It turned out that the zones that are responsible for controlling appetite, emotions and cognitive functions are primarily affected.
According to a new study, presented at the annual meeting of the Radiological Society of North America, signs of damage were found in the brains of obese adolescents. Scientists say they are associated with an inflammatory process in the nervous system, sciencedaily.com writes.
Recent evidence suggests that obesity causes inflammation in the nervous system, which can damage important parts of the brain. New developments in MRI diagnostics have allowed researchers to directly study this damage.
Obesity in young people has become a serious public health problem. According to the Centers for Disease Control and Prevention, in the United States, the percentage of obese children and adolescents has more than tripled since the 1970s. According to the World Health Organization, the number of overweight or obese children aged five and younger has increased from 32 million in the world in 1990 to 41 million in 2016.
Researchers compared the results of MRI in 59 obese adolescents and in 61 healthy adolescents aged 12 to 16 years. Thus, they derived a parameter called fractional anisotropy (FA), which correlates with the state of the white matter of the brain. A decrease in FA indicates an increase in white matter damage.
Studies have shown a decrease in FA in obese adolescents in areas located in the corpus callosum (a bundle of nerve fibers that connects the left and right hemispheres of the brain). A decrease in FA was also found in the middle orbitofrontal gyrus, an area of the brain associated with emotional control and a reward pattern. In no area of the brain did obese patients have elevated levels of FA.
“Brain changes found in obese teens are related to areas responsible for controlling appetite, emotion, and cognitive function,” said study co-author Pamela Bertolazzi, a biomedical scientist at the University of São Paulo in Brazil.
This type of damage has been linked to resistance to leptin, a hormone that helps regulate energy levels and fat stores. In some obese people, the brain does not respond to leptin, forcing them to continue to eat, despite an adequate or excessive supply of fat. This condition causes fat cells to produce even more leptin.
Deterioration in white matter has also been linked to insulin, a hormone that helps regulate blood sugar. Obese people often suffer from insulin resistance, which leads to type II diabetes.
“In the future, we would like to repeat brain MRI in these adolescents after multidisciplinary treatment and weight loss to assess whether brain changes are reversible or not,” added Dr. Bertolazzi.