Our body produces an enzyme, called superoxidase dismutase (SOD), which renders electrons to the free radicals and make them harmless. Our body produces this enzyme in small quantities, so when there are large quantities of free radicals in the cells, our body uses antioxidants in addition to SOD to neutralize these free radicals and protect cells. Only CoenzymeQ10 and Glutathione are the antioxidants that are produced in the human body, while the rest others are obtained from the diet.
Thus, it can be said that antioxidants provide a complex protection system to the body. Some of the major antioxidants are Vitamin E, Vitamin C, carotenoids, lipoic acid, zinc, selenium, and even proteins like albumin, ferritin and so on. Antioxidants can either be naturally occurring or can be synthesized artificially.