Could a diabetes drug help prevent dementia?

Many studies show that people with type 2 diabetes are at a higher risk of developing dementia than the general population. Could a diabetes drug help prevent dementia? There may be good news ahead for the diabetes community. The exciting results of a recent research study suggest that metformin may significantly lower this risk of dementia.

Metformin is one of a class of medications called ‘biguanides’. It is used to help control blood sugar levels and is often the first drug prescribed for people with type 2 diabetes.

The 5-year research study was conducted by scientists at Kaiser Permanente in Oakland, California. It was a population-based preliminary study that reviewed data on close to 15,000 individuals with diabetes. All were aged 55 or older and, at the start of the study, had just been prescribed a single diabetes drug to help control their blood sugar levels. The drugs under observation in the study were metformin, sulfonylureas (SU), thiazolidinediones (TZDs) and insulin.

Over the course of the study, almost 10% of the people under observation were diagnosed with dementia.  The incidence of dementia in individuals taking metformin was markedly less than in those taking the other diabetes drugs. This was reported as a 20% reduced risk of dementia among the people who were taking metformin during the study.

This particular type of study is described as ‘observational and population-based’. This means that the study was not designed to prove cause and effect, but was able to find an association between metformin and reduced dementia risk. The study author Dr. Rachel Whitmer reported that the findings provide “preliminary evidence that metformin may have benefits on brain health.”

Building on evidence from animal models and cell culture studies, some scientists theorize that metformin may play a role in developing new brain cells (neurogenesis). “Research in animals suggests that metformin may contribute to the creation of new brain cells and enhance spatial memory,” said Dr. Whitmer.

The findings from the study were presented in July in Boston at the Alzheimer’s Association International Conference (AAIC) 2013.

The AAIC press release on the topic reported that therapeutic trials are now underway to assess metformin as a potential therapy for dementia and mild cognitive impairment, which is thought to be, in some cases, a precursor to Alzheimer’s disease.