ABSTRACT
Antioxidants and free radicals are essential to human health. In low concentrations, free radicals are beneficial to the human body. Free radicals protect the body against infectious agents, detoxify xenobiotics, and play an important role in cell growth. However, the accumulation of excess free radicals in the body often leads to a condition known as oxidative stress. This in turn can lead to the development of several diseases, including cancer, aging, cardiovascular disease, rheumatoid arthritis, renal disorders, neurological disease, pulmonary disease, and ocular disorders. Antioxidants protect the body from oxidative stress by neutralizing the oxidative effects of free radicals. Antioxidants are not produced naturally by the human body. Instead, the human diet must consist of antioxidants from food sources, vitamins, and supplements. The consumption of large quantities of antioxidants, however, can have deleterious effects as well. For example, coenzyme Q10 can cause severe hemorrhaging and may even act as a prooxidant in large quantities (Sen and Chakraborty 2011). Maintaining an appropriate balance of free radicals and antioxidants in the body is therefore vital to health maintenance.
