Amino-Acid Restrictions Linked to Longer Healthy Lifespan, Review Finds

A comprehensive review of over 350 studies finds that lowering total dietary protein or restricting specific essential amino acids—especially isoleucine and methionine—may promote longevity and better metabolic health by activating repair pathways (FGF21, autophagy) and dampening growth signals (mTORC1, GCN2). Benefits observed in animals and some human data; however, protein needs vary with age and activity, and excessive restriction could harm older adults by raising sarcopenia risk. The authors stress optimizing amino-acid balance rather than simply eating less protein, and more human research is needed.