New study finds a common supplement ingredient for cognitive enhancement may lead to a shorter lifespan

A common supplement ingredient may have some unwanted side effects. While many high performers use L-tyrosine to manage stress and improve their memory, new data suggests that they may be harming their long-term health by doing so. A new study found that men with higher levels of tyrosine, which is commonly used to enhance cognitive function, had a shorter lifespan, raising questions about the efficacy of popular dietary supplements, including ashwagandha and lion’s mane mushroom. Scientists from the University of Hong Kong and the University of Georgia analyzed data from over 250,000 individuals registered in the UK Biobank, a large health database that collects and stores medical information from volunteers. The study, which was published in Aging last fall, found that men who had genetically higher tyrosine levels lived, on average, one year less than those with normal levels. The role of tyrosine Tyrosine is a nonessential amino acid responsible for producing dopamine, adrenaline, and other brain chemicals that regulate your mood, focus, and stress response. In the study, the researchers also focused on phenylalanine, the raw material the body converts into tyrosine, which is often found in protein-rich foods like meat, eggs, dairy, beans, and soy, and commonly added to dietary supplements and energy products, according to SciTechDaily. Tyrosine’s link to longevity To consider the role of tyrosine in longevity, the researchers analyzed the data with Mendelian randomization—a technique that uses genetic differences to test whether something actually causes a health outcome rather than just coinciding with it. Initially, the study found that both increased levels of phenylalanine and tyrosine were linked to a high risk of an earlier death. But once the scientists accounted for the amino acid’s overlapping effects, only tyrosine consistently pointed toward a shorter lifespan. The researchers found that this outcome was especially pronounced in men; higher tyrosine