Free radical production occurs continuously in all cells as part of normal
cellular function. However, excess free radical production originating from
endogenous or exogenous sources might play a role in many diseases. Antiox
idants prevent free radical induced tissue damage by preventing the formati
on of radicals, scavenging them, or by promoting their decomposition. This
article reviews the basic chemistry of free radical formation in the body,
the consequences of free radical induced tissue damage, and the function of
antioxidant defence systems, with particular reference to the development
of atherosclerosis.