Taurine slows aging in mice. Will it ever work for people?

An ingredient common in energy drinks and baby formula makes mice healthier and extends their life spans. It also appears to make worms live longer and improves the health of middle-aged monkeys, a large international group of scientists reports in the June 9 Science.

The ingredient, an amino acid called taurine, is made by our bodies, and we eat it in meats (SN: 7/21/22). It’s not known whether extra taurine slows aging in people or if it is even good for us, though the new study turned up an association between lower levels of the amino acid and conditions such as diabetes and obesity.

Aging “is one of the great biological unknowns,” says biologist and cardiologist Toren Finkel of the University of Pittsburgh, who was not involved in the study. “So any way you can chip away at that edifice is great. And this is a new set of findings that deserves to be followed up.”

The results, 11 years in the making, center on taurine in part because scientists found its levels fall with age in the blood of mice, monkeys and humans. As far as amino acids go, taurine is an oddball: Unlike other more familiar amino acids, it doesn’t get incorporated into proteins. Nevertheless, it has a range of suspected jobs in the body, from helping the developing brain to eye health to digestion.

Molecular physiologist Vijay Yadav of Columbia University Irving Medical Center and colleagues found that extra taurine extended mice’s median life spans by 10 to 12 percent. For example, the median life span for female mice that didn’t get extra taurine was around 29 months. With taurine, that increased to nearly 33 months. Taurine led to a similar life span boost for shorter-lived worms; C. elegans went from a median of almost 20 days to about 23 days on the highest doses tested.

Taurine was also linked with health in mice and female monkeys. Extra taurine led to improvements in aspects of bone strength, muscle coordination and memory in experiments with groups of five to 10 mice. Six middle-aged rhesus macaques fed extra taurine for six months seemed healthier, weighed less, had denser bones and showed signs of better metabolic health compared with five monkeys that didn’t get extra.

The mice experiments used taurine levels that would be equivalent to about 3 or 6 grams per day for an adult human, Yadav says. A typical energy drink contains 1 gram. There aren’t obvious, known risks of taurine, but thorough long-term studies at these high doses for people have not been done.

Yadav and his colleagues did look at data of nearly 12,000 people and found that individuals with obesity or diabetes had less taurine in their blood than people without the condition. Those links are correlations; it’s not known whether low taurine had a part in causing those conditions. In a separate experiment, an intense bout of exercise led to more taurine in people’s blood. As to whether taurine supplements improve people’s health, “we need to wait for a clinical trial,” Yadav says.

For now, taurine “is promising as a life span and health-span intervention,” says John Tower, a molecular biologist and geneticist who studies aging at the University of Southern California in Los Angeles who wasn’t involved in the study. But lots of questions remain, he says, including what taurine actually does in the body and whether it works similarly in different animals, including people. “We’ve got a long way to go.”

Finkel is circumspect, too. Because aging is so complex, a singular fountain of youth probably doesn’t exist. “I think there are going to be many tributaries of youth,” he says. “And so maybe this is a tributary, not a fountain.”