Free radicals are produced by the body when you breathe, digest food, exercise or even sleep. They are naturally occuring as they are created by emotional stress, ultraviolet light, radiation and air pollution. Free radicals damage the body by causing deterioration of the cells, lower the defences against diseases and putting the body into a stress' state.
To counter the effect of free radicals, a balance of antioxidants is required. The most important Antioxidants include: Beta-carotene, Vitamin C, Vitamin E, Zinc, Selenium and components found in certain plants including Turmeric, and Ginkgo biloba.
Antioxidants can be obtained by eating a healthy and balanced diet, but taking a supplement might be desirable to achieve an optimal intake of antioxidants.