Metformin May Offer Defense Against Dementia in Type 2s

Not only can the diabetes drug metformin help control blood sugar levels, it may also reduce the risk of dementia, a health risk that’s elevated for those with diabetes.

A recent study found that those taking metformin to help control blood glucose were 20 percent less likely to develop dementia over the course of the five-year study than those who were taking sulfonylureas to control their diabetes symptoms instead.

“Metformin could have a possible neuroprotective effect in the brain,” said Dr. Rachel Whitmer, an epidemiologist in the division of research at Kaiser Permanente in Oakland, Calif., and author of the study.

According to researchers, those with type 2 diabetes have twice the risk of developing dementia compared to persons without the disease. The Kaiser study is the first of its kind to look into the relationship between diabetes drugs and dementia.

As part of the study, researchers looked at the data of nearly 15,000 patients 55 and older with type 2 diabetes, each of whom was beginning one of four single-drug therapies to treat their disease.

The therapies under review included metformin, which encourages the liver to produce less glucose, sulfonylureas, which stimulate the production of insulin to control blood sugar, thiazolidinediones , which make muscle and fat tissue more receptive to insulin, and synthetic insulin.

Over the course of the five-year study, 10 percent of the patients in all drug categories were diagnosed with dementia.

Of those taking metformin, patients were 20 percent less likely of developing dementia than those taking sulfonylureas, though there was no difference in the incidents of dementia between those taking sulfonylureas and those prescribed either thiazolidinediones or insulin.

Whitmer said the results could mean that metformin, which reduces inflammation in the body, might also play a role in encouraging the production of new brain cells.

The theory sparked interest from experts in the fields of both diabetes and dementia.

“The idea that how we treat diabetes could affect all-cause dementia is very exciting,” said Dr. Richard Lipton, director of the division of cognitive aging and dementia at Montefiore Medical Center in New York City, in an interview with the syndicated news service HealthDay.

“Insulin promotes the survival of certain nerve cells. A drug like metformin, an insulin sensitizer in the body, may also be an insulin sensitizer in the brain,”Lipton said. “We know that people with Alzheimer’s lose brain volume, which may be a poor replacement of nerve cells. The notion that metformin might promote neurogenesis and brain cell replacement is a very attractive hypothesis.”