BILL HEMMER, CNN ANCHOR: A number of adults have jumped on the antioxidant bandwagon, and they are popping megadoses of some vitamins, this in hopes of staying healthy. But CNN medical correspondent Eileen O'Connor says, a new report finds that too much of a good thing just might make you sick.</s>EILEEN O'CONNOR, CNN MEDICAL CORRESPONDENT (voice-over): The Institute of Medicine says, there's not enough evidence to support claims that taking massive doses of dietary antioxidants, like Selenium, vitamins C and E, and carotenoids, can actually prevent chronic disease. These antioxidants can be found naturally in juices, fruits, vegetables like avocados, or carrots, some wheat germs and other grains, and in the case of Selenium in beans, meat, and fish, like tuna.</s>MARET TRABER, IOM COMMITTEE MEMBER: Ideally, you can get all of these nutrients by eating a very good diet.</s>O'CONNOR: Antioxidants work by counteracting the negative effects of oxygen and nitrogen build-up in the body, build-up that takes place as a normal part of our body's processing of food, and that can actually interfere with the work of the body's cells, even causing damage. While some companies who market antioxidant supplements claim they can reduce the risk of disease like cancer, cardiovascular disease, and even cataracts, the Institute of Medicine says the evidence is lacking. In fact, the IOM set upper levels on recommended daily consumption. Like some nutritionists, they believe there is such a thing as too much of a good thing.</s>CYNDI REESER, NUTRITIONIST: Since these supplements are not providing nutrients in the ratios that would normally occur in foods, it is easy to get nutrients in undesirable proportions and to overdo it, and this can have health consequences.</s>O'CONNOR: What is needed, say the scientists on the panel, is more study to determine how to maximize the positive health effects of antioxidants. Eileen O'Connor, CNN, Washington.
Antioxidant Debate: Too Much of a Good Thing?