What do bright red strawberries, midnight-hued blueberries, black and red beans, and deep green spinach have in common? Not only do they tantalize our taste buds, but also they're all rich sources of antioxidants.
Antioxidants are nutrients that are thought to have a positive effect on health. The most popular antioxidants are vitamin C, vitamin E and beta-carotene, which are found naturally in whole foods. Antioxidants have been credited with preventing cardiovascular disease, slowing the deterioration of mental function associated with aging, preventing cancer and slowing or even reversing the aging process itself.
Sound too good to be true? Unfortunately, that is the conclusion of some important new research -- especially when antioxidants are taken in the form of supplements or pills.
For example, a recent clinical trial examined the effect on elderly people of taking 500mg of vitamin C, 400 IU of vitamin E and 15mg of beta-carotene for nearly seven years. Six cognitive function tests were performed at the beginning and end of the study. Researchers observed no benefit among those taking the antioxidant supplements. These results shed doubt on claims that antioxidant supplements can slow the loss of mental function associated with aging.
Because serum vitamin C levels are often low in people with diabetes, it was thought that extra vitamin C might be beneficial. However, a study of almost 2,000 older women with diabetes found a negative correlation between taking vitamin C supplements and the risk of dying from cardiovascular disease.
Researchers concluded that those who took supplements of vitamin C (300 mg or more per day) were more than twice as likely to die from cardiovascular disease as those who did not take vitamin C supplements. This study found no association between vitamin C intake from foods and cardiovascular disease.
The most popular antioxidant supplement in the United States today is vitamin E, despite growing evidence that it has little or no benefit. A large meta-analysis of 19 of the best-controlled studies on vitamin E supplements in people 47 to 84 years of age found no evidence that vitamin E supplements were beneficial.
Recent research indicates that vitamin E may promote hemorrhagic strokes as well as interfere with the effects of certain cholesterol-reducing medications.
The University of California at Berkeley Wellness Letter states that the university's School of Public Health "can no longer recommend vitamin E pills -- or any other antioxidants supplements. There are simply too many unanswered questions: Is one form of vitamin E supplement preferable? What dose is best? Should vitamin E be taken with other antioxidants? Is it possible that only the vitamin E in food is beneficial?"
The belief that antioxidant supplements could improve health and longevity of most Americans largely has been discredited. Without reliable, scientific evidence about who would derive more benefit than harm from taking these supplements, it is advisable to avoid them.
At this time, the best way to take advantage of the potential health benefits of antioxidants is the natural way -- by eating whole foods such as fruits, vegetables, whole grains and beans.
Lisa A. Bankard, M.S., coordinates the Wellness Program at Yampa Valley Medical Center.