Lifelong restriction of dietary valine has sex-specific benefits for health and lifespan in mice.

Dietary protein is a key regulator of metabolic health in humans and rodents. Many of the benefits of protein restriction are mediated by reduced intake of dietary branched-chain amino acids (leucine, valine and isoleucine) and restriction of the branched-chain amino acids is sufficient to extend healthspan and lifespan in mice. Here we find that valine restriction (Val-R) improves metabolic health in C57BL/6J mice, promotes leanness and glycemic control across ages, and reduces frailty, cancer prevalence and senescent cell burden in both sexes while increasing median male lifespan by 23%. Assessing gene relationships across tissues, we identified a liver gene module enriched in mitochondrial pathways and increased mitochondrial respiration in Val-R-fed male mice. Our results demonstrate that Val-R improves multiple aspects of healthspan in mice of both sexes, extends lifespan in male mice and suggests that interventions that mimic Val-R may have translational potential for aging and age-related diseases.