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By Keith Mulvihill
NEW YORK, Mar 06 (Reuters Health) - Healthy individuals may be not be getting the benefits they expect from taking vitamin E supplements, according to a new study published in The Journal of the American Medical Association.
Researchers showed that supplementing the diets of healthy people with vitamin E had no effect on the rate of "oxidative damage" in their bodies, a finding that questions the value of taking the popular vitamin supplement.
Oxidative damage is caused by the activity of "free radicals"--compounds released during normal cell processes. Experts have linked oxidative stress to a number of major illnesses, including cancer and heart disease. Antioxidants such as vitamins C and E are thought to reduce levels of free radical activity.
To test whether taking vitamin E supplements cuts oxidative stress, Dr. Emma A. Meagher, from the University of Pennsylvania in Philadelphia, and colleagues gave 30 healthy men and women aged 18 to 60 either an inactive placebo or vitamin E in dosages that ranged from 200 to 2,000 international units (IU) per day.
The investigators saw an increase in circulating vitamin E levels after 8 weeks in people taking the supplements compared with those taking the placebo. However, the level of oxidative damage, measured via chemicals released in the urine, remained nearly unchanged regardless of the varying doses of vitamin E taken.
"In theory, we should have seen the amount of these chemicals drop over time, but they stayed roughly the same and compared similarly to the subjects in the placebo group," Dr. Tim Byers, a professor of preventative medicine at the University of Colorado School of Medicine in Denver, told Reuters Health in an interview. Byers was not part of the study.
The study is one of the first to look at the effect of vitamin E on oxidation in the body, Byers explained. "Previous studies relied more on test tube-like measurements. This study is good because it measures oxidative damage actually occurring within the living body," he said in an interview.
"The information provided in this study along with the results of other lager studies add up and say to me that vitamin E does not result in favorable outcomes for reducing death rates, or rates of heart disease or stroke. Vitamin E is not really protecting against oxidative harm to (fats) as many researchers had thought it would," Byers said.
And the results carry implications for other supplements, Byers pointed out.
"There are many people taking lots of high doses of supplements on the promise that it might have some benefit. A pattern is beginning to develop as more research is done," Byers said. "Nutritional supplements do not appear to be as beneficial as previously thought. Whole food intake, on the other hand, does appear to be beneficial."
The bottom line is that people should focus their energies on eating healthy, well-balanced meals, he added.
Foods that contain vitamin E include nuts, vegetable oils, unprocessed cereal grains, fruits, vegetables and meat.
SOURCE: The Journal of the American Medical Association 2001;285:1178-1182.
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