Monday, October 23, 2006

Strength Training Improves Artery Function Among Healthy Men in their 60's

NEW YORK (Reuters Health) - Despite some concerns to the contrary,
strengthening exercises appear to help, not harm, older adults' artery
function, a small study suggests.

In general, experts advise that young and old alike include both aerobic
activities and strength training in their exercise routines. For older
adults, the benefits may include stronger muscles and bones, fewer physical
limitations and a lower risk of falls and fractures.

However, research in young adults has found that strength-building
resistance exercises seem to increase "stiffness" in the arteries -- effects
that would be concerning in older adults, whose risk of heart disease and
stroke is already elevated.

In the new study, however, Japanese researchers found that strength training
seemed to improve artery function in a group of healthy men in their 60s.

The researchers, led by Dr. Seiji Maeda of the University of Tsukuba, report
their findings in the British Journal of Sports Medicine.

Specifically, a 12-week leg strengthening regimen boosted the men's blood
levels of nitric oxide, a chemical that helps dilate the arteries. Nitric
oxide levels in the blood are a marker of how well the artery walls are

On the other hand, non-invasive tests found no evidence connecting strength
exercises to stiffening in the body's major arteries.

"The results suggest that resistance training in older adults would produce
beneficial effects on the vasculature without any unfavorable effects,"
Maeda's team writes.

Still, the researchers note, larger, more extensive studies should continue
to follow the long-term effects of strength training on older adults' artery

SOURCE: British Journal of Sports Medicine, October 2006.

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Thursday, October 19, 2006

Exercise helps keep your brain in shape

Daily walks, mental challengers, nutrition can help stave off Alzheimer's, Parkinson's diseases.

A fast spin on the dance floor or taking daily walks might help keep the brain in top shape as people age -- and might reduce the risk of developing age-related diseases such as Alzheimer's or Parkinson's, experts now say.

Both Alzheimer's and Parkinson's are degenerative, incurable diseases of the brain. Both are more common in older people; together they afflict more than 5 million people in the United States. Alzheimer's causes memory problems, and Parkinson's leads to tremors and shakiness, but the diseases often overlap: Some people with Parkinson's also have memory loss.

Growing evidence now suggests that lifestyle factors such as diet, exercise and challenging activities, might help ward off or delay the onset of neurodegenerative diseases, possibly by building connections between brain cells or even spurring the production of new brain cells. People who power up the brain in this way may have a better shot at reaching old age with a brain that still performs at top speed, says Elizabeth Edgerly, a brain expert at the Alzheimer's Association.

To keep the brain healthy:

  • Stay fit. Physical activity boosts the blood supply to the brain, and that keeps brain cells well nourished.

Edgerly recommends taking a walk, swimming, yoga or anything that's physically active three to five days a week. Spend about 30 minutes a day on such activities if you can, but a study suggested that even a 15-minute daily walk could reduce the risk of Alzheimer's.

"My guess is that we're going to discover that we should be exercising most days of the week," said Michael Zigmond, a Parkinson's researcher at the University of Pittsburgh.

He and other experts say workouts that involve a mental challenge might be better for the brain than those that are routine. So learning a series of complex dance moves might be better than zoning out while riding a stationary bike; a 2005 study found that older men and women who learned to tango got measurable improvements in balance and memory, skills that might help compensate for early signs of a brain disease.

  • Challenge your mind. The mental decline that goes along with old age can be traced to altered connections between brain cells, Edgerly says. But stimulating leisure activities can help keep those connections strong. Activities such as playing chess or card games such as poker, going to the theater, reading a book or learning how to play a musical instrument might help keep older brain cells agile and less vulnerable to damage, she says.

  • Eat a healthful diet, one loaded with colorful fruits and vegetables. Neurodegenerative diseases such as Alzheimer's and Parkinson's are tied to damage done by free radicals, highly reactive molecules that are byproducts of metabolism, says James Joseph, a researcher at Tufts University. Fruits and vegetables contain antioxidants, powerful substances that combat free radical damage and might help protect the brain, he says.

