However, “by altering insulin resistance in midlife, it may be possible to reduce future risk of Alzheimer’s disease,” Bendlin said. Medications and a healthy lifestyle are possible ways to do that, she said.
According to the American Diabetes Association, 29.1 million Americans have diabetes, and more than half of adults older than 64 have prediabetes. Poor diet, obesity and sedentary lifestyles are associated with insulin resistance, Bendlin noted.
“Healthier lifestyles may contribute to healthier brain aging by reducing insulin resistance,” Bendlin said.
One expert cautioned that having prediabetes, or insulin resistance, doesn’t mean you’re doomed to develop Alzheimer’s, the most common form of dementia.
This study shows that insulin resistance may make mental functioning worse and may be linked to reduced use of insulin in areas of the brain associated with Alzheimer’s disease, but this does not mean that insulin resistance leads to Alzheimer’s, said Dr. Luca Giliberto, an investigator at the Litwin-Zucker Research Center for the Study of Alzheimer’s Disease at the Feinstein Institute for Medical Research in Manhasset, N.Y.
“We do not know what causes Alzheimer’s disease,” said Giliberto, who was not involved in the study. “We don’t know if lowering blood sugar will prevent Alzheimer’s.”