Tyrosine and lifespan were examined in a large population analysis that suggests higher levels of the amino acid may be tied to shorter life expectancy in men, with no similar association observed in women.
Researchers led by Jie V. Zhao, Yitang Sun, Junmeng Zhang, and Kaixiong Ye from the University of Hong Kong and the University of Georgia assessed whether phenylalanine and tyrosine, two amino acids central to metabolism and brain function, are linked to longevity. Their analysis points to a sex-specific pattern. Elevated tyrosine was associated with reduced life expectancy in men, while no significant effect emerged in women, according to the study.
The authors said the findings could help illuminate biological reasons behind sex differences in aging and longevity. They cautioned that further work is required before any clinical or lifestyle guidance can be drawn from the results. The research appears in the journal Aging-US under the title, “The role of phenylalanine and tyrosine in longevity: a cohort and Mendelian randomization study.”
Why tyrosine and lifespan drew scrutiny
Amino acids are building blocks of proteins and play roles in multiple biological pathways. Phenylalanine and tyrosine occur naturally in protein-containing foods and are also sold as dietary supplements.
Beyond protein synthesis, these amino acids are involved in key processes. Tyrosine is a precursor for neurotransmitters including dopamine, a chemical messenger involved in mood, motivation, and cognition.
Despite these functions, the long-term effects of varying phenylalanine and tyrosine levels on aging are not well understood.
More than 270,000 participants analyzed
To probe potential links, the team examined data from over 270,000 participants in the UK Biobank, a repository of health and genetic information from volunteers in the United Kingdom.
The researchers applied two approaches. They evaluated associations between blood levels of phenylalanine and tyrosine and mortality-related outcomes and predicted lifespan. They also employed genetic techniques to explore whether the relationships could extend beyond simple correlation.
One key method was Mendelian randomization, which uses naturally occurring genetic variation to test whether a biological factor may contribute to an outcome. Because genetic variants are present before lifestyle exposures and disease development, this approach can offer stronger clues about causality than observational analyses alone.
Initial analyses suggested that higher concentrations of both amino acids were linked to increased mortality risk. After deeper evaluation, tyrosine consistently remained associated with adverse outcomes.
Tyrosine linked to shorter male lifespan
Genetic analyses indicated that elevated tyrosine may have a potentially causal connection with reduced lifespan in men. The researchers estimated that increased tyrosine could shorten male life expectancy by nearly one year.
No comparable effect was detected in women. The association also persisted after accounting for phenylalanine and related factors, suggesting tyrosine itself may have an independent relationship with aging.
The investigators reported that men generally exhibited higher tyrosine levels than women. That disparity could contribute to the known gap in average lifespan between sexes, though the findings do not establish tyrosine as the cause of that difference.
“Phenylalanine showed no association with lifespan in either men or women after controlling for tyrosine.”
Possible biological explanations
The mechanisms behind the observed link remain uncertain. One hypothesis involves insulin resistance, a reduced cellular response to insulin that is associated with age-related diseases and could connect higher tyrosine to shorter lifespan.
Another possibility centers on stress-related neurotransmitter pathways derived from tyrosine. Differences in hormone signaling between men and women may help explain the sex-specific findings. These ideas remain speculative and require additional research.
What it could mean for tyrosine supplements
Tyrosine is commonly marketed as a supplement for focus, alertness, and mental performance. The study raises questions about whether chronically high tyrosine levels might have unintended long-term effects.
The researchers did not test tyrosine supplements directly, so the results do not show that taking a tyrosine supplement shortens lifespan. Instead, the analysis linked measured tyrosine levels in the body with longevity outcomes.
The authors suggest that individuals with unusually high tyrosine levels might consider dietary strategies to reduce exposure, such as moderating protein intake, though it is unknown whether lowering tyrosine would extend life or improve health.
Further studies are needed to confirm the findings, clarify underlying biology, and determine whether diet or lifestyle changes can safely modulate tyrosine levels to support healthy aging. Related research on how diet influences aging includes a recent sea squirts aging study that links dietary factors to cognitive recovery.