High Blood Tyrosine Levels Linked to Shorter Male Lifespan, Study Finds

Researchers analyzed data from more than 270,000 adults and found that men with higher blood levels of the amino acid tyrosine lived, on average, about a year less than men with lower levels. The study combined observational records with genetic analysis to strengthen the association. Tyrosine is a naturally occurring amino acid found in protein‑rich foods and is also sold as a dietary supplement marketed for focus and mental performance. No similar effect was seen in women. The results raise questions about the safety of high‑dose tyrosine supplements for men and suggest that further studies are needed to clarify optimal intake levels.