A man looks at his laptop while holding a bottle of pillsShare on Pinterest
New research indicates a drug used to treat type 2 diabetes may help lower the risk of dementia. Fertnig/Getty Images
  • Researchers are saying the drug pioglitazone may help reduce the risk of dementia.
  • The medication, sold under the brand name Actos, is prescribed to treat type 2 diabetes.
  • Experts say a healthy diet and regular aerobic exercise are also ways to reduce the risk of type 2 diabetes as well as dementia.

Diabetes is a known risk factor for dementia.

In fact, people with type 2 diabetes can have double the risk of developing the progressive brain disease compared to people without diabetes.

Now, researchers say the drug pioglitazone, which is sold under the brand name Actos to treat type 2 diabetes, can help reduce the risk of dementia.

However, researchers also say they don’t know whether it’s the drug itself that seems to reduce dementia risk or the fact that it improves type 2 diabetes symptoms that are behind the association.

Or, perhaps both.

In their study, published today in the journal Neurology, researchers report that the reduction of dementia risk among people taking pioglitazone was most pronounced for those who had a prior history of stroke or ischemic heart disease.

Researchers led by Dr. Eosu Kim of Yonsei University in South Korea studied a group of 91,218 people newly diagnosed with type 2 diabetes who did not have dementia, including 3,467 who received pioglitazone.

Over an average follow-up of 10 years, the researchers found that about 8% of the people taking pioglitazone developed dementia, compared to 10% of those who were not taking the medication.

After controlling for other factors that could affect dementia risks, such as high blood pressure, smoking, and physical activity, the authors reported that people taking pioglitazone were 16% less likely to develop dementia.

Among those with a history of ischemic heart disease or stroke, the risk was reduced by 54% and 43%, respectively.

Researchers also reported that, generally, the longer people took pioglitazone, the stronger the dementia risk reduction appeared to be.

People taking pioglitazone also were less likely to suffer a stroke during the study period, according to the researchers.

“Since dementia develops for years before diagnosis, there may be an opportunity for intervening before it progresses,” said Kim. “These results may suggest that we could use a personalized approach to preventing dementia in people with diabetes in the case that they have a history of ischemic heart disease or stroke.”

Pioglitazone is one of a class of drugs called thiazolidinediones that lower blood sugar levels among people with diabetes by addressing insulin resistance.

Kim noted that prior studies of pioglitazone did not seem to reduce dementia risk among individuals.

“It’s likely that a critical factor affecting the effectiveness is the presence of diabetes,” said Kim.

Dr. Allison Reiss, a member of the Alzheimer’s Foundation of America’s Medical, Scientific and Memory Screening Advisory Board as well as an associate professor of medicine at NYU Long Island School of Medicine, said it’s likely that both the drug itself and its impact on insulin resistance explain the apparent protective effects against dementia.

“Many drugs that treat diabetes will also have collateral good effects on inflammation and metabolism and blood vessels, so it’s very hard to tease apart,” she told Healthline.

Dr. Eliud Sifonte, an endocrinologist at NYU Langone Medical Associates in West Palm Beach, Florida, told Healthline that past studies have shown that pioglitazone reduces the thickening of the carotid artery and reduces stroke risk.

“It is likely that in people with glycemic disorders like prediabetes or diabetes, pioglitazone is reducing the risk of strokes and possibly dementia independent of [treating diabetes],” said Sifonte.

The association between diabetes and dementia is well known.

“Many consider diabetes as an equivalent of cardiovascular disease,” said Sifonte. “Patients with diabetes tend to suffer from hypertension, hyperlipidemia, and overweight/obesity.”

“Dementia can be caused by lack of good blood/nutrition and oxygen flow to the brain and diabetes is very damaging to blood vessels everywhere and certainly to those that supply the brain. This can lead to vascular dementia,” Reiss said. “Chronic high blood sugar is very damaging to nerve cells and disrupts their function.”

“Another factor is that inflammation in the brain and body are increased in diabetes and inflammation is a contributor to Alzheimer’s pathology,” she said. “Inflammation causes metabolic stress that harms the brain.”

Experts said that even absent drugs such as pioglitazone, there are many ways that people with type 2 diabetes can reduce their risk of developing dementia.

Blood sugar control, particularly early on after the diagnosis of type 2 diabetes, as well as regular aerobic exercise, following a healthy diet like the Mediterranean diet with minimal to no processed foods, and quitting smoking can lower risk, said Sifonte.

“[Don’t] let the possibility of developing dementia leave a cloud over your life,” said Reiss. “Be optimistic that breakthroughs are on the way and healthcare specialists and researchers around the world are working on the problem.”

“Next, stay healthy and active,” she said. “Eat a balanced diet full of whole foods and with minimally processed foods. Since the pandemic, I have seen many people very low in vitamin D and so, although whole foods are preferred over supplements, if you do not get much sun exposure, a vitamin D supplement may be a good idea,” she added.

“Exercise, keep your heart healthy, control your blood sugar and blood pressure, and reduce stress as needed,” Reiss concluded. “Stay away from illicit drugs and tobacco and limit alcohol. Quality of life is key. Being involved with family, friends, and the community enriches and brings satisfaction and joy. Stay informed and stay positive.”