- Obesity could trigger inflammation in the nervous system, damaging crucial parts of the brain.
- These alterations in the brain are responsible for cognitive functions, emotions, and control of appetite.
In recent decades, obesity in children and teenagers has become a major public health concern in the United States. Obese children are more likely to develop serious diseases in adulthood.
According to the Centers for Disease Control and Prevention report, about 13.7 million children and adolescents are obese and 41 million infants and young children less than 6 years old are either overweight or obese.
Studies have proven that obesity leads to increased risk of impaired glucose tolerance, diabetes, high blood pressure, high cholesterol, musculoskeletal discomfort, and breathing problems. It turns out that obesity can also cause various damages in the brain.
Recently, researchers discovered some damages in MRI scans that may be associated with inflammation in the brains of adolescents with obesity. The evidence indicates that obesity could trigger inflammation in the nervous system, damaging crucial parts of the brain.
Comparing The Brains Of Obese and Healthy Adolescents
To precisely study the brain, researchers used the diffusion-weighted magnetic resonance imaging (DW-MRI) technique, in which diffusion of water molecules is utilized to generate contrast in MRI.
In this particular case, they employed a special type of DW-MRI called diffusion tensor imaging to map white matter tractography in the brain of 120 adolescents. 61 of them were healthy adolescents and 59 were suffering from obesity. All subjects were aged between 12 and 16 years.
Reference: Radiological Society of North America
Researchers compared their MRI scans and extracted a scalar value (for each brain) called fractional anisotropy (FA). The value indicates the state of white matter in the brain: the lower the FA, the higher the damage in the white matter.
They found a reduction of FA values in all obese patients. The decrease of FA was observed in two different parts of their brains:
- Corpus callosum: a thick band of nerve fibers that splits the cerebral cortex lobes into right and left hemispheres.
- Orbitofrontal gyrus: a prefrontal cortex region in the frontal lobes, which is involved in the decision-making process.
Overall, these alterations in the brain of obese adolescents are responsible for cognitive functions, emotions, and control of appetite. Some obese patient’s brain doesn’t respond to leptin, a hormone that regulates energy balance by inhibiting hunger.
Therefore, obese people keep eating despite excessive fat stores and gradually develop a condition called leptin resistance. The decrease of FA is also linked with insulin levels. This means people with obesity also suffer from insulin resistance.
The findings show a positive correlation between brain alterations and hormones like insulin and leptin. The pattern of brain damage is also associated with inflammatory markers.
However, more studies are required to validate the results. In the coming years, researchers will repeat brain MRI in obese patients after professional treatment for weight loss to analyze if these brain alterations are reversible or not.