Antioxidants
counteract the oxidizing (burning) effects of free radicals, harmful molecules that can cause cellular damage throughout the body. Besides leading to heart and coronary artery disease by promoting the buildup of plaque in the walls of blood vessels, oxidation may increase your risk of developing health problems as diverse as cataracts and Alzheimer's disease. And oxidation can cause cellular damage that may eventually result in malignancy. Antioxidants can interrupt this process, potentially conferring protection from cancer. Some scientists believe that, in high enough doses, antioxidants can even reverse the growth of cancers that have already taken hold.
The body produces its own antioxidants that combine with free radicals to help keep the oxidation process in check. But a number of scientists believe that the body often cannot produce enough antioxidants on its own, especially when confronted with exposure to environmental contaminants like cigarette smoke and polluted air. They recommend antioxidant supplementsand supplementation has, in fact, become extremely popular.
When embarking on a regular supplementation program, however, it's important to keep two points in mind. First, there's a growing body of evidence suggesting that antioxidants in pill form may not provide the same benefits as those obtained from natural foods. Second, just as with many other substances, more of an antioxidant is not always better. Beyond certain levels, some actually become toxic. For instance, The U.S. Institute of Medicine has set an upper daily intake level of 2 grams for vitamin C and 1 gram for alpha-tocopherol (equivalent to about 1,500 IU of natural vitamin E or 1,100 IU of synthetic vitamin E). A high antioxidant level can help improve memory and reduce build-up of bad cholesterol.