A new study has found that men with genetically higher levels of the amino acid tyrosine may live slightly shorter lives, raising fresh concerns about nutrients commonly promoted for focus, energy, and mental performance.
Researchers from the University of Hong Kong and the University of Georgia analyzed genetic and health data from more than 270,000 participants in the UK Biobank.
The findings, published in Aging, showed that men with higher tyrosine levels appeared to live nearly one year less on average.
The same clear association was not observed in women.
Tyrosine and its precursor phenylalanine are amino acids naturally found in protein-rich foods such as:
- Meat
- Eggs
- Dairy products
- Beans
- Soy products
- Nuts and seeds
Both are also widely used in dietary supplements and energy products marketed for concentration and stress management.
Researchers said tyrosine plays a key role in producing brain chemicals, including dopamine, norepinephrine, and epinephrine, which are linked to alertness, mood, and stress response.
However, scientists noted that biological systems supporting short-term mental performance could potentially have long-term effects on aging.
The study used a genetic research method known as Mendelian randomization to examine whether tyrosine may directly influence lifespan.
Initially, both tyrosine and phenylalanine appeared linked to earlier mortality, but after further analysis, only tyrosine remained consistently associated with shorter lifespan.
Key findings included:
- Men with higher tyrosine levels showed an average lifespan reduction of about 0.9 years
- Women did not show a statistically significant association
- Men naturally tend to have higher tyrosine levels than women
Researchers suggested this difference may partly contribute to the global life expectancy gap between men and women.
The study also pointed to possible biological mechanisms linking tyrosine with aging, including:
- Insulin resistance
- Stress-response pathways
- Hormonal interactions involving testosterone and estrogen
- Nutrient-sensing pathways associated with aging
Scientists stressed that the findings do not prove tyrosine supplements directly shorten lifespan and warned against drawing broad conclusions about protein-rich foods.
They emphasized that tyrosine remains essential for normal brain and body function.
The researchers said future studies are needed to determine whether long-term dietary strategies or lifestyle changes could safely regulate tyrosine levels and support healthy aging.
