Mendelian randomisation study links elevated blood tyrosine to shorter male lifespan
A large observational and genetic analysis of more than 270,000 individuals associates higher circulating tyrosine with reduced life expectancy in men, with no equivalent signal detected in women.
A study drawing on data from more than 270,000 individuals has found an association between higher blood concentrations of the amino acid tyrosine and a shorter lifespan specifically in men. The analysis combined conventional observational data with Mendelian randomisation — a technique that uses naturally occurring genetic variants as instrumental variables to test for causal relationships — to strengthen the inference beyond simple correlation. Elevated tyrosine was associated with a reduction in male life expectancy of approximately one year in the modelled estimates; no statistically significant effect was observed in women.
Tyrosine is a non-essential amino acid present in protein-rich foods including meat, fish, eggs, and dairy, and is widely marketed as a dietary supplement promoted for cognitive performance and mental alertness. The finding raises questions about sex-specific metabolic handling of tyrosine and whether the amino acid, or a downstream metabolite, mediates the observed effect on longevity.
The ScienceDaily report does not identify the publishing institution, lead research group, or journal. It is not possible from the available lede to assess sample composition, the specific genetic instruments used, or how potential confounders were handled. Researchers in nutritional genomics, epidemiology, and the genetics of ageing are likely to want to examine the primary publication. The sex-specific pattern is a finding of particular interest for those studying sexual dimorphism in complex traits.
The study does not constitute a basis for recommendations about tyrosine intake; its findings are an illustrative result from a published epidemiological model.
Plain-language version
For patients, families, and general readers. Educational only — not medical advice.
A large study involving more than 270,000 people found that men with higher levels of a naturally occurring amino acid called tyrosine in their blood tended to have shorter lifespans. Women in the same study showed no similar pattern. The researchers used a method called Mendelian randomisation, which uses genetic information to test whether a factor is likely to be genuinely linked to an outcome, rather than just appearing alongside it by chance.
Tyrosine is found naturally in protein-rich foods like meat, fish, eggs, and cheese. It is also sold as a supplement. This study does not tell us whether taking or avoiding tyrosine supplements would change lifespan — it describes a statistical association found in a large population dataset, not a tested intervention.
The original research journal and institution were not named in the available report. This is an educational summary, not medical advice. If anything here raises questions for you, please speak with your GP or a clinical professional.
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Primary source ScienceDaily · 2026-09-06Popular brain supplement linked to shorter lifespan in men