Higher levels of the amino acid tyrosine are linked to a shorter lifespan in men, according to a new study published in the journal Aging-US. The research, conducted by scientists at the University of Hong Kong and the University of Georgia, suggests that this connection may contribute to the observed difference in longevity between men and women.
The study analyzed data from over 270,000 participants in the UK Biobank, utilizing both observational data and genetic techniques. Led by Jie V. Zhao, Yitang Sun, Junmeng Zhang, and Kaixiong Ye, the research team investigated the relationship between blood levels of phenylalanine and tyrosine and overall mortality. While initial analysis indicated a potential link between both amino acids and increased risk of death, further investigation revealed that only tyrosine consistently correlated with reduced life expectancy in men.
Genetic modeling indicated that men with elevated tyrosine levels could, on average, live nearly one year less. No such association was found in women. Researchers emphasized that this finding remained significant even after accounting for other factors, including levels of phenylalanine, strengthening the possibility that tyrosine itself plays an independent role in aging.
Phenylalanine and tyrosine are both amino acids crucial for metabolism and brain function, naturally occurring in protein-rich foods and commonly available as dietary supplements. Tyrosine is a precursor to neurotransmitters like dopamine, influencing mood, motivation, and cognitive performance. This has led to growing interest in its role in aging research, particularly concerning cognitive decline.
Scientists are currently exploring potential biological mechanisms behind the observed link between tyrosine and lifespan. One hypothesis centers on insulin resistance, a condition associated with numerous age-related diseases. Tyrosine is also involved in the production of stress-related neurotransmitters, potentially impacting metabolic and hormonal pathways differently in men and women. Variations in hormone signaling may explain why the effect was observed primarily in men, who generally exhibit higher tyrosine levels than women.
The findings raise questions about the long-term health implications of tyrosine supplementation, which is often marketed to enhance focus and mental performance. While the study did not directly assess the effects of tyrosine supplements, the researchers suggest that individuals with high tyrosine levels might benefit from dietary adjustments, such as moderating overall protein intake, to potentially lower their levels.
“Phenylalanine showed no association with lifespan in either men or women after controlling for tyrosine,” the researchers noted, highlighting the specificity of the observed effect.
Further research is planned to confirm these results and to determine whether targeted interventions, including dietary or lifestyle changes, can safely reduce tyrosine levels and promote increased longevity. The study’s findings underscore the complexity of the aging process and the potential for sex-specific differences in nutritional needs and responses.
Recent reporting from ScienceDaily, SciTechDaily, The Jerusalem Post, and Google News confirms the study’s findings and the growing concern surrounding the potential downsides of popular brain supplements. ScienceDaily and SciTechDaily both reported on the study’s link between tyrosine and reduced lifespan in men.