A group of organic or inorganic substances capable of preventing the genotoxic and carcinogenic effects of free-radical compounds. Antioxidants bind to and neutralize ('scavenge') free radicals, thereby transforming them into non-toxic compounds and blocking their genotoxic and carcinogenic effects. This class of agents includes the vitamins C and E, the carotenoids, and selenium. Organic antioxidants are found in high concentrations in fruits, seeds and vegetables. (NCI04)

A substance that protects cells from the damage caused by free radicals (unstable molecules made by the process of oxidation during normal metabolism). Free radicals may play a part in cancer, heart disease, stroke, and other diseases of aging. Antioxidants include beta-carotene, lycopene, vitamins A, C, and E, and other natural and manufactured substances.

Agent used to stabilize a system against oxidative degradation. (Adapted from Medicinescomplete)

Naturally occurring or synthetic substances that inhibit or retard the oxidation of a substance to which it is added; counteract the harmful and damaging effects of oxidation.

Substances that protect the body from molecules that damage cells (free radicals); examples include beta carotene, vitamin C, vitamin A, and vitamin E.

Antioxidants are man-made or natural substances that may prevent or delay some types of cell damage. Antioxidants are found in many foods, including fruits and vegetables. They are also available as dietary supplements. Examples of antioxidants include Beta-carotene; Lutein; Lycopene; Selenium; Vitamin A; Vitamin C; Vitamin E. Vegetables and fruits are rich sources of antioxidants. There is good evidence that eating a diet with lots of vegetables and fruits is healthy and lowers risks of certain diseases. But it isn't clear whether this is because of the antioxidants, something else in the foods, or other factors. High-dose supplements of antioxidants may be linked to health risks in some cases. For example, high doses of beta-carotene may increase the risk of lung cancer in smokers. High doses of vitamin E may increase risks of prostate cancer and one type of stroke. Antioxidant supplements may also interact with some medicines. To minimize risk, tell you of your health care providers about any antioxidants you use. NIH: National Center for Complementary and Integrative Health