Scientists have found out how excess weight affects the brain

Scientists from an international team led by Jody Painter have found that a high body mass index may be a cause of reduced cerebral cortex thickness, rather than merely a concurrent factor, Molecular Psychiatry reports.

Specialists were aware of the link between excess body weight and changes in brain structure, but the cause-and-effect nature of these changes remained unclear. The new study used the Mendelian randomization method, which allows identifying causation through genetic differences inherited from parents.

"Body mass index data were taken from genome-wide studies that combined information on 681,275 people of European descent. Brain cortex thickness data were obtained from the work of a large international neuroimaging consortium that studied up to 23,183 individuals," the report states.

According to the results, a higher BMI is associated with a reduction in average cortex thickness, particularly in areas responsible for movement and visual recognition.

In addition, visceral fat and high levels of C-reactive protein, which is a marker of chronic inflammation, also have an impact on the brain.

The researchers stated that their work provides evidence that "excess weight may directly lead to structural changes in the brain and increase the risk of neuropsychiatric diseases."