BUFFALO, NY — November 13, 2025 — A new #research paper was #published in Volume 17, Issue 10 of Aging-US on October 3, 2025, titled “The role of phenylalanine and tyrosine in longevity: a cohort and Mendelian randomization study.”

In this study led by Jie V. Zhao, Yitang Sun, Junmeng Zhang, and Kaixiong Ye from the University of Hong Kong and the University of Georgia, researchers investigated whether two amino acids, phenylalanine and tyrosine, affect how long people live (lifespan). The results suggest that higher levels of tyrosine are linked to shorter life expectancy in men, pointing to potential sex-specific approaches to promoting longevity.

Phenylalanine and tyrosine are amino acids involved in metabolism and brain function. Both are found in protein-rich foods and dietary supplements, but their long-term effects on aging are not well understood. Tyrosine, in particular, is a building block of neurotransmitters such as dopamine, which regulate mood and cognitive function, making it a molecule of interest in aging research.

The study analyzed data from more than 270,000 individuals in the UK Biobank. Using both observational and genetic methods, the researchers examined the associations between blood levels of phenylalanine and tyrosine with overall mortality and predicted lifespan. Although both amino acids were initially linked to higher mortality risk, only tyrosine showed a consistent and potentially causal association with reduced life expectancy in men. Genetic analyses estimated that elevated tyrosine levels could shorten men’s lifespan by nearly one year. No significant effect was observed in women.

These findings remained consistent even after adjusting for related factors, including the role of phenylalanine. This suggests that tyrosine may independently influence aging. The researchers also observed that men tend to have higher tyrosine levels than women, which could partly explain the gender gap in lifespan.

“Phenylalanine showed no association with lifespan in either men or women after controlling for tyrosine.”

The exact mechanisms behind this effect are still under investigation. However, tyrosine’s involvement in insulin resistance and the production of stress-related neurotransmitters may be contributing factors. Insulin resistance is associated with many age-related diseases, and hormone-related pathways influenced by tyrosine may differ between men and women, potentially explaining the sex-specific outcomes.

Although tyrosine is commonly marketed as a supplement for enhancing focus and mental performance, the study raises concerns about its long-term impact on lifespan. While the researchers did not directly study tyrosine supplementation, their findings suggest that people with high tyrosine levels may benefit from dietary adjustments. Strategies such as protein restriction could help reduce tyrosine levels and support healthier aging.

Further studies are needed to confirm these findings and explore whether diet and lifestyle changes can safely lower tyrosine levels to promote longevity.

DOI - https://doi.org/10.18632/aging.206326

Corresponding author - Jie V. Zhao - janezhao@hku.hk

Abstract video - https://www.youtube.com/watch?v=rr0G44TD36M

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