Common Diabetes Drug Lengthens Lifespan by a Third in Worms
Researchers found that a commonly prescribed type 2 diabetes drug may actually significantly lengthen lifespan.
According to the study published March 28 in the journal Cell, the diabetes 2 drug metformin slows down the aging process by mimicking the effects of dieting.
Previous studies have shown that a calorie-restricted diet improves health in later life and extends lifespan in a variety of animals from the simple worm to the rhesus monkey. Researchers from the current study found that metformin may act in the same way as calorie-restriction in lengthening lifespan.
Researcher Dr. Filipe Cabreiro from the Institute of Healthy Ageing at University College London studied the effects of metformin by looking at C. elegans worms that were exposed to E. coli bacteria, a relationship, researchers say, that is similar to the relationship between us and the "healthy" bacteria that lives in our gut.
Researchers found that worms treated with the diabetes 2 drug lived on average six days longer than worms not treatment with the drug. Researchers said the six added days is equivalent to about a third of the worm's normal lifespan.
"It seems to work by altering metabolism in the bacteria that live in the worm, which in turn limits the nutrients that are available to the worm host and has a similar effect to restricting the diet," Cabreiro explained in a statement.
Gut bacteria are important because it helps their host organism digest and extract nutrition from food. Previous research has linked defects in gut bacteria to metabolic disease such as obesity, diabetes, inflammatory bowel disease and cancer. Other studies have also suggested that gut bacteria may influence the aging process, but researchers say the current study is the first to suggest a mechanism for how the process works.
Researchers found that metaformin disrupted the bacteria's ability to metabolize folate, a type of B-vitamin, and methionine, one of the building blocks of proteins. The study found that the drug lengthened the lives of the worms by limiting the nutrients available to them. Researchers say the process mimics the effects of dietary restriction, which has previously been show to lengthen lifespan in a number of animals.
Researchers noted that when they added an excess of sugar to the worm's diet, the life-extending effects of metformin were cancelled out. They explained that because metaformin is used to treat diabetes that causes elevated glucose levels in the blood, this particular finding is especially important for understanding how the drug works in people.
"We don't know from this study whether metformin has any effect on human ageing. The more interesting finding is the suggestion that drugs that alter bacteria in the gut could give us a new way of treating or preventing metabolic diseases like obesity and diabetes," co-author Professor David Gems said in a statement.