by increasing food intake while the monkeys still exercised.

Williams worked with Judy L. Cameron, associate professor of psychiatry and cell biology and physiology at the University of Pittsburgh. Dana L. Helmreich and David B. Parfitt, then graduate students, and Anne Caston-Balderrama, at that time a post-doctoral fellow at the University of Pittsburgh, were also part of the research team. The researchers decided to look at an animal model to understand the causes of exercise-induced amenorrhea because it is difficult to closely control factors, such as eating habits and exercise, when studying humans. They chose cynomolgus monkeys because, like humans, they have a menstrual cycle of 28 days, ovulate in mid-cycle and show monthly periods of menses.

“It is difficult to obtain rigorous control in human studies, short of locking people up,” says Williams.

Previous cross-sectional studies and short-term studies in humans had shown a correlation between changes in energy availability and changes in the menstrual cycle, but those studies were not definitive.

There was also some indication that metabolic states experienced by strenuously exercising women were similar to those in chronically calorie restricted people. However, whether the increased energy utilization which occurs with exercise or some other effect of exercise caused exercise-induced reproductive dysfunction was unknown.

“The idea that exercise or something about exercise is harmful to females was not definitively ruled out,” says Williams. “That exercise itself is harmful would be a dangerous message to put out there. We needed to look at what it was about exercise that caused amenorrhea, what it was that suppresses ovulation. To do that, we needed a carefully controlled study.”

After the researchers monitored normal menstrual cycles in eight monkeys for a few months, they trained the monkeys to run on treadmills, slowly increasing their daily training schedule to about six miles per day. Throughout the training period the amount of food provided remained the standard amount for a normal 4.5 to 7.5 pound monkey, although the researchers note that some monkeys did not finish all of their food all of the time.

The researchers found that during the study “there were no significant changes in body weight or caloric intake over the course of training and the development of amenorrhea.” While body weight did not change, there were indications of an adaptation in energy expenditure. That is, the monkeys’ metabolic hormones also changed, with a 20 percent drop in circulating thyroid hormone, suggesting that the suppression of ovulation is more closely related to negative energy balance than to a decrease in body weight.

To seal the conclusion that a negative energy balance was the key to exercise-induced amenorrhea, the researchers took four of the previous eight monkeys and, while keeping them on the same exercise program, provided them with more food than they were used to. All the monkeys eventually resumed normal menstrual cycles. However, those monkeys who increased their food consumption most rapidly and consumed the most additional food, resumed ovulation within as little as 12 to 16 days while those who increased their caloric intake more slowly, took almost two months to resume ovulation.

Williams is now conducting studies on women who agree to exercise and eat according to a prescribed regimen for four to six months. She is concerned because recreational exercisers have the first signs of ovulatory suppression and may easily be thrust into amenorrhea if energy availability declines. Many women that exercise also restrict their calories, consciously or unconsciously.

“Our goal is to test whether practical guidelines can be developed regarding the optimal balance between calories of food taken in and calories expended through exercise in order to maintain ovulation and regular menstrual cycles,” says Williams. “This would then ensure that estrogen levels were also maintained at healthy levels. This is important because estrogen is a key hormone in the body for many physiological systems, influencing bone strength and cardiovascular health, not just reproduction.”

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Article adapted by MD Sports Weblog from original press release.
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Contact: A’ndrea Elyse Messer
Penn State

The old adage “use it or lose it” is truer than ever. People who maintain a vigorously active lifestyle as they age gain less weight than people who exercise at more moderate levels, according to a first-of-its-kind study that tracked a large group of runners who kept the same exercise regimen as they grew older. The study also found that maintaining exercise with age is particularly effective in preventing extreme weight gain, which is associated with high blood pressure, high cholesterol, diabetes, and other diseases.

The study, conducted by Paul Williams of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), followed 6,119 men and 2,221 women who maintained their weekly running mileage (to within three miles per week) over a seven-year period. On average, the men and women who ran over 30 miles per week gained half the weight of those who ran less than 15 miles per week.

