Tyrosine, an amino acid sold as a popular brain-boosting supplement, has been linked to a shorter lifespan in men, according to a large study of more than 270,000 people. The research combined observational data with genetic analysis to examine the relationship between blood tyrosine levels and longevity.
The findings suggest that elevated tyrosine could potentially reduce male life expectancy, though the study summary does not specify the exact number of years. The association was reported specifically for men, indicating a sex-specific effect.
Because the study uses both observational and genetic methods, the consistency across the two approaches strengthens the evidence, but it does not prove causation. The researchers caution that popular supplements containing tyrosine may carry unintended risks for men.