Abstract: We often hear that eating less protein may help extend lifespan, but what if the real story lies in specific amino acids rather than protein as a whole? In a large-scale study of over 270,000 participants from the UK Biobank, researchers examined two closely related amino acids: phenylalanine and tyrosine. Observational data showed that higher levels of both were linked to increased mortality risk. However, when genetic methods were applied to reduce confounding, tyrosine stood out as the more consistent factor associated with shorter lifespan. This suggests that the biological effects of protein restriction may be driven, at least in part, by how it influences circulating tyrosine levels.
Interestingly, the association appeared stronger in men than in women, pointing toward potential sex-specific mechanisms in aging biology. Even after adjusting for phenylalanine, genetically predicted higher tyrosine remained linked to reduced life expectancy in men. Given tyrosine’s role in insulin signaling, metabolic regulation, and as a precursor to key neurotransmitters like dopamine and norepinephrine, it may influence longevity through multiple interconnected pathways. While this study does not directly evaluate dietary supplementation, it raises important questions about long-term tyrosine exposure and personalized nutrition strategies aimed at healthy aging.
Get the full article here: https://www.aging-us.com/article/206326/text
