Metformin, the Common Type 2 Diabetes Drug, May Help Prevent Dementia

A widely used type 2 diabetes drug may be linked to a significantly lower risk of dementia decades later, according to a new U.S. study, reported by “Science.”

The study analyzed long-term data from the Diabetes Prevention Program (DPP) and the Diabetes Prevention Program Outcomes Study (DPPOS), a research program that began in the late 1990s and has followed for many years people at high risk of developing type 2 diabetes.

Researchers analyzed 1,483 people, with an average age of 74, who initially had a high risk for type 2 diabetes.

Participants were randomly assigned to groups taking metformin, placebo, or following an intensive lifestyle-change program.

The results showed that people initially assigned to the metformin group had an average of 15.5 years of exposure to the drug during the follow-up period.

When cognitive functions were assessed during 2022–2024, long-term metformin use was associated with 60% lower odds of dementia compared with the placebo group, and 62% lower odds compared with the group that followed the intensive lifestyle intervention.

Metformin was also associated with slightly better performance on memory tests during the follow-up years.

However, the researchers stress that the results should be interpreted with caution.

Metformin is a drug used mainly for treating type 2 diabetes and should be taken only on a doctor’s advice.

In conclusion, the study offers a promising signal that long-term metformin use may also benefit brain health, but more data is needed before this link can be considered proven.