ABSTRACT
Aging is characterized by a progressive decline in the efficiency of physiological function and by the increased susceptibility to disease and death. The premise of the mitochondrial free radical theory of aging is that mitochondria are both producers and targets of reactive oxidative species. In the aging brain, as well as in the case of several neurodegenerative diseases, there is a decline in the normal antioxidant defense mechanisms, which increases the vulnerability of the brain to the deleterious effects of oxidative damage. Aging also is accompanied by changes in membrane fatty acid composition, including a decrease in the levels of polyunsaturated fatty acids and an increase in monosaturated fatty acids. The chapter summarizes some of the literature that supports a role for oxidative stress as one aspect of age and disease that contributes to declines in function of the central nervous system. The oxidative stress theory of aging has also come to include a role for inflammation.
