Tyrosine, an amino acid widely marketed as a cognitive enhancer to sharpen focus, may be linked to a significant reduction in male longevity. New research indicates that elevated concentrations of tyrosine in the blood correlate with shorter life expectancy in men, with genetic modeling suggesting an average lifespan reduction of nearly one year.
The study, titled "The role of phenylalanine and tyrosine in longevity: a cohort and Mendelian randomization study," was published in the international journal Aging on October 3, 2025. The research was a collaborative effort between teams from the University of Hong Kong and the University of Georgia.
Tyrosine: The 'Brain Chemistry' Component Found in Protein and Supplements
Tyrosine and phenylalanine are fundamental amino acids that serve as the building blocks of protein. They occur naturally in protein-rich foods such as meat, fish, dairy, and legumes, and are also easily accessible as key ingredients in supplements marketed for "focus and condition." Tyrosine, in particular, has gained popularity for its role in synthesizing neurotransmitters like dopamine, which governs mood, motivation, and cognitive performance.
Despite its use in "brain hacking," the long-term impact of these substances on the aging process has remained unclear. To investigate, the research team analyzed health and genetic data from over 270,000 individuals using the UK Biobank. The study utilized both observational methods to assess mortality risk and Mendelian randomization (MR) analysis, which uses genetic variations to explore potential causal relationships.
Initial findings suggested that both tyrosine and phenylalanine were associated with mortality. However, as the researchers adjusted for confounding factors, the signal for phenylalanine dissipated. The only consistent correlation that remained was for tyrosine: higher levels in men were tied to a decline in life expectancy. Notably, no such association was found in women, and the researchers pointed out that men typically maintain higher baseline tyrosine levels, which may offer new insights into the global gender gap in longevity.
Causality and Caution: Does Tyrosine Directly Shorten Life?
Scientists have yet to determine why tyrosine acts as a "lifespan-shortening signal" exclusively in men. Current hypotheses include a potential link to insulin resistance—a precursor to various metabolic disorders—or the possibility that male hormonal systems process tyrosine-driven neurotransmitter pathways differently than those of women.
The significance of this study lies in its use of large-scale genetic data to identify tyrosine as a biological marker for longevity in men. However, the researchers emphasized that the study did not involve the direct administration of tyrosine supplements to observe long-term outcomes. Consequently, it cannot be definitively concluded that taking tyrosine supplements will inherently shorten one's lifespan.
The research team noted the need for further study into whether those with naturally high tyrosine levels can improve their prospects through dietary interventions. However, the specific lifestyle and nutritional strategies required to safely regulate tyrosine while maintaining health benefits have yet to be verified.
Source of the paper: The role of phenylalanine and tyrosine in longevity: a cohort and Mendelian randomization study. Aging, 2025; 17 (10): 2500 DOI: 10.18632/aging.206326.
