(1) Any substance that reduces oxidative damage (damage due to oxygen) such as that caused by free radicals. Free radicals are highly reactive chemicals that attack molecules by capturing electrons and thus modifying chemical structures.
Well-known antioxidants include a number of enzymes and other substances such as vitamin C, vitamin E and beta carotene (which is converted to vitamin A) that are capable of counteracting the damaging effects of oxidation. Antioxidants are also commonly added to food products like vegetable oils and prepared foods to prevent or delay their deterioration from the action of air.
Antioxidants may possibly reduce the risks of cancer and age-related macular degeneration (AMD). Antioxidants clearly slow the progression of AMD.
(2) Antioxidants are substances that may protect your cells against the effects of free radicals. Free radicals are molecules produced when your body breaks down food, or by environmental exposures like tobacco smoke and radiation. Free radicals can damage cells, and may play a role in heart disease, cancer and other diseases. Some may even help strengthen the immune system.
Antioxidant substances include:
Beta-carotene Lutein Lycopene Selenium Vitamin A Vitamin C Vitamin E
Antioxidants are found in many foods. These include fruits and vegetables, nuts, grains, and some meats, poultry and fish.