Research Links Widely Used Brain Supplement to Lower Male Longevity

Higher blood levels of the amino acid tyrosine may be linked to shorter lifespans in men, according to a new study published in Aging-US.

The research was conducted by scientists from the University of Hong Kong and the University of Georgia. The team investigated whether circulating levels of phenylalanine and tyrosine are associated with overall mortality and life expectancy.

Phenylalanine and tyrosine are essential components of protein metabolism and are naturally present in foods such as meat, dairy, nuts, and legumes. Tyrosine is particularly important because it serves as a precursor for neurotransmitters like dopamine, norepinephrine, and epinephrine, which regulate mood, stress response, and cognitive function.

Although these amino acids are widely consumed and even marketed as supplements, their long-term effects on aging are not fully understood.

The researchers analyzed health and genetic data from more than 270,000 participants in the UK Biobank. Using both observational methods and Mendelian randomization—a genetic approach that helps clarify cause-and-effect relationships—they assessed whether higher amino acid levels were linked to shorter lifespans.

While initial analyses suggested both phenylalanine and tyrosine were associated with increased mortality risk, more rigorous modeling showed that only tyrosine had a consistent and potentially causal link, specifically in men.

The findings indicated that men with genetically higher tyrosine levels could live nearly one year less on average. No meaningful association was found in women. Researchers noted that men generally have higher tyrosine concentrations, which may partly contribute to sex-based differences in longevity.

Although the study did not directly evaluate tyrosine supplements, the results raise important questions about long-term intake and metabolic health. Further research is needed to understand the biological mechanisms involved and whether dietary adjustments could help support healthier aging.

REFERENCE: Jie V. Zhao, Yitang Sun, Junmeng Zhang, Kaixiong Ye. The role of phenylalanine and tyrosine in longevity: a cohort and Mendelian randomization study. Aging, 2025; 17 (10): 2500 DOI: 10.18632/aging.206326