Childhood obesity not only poses risks to physical health but also leaves destructive traces in the brain, according to a study utilizing MRI scans. The Centers for Disease Control and Prevention (CDC) estimates that approximately one in five children in the United States is obese, while in the Netherlands, nearly 16% of children were overweight last year. Researchers conducted one of the largest long-term studies to date, aiming to assess brain development and brain health in children with obesity.

The Obesity Epidemic: 

The obesity epidemic is hitting the United States hard, with approximately one in five children affected by severe obesity. In response to this concerning trend, researchers embarked on an extensive long-term study to examine the brain health and development of children with obesity. The study utilized MRI scans to provide a comprehensive analysis.

Structural Brain Changes: 

The study involved nearly 12,000 children aged nine and ten from various American hospitals. The researchers aimed for a representative sample through the Adolescent Brain Cognitive Development (ABCD) study. After excluding children with eating disorders, neurological and psychiatric conditions, and traumatic brain injuries, the research group consisted of 5,169 children. Based on the children’s BMI z-scores (adjusted measurements of relative weight considering age, gender, and height), the prevalence of overweight and obesity within the study group was 21% and 17.6%, respectively.

To assess the brain health, the researchers examined changes in cerebral blood flow, connectivity between neural brain regions in resting state, and abnormalities in white matter within the corpus callosum—the main connection between the brain’s two hemispheres. The study controlled for factors such as age, gender, race, and socioeconomic status.

Impaired White Matter: 

The study revealed structural brain changes in children with overweight and obesity. The white matter of the corpus callosum was noticeably affected, along with reduced white matter within the brain hemispheres, particularly in structures connecting different brain lobes. These changes were detected at an early age, raising concerns. Additionally, the outer layer of the brain, known as the cortex, was found to be thinner in obese children on average. Although the cortex is only a few millimeters thick, it plays a vital role in higher brain functions, including memory. Thinning of the cortex is associated with a qualitative and quantitative decline in these higher brain functions.

Significance and Future Research: 

The findings of the study provide neurological explanations for previous research indicating that higher BMI in children is linked to poor cognitive function and lower academic performance. The ongoing ABCD study will continue to monitor potential changes occurring in children with higher weight and BMI z-scores over the next six to ten years. This long-term study offers valuable insights into the impact of weight and BMI on brain health in childhood.

Conclusion: The study’s results demonstrate that higher weight and BMI in children are associated with impaired brain structures, connectivity, and functional networks. These findings highlight the importance of addressing not only the physical health but also the brain health of children affected by obesity.

Source: This article was published on November 28, 2022, and written by Jeannette Kras.