Current concepts: III. Molecular aspects of dietary modulation of transcription and enhanced longevity

Dietary restriction is a known means of prolonging the life span of animals. How diet can increase longevity at the molecular level is not yet known. As organisms age, there is a decrease in the ability ot synthesize RNA and a decrease in protein synthesis indicating that there is an overall loss in gene expression. In addition, a decrease in protein turnover is evident indicating a lack of cellular renewal because of the accumulation of tissue protein. Evidence is presented in this review, that certain dietary regimens appear to be capable of enhancing the synthesis of mRNA and probably also produce enhanced turnover of tissue proteins. It is proposed that the physiological "stress" produced by restricted feeding paradigms can enhance gene expression and that this may be a significant factor in the maintenance of cellular homeostasis for a longer period of time.