A new imaging study, led by a team from Yale University, has found a high density of cells in a certain brain region can effectively predict future weight gain in children. The research suggests an inflammatory response in the brain, triggered by poor diet, can subsequently influence future overeating.
“Inflammation is known to be associated with obesity, but exactly how it is operating in the human brain has been challenging to investigate,” says Richard Watts, senior author on the new study.
The new study focused on a brain region called the nucleus accumbens. This region is part of the brain’s reward processing system, and prior research has directly linked hyperactivity in the nucleus accumbens to overeating, weight gain and diet failure.
The research examined data from the Adolescent Brain Cognitive Development (ABCD) study, an ongoing project following thousands of children that is investigating the relationship between brain development and child health. A relatively new MRI technique was also leveraged, called Restriction Spectrum Imaging, allowing for novel insights into tissue microstructures within the brain.
A cohort of around 2,000 nine-year-old children was gathered and the researchers initially found a strong correlation between increased waist circumference and a higher cell density in the nucleus accumbens. Looking at the longer term follow-up data revealed an even more compelling finding – cell density in the nucleus accumbens could effectively be used to predict future weight gain over the subsequent year.
The study, published in the journal Proceedings of the National Academy of Sciences, hypothesizes a variety of possible explanations for this relationship. But the general mechanistic framework presented in the study suggests a feedback loop where a poor diet can lead to chronic stimulation of food reward brain regions. This results in increased cellularity within those brain regions triggering subsequent overeating.
“It’s a vicious cycle,” explains co-author BJ Casey. “Eating bad food leads to wanting more bad food. These data provide a possible brain mechanism for this idea.”
Prior animal research has shown diet-induced obesity can induce local neuroinflammation in the nucleus accumbens so there is a reasonable hypothesis suggesting inflammatory processes triggered by poor diet could explain the increased cellularity in certain brain regions. However, the researchers do note there are challenges in examining this process clearly in human brains and future study is necessary to better understand the mechanisms that may be at work.
“This study is a step towards better understanding the neurobiological mechanisms underlying childhood weight gain, which will be critically important to inform early intervention and obesity prevention strategies,” adds Casey.
The new study was published in the journal PNAS.
Source: Yale University