One of the world’s most commonly used medications may be more beneficial than advertised. A new study this month suggests that metformin may slow aging in the bodies and brains of monkeys. While more human studies are needed to confirm these findings, the drug is both cheap and already widely available.
Metformin is a valuable medicine that has long been used safely to treat type 2 diabetes and is included on the World Health Organization’s list of essential medicines. For these people, it helps lower blood sugar levels. Metformin is also used as an off-label medication for weight loss (with limited effectiveness) and to control symptoms of the hormonal condition polycystic ovary syndrome (PCOS). Over the years, some studies have suggested that the drug’s physical effects, particularly in reducing inflammation, may make it even more useful. One of the most striking of these studies showed that metformin improved brain function and slowed cognitive decline in older patients. While metformin may not directly extend our lifespan, it may extend our “healthspan”—the time we remain in relatively good health.
Most of the evidence for metformin’s anti-aging efficacy comes from indirect observational data or studies in animals less closely related to humans, such as rodents. But in their new study published last week in the journal cellA large group of researchers in China has taken an important step toward addressing this data gap.
Scientists conducted a 40-month study on adult male cynomolgus monkeys (cynomolgus monkey), roughly equivalent to a human life span of 13 years. During the study, they gave metformin to 12 elderly monkeys at regular intervals and compared the monkeys’ health with two different control groups that did not receive the drug: one group of 16 elderly monkeys and the other of 18 younger monkeys. Composed of middle-aged monkeys.
Based on extensive testing, including brain scans, the researchers created a model to estimate the expected and actual biological age of different organs in the monkeys. Monkeys who took metformin tended to show slower signs of aging, particularly in their livers and brains, compared to older monkeys who didn’t take metformin. According to the researchers’ calculations, metformin made the monkeys’ brains look 6 years younger on average, which could mean the human brain is 18 years younger on average.
“Our study pioneers the systematic reduction of multidimensional biological age in primates via metformin, paving the way for advancing pharmaceutical strategies to combat aging in humans,” the researchers wrote.
This appears to be the first direct test of metformin’s anti-aging potential in primates. But the study’s results are still based on a small sample size, and cynomolgus monkeys may have important biological differences that may affect metformin’s activity. These caveats mean we can’t be certain that metformin acts as a fountain of youth in humans, at least not yet. But the results do provide more motivation to keep digging.
Researchers have begun working with Merck on a Phase II trial that will test metformin as an anti-aging drug in 120 people. That’s not the only potential win for metformin this month. On Tuesday, researchers funded by the National Institutes of Health (NIH) published a study that found people taking metformin to treat diabetes were less likely to die from a covid-19 infection or a prolonged infection than those taking other diabetes medications — —Latest evidence suggests metformin may be a valuable long-term treatment for COVID-19.
