SCI/NEWS: anti-oxidants, exercise, calorie restriction slow rat aging

Han Huang (
Thu, 28 Jan 1999 15:43:52 -0500


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             Institution: University Of Florida 
             Contact: Steve Orlando , News Desk Editor 
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             UF Researcher Finds Way To Slow The Aging

             Writer: Kristin Harmel 

             Source: Christiaan Leeuwenburgh, (352)

             GAINESVILLE, Fla. --- Contrary to what
             Juan Ponce de Leon thought when he searched
             for it in the 16th century, the fountain of youth
             is made of anti-oxidants, not water, and it's a
             lot easier to find than the famed explorer

             In a study published in this month's American
             Journal of Physiology, Christiaan
             Leeuwenburgh, a professor in the University of
             Florida's College of Health and Human
             Performance, found that anti-oxidant
             intervention, which can come from taking
             vitamin supplements or from a steady routine of
             exercise, slows parts of the aging process. 

"Our most significant finding was that
anti-oxidant intervention slows down basal skeletal muscle oxidation, which causes the body to age," said Leeuwenburgh, who did the study with Jay Heinecke, John Holloszy and Polly Hansen of the Washington University School of Medicine. "This is the first evidence of this." Regular exercise or a diet including plenty of anti-oxidants such as vitamin E, vitamin C and beta carotene, all of which fight the tendency of oxygen to slowly break down muscle mass, might protect against the type of tissue and muscle loss that occur as individuals grow older, Leeuwenburgh said.
"When an individual grows old, we all know
that the person loses a lot of muscle mass," Leeuwenburgh said. "One of the mechanisms that causes this is increased oxidant production, in a process known as muscle oxidation. Regular exercise or anti-oxidant supplements could potentially improve and protect against this oxidative stress, which may have direct implications on tissue loss and the aging process." Leeuwenburgh divided rats into two groups, one of which was given an anti-oxidant diet of beta carotene and vitamins E and C. After 21 months, the rate of muscle oxidation for the rats in the anti-oxidant groups was 50 percent lower than the rate for the rats in the control group. Some of the rats that were not fed anti-oxidants were exercised regularly, and they, too, showed a decrease in muscle oxidation.
"We were surprised to see that regular exercise
training was about as effective in reducing levels of oxidation as a diet of anti-oxidants," Leeuwenburgh said. "The combined effect of anti-oxidants and exercise, however, didn't cause a significantly lower level of muscle oxidation, which was interesting." The study also was the first of its kind to show that levels of oxidation in the body can be determined noninvasively, by using specific markers in the urine. This will allow people to measure their levels of muscle oxidation more quickly and easily.
"People are talking a lot about oxidative stress
these days, but we didn't previously have a way to measure it noninvasively," said Heinecke, a professor in the department of internal medicine at Washington University in St. Louis and one of Leeuwenburgh's partners in the study. "It's nice to be able to measure this without going inside the body." The marker found in the urine also may be useful as an indicator of other medical problems, which will contribute not only to slowing the aging process but also to protecting people against various diseases.
"This marker could be useful in assessing a
variety of conditions, like Alzheimers, atherosclerosis, cancer and the aging process itself," Leeuwenburgh said. "They've all been associated with increased free-radical formation, which can be detected in the urine." A previous study by Leeuwenburgh also showed that a decrease in caloric intake, which can lead to a longer life span because of a reduction in the body's rate of metabolism, also causes a similar decrease in skeletal muscle oxidation. Leeuwenburgh recommends an increase of daily anti-oxidant intake, especially in the form of vitamin E, because it also has been proven to protect against heart disease. In addition, he says that exercising more and eating less -- both of which have been promoted for years as ways to stay healthy in everyday life -- also will increase the human life span and help people stay younger longer.
"A big problem in society is that we're not
active enough, and things like fast food contribute to an almost toxic lifestyle," he said.
"If we could increase our daily activities and be
more conscious of what we eat, we'll come a long way."