CHICAGO — Studies continue to show that childhood obesity puts kids at greater risk for developing diseases like Type 2 diabetes and hypertension. However, there’s a less talked about problem that excess weight at a young age could cause — poor brain health. Researchers working with the Radiological Society of North America found that children with a higher body mass index before reaching adolescence also displayed poorer cognitive functioning.
“We know being obese as an adult is associated with poor brain health,” says researcher Simone Kaltenhauser, a post-graduate research fellow in radiology and biomedical imaging at the Yale School of Medicine. “However, previous studies on children have often focused on small, specific study populations or single aspects of brain health.”
Kaltenhauser and the team used MRI data from the Adolescent Brain Cognitive Development (ABCD) study to reach their findings. This study included 11,878 children between nine and 10 years-old from 21 centers across the country in order to provide a diverse dataset that is representative of the greater population. The team excluded children with eating disorders, neurodevelopmental and psychiatric diseases, and traumatic brain injuries. Ultimately, the research examined just over 5,100 children. According to BMI z-scores, which measure relative weight, adjusting for age, sex, and height, 21 percent and 17.6 percent were overweight or obese, respectively.
The team then evaluated brain health by examining information from structural MRI and resting-state functional MRI (fMRI) scans, which help capture changes in blood flow. Additionally, the team used diffusion tensor imaging to study the brain’s white matter.
After correcting for confounding factors like age, sex, race-ethnicity, left or right-handedness, and socioeconomic status, the researchers found that brain structure was altered in children of greater weight and BMI z-scores. Obese children also displayed impaired white matter integrity. Specifically, the white matter in the corpus callosum, which connects the two sides of our brains and allows them to communicate with each other, was damaged. Further, the team noted that the brain’s cortex, which is critical for overall cognitive function, was thinner.
“It is striking that these changes were visible early on during childhood,” Kaltenhauser says in a media release. “We expected the decrease in cortical thickness among the higher weight and BMI z-score children, as this was found previously in smaller subsamples of the ABCD study.”
“However, we were surprised by the extent of white matter impairment.”
Senior author Sam Payabvash, M.D., a neuroradiologist and assistant professor of radiology and biomedical imaging at the Yale School of Medicine, adds that the findings from this work help mechanistically explain other studies that link a high BMI in children with decreased cognition and academic performance. Dr. Payabvash suggests continuously following these children over six to 10 years to monitor brain changes as they grow.
Researchers presented these findings at a previous meeting of the Radiological Society of North America (RSNA) in 2022.