Carried out by researchers at the University of Vermont and Yale University, the new study looked at 3,190 nine- and 10-year-olds who were taking part in the Adolescent Brain Cognitive Development study (ABCD), which followed participants over a 10-year period.
Every two years, the participants were interviewed by researchers, asked to undergo a series of tests and brain scans and provide blood samples.
The findings, published in JAMA Pediatrics, showed that the children who had a higher body mass index tended to have a thinner cortex, especially in the prefrontal cortex, which is significant according to the researchers as executive function (skills that help with memory, impulse control and planning) are controlled in this part of the brain.
In addition, the results of a test completed by the children in the study also confirmed previous findings, which is that children with a higher BMI are more likely to have lower working memory — the temporary storage and managing of information in the brain.
“Our hypothesis going into the study was that the thickness of the cerebral cortex would ‘mediate’ — or serve as an explanatory link for — the relationship between BMI and executive function,” said lead author Jennifer Laurent, who added that more research is now needed to explore the link between children’s BMI, structural changes in the brain and executive function.
“It could be that a thinner prefrontal cortex is affecting decision-making in some children, and they make unhealthy dietary choices as a result, which could lead to obesity,” Laurent said, or that obesity leads to the brain changes. “We know from rodent models and adult studies that obesity can induce low grade inflammatory effects, which actually do alter cellular structure,” says Laurent.
“With prolonged exposure to obesity, it is possible that children have chronic inflammation, and that may actually be affecting their brain in the long term,” she explains.
“We would want to proactively encourage changes in kids’ diets and exercise levels at a young age with the understanding that it’s not only the heart that is being affected by obesity, it is perhaps also the brain.”