A new study featured in Aging-US delves into the relationship between two common amino acids and their potential impact on human longevity. The paper, titled “The Role of Phenylalanine and Tyrosine in Longevity: A Cohort and Mendelian Randomization Study,” investigates whether the concentrations of these nutrients in the bloodstream correlate with lifespan.
Led by researchers Jie V. Zhao, Yitang Sun, Junmeng Zhang, and Kaixiong Ye from the University of Hong Kong and the University of Georgia, the study specifically examined phenylalanine and tyrosine. Their findings indicate that higher levels of tyrosine may be linked to a shorter life expectancy in men, suggesting that strategies for promoting longevity might need to be tailored according to gender.
Amino Acids, Brain Function, and Aging
Phenylalanine and tyrosine are amino acids vital for metabolism and cognitive function. They are abundant in protein-rich foods and commonly available as dietary supplements. However, the precise effects of these compounds on the aging process remain partially unclear.
Tyrosine is particularly significant due to its role in synthesizing neurotransmitters like dopamine, which impact mood, motivation, and cognitive abilities. Its influence on brain chemistry has led to growing interest in its role in aging research.
Large UK Biobank Study Examines Lifespan
To uncover potential associations with longevity, the researchers analyzed health and genetic data from over 270,000 participants in the UK Biobank. They employed both observational data and genetic analysis to determine whether blood levels of phenylalanine and tyrosine had any correlation with overall mortality and predicted lifespan.
Initially, both amino acids seemed to indicate a heightened risk of death. However, further examination revealed that only tyrosine consistently showed a potentially causal relationship with reduced life expectancy in men. Genetic modeling indicated that men with elevated tyrosine levels might have an average lifespan nearly one year shorter than those with lower levels. No significant association was discovered in women.
This connection persisted even after accounting for other factors, including phenylalanine levels. This strengthens the hypothesis that tyrosine may independently influence the aging process. The researchers also noted that men typically exhibit higher levels of tyrosine compared to women, which may contribute to the observed difference in lifespan between the sexes.
“Phenylalanine showed no association with lifespan in either men or women after controlling for tyrosine.”
Possible Biological Explanations
Scientists continue to explore the reasons behind tyrosine’s potential influence on lifespan in men. One theory points to insulin resistance, a condition frequently linked to various age-related diseases. Additionally, tyrosine’s role in producing stress-related neurotransmitters could affect metabolic and hormonal pathways differently in men and women. This variation in hormonal signaling may help explain the observed effects being limited to men.
Supplement Use and Longevity Questions
Tyrosine is commonly marketed as a supplement aimed at enhancing focus and cognitive performance. Although this study did not directly assess the effects of tyrosine supplements, the findings prompt important questions regarding their long-term implications for health and lifespan.
The researchers recommend that individuals with high levels of tyrosine consider dietary adjustments. Strategies such as moderating overall protein intake might help lower tyrosine levels and promote healthier aging.
Further research will be necessary to validate these findings and to determine if diet or lifestyle changes can safely reduce tyrosine levels, ultimately supporting longer life.
