Highly reactive oxygen radicals are formed during normal oxidative metabolism and in response to infection and some chemicals. They cause damage to fatty acids in cell membranes, and the products of this damage can then cause damage to proteins and DNA. The most widely accepted theory of the biochemical basis of much cancer, and also of atherosclerosis and possibly kwashiorkor, is that the key factor in precipitating the condition is tissue damage by radicals. A number of different mechanisms are involved in protection against, or repair after, oxygen radical damage, including a number of nutrients, especially vitamin E, carotene, vitamin C, and selenium. Collectively these are known as antioxidant nutrients.
Subjects: Medicine and Health.