Taurine

Taurine has multiple, partly understood mechanisms. It is a major intracellular osmolyte, contributing to cell-volume regulation in tissues exposed to osmotic stress (kidney, brain). It conjugates with bile acids in the liver to form taurocholic acid, supporting fat digestion and cholesterol clearance. In the heart, taurine modulates intracellular calcium handling at the sarcoplasmic reticulum and acts as a positive inotrope at high tissue concentrations — the mechanism behind its benefits in heart failure. In skeletal muscle, taurine supports excitation-contraction coupling and reduces exercise-induced oxidative stress. CNS effects are mediated by partial agonism at GABA-A and glycine receptors, contributing to mild anxiolytic and sleep-supportive properties at higher doses. Taurine is also a direct antioxidant — its sulfonate group quenches hypochlorous acid and other reactive species, particularly important in mitochondria where taurine is concentrated and supports the integrity of the electron transport chain via tRNA modification (the 5-taurinomethyluridine modification of mitochondrial tRNA-Leu). The 2023 longevity findings appear linked to this mitochondrial role — taurine deficiency is one of the molecular signatures of ageing across species.