Not only can the drug metformin help to effectively manage type 2 diabetes, it may also give older women a better chance of living to the grand old age of 90, according to new research – thanks, it seems, to a variety of anti-aging effects.
The research used data from a long-term US study of postmenopausal women. Records on a total of 438 women were picked out – half who took metformin for their diabetes, and half who took a different diabetes drug, called sulfonylurea.
While there are a lot of caveats and asterisks to the study, those in the metformin group were calculated to have a 30 percent lower risk of dying before the age of 90 than those in the sulfonylurea group.
"Metformin has been shown to target multiple pathways of aging and therefore has been postulated as a drug that may extend human longevity," write the researchers in their published paper.
"We found that metformin initiation increased exceptional longevity compared with sulfonylurea initiation among women with type 2 diabetes."
We already know quite a lot about metformin. It's been around for decades, and is considered a gerotherapeutic: a drug able to slow down various aging processes in the body. For example, it's been shown to limit DNA damage and promote gene activity associated with long life.
Previous studies have shown metformin can put the brakes on wear and tear in the brain, and even reduce the risk of long COVID. However, scientists aren't yet sure that the drug extends lifespan, especially in humans – which is part of the reason for this study.
This research can't prove cause and effect like a randomized control trial (RCT) might be able to, because the participants weren't randomly assigned to one treatment or the other – rather, they were following professional advice. What's more, there was no placebo group given no treatment at all. The overall sample size wasn't particularly large, either.
However, the study also has its strengths – not least the average 14 to 15 years of follow-up, which goes way beyond the length a standard RCT would be able to. That's important when you're trying to see how lifespan is affected.
"A key advantage of our analysis was the long follow-up period after treatment initiation enabled by examination of a cohort with extensive follow-up from midlife to ages 90 and older, which is not feasible in typical randomized controlled trials," write the researchers.
RCTs could be something that follows further down the line to dig deeper into these results, the researchers suggest. In the meantime, with the global population continuing to skew older and older, studies continue to find ways of keeping us healthier for longer, and reducing damage to the body as we age.
"The geroscience hypothesis posits that biological aging is malleable and that slowing biological aging may delay or prevent the onset of multiple age-related diseases and disability," write the researchers.
"A key goal of geroscience is to identify novel therapeutic and preventive interventions that slow biological aging."
The research has been published in the Journal of Gerontology: Medical Sciences.