According to the Food and Nutrition Board of the National Research Council in the United States, dietary antioxidants are ” substance in food which significantly decreases the adverse effects of reactive oxygen species, reactive nitrogen species, or both on normal physiologic function in humans” . Antioxidants help the body cope with potentially damaging reactive oxident species. When the body cells use oxygen , they produce free radicals or by-products such as superoxide and nitric oxide . Free radicals are a product of tissue metabolism.

Antioxidants act as scavengers for these free radicals and help repair the damage caused by them.

Both zinc and sellenium are known to be involved in protecting the body against oxidant stress.
Vitamin C and E are the main nutrients which possess radical-quenching properties.

Fruit and vegetables are the best source of antioxidants