Potential Health Risks of High Tyrosine Levels in Men

Research suggests potential health risks associated with the amino acid tyrosine for men. Published in the journal Aging-US on June 15, 2026, the study links high tyrosine levels with a shorter lifespan in men.

Why Tyrosine Matters

Tyrosine, an amino acid, is crucial for bodily functions. It acts as a component for proteins and supports processes like tissue repair and enzyme production. Alongside phenylalanine, tyrosine impacts metabolism and brain activity. Naturally present in foods such as meat, fish, eggs, and dairy, it is also sold in supplements for concentration and energy. This amino acid aids in producing neurotransmitters like dopamine, norepinephrine, and epinephrine, influencing mood and attention.

What the Study Looked At

Researchers analyzed data from over 270,000 U.K. Biobank participants to understand if amino acids affect lifespan. Jie V. Zhao, Yitang Sun, Junmeng Zhang, and Kaixiong Ye led the study from the University of Hong Kong and the University of Georgia. They used two methods: observed links between amino acid levels and mortality, and Mendelian randomization to test causal relationships.

What They Found

Initially, both phenylalanine and tyrosine seemed linked to increased mortality risk. However, only tyrosine showed a consistent connection to shorter lifespan in men. Genetic estimates indicated men with higher tyrosine levels might live nearly a year less. Women showed no significant association. Men’s naturally higher tyrosine levels could partly explain gender lifespan differences. Phenylalanine showed no lifespan link once tyrosine was considered.

What Could Explain the Link

The study does not pinpoint one cause but suggests several biological pathways. Insulin resistance, linked to diseases like type 2 diabetes and cardiovascular disorders, may play a role. Tyrosine affects neurotransmitter production, potentially altering stress responses and affecting health. Hormonal differences might explain why the effect was observed only in men.

What It Means for Supplements

Tyrosine is common in supplements for focus under stress. The study did not examine supplements directly or assess their impact on lifespan, focusing only on natural tyrosine levels. Findings indicate potential concerns for long-term health, although tyrosine supplements were not deemed harmful. Lowering protein intake might reduce tyrosine levels, but its effect on healthy aging is uncertain.

What Happens Next

This study highlights interest in nutrients affecting both brain function and aging. Further research is needed to confirm these results in other groups and to explore the biological processes involved. Future investigations aim to assess safe dietary or lifestyle changes to regulate tyrosine levels.