It is always interesting to see data on life span in short lived species for an intervention with a fair amount of human data for health benefits. The broad pattern is that short-lived species exhibit a much greater extension of life in response to interventions, but on the other hand near all of the data is focused on only a few different ways to alter metabolism, such as the upregulation of stress responses and increased cell maintenance observed in calorie restriction. Supplementation with β-hydroxy-β-methylbutyrate is yet another way to manipulate the systems of regulation linking nutrient availability and cell maintenance, in an attempt to capture some fraction of the benefits of exercise and calorie restriction.
Two lifestyle interventions that may improve muscle function and attenuate the negative physical outcomes of the aging process include exercise and dietary protein and amino acid supplementation. At the molecular level, leucine serves as a direct substrate for muscle protein synthesis as well as an activator of protein synthesis through the multi-protein complex mechanistic Target of Rapamycin Complex 1 (mTORC1). Branched-chain amino acid aminotransferase transaminase (BCAT) converts leucine to keto-isocaproic acid (KIC), which is then reduced to