His studies of diets rich in such foods show that older rats get a boost in the ability to remember and stay balanced. He says humans might get the same benefit and recommends adding blueberries, strawberries, spinach and other colorful fruits and vegetables to a whole-grain diet that includes low-fat dairy foods and very little junk or fast food fare.

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Tuesday, October 17, 2006

You Can't Burn Too Much Energy

Research disproves theory that physical activity may actually decrease lifespan

By Rick Ansorge
HealthDay Reporter

FRIDAY, Oct. 13 (HealthDay News) -- If you're a fitness buff, the increased amount of energy you burn during your lifetime probably won't shorten your life, new research shows.

That may seem counterintuitive, considering the many proven benefits of a physically active lifestyle. But one scientific theory, the "rate-of-living" theory, suggests that increased physical activity may actually result in a decreased lifespan.

The theory holds that every organism is born with a set amount of energy to expend. Once its allotment of calories is burned up, its health declines and it dies, according to the theory.

"We've found further proof, which adds to a growing body of evidence, that the rate-of-living theory is not valid," said Theodore Garland Jr., a biology professor at the University of California, Riverside and co-author of a study presented this week at the American Physiological Society conference in Virginia Beach, Va.

The study involved 300 mice, 200 of which had been bred over many generations to love to run on wheels. One hundred of these "runner" mice had access to wheels and 100 did not. The other 100 mice were regular laboratory mice with wheels in their cages.

The runner mice with wheels in their cages expended 25 percent more energy during their lifetimes than the other two groups of mice, the researchers found.

"According to the rate-of-living theory, the physically active mice should have died sooner than the sedentary mice," Garland said. But they didn't. The average lifespan of the physically active runner mice and the sedentary runner mice were virtually identical: 735 days vs. 725 days.

The regular laboratory mice lived the longest of all -- an average of 826 days. This also contradicts the rate-of-living theory, which would have predicted that the runner mice without the wheels and the lab mice with a wheel would have the same average lifespan because they expended the same amount of energy.

"The shorter lifespan cannot, therefore, be explained by a difference in metabolism," study author Lobke Vaanholt, of the University of Groningen, the Netherlands, said in a statement. "There must be something else going on that causes these animals to age and die."

Garland speculated that genetic dissimilarities between the runner mice and the laboratory mice might be responsible.

"These lines of mice have had separate breeding pools for over 30 generations," Garland said. "They differ in a lot of ways, so in a sense they're apples and oranges. The situation is similar to small, human populations that have been separated for many generations. Any differences in lifespan could be attributable to a variety of genetic differences."

During another portion of the study, the researchers selected 40 mice from each group to assess their energy expenditure, body composition and antioxidant enzyme levels in their hearts and livers.

Because an increased activity level is associated with a higher metabolic rate and more oxidative stress, the researchers expected to see increased levels of antioxidant enzymes in the runner mice with wheels. But they found that all three groups of mice had the same amount of antioxidant enzyme activity during assessments at age 2 months, 10 months, 18 months and 26 months.

"I was a little surprised by this, given some of the previous results we've seen," Garland said. In 2002, Garland and another group of researchers found higher levels of antioxidant liver enzymes in runner mice, especially in females.

New research must examine whether tissues outside the liver and heart generated additional antioxidants to help cope with the increased oxidative stress brought on with increased activity and metabolic rate, Vaanholt said in a statement. Future studies should also examine other possible mechanisms, one of which is that increased physical activity helps improve DNA repair rates.

As scientists learn more about the intricate and interrelated effects of exercise, diet and genes on aging, at least there's general agreement about one thing: Exercise is good for you.

"Aside from any possible benefits for lifespan, exercise in moderation has been shown to have many positive effects, including on health span, immune function, heart disease and mental health," Garland said.

More information

For more on healthy aging, visit the U.S. Centers for Disease Control and Prevention.

SOURCES: Theodore Garland Jr., Ph.D., professor, biology, University of California, Riverside; Oct. 9, 2006, presentation, American Physiological Society conference, Virginia Beach, Va.

