Diet restriction and fruits of the tree of life

Diet restriction extends life in a wide variety of species. However, given that the exact mechanism(s) underlying this phenomenon are not fully understood, its significance is still a matter of debate. Early studies ascribed longevity as a direct reaction to energy depletion in the form of a reduced metabolic rate, improved cellular renewal, and decreased oxidative damage. A more complicated response was later revealed when the roles of autophagy and the regulation of protein translation were ultimately recognized. Evidence for such ‘reprogramming’ was compounded with the discovery of the contribution of key factors such as AMPK and the mammalian SIR2 family in the regulation of the physiological changes which occur following dietary restriction. More recent work suggests that the cellular response is finely controlled by the neuroendocrine system. The potential of these mechanisms to combat the aging process is discussed.