Mammalian and bird aging, oxygen radicals, and restricted feeding

Abstract

In this chapter, the relationship of aging with oxidative stress is reviewed. Endogenous tissue antioxidants do not determine aging because they correlate inversely with the maximum longevity of animals and the experimental modification of their levels can change survival and mean but not maximum lifespan. On the other hand, long-lived mammals or birds consistently show low rates of mitochondrial oxygen radical generation and a low degree of membrane fatty acid unsaturation, which can be responsible for their slower rates of aging. Oxidative damage to mitochondrial DNA is also lower in long-lived than in short-lived species. Caloric restriction, the only known manipulation, which decreases the rate of aging, also lowers mitochondrial ROS generation and oxidative damage to mitochondrial DNA in rodents. Such decrease in mitochondrial ROS production has been localized in complex I in rat heart and liver.