“To my knowledge, this is the only study of its type,” says Williams, a staff scientist in Berkeley Lab’s Life Sciences Division. “Other studies have tracked exercise over time, but the majority of people will have changed their exercise habits considerably.”

The research is the latest report from the National Runners’ Health Study, a 20-year research initiative started by Williams that includes more than 120,000 runners. It appears in the May issue of the journal Medicine and Science in Sports and Exercise.

Specifically, between the time subjects entered the study and when they were re-contacted seven years later, 25-to-34-year-old men gained 1.4 pounds annually if they ran less than 15 miles per week. In addition, male runners gained 0.8 pounds annually if they ran between 15 and 30 miles per week, and 0.6 pounds annually if they ran more than 30 miles per week.

This trend is mirrored in women. Women between the ages of 18 and 25 gained about two pounds annually if they ran less than 15 miles per week, 1.4 pounds annually if they ran 15 to 30 miles per week, and slightly more than three-quarters of a pound annually if they ran more than 30 miles per week. Other benefits to running more miles each week included fewer inches gained around the waist in both men and women, and fewer added inches to the hips in women.

“As these runners aged, the benefits of exercise were not in the changes they saw in their bodies, but how they didn’t change like the people around them,” says Williams.

Although growing older and gaining weight is something of a package deal, it isn’t the same in everyone. The lucky few remain lean as they age, most people pack on several pounds, and some people become obese. The latter group is particularly at risk for high blood pressure, high cholesterol, and diabetes. Fortunately, Williams’ results show that maintaining exercise can combat such extreme weight gain.

“Getting people to commit to a vigorously active lifestyle while young and lean will go a long way to reducing the obesity epidemic in this country,” says Williams.

Another paper published in the November 2006 issue of the journal Obesity by Williams and Paul Thompson of Hartford (CT) Hospital found that runners who increased their running mileage gained less weight than those who remained sedentary, and runners that quit running became fatter.

“The time to think about exercise is before you think you need it,” says Williams. “The medical journals are full of reports on how difficult it is to regain the slenderness of youth. The trick is not to get fat.”

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Article adapted by MD Sports Weblog from original press release.
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Contact: Dan Krotz
DOE/Lawrence Berkeley National Laboratory

Williams’ research was funded by the National Heart, Lung and Blood Institute. The study in the May issue of the journal Medicine and Science in Sports and Exercise is entitled Maintaining Vigorous Activity Attenuates 7-yr Weight Gain in 8,340 Runners.

Golfers averaged more than 13,000 steps in walking to play 18 holes, and even those using carts logged more than 6,000 steps. Guidelines published by ACSM and others recommend walking 10,000 steps per day to maintain cardiovascular fitness and effectively control weight.

“This illustrates an enjoyable way to get the health benefits of walking,” said Cristina Sanders, lead researcher for the study, who presented the findings as part of her graduate work at the University of Colorado, Colorado Springs. “Some people play golf for 40 or 50 years, and it can be quite beneficial.” While previous studies have measured the energy expenditure of individual golfers, this study thought to be the first using pedometers.

Researchers asked golfers at three courses to wear a pedometer while they played 18 holes and noted their height, weight, and handicap. They also noted number of players in each subject’s group, whether he would walk or use a cart, and which tee box he played. After the round, researchers recorded how many steps each golfer walked.

“We had expected that golfers using a cart might take one-quarter as many steps as those who walked the course,” Sanders said. “We were surprised to find that, depending on the course, cart users logged up to half as many steps.” Measuring each course by GPS (global positioning satellite) allowed researchers to calculate minimum course distances, including tee-to-green, green-to-tee, and intermediate path point distances (bridges, paths around lakes, etc.) for each tee box on every hole. These minimum course distances averaged 25 percent longer than the published course playing distances.

Walking golfers and cart golfers took 13,145 +/- 1,736 steps and 6,280 +/- 1,428 steps, respectively. Interestingly, Sanders and her colleagues found no correlation between step count and the golfers’ height, handicap or tee box. Self-reported weight of walking golfers, though, averaged about 8.5 pounds less than that of golfers who used carts.

The golfers in Sanders’ study were all men. She proposed that future research include women, who often play from different tees.  Also of interest, she said, would be a large-scale look into golfers’ energy expenditure, accounting for the extra effort associated with carrying clubs or using pull carts.

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Article adapted by MD Sports Weblog from original press release.
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Contact: Communications and Public Information
American College of Sports Medicine

Although bottled water is perceived as a healthier, safer choice over tap water in consumer surveys, that is not necessarily always true, says sports nutritionist Cynthia Sass, R.D., C.S.S.D

In a presentation at the American College of Sports Medicine (ACSM) 11th-annual Health & Fitness Summit & Exposition in Dallas, Texas, Sass outlined the basics of water consumption, comparing bottled and tap varieties.

“Twenty-five percent of all bottled water is actually repackaged tap water,” said Sass.  ““The more a consumer knows about the realities of bottled and tap water, the savvier they can be about selecting water based on costs, preferences and accessibility.”

Is Bottled Best?
In a recent Gallop survey, most consumers indicated they drink bottled water based on their perception it is safer and purer than tap water.  Taste was the second leading reason, while bottled water’s convenience was also a factor.

Bottled water is considered a food, and thus regulated by Food and Drug Administration (FDA).  Tap water is regulated by the U.S. Environmental Protection Agency (EPA).  Both varieties are subject to testing for contaminants, although Sass points out there is no perfect system – both bottled and tap may contain contaminates such as bacteria, arsenic, lead or pesticides.  Independent tests by groups such as the National Resources Defense Council have found:

• Sixty to 70 percent of all bottled water in the United States is packaged and sold within the same state, which exempts it from FDA regulation.  One in five states do not regulate that bottled water.
• While most cities meet the standards for tap water, some tap water in the 19 U.S. cities tested was found to contain arsenic, lead, and pesticides.
• In 1,000 bottles of 103 different brands of bottled water, 22 percent contained synthetic chemicals, bacteria and arsenic.

Most healthy adults can tolerate trace amounts of these contaminates if exposed, but Sass notes some people are more vulnerable and should be more aware of their water source.  These people include cancer patients undergoing chemotherapy, patients who are HIV+ positive or recovering from a transplant or major surgery, and pregnant women, children, and elderly adults. 

For them especially, Sass recommends bottled water treated with reverse osmosis, municipal tap water with a filtering system certified by the National Sanitation Foundation (NSF) or distilled water.  (Most packaging on certified filter devices bear the NSF seal.)

“Bottled” Facts
According to Sass, other selection criteria for consumers may include:

Cost:  Bottled water can cost approximately $1 for a gallon jug, while tap water costs pennies on the dollar.  Distilled water or water treated with reverse osmosis (water captured into vapor so that all solids are left behind and then recaptured into fluid) are purer and considered safe, but are also more expensive.

Packaging:  Sass says a filtering system for tap water may be a better consideration for the environment.  She also pointed out that over time, plastic containers can leak chemicals into the water.  Consumers should look for an expiration date, and store water in cool, dark place.  For this reason, water bottles are not meant to be re-used.

Marketing:  Fitness and specialty waters do not contribute to an athletic advantage or edge.  In fact, vitamin-fortified waters, which provide high daily-value percentages per cup, may pose a risk for oversupplementation.  “Think of your one-a-day vitamin,” says Sass.  “Some of these waters are multi-vitamins in a bottle, so read the label and compare with the rest of your daily intake, including food.”

“Bottled water doesn’t deserve the nutritional halo that most people give it for being pure,” she says.  “If you’re not an exclusive bottled water drinker, you may find it worthwhile to check into filtering your tap water to save money.”

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Article adapted by MD Sports Weblog from original press release.
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Contact: Communications and Public Information
American College of Sports Medicine

Don’t drink alcohol. Take vitamins. Avoid eating eggs. We’ve heard these pieces of nutritional advice for years – but are they accurate?

Not necessarily, say two exercise physiologists who presented at the American College of Sports Medicine (ACSM) 11th-annual Health & Fitness Summit & Exposition in Dallas, Texas. Wendy Repovich, Ph.D., FACSM, and Janet Peterson, Dr.P.H., FACSM, set out to debunk the “Top 10 Nutrition Myths.”

According to Repovich and Peterson, these nutrition myths are:

10. Eating carbohydrates makes you fat. Cutting carbs from your diet may have short-term weight loss benefits due to water loss from a decrease in carbohydrate stores, but eating carbs in moderation does not directly lead to weight gain. The body uses carbs for energy, and going too long without them can cause lethargy.

9. Drink eight, 8-oz. glasses of water per day. You should replace water lost through breathing, excrement and sweating each day – but that doesn’t necessarily total 64 ounces of water. It’s hard to measure the exact amount of water you have consumed daily in food and drink, but if your urine is pale yellow, you’re doing a good job. If it’s a darker yellow, drink more H2O.

8. Brown grain products are whole grain products. Brown dyes and additives can give foods the deceiving appearance of whole grain. Read labels to be sure a food is whole grain, and try to get three-ounce equivalents of whole grains per day to reduce the risk of heart disease, diabetes, and stroke.

7. Eating eggs will raise your cholesterol. This myth began because egg yolks have the most concentrated amount of cholesterol of any food. However, there’s not enough cholesterol there to pose health risks if eggs are eaten in moderation. Studies suggest that eating one egg per day will not raise cholesterol levels and that eggs are actually a great source of nutrients.

6. All alcohol is bad for you. Again, moderation is key. Six ounces of wine and 12 ounces of beer are considered moderate amounts, and should not pose any adverse health effects to the average healthy adult. All alcohol is an anticoagulant and red wine also contains antioxidants, so drinking a small amount daily can be beneficial.

5. Vitamin supplements are necessary for everyone. If you eat a variety of fruits, vegetables, and whole grains, along with moderate amounts of a variety of low-fat dairy and protein and the right quantity of calories, you don’t need to supplement. Most Americans do not, so a multi-vitamin might be good. Special vitamin supplements are also recommended for people who are pregnant or have nutritional disorders.

4. Consuming extra protein is necessary to build muscle mass. Contrary to claims of some protein supplement companies, consuming extra protein does nothing to bulk up muscle unless you are also doing significant weight training at the same time. Even then the increased requirement can easily come from food. A potential problem with supplements is the body has to work overtime to get rid of excess protein, and can become distressed as a result.

3. Eating fiber causes problems if you have irritable bowel syndrome (IBS). There are two kinds of fiber: soluble and insoluble. Insoluble fiber can cause problems in IBS sufferers; soluble fiber, however, is more easily absorbed by the body and helps prevent constipation for those with IBS. Soluble fiber is found in most grains.

2. Eating immediately after a workout will improve recovery. Endurance athletes need to take in carbohydrates immediately after a workout to replace glycogen stores, and a small amount of protein with the drink enhances the effect. Drinking low-fat chocolate milk or a carbohydrate drink, like Gatorade, is better for the body, as they replace glycogen stores lost during exercise. Protein is not going to help build muscle, so strength athletes do not need to eat immediately following their workout.

1. Type 2 diabetes can be prevented by eating foods low on the glycemic index. High levels of glucose are not what “cause” diabetes; the disease is caused by the body’s resistance to insulin. Foods high on the glycemic index can cause glucose levels to spike, but this is just an indicator of the presence of diabetes, not the root cause.

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Article adapted by MD Sports Weblog from original press release.
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Contact: Communications and Public Information
American College of Sports Medicine

The American College of Sports Medicine is the largest sports medicine and exercise science organization in the world. More than 20,000 International, National and Regional members are dedicated to promoting and integrating scientific research, education and practical applications of sports medicine and exercise science to maintain and enhance physical performance, fitness, health and quality of life.