A common amino acid found in protein-rich foods and sold as a brain-boosting supplement may be linked to a shorter lifespan in men, according to a large new study.
The research
Researchers from the University of Hong Kong and the University of Georgia analyzed data from more than 270,000 participants in the UK Biobank. They focused on two amino acids: phenylalanine and tyrosine. Tyrosine is particularly important because the body uses it to make dopamine, a neurotransmitter involved in mood, motivation, and focus.
Using both observational data and a genetic method called Mendelian randomization, the team found that higher tyrosine levels were associated with a nearly one-year shorter lifespan in men. No significant effect appeared in women. The study was published in the journal Aging-US in September 2026.
The researchers also noted that men generally have higher tyrosine levels than women, which could help explain some of the sex differences in average lifespan, though more research is needed.
Why it matters
Tyrosine is a popular supplement for improving focus and mental performance. While it's naturally present in foods like chicken, fish, dairy, and nuts, many people take concentrated doses in pill form. If confirmed, this finding suggests that long-term high tyrosine levels might have unintended effects on longevity, especially for men.
However, the study doesn't prove that tyrosine directly shortens life. It's an association, and the genetic analysis strengthens the link, but it's not conclusive.
What you can do
If you're a man considering tyrosine supplements, it might be wise to be cautious, especially if you're already consuming plenty of protein. Talk to a healthcare provider about your individual needs. For most people, getting amino acids from whole foods is a balanced approach.
Remember, brain health is complex. While supplements can help in some cases, they're not a substitute for sleep, exercise, and a varied diet.
Source: ScienceDaily Mind & Brain
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