Tyrosine and Men's Lifespan: What a Large Study Found

What did the tyrosine and lifespan study find?

The research, published in Aging in October 2025, combined mortality records with genetic analyses using parental ages as a proxy for lifespan. Results in women varied by analytical method, and the observational comparison did not establish a statistically significant difference between sexes. These qualifications matter when interpreting headlines suggesting an exclusively male risk. [Original study](https://pmc.ncbi.nlm.nih.gov/articles/PMC12606968/)

Tyrosine has several normal biological functions. The National Cancer Institute describes it as an amino acid that the body can manufacture from phenylalanine. It contributes to protein production and helps form catecholamine chemical messengers, thyroid hormone and melanin. Its classification as nonessential means the body can usually produce it; it does not mean tyrosine is biologically unnecessary. [NCI tyrosine resource](https://edrn.cancer.gov/data-and-resources/biomarkers/tyrosine/)

Can genetic research show whether tyrosine supplements are harmful?

Mendelian randomization uses inherited genetic differences to investigate whether an exposure contributes to a health outcome. Because genetic variants precede most illnesses and lifestyle choices, this approach can reduce some problems affecting conventional observational research, including reverse causation, where developing disease changes the measured exposure. A BMJ methods guide explains why this can strengthen evidence while still requiring careful interpretation. [BMJ guide to Mendelian randomization](https://www.bmj.com/content/362/bmj.k601)

The method depends on assumptions: the selected variants must reliably relate to the exposure, and their relationship with the outcome must not operate through unrelated pathways. Lifelong genetic differences also need not reproduce the effect of starting a supplement at a particular age. Applied here, that means the findings should guide further investigation rather than supply a predicted lifespan change for an individual supplement user. Clinical recommendations require supporting evidence from other research designs. [BMJ interpretation guidance](https://www.bmj.com/content/362/bmj.k601)

What should people taking brain health supplements do?

The NIH Office of Dietary Supplements recommends discussing supplement use with a doctor, pharmacist or dietitian. Bring the product label and a record of how much you take, how often you take it and which medicines you use. Supplements can have biological effects and interact with medications. A useful review considers whether there is evidence of benefit for the intended purpose and whether the ingredients or amounts create avoidable risks. [NIH supplement guidance](https://ods.od.nih.gov/factsheets/WYNTK-Consumer/)

Marketing language about supporting brain function does not establish a clinical benefit. NIH explains that the FDA does not determine supplement effectiveness before products are marketed. Independent quality testing can help assess manufacturing and contents, but a quality seal does not guarantee safety or effectiveness. Supplements also cannot replace the variety of foods needed for a healthy eating pattern. [NIH guidance on effectiveness and quality](https://ods.od.nih.gov/factsheets/WYNTK-Consumer/)