Antioxidants are the substance that inhibits oxidation or inhibits reactions promoted by oxygen or peroxides or superoxide ions. They play a major role in strengthening the body's defense against free radicals. Free radicals can lead to oxidation of DNA and accumulation of somatic mutations due to formation of oxidation adducts. There are many sources of free radicals, for instance, cosmic rays, heavy metals like lead, mercury or cadmium, components of cigarette smoke like benzopyridines, and how can we forget those yummy salty potato chips! Antioxidants have the ability to stabilize free radicals capable of oxidation reaction. They are present in various fruits which are rich sources of vitamin C, like oranges and lemons and also in some forms of green vegetables. The presence of certain levels of antioxidants can be detected by various antioxidant check kits which are often based on urine sampling. The samples are treated with an estimated count of free radicals, and the unbound antioxidants or the free radicals are then estimated to statistically find the concentration of the antioxidants in the sample.