Amino acid in energy drinks makes mice live longer and healthier | Science

Researchers first sifted the amino acid taurine from a sample of ox bile in 1827. Today, it’s better known as one of the main ingredients in many energy drinks. But it may do more than drive sales of these beverages. A study published today in Science suggests boosting taurine levels increases life span in mice and improves the physical condition of middle-aged monkeys, hinting it could do the same for people.

“This might be something that could be used to fight aging-related diseases or increase life span in humans,” says molecular physiologist Dudley Lamming of the University of Wisconsin School of Medicine and Public Health, who wasn’t connected to the study. “We need to figure that out.”

Taurine’s known roles include helping cells balance their water content and aiding the liver’s production of bile, a fluid that promotes digestion. Our bodies make some of the taurine we need, but we can also obtain it by eating foods such as shellfish and meat. Taurine has long been sold as a dietary supplement that purportedly increases exercise performance and strength. Many energy drinks are brimming with it. A single can of some drink brands can contain about one-third of the daily maximum intake recommended by the Mayo Clinic.

Although data showing the clinical benefits of taurine supplementation are sparse, studies have found that as people age, its levels dwindle. That decline spurred molecular physiologist Vijay Yadav of Columbia University to ask whether taurine, as he puts it, “is a passenger or a driver” of aging.

To find out, Yadav and colleagues gave hefty amounts of taurine to middle-aged mice and tracked the animals for 2 years. The doses were the rodent equivalents of what a person might get by drinking three to six cans of some energy drinks, but were below the highest level found safe in humans. The rodents lived about 10% to 12% longer than mice that didn’t receive the additional taurine. Compared with their peers, the taurine-boosted rodents were also healthier. Not only were their muscles and bones stronger, but they were also leaner, less anxious, performed better in coordination tests, and boasted sharper memories. Mice given extra taurine also scored higher on a variety of physiological and cellular health measures. The rodents’ DNA accrued less damage over time, as indicated by the levels of a DNA oxidation marker in the blood, and they had more stable blood sugar levels.

“All these seemed too good to be true,” Yadav says. So the researchers tested taurine in other animals. They found that like in the mice, taurine extends the lives of nematodes. The molecule also appeared to boost the health of graying rhesus monkeys. After 6 months of eating extra taurine, the monkeys, which were comparable to humans 45 to 50 years old, showed many of the same physiological improvements as the mice, including increased bone density, lower blood sugar, and less DNA damage. However, it’s too early to tell whether the supplement affects the monkeys’ life spans.

Turning to humans, Yadav and colleagues analyzed taurine blood level data from nearly 12,000 people enrolled in a 25-year U.K. health study. Participants with high levels of taurine were generally healthier in many respects, with lower rates of obesity and diabetes and lower cholesterol levels, the researchers report.

“Taurine is hitting the aging brake,” Yadav says. But the molecule didn’t reverse any of the damage associated with aging. “It is not putting the vehicle in reverse gear,” he says. He adds that the study was not funded by energy drink or taurine supplementmakers, and the researchers have no financial ties to these companies.

The study “opens up profound questions about possible benefits” of taurine, says David Allison, a geroscientist at the Indiana University Bloomington School of Public Health. But he cautions that “it’s not proven that taurine supplements will prolong life or slow aging in humans.”

There are simpler explanations than taurine’s supposed antiaging properties for many of the health effects the researchers observed, adds biochemist Charles Brenner of the Beckman Research Institute of City of Hope. For example, the mice that received taurine were leaner, and that effect could account for their higher scores on measures such as grip strength. “If a mammal maintains better body composition, lots of other things will work better,” he says.

Even if taurine does come with health benefits for humans, it’s not clear what the effective dose should be, says Christine Perdan Curran, a developmental neurotoxicologist at Northern Kentucky University who has studied the safety of energy drinks.

A few small clinical trials have gauged whether taurine supplements help older people. For instance, researchers in one study gave taurine to women between ages 55 and 70 and found that it boosted their defenses against harmful molecules known as reactive oxygen species, which cause tissue damage. Ellen Cristini de Freitas of the University of São Paulo, who led that study, says that to be confident of taurine’s effects, “long-term, well-controlled trials using … varying doses of taurine supplementation are required.”

Yadav and colleagues are now trying to organize just such a trial, which could be expensive given how long it might take. If they succeed, taurine would join several other potential antiaging compounds, including the diabetes drug metformin and the organ transplant drug rapamycin, that are scheduled to go into clinical trials within a year or so. “In the next 3 to 5 years, we will have a basketful of antiaging molecules,” Yadav predicts.

But until researchers learn more about taurine’s potential benefits, Curran advises caution. “As a toxicologist, I would say, ‘Don’t go out and gobble a bunch of taurine.’”

Researchers first sifted the amino acid taurine from a sample of ox bile in 1827. Today, it’s better known as one of the main ingredients in many energy drinks. But it may do more than drive sales of these beverages. A study published today in Science suggests boosting taurine levels increases life span in mice and improves the physical condition of middle-aged monkeys, hinting it could do the same for people.

“This might be something that could be used to fight aging-related diseases or increase life span in humans,” says molecular physiologist Dudley Lamming of the University of Wisconsin School of Medicine and Public Health, who wasn’t connected to the study. “We need to figure that out.”

Taurine’s known roles include helping cells balance their water content and aiding the liver’s production of bile, a fluid that promotes digestion. Our bodies make some of the taurine we need, but we can also obtain it by eating foods such as shellfish and meat. Taurine has long been sold as a dietary supplement that purportedly increases exercise performance and strength. Many energy drinks are brimming with it. A single can of some drink brands can contain about one-third of the daily maximum intake recommended by the Mayo Clinic.

Although data showing the clinical benefits of taurine supplementation are sparse, studies have found that as people age, its levels dwindle. That decline spurred molecular physiologist Vijay Yadav of Columbia University to ask whether taurine, as he puts it, “is a passenger or a driver” of aging.

To find out, Yadav and colleagues gave hefty amounts of taurine to middle-aged mice and tracked the animals for 2 years. The doses were the rodent equivalents of what a person might get by drinking three to six cans of some energy drinks, but were below the highest level found safe in humans. The rodents lived about 10% to 12% longer than mice that didn’t receive the additional taurine. Compared with their peers, the taurine-boosted rodents were also healthier. Not only were their muscles and bones stronger, but they were also leaner, less anxious, performed better in coordination tests, and boasted sharper memories. Mice given extra taurine also scored higher on a variety of physiological and cellular health measures. The rodents’ DNA accrued less damage over time, as indicated by the levels of a DNA oxidation marker in the blood, and they had more stable blood sugar levels.

“All these seemed too good to be true,” Yadav says. So the researchers tested taurine in other animals. They found that like in the mice, taurine extends the lives of nematodes. The molecule also appeared to boost the health of graying rhesus monkeys. After 6 months of eating extra taurine, the monkeys, which were comparable to humans 45 to 50 years old, showed many of the same physiological improvements as the mice, including increased bone density, lower blood sugar, and less DNA damage. However, it’s too early to tell whether the supplement affects the monkeys’ life spans.

Turning to humans, Yadav and colleagues analyzed taurine blood level data from nearly 12,000 people enrolled in a 25-year U.K. health study. Participants with high levels of taurine were generally healthier in many respects, with lower rates of obesity and diabetes and lower cholesterol levels, the researchers report.

“Taurine is hitting the aging brake,” Yadav says. But the molecule didn’t reverse any of the damage associated with aging. “It is not putting the vehicle in reverse gear,” he says. He adds that the study was not funded by energy drink or taurine supplementmakers, and the researchers have no financial ties to these companies.

The study “opens up profound questions about possible benefits” of taurine, says David Allison, a geroscientist at the Indiana University Bloomington School of Public Health. But he cautions that “it’s not proven that taurine supplements will prolong life or slow aging in humans.”

There are simpler explanations than taurine’s supposed antiaging properties for many of the health effects the researchers observed, adds biochemist Charles Brenner of the Beckman Research Institute of City of Hope. For example, the mice that received taurine were leaner, and that effect could account for their higher scores on measures such as grip strength. “If a mammal maintains better body composition, lots of other things will work better,” he says.

Even if taurine does come with health benefits for humans, it’s not clear what the effective dose should be, says Christine Perdan Curran, a developmental neurotoxicologist at Northern Kentucky University who has studied the safety of energy drinks.

A few small clinical trials have gauged whether taurine supplements help older people. For instance, researchers in one study gave taurine to women between ages 55 and 70 and found that it boosted their defenses against harmful molecules known as reactive oxygen species, which cause tissue damage. Ellen Cristini de Freitas of the University of São Paulo, who led that study, says that to be confident of taurine’s effects, “long-term, well-controlled trials using … varying doses of taurine supplementation are required.”

Yadav and colleagues are now trying to organize just such a trial, which could be expensive given how long it might take. If they succeed, taurine would join several other potential antiaging compounds, including the diabetes drug metformin and the organ transplant drug rapamycin, that are scheduled to go into clinical trials within a year or so. “In the next 3 to 5 years, we will have a basketful of antiaging molecules,” Yadav predicts.

But until researchers learn more about taurine’s potential benefits, Curran advises caution. “As a toxicologist, I would say, ‘Don’t go out and gobble a bunch of taurine.’”