Obesity creates brain damage in teens

Obesity creates brain damage in teens

Recently researchers have used MRI to find out the effects of the damages creating inflammation in the brain because of fatness in adolescents. The study is going to be published in the Radiological Society of North America (RSNA) annual meeting next month. 

Nowadays obese adolescents are facing serious health threats. The rate of percentage of children and adolescents with obesity has become apparent. The reports from the 1970s show that the number has risen dramatically in this decade and the rate has tripled in the U.S. This research was led by the Centers for Disease Control and Prevention. According to the collected data by the World Health Organization shows that the number hopped to 41 million in 2016 from 32 million in 1990 in overweight infants and children to age five. 

Obesity is caused by gaining weight. It affects the nervous system by triggering inflammation into them. The inflammation can damage many important areas in our brains. Diffusion tensor imaging (DTI) is a process in MRI that tracks the diffusion of water along the brain's signal-carrying white matter tracts. It paved the research team to identify the damage caused by obesity directly. 

They compared the 59 obese adolescents and 61 healthy adolescents. Their age limit was from 12 to 16 years. By applying this method, they derived a new measure naming fractional anisotropy (FA). This is used to build a correlation with the brain's white matter’s condition. Any reduction in FA directly increases damage in the white matter. 

The effects of FA reduction are seen in obese adolescents’ brains. There is a bundle of nerve fibers that connects the left and right hemispheres of the brain. Its name is “corpus callosum.” obesity affects some regions in that area. Another area that is affected by the decrease of FA is the middle orbitofrontal gyrus. This part of the brain deals with emotional control and the reward circuit. No instance of FA increasing was detected in obese patients.   

Pamela Bertolazzi, a Ph.D. student from the University of São Paulo in Brazil is hoping to be a biomedical scientist soon. She is one of the co-author of the research. She says, “Brain changes found in obese adolescents related to important regions responsible for the control of appetite, emotions and cognitive functions.”

Leptin is a kind of inflammatory markers and it is interrelated with the pattern of the damage. Leptin is a hormone from fat cells. This hormone works to regulate energy levels and fat stores. The problem of obese people’s brains is that they do not respond to leptin. So, they keep eating instead of having enough fat stores. The term is coined as “leptin resistance” that enables the fat cells to continue producing more leptin.  

The bad condition of white matter also affects the level of insulin. Insulin is a pancreas originated hormone that keeps blood sugar level in control. Obese people sometimes become insulin resistant. It means insulin does not effective in their bodies. 

"Our maps showed a positive correlation between brain changes and hormones such as leptin and insulin," Dr. Bertolazzi said. "Furthermore, we found a positive association with inflammatory markers, which leads us to believe in a process of neuroinflammation besides insulin and leptin resistance."

He is in the opinion that further studies are required to understand how severe this inflammation in young people can be. They will focus on the structural changes in the brain as a consequence of obesity. 

"In the future, we would like to repeat brain MRI in these adolescents after multi-professional treatment for weight loss to assess if the brain changes are reversible or not," she added.