Obesity appears to be strongly linked to structural changes in the brains of rats and humans, according to new research.
During a study of high-fat diets in the brains of mice and rats bred to become obese, researchers found evidence of early and lasting injury to a specific part of the hypothalamus.
Then using brain imaging, the researchers also found signs of similar damage in the same area of the brain in obese humans.
“Obese individuals are biologically defending their elevated body weight,” said Dr. Michael W. Schwartz, professor of medicine at the University of Washington, who led the