Common 'Focus' Amino Acid Tyrosine Linked to Shorter Lifespan in Men, Study Finds — But Effect Limited to About One Year"

 

A massive genetic and cohort study has uncovered an unexpected downside to tyrosine — an amino acid commonly found in protein foods and sold as a popular brain supplement for enhanced concentration and mood.

Published in Aging and drawing from data on over 270,000 people, the research indicates that higher circulating tyrosine levels are associated with reduced life expectancy specifically in men, potentially shortening lifespan by nearly one year.

Tyrosine is a building block for key neurotransmitters like dopamine, which is why it's a staple in many nootropic formulas marketed for better focus, motivation, and cognitive performance. While naturally occurring in foods like dairy, meat, nuts, and eggs, supplemental forms are widely available over-the-counter.

Led by researchers from the University of Hong Kong and the University of Georgia, the study first observed links between both tyrosine and its precursor phenylalanine with higher mortality. However, advanced analysis — including Mendelian randomization using genetic variants to mimic randomized trials — isolated tyrosine as the key factor in men. The association held after controlling for related factors, with no clear effect in women.

"Genetic modeling suggested that men with elevated tyrosine levels could live nearly one year less on average," the researchers noted. This points to possible sex differences in how tyrosine metabolism influences aging pathways.

The findings do not mean tyrosine is inherently harmful — it's essential for brain function — but they highlight potential risks from chronically high levels, whether from diet or heavy supplementation. The authors suggest that strategies to lower tyrosine in those with elevated concentrations could support longevity, though clinical trials are needed to confirm this.

Experts caution that this is an associational study, not proof of direct causation from supplements. More research is required before changing recommendations on tyrosine use. For now, moderate intake from food sources remains generally safe, and anyone concerned about supplement regimens should consult a healthcare provider.

This discovery adds to growing evidence that nutrients affecting brain chemistry may have nuanced, sex-specific impacts on healthy aging.