Under the Hood

Obesity And Diabetes May Make You Dumb, Study Finds

A new study shows being overweight or having a diabetes could affect a person’s ability to understand and learn new things. Researchers said they found the direct link between higher rates of cognitive impairment and obesity and diabetes. 

The findings, published in the Journal of Neuroscience, suggest that the two conditions could trigger the chronic activation of the receptor Adora2a that then breaks an important barrier in the brain that supports learning and memory. The researchers from Medical College of Georgia said that preventing the increased release of Adora2a could protect people from the negative effects of obesity and diabetes. 

"We know that obesity and insulin resistance break down the blood brain barrier in humans and animal models, but exactly how has remained a mystery," Alexis Stranahan, a neuroscientist at the MCG Department of Neuroscience and Regenerative Medicine, said in a statement. "It's got transporters that can move things across and what is happening in the brain and in the blood can change the way it operates."

Adora2a actually supports healthy relationships between brain activity and blood flow. However, when released at high levels, which happens in obese people, the receptor can cause problems in the brain. 

For the study, the researchers fed young mice with a high-fat diet as well as fasting glucose and insulin concentrations, which later led to obesity and potential diabetes. Stranahan and the research team then conducted cognitive tests on mice during the study, including object recognition and maneuvering a water maze. They also assessed the animals’ normal functions, like simple motor functions. 

Results show that obesity and diabetes exposed the brain of the animals to molecules and affected blood vessels that caused inflammation and cognitive impairment.

The researchers plan to conduct further study to see which signals activate Adora2 in the obese mice. 

Swedish researchers previously found that obesity could affect the blood brain barrier by increasing the levels of the major antibody, known as immunoglobulin G. The earlier study was the first to suggest that obesity and diabetes could allow some factors to travel from the blood to the brain, which affects a person’s mental performance.