Taurine

Taurine (2-aminoethanesulfonic acid) is a sulfur-containing compound found at high concentrations in the heart, skeletal muscle, retina, and brain. Despite being categorized as an amino acid, it is not incorporated into proteins — it functions instead in osmoregulation, modulation of calcium homeostasis, membrane stabilization, conjugation of bile acids, and antioxidant defense. The human body can synthesize taurine from methionine and cysteine, but dietary sources (primarily meat and seafood) contribute meaningfully to circulating levels. The most consequential recent development in taurine research is Singh et al. (2023), published in Science, which reported that taurine levels decline substantially with age across species — including humans — and that taurine supplementation extended median lifespan by approximately 10–12% in middle-aged mice and improved multiple health span markers including bone density, muscle strength, energy expenditure, gut microbiome composition, immune function, and reduced cellular senescence. The paper also included preliminary non-human primate data with directionally consistent findings. This is high-impact work from a rigorous group and published in a top-tier journal. However, the critical caveat is that lifespan benefit in humans has not been established — the human data in the paper is cross-sectional (circulating taurine correlates with health markers), and the history of mouse longevity interventions translating to humans is mixed at best. Cardiovascular evidence is more developed. Epidemiological data — particularly from Japanese populations with high seafood and taurine intake — has associated higher taurine status with lower rates of cardiovascular mortality. Mechanistically, taurine modulates intracellular calcium signaling, reduces oxidative stress, and may attenuate vascular inflammation. Controlled trials have shown modest reductions in blood pressure and improvements in exercise tolerance in populations with cardiovascular disease, though large-scale RCTs in healthy adults are lacking. Exercise performance data is preliminary and mixed. Systematic review evidence (Kurtz et al., 2021) suggests taurine supplementation (1–6 g/day) may modestly reduce exercise-induced oxidative stress and markers of muscle damage, with some improvements in endurance performance. Effect sizes are generally small and study designs are heterogeneous. Taurine is widely considered safe at supplemental doses up to 3 g/day, and higher doses (up to 6 g/day) have been studied without serious adverse events. It is worth noting that taurine in energy drinks (typically 1–2 g per can) is often conflated with isolated taurine supplementation — the concerns around energy drinks largely relate to high caffeine content and combined stimulants, not taurine itself.