Taurine may help curb age-related inflammation in a surprising way

A new study suggests that taurine, one of the most common amino acids in the human body, may play a more important role in healthy aging than previously appreciated. It is not a cure-all for aging, but the findings point to a meaningful link between taurine and staying healthier later in life.

Research from the Yale School of Medicine builds on earlier findings from 2023 that connected taurine levels with healthy aging and longevity in animal models. Until now, however, the exact way this amino acid affects our cells had remained unclear.

The latest work helps explain why taurine may matter for limiting inflammaging, the low-grade chronic inflammation that becomes more common with age. While it is not the only factor that shapes lifespan, evidence suggests it is an important part of how well we age.

The team found that taurine influences how the innate immune system detects danger signals. This arm of immunity acts as the body’s rapid response system against new pathogens or other biological threats, while the adaptive immune system provides a slower, memory-based response. If the innate “first line of defense” cannot stop an invader, the adaptive system is activated.

Inflammation is the innate immune system’s main weapon. But as people age, immune function weakens, making it harder to fight infections while increasing the risk of broad inflammatory disorders.

“Since the innate immune system does not have specific receptors for each and every different type of danger signal, this pattern recognition has always been a mystery,” said senior author Vishwa Deep Dixit, PhD, director of the Yale Center for Research on Aging (Y-Age).

Researchers also found that beyond supporting innate immunity, higher taurine levels may help reduce symptoms of inflammaging.

“Biology has lots of surprises,” Dixit said. “And the biggest surprise in this study is that taurine is controlling the innate sensing mechanism.”

Interest in taurine grew after earlier work showed that people who restricted calories for up to 12 months had higher taurine levels than those without a diet regimen. Calorie restriction has also been associated with lower inflammation, but it was not clear whether taurine was directly involved or merely a byproduct.

“We wanted to test whether taurine is just a passenger or a driver of the reduction in inflammatory response caused by caloric restriction,” Dixit said.

Although scientists expected taurine levels to decline with age, blood serum comparisons told a different story. When the Yale team compared samples from adults aged 20 to 40 with those from people aged 60 to 99, taurine was actually higher in the older group.

That result led the researchers to suspect the body may increase taurine production with age in an effort to counter inflammation caused by a weakening innate immune system.

A major part of inflammaging involves activation of the NLRP3 inflammasome, a molecular complex that can become overactive in aging tissue. The researchers then asked whether taurine helps keep NLRP3 under control.

To test this, they grew macrophages, the immune cells that engulf and destroy harmful targets, and exposed them to threats including bacterial toxins.

When the cells responded, NLRP3 complexes assembled inside the macrophages. During that process, the macrophages released as much as 80% of their taurine. When taurine was restored, it blocked the inflammation driven by NLRP3 activity.

“Now we know that taurine allows immune sensing and is one of the brakes within the cells that is keeping the inflammasome in check,” Dixit said.

When the researchers reduced taurine levels in mouse macrophages, NLRP3-related inflammation increased even in young animals.

“What we have answered is the first step of the puzzle in what causes this very critical innate immune system sensor to be activated,” Dixit added.

The researchers still do not know why aging innate immune cells leak taurine when they detect danger signals, or where the amino acid ultimately goes in the body. They hope to answer those questions next.

Because taurine does not appear to decline with age, simply eating more of it through foods such as seafood, dark meats and seaweed is unlikely to offset inflammaging. But if future research shows how to help aging macrophages retain taurine, the discovery could offer a way to slow one of the more unavoidable aspects of aging.

The study was published in the journal Cell.