The study shows that impaired insulin sensitivity, which generally accompanies obesity, may serve as a mediator between midlife obesity and cognitive decline later on. Researchers chose to examine insulin sensitivity because insulin helps regulate people's metabolism and also affects cognitive functions.

The study exemplifies the aim of Haley's lab, which is to use neuroimaging in middle-aged individuals to provide early identification of risk for cognitive decline later in life.

"Generally, very few people study the middle-aged segment of the population, but that's when many chronic diseases are first identified and neurodegenerative processes are triggered," says Haley. "We found that while behavioral performance of obese middle-aged individuals may be the same - they can complete the same cognitive tasks as normal weight individuals - their brain is already doing something different to produce that outcome."

Haley and Gonzales are planning a follow up study to determine if a 12-week exercise intervention can reverse the observed differences in brain response.

Source: University of Texas at Austin