Last Updated: Oct. 13, 2006

Copyright © 2006 ScoutNews LLC. All rights reserved.

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Thursday, October 12, 2006

Daily weighing key to keeping lost pounds off

NEW YORK (Reuters Health) - Losing excess weight is often easier than
keeping it off. A new study shows that stepping on a scale every day, and
adjusting eating and exercise habits accordingly, can go a long way in
helping dieters maintain a weight loss.

"If you want to keep lost pounds off, daily weighing is critical," said Dr.
Rena R. Wing in a statement accompanying the study appearing in The
New England Journal of Medicine this week.

"But stepping on a scale isn't enough. You have to use that information to
change your behavior, whether than means eating less or walking more. Paying
attention to weight -- and taking quick action if it creeps up -- seems to
be the secret to success," noted Wing, who is director of the Weight Control
and Diabetes Research Center at The Miriam Hospital and professor of
psychiatry and human behavior at Brown Medical School in Providence.

The finding comes from a study in which Wing and colleagues split 314
successful dieters who'd lost at least 10 percent of their body weight --
averaging nearly 20 percent of their body weight or 42 pounds -- within the
last two years, into a control group and two intervention groups.

Women in the control group received newsletters in the mail four times per
year on the importance of eating right and exercising.

Women in the intervention groups were taught -- either in face-to-face group
meetings or via an online program -- techniques known to prevent weight
regain such as advice to eat breakfast, get an hour of physical activity
each day and weigh themselves daily.

The women reported their weight weekly and were given a goal of maintaining
their weight to within five pounds. Women in the intervention groups were
also introduced to a color-based weight-monitoring system. Women who
remained within three pounds of their starting weight after the weekly
check-in fell into the "green zone," and received encouraging phone messages
and green rewards, such as mint gum.

Gaining between three and four pounds landed women in the "yellow zone" and
prompted advice to tweak their eating and exercise habits, while gaining
five pounds or more landed one in the "red zone," prompting advice and
encouragement to restart active weight-loss efforts.

The investigators report that significantly fewer women in the intervention
groups regained five or more pounds during the 18-month long study; 72
percent of women in the control group regained five or more pounds, compared
with 46 percent in the face-to-face intervention group and 55 percent in the
Internet group.

"The Internet intervention worked, but the face-to-face format produced the
best outcomes," Wing said.

Daily weighing was key to keeping the weight off, the authors say, noting
that women in the intervention groups who stepped on the scale each day were
82 percent less likely to regain lost weight compared to those who did not
weigh themselves daily.

However, in the control group, daily weighing had little impact on the
amount of weight regained. This suggests, Wing said, that women in the
intervention groups used the information from the scale to make constructive
changes in their eating and exercise habits.

SOURCE: The New England Journal of Medicine, October 12, 2006.

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Tuesday, October 10, 2006

Heavier Weight Tied to Poorer Cognitive Function

By Amy Norton Mon Oct 9

NEW YORK (Reuters Health) - Overweight middle-aged adults tend to score more
poorly on tests of memory, attention and learning ability than their thinner
peers do, researchers reported Monday.

The findings, they say, suggest that a heavier weight in middle age may mean
a higher risk of dementia later in life.

Reporting in the journal Neurology, the researchers speculate that higher
rates of cardiovascular disease or diabetes might help explain the link. But
it's also possible that substances produced by fat cells, such as the
hormone leptin, have direct effects on the brain.
Both obesity and dementia, including Alzheimer's disease, are becoming
increasingly common, noted lead study author Dr. Maxime Cournot, of Toulouse
University Hospital in France.

"Our results, along with other previous studies, strongly suggest a greater
risk of dementia in these (overweight) persons at middle-age," Cournot told
Reuters Heath.

The study included 2,223 healthy French adults who were between the ages of
32 and 62 in 1996. At that time, they took a battery of standard cognitive
tests, assessing abilities like memory, attention and speed of learning.
Five years later, they took the tests again.

In general, the researchers found, people with a high body mass index (BMI)
garnered lower test scores than those with a lower BMI. They also tended to
show greater cognitive decline between the two test periods.

Factors such as age, education and general health did not seem to explain
the link.

According to Cournot, the tests used in the study are sensitive enough to
detect "small variations" in cognition, and the weight-related differences
seen among these healthy middle-aged adults would probably not be obvious in
daily life.

But over time, the researcher explained, there could be more apparent
effects on the rate of age-related mental decline.

It's possible, according to Cournot's team, that excess fat cells have some
direct effect on brain function. For example, some studies suggest the
"hunger" hormone leptin, which is produced by fat cells, plays a role in
learning and memory.

And although these study participants were in generally good health,
disorders like elevated blood pressure and diabetes could act as a bridge
between high BMI and poorer cognitive function.

Thickening and hardening of the blood vessels supplying the brain can
contribute to dementia, Cournot noted. Similarly, diabetes may harm
cognition by either leading to artery disease or via direct effects of the
hormone insulin on brain cells.

Regardless of what the impact of weight on dementia risk turns out to be,
Cournot said, there are already many reasons to maintain a healthy weight.
The potential effects on mental function, the researcher added, may give
people added motivation to change their lifestyle habits.

SOURCE: Neurology, October 10, 2006.

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Monday, October 09, 2006

Clinton deal cuts school snack foods

by KAREN MATTHEWS Associated Press Writer

NEW YORK - Snacks sold in schools will have to cut the fat, sugar and salt under the latest crackdown on junk food won by former President Clinton.

Just five months after a similar agreement targeting the sale of sodas in schools, Clinton and the American Heart Association announced a deal Friday with several major food companies to make school snacks healthier _ the latest assault on the nation's childhood obesity epidemic.

"By working with schools and industry to implement these guidelines, we are helping to give parents peace of mind that their kids will be able to make healthier choices at school," said Dr. Raymond Gibbons, president of the heart association.

The agreement with Kraft Foods Inc., Mars Inc., Campbell Soup Co., Groupe Danone SA and PepsiCo Inc. sets guidelines for fat, sugar, sodium and calories for snack foods sold in school vending machines, stores and snack bars. Those companies make everything from M&M's, yogurt and granola bars to Frito-Lay potato chips, Snickers bars and canned soups.

Under the guidelines, most foods won't be permitted to derive more than 35 percent of their calories from fat and more than 10 percent from saturated fat. There will be a limit of 35 percent for sugar content by weight.

An example of a snack that would be banned is a Snickers bar, which has 280 calories, 130 of them from fat. The candy bar has 30 grams of sugar out of 58.7 total grams.

Gibbons said Thursday the guidelines are based on the recommendations of leading scientists "as to what we should be doing to provide more nutritious foods for our kids."

Charles Nicolas, a spokesman for PepsiCo, which owns Frito-Lay and Quaker, said Frito-Lay already has products that meet the guidelines, such as baked potato chips and reduced-sugar chewy bars.

"We're going to change a few recipes so that more snacks meet those guidelines as well," he said.

Kraft said in a statement that it would add the sodium and calorie caps to its nutrition guidelines "and extend these guidelines to include all of our competitive foods sold in schools."

The William J. Clinton Foundation teamed up with the heart association to form the Alliance for a Healthier Generation in 2005. The alliance was formed to combat childhood obesity, which has been blamed for an increase in early-onset diabetes and other ills.

In May, the alliance announced an agreement with beverage industry leaders to sell only water, unsweetened juice and low-fat and nonfat milk in elementary and middle schools. Diet sodas and sports drinks are still being sold in high schools.

Officials said that agreement covered 87 percent of the soft drink market in public and private schools.

Bob Harrison, executive director of the alliance, said the snack-food industry is not as concentrated as the beverage industry, so the reach of this agreement will not be as wide as the earlier one.

But he said the five companies participating in the new agreement are market leaders and their influence will be felt.

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