Diabetes drug metformin has anti-ageing effects and extends the life of male mice, a new research suggests.
Scientists believe metformin may mimic the effects of extreme calorie restriction.
This regime, which is based on eating a very low calorie diet, is thought to promote healthy ageing.
The human implications of the study are unclear, the researchers report in the journal, Nature Communications.
Rafael de Cabo, of the National Institute on Ageing in Baltimore, Maryland, said calorie restriction in laboratory animals had been shown to increase their lifespan.
His team is searching for interventions – such as a drug – that can mimic these effects.
Metformin is one of the most widely prescribed treatments for type-2 diabetes, which occurs mainly in people above the age of 40. It is also used to treat metabolic syndrome, a combination of diabetes, high blood pressure and obesity.
Previous work has shown that metformin can extend the lifespan of simple organisms such as worms, but studies in flies and mammals have given conflicting evidence.
The scientists gave one of two different doses of metformin to middle-aged male mice and found that lower doses increased lifespan by about 5%, and also delayed the onset of age-associated diseases. But they said the higher dose of metformin was toxic and reduced the lifespan of mice.
Further studies were needed to determine if metformin has any effect on human health and lifespan, said Dr. Rafael de Cabo.
“These are very promising results that need to be translated to humans via clinical studies,” he said.
He said the best current advice was to eat a good diet and exercise.
“Right now the best that we can say is probably what your grandmother told you,” Dr. Rafael de Cabo.
“Eat a good diet and exercise are the only two things that we know for sure that they work very well in humans.”