An analysis drawing on UK Biobank data reports that higher circulating levels of the amino acid tyrosine were associated with a modest reduction in estimated lifespan in men—about 0.9 years in one genetic analysis—while the association was weaker and not statistically clear in women.
A study in the journal Aging examined whether the amino acids phenylalanine and tyrosine are linked to longevity using UK Biobank data and genetic methods designed to strengthen causal inference.
In analyses of baseline blood measurements and in Mendelian randomization—an approach that uses genetic variants as proxies for lifelong differences in exposure—higher tyrosine levels were associated with shorter lifespan estimates in men. The paper reported an estimated reduction of about 0.91 years of life in men (95% confidence interval: −1.60 to −0.21) in one Mendelian randomization analysis, while the corresponding estimate in women (−0.36 years) was not statistically clear.
The researchers also assessed phenylalanine, a precursor of tyrosine. Their results suggested that phenylalanine did not show an independent association with lifespan once tyrosine was taken into account.
Tyrosine is found naturally in protein-containing foods and is also sold as a dietary supplement, often marketed for focus and stress response. The researchers emphasized that their analyses evaluated blood levels of these amino acids rather than supplement use, and they called for further work to clarify mechanisms and whether diet-related changes could affect health outcomes.
The findings show an association rather than proof that increasing tyrosine intake shortens life, and the study’s authors noted that additional research is needed to understand the biological pathways that could explain the sex-specific pattern observed in their analyses.
