© Science and Education Publishing DOI:10.12691/jnh-2-3-2 Free Radicals and Antioxidants: Role of Enzymes and Nutrition

Abstract Free radicals are substances normally produced by the human body as one of the defense mechanisms against harmful substances. When the rate of their production exceeds the antioxidant capacity of the body, oxidative stress occurs. Oxidative stress carries harmful effects to all the body systems and is implicated in the pathogenesis of various diseases including hypertension, atherosclerosis, diabetes mellitus and cancer. Enzymatic and non-enzymatic antioxidants play an important role in protection of the body against the harmful effec ts of free radicals