A drug that has been used for decades to treat diabetes may become an unexpected ally in the fight against dementia and premature death. This conclusion was reached by scientists from Taiwan after analyzing data from nearly half a million overweight people. The study was published in the journal Diabetes Obesity and Metabolism (DOM).

The study covered 452,777 adults who were overweight or obese. Over a 10-year follow-up period, more than 35,000 cases of dementia and over 76,000 deaths were recorded among them. However, both figures were significantly lower among those who took metformin.

The risk of death among patients taking the drug was reduced by 26–28%, and the risk of developing dementia was 8–12% lower compared to those who did not use metformin. Moreover, the protective effect was evident in all categories, from moderate to severe obesity.

“The results are encouraging,” said study co-author Dr. Chieh-Feng Chen of Taipei Medical University. “But more research is needed to understand exactly how metformin affects the brain and lifespan.”

Metformin has long been studied as a potential “longevity drug”: its anti-inflammatory and metabolic properties are of interest not only to endocrinologists but also to gerontologists. The new study supports the hypothesis that it may influence the aging process — and possibly become part of the prevention of neurodegenerative diseases.