A brain-boosting nutrient may sharpen your mind but knock years off your life.
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nutrient → boost → life
Research suggests the popular supplement ingredient, widely touted for improving focus and cognitive performance, may have a surprising downside when it comes to longevity.
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it → suggest → longevity
Scientists found that men with higher levels of the substance in their blood tended to have shorter lifespans — but women don’t appear to pay the same price.
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women → find → price
In the study, scientists from the University of Hong Kong and the University of Georgia analyzed health and genetic information from more than 270,000 people in the UK Biobank.
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scientists → analyze → Biobank
The researchers were focusing on two amino acids — phenylalanine and tyrosine — and whether they might play a role in aging.
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they → focus → aging
Both are essential building blocks for proteins, but tyrosine also helps the body make dopamine, adrenaline and other brain chemicals involved in mood, focus and stress response.
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body → help → response
Phenylalanine, meanwhile, is converted into tyrosine in the body.
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Phenylalanine → convert → body
Both amino acids occur naturally in protein-packed foods and are also commonly found in dietary supplements.
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acids → occur → supplements
To investigate whether the nutrients play a role in longevity, the researchers first looked at participants’ blood levels and compared them with their mortality and predicted lifespan.
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researchers → investigate → mortality
They then used a genetic testing method called Mendelian randomization, which involves looking at natural genetic differences between people to help determine whether one factor might actually cause another.
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factor → use → another
The team found that men with more tyrosine in their blood appeared to have shorter lifespans — with elevated levels associated with nearly a year shaved off their lives.
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levels → find → lives
Women, however, didn’t appear to have the same link.
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Women → appear → link
“Phenylalanine showed no association with lifespan in either men or women after controlling for tyrosine,” the study authors wrote.
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authors → show → tyrosine
Researchers don’t yet fully understand why higher tyrosine levels might be linked to shorter lifespans in men, but they have a few ideas.
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they → understand → ideas
One involves insulin resistance, a condition in which the body’s cells become less responsive to insulin, the hormone that helps regulate blood sugar.
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that → involve → sugar
Tyrosine plays an important role in the signaling process that allows insulin to tell cells to take up sugar from the bloodstream.
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insulin → play → bloodstream
While the amino acid is essential for normal cellular function, researchers have suggested that having too much tyrosine circulating in the blood could potentially disrupt that process.
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having → suggest → process
Insulin resistance is associated with a range of health problems that become more common with age — including neurodegenerative diseases, high blood pressure, cardiovascular disease and Type 2 diabetes — all of which can affect longevity.
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all → associate → longevity
Tyrosine may also play a role through the brain chemicals it helps produce, which are involved in mood and stress.
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which → play → mood
The researchers suggested that differences in these chemicals between the sexes could help explain why the link to shorter lifespan appeared in men but not women.
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link → suggest → men
Taking things a step further, they theorized that tyrosine could play some role in the well-documented longevity gap between men and women.
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tyrosine → take → men
However, they stressed that their study doesn’t prove the amino acid is responsible for the difference in average lifespan.
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acid → stress → lifespan
While notable, the findings don’t mean you should dump your supplements down the drain.
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you → mean → drain
The researchers didn’t directly test products that contain tyrosine, and there’s no proof that taking them will shorten your life.
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taking → test → life
After all, other research suggests that tyrosine has real benefits for mental focus, improving memory and boosting cognitive function under stress.
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tyrosine → suggest → stress
Instead, the study authors suggested that people with unusually high blood concentrations of tyrosine might potentially benefit from dietary changes aimed at lowering those levels.
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people → suggest → levels
Tyrosine-rich foods include chicken, turkey, beef, lamb, fish, hard cheeses, eggs, sesame seeds, soybeans and nuts.
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foods → include → chicken
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