Antioxidants -- mainly vitamins C and E, selenium, and beta-carotene -- are the darlings of the nutritional-supplement world. But the nation's top scientists have studied the evidence, and they're saying the same thing nutritionists have said for years:
Most of us don't need antioxidant supplements, as long as we eat a healthy diet.
According to a report by the Institute of Medicine, a part of the National Academies of Sciences, researchers found no evidence that large doses of antioxidants prevent chronic diseases. Seems like a contradiction to what you've heard? Here are the facts.
While there is evidence that free radicals (compounds that cause damage to cells) are linked to a risk of cancer and heart disease, there is no proof (at least, not yet) that antioxidants in humans attack free radicals or limit their damage. It's only been proven in laboratories. Therefore, no evidence exists that taking megadoses of antioxidants prevents cancer, heart disease, or Alzheimer's disease. "The public is very confused because often when these studies get reported, all the facts aren't in," says Sandra Schlicker, director of the study at the Institute of Medicine.
The National Institutes of Health panel did revise the recommended Dietary Allowances (RDAs) -- the minumum amount needed for good health. And, for the first time, they set an upper-intake level -- the most a person can take without risking health problems. This doesn't mean larger amounts are harmful, just that not enough research exists to say for sure that bigger doses are safe. In revising the RDAs, the experts looked at published studies and focused on trials involving humans -- not animals.
The take-home message of this report is simple: Eat more fruits and vegetables every day. While the panel did not say how many to eat, it did endorse the five-a-day eating plan, which advises people to eat at least five servings of fruits and vegetables a day. A typical serving is one apple, orange, or pear, 1/2 cup of berries, cut-up fruit, or cooked vegetables. One 6-ounce glass of juice also is considered a serving.