Metabolic HealthHow Amino Acid Metabolism Drives Disease and Aging Across Every Body System
Amino acids do far more than build proteins — they regulate nutrient sensing, redox balance, epigenetics, and the gut microbiome. This comprehensive review examines how amino acid metabolism supports every major organ system and how disruptions in these pathways contribute to disease. Key mechanisms covered include branched-chain amino acid (BCAA) signaling, mTORC1 and GCN2 nutrient sensing, glutathione-dependent antioxidant defense, and one-carbon metabolism. When these networks break down, the consequences range from excitotoxicity and endothelial dysfunction to insulin resistance, inflammation, and immune escape in cancer. The review also critically evaluates whether circulating amino acid signatures are true disease drivers or merely biomarkers, and surveys emerging therapeutic strategies — dietary modification, enzyme-based therapies, transporter targeting, and microbiome interventions — while honestly assessing why some late-stage clinical trials have failed.
