A large study involving more than 270,000 people suggests that one common amino acid may be tied to how long men live. Researchers led by Jie V. Zhao, Yitang Sun, Junmeng Zhang, and Kaixiong Ye from the University of Hong Kong and the University of Georgia examined whether phenylalanine and tyrosine, two amino acids involved in metabolism and brain function, are connected to lifespan (lifespan).
Their results point to a notable difference between men and women. Higher tyrosine levels were associated with shorter life expectancy in men, while no significant effect was detected in women. The findings could eventually help scientists better understand why aging and longevity differ between the sexes, although much more research is needed before the results can be translated into health recommendations.
The research was published in Aging-US titled "The role of phenylalanine and tyrosine in longevity: a cohort and Mendelian randomization study." Amino acids are the molecular building blocks that the body uses to make proteins. Phenylalanine and tyrosine are both found in foods that contain protein, and they are also available in dietary supplements. Beyond their role in protein production, these amino acids participate in important biological processes.
Tyrosine is especially interesting because the body uses it to produce neurotransmitters such as dopamine. Neurotransmitters are chemical messengers that allow nerve cells to communicate, and dopamine helps regulate functions that include mood, motivation, and thinking. Despite these important roles, scientists still do not fully understand how long-term differences in phenylalanine and tyrosine levels might influence aging.
To investigate, the researchers analyzed information from more than 270,000 participants in the UK Biobank, a large research database containing health and genetic data from people in the United Kingdom. The team used two complementary approaches. First, they looked for associations between blood concentrations of phenylalanine and tyrosine and outcomes related to death and predicted lifespan.
They also used genetic methods to investigate whether the relationships might go beyond a simple association. One of those approaches was Mendelian randomization. This method uses naturally occurring genetic differences among people as a way to test whether a particular biological factor may contribute to an outcome.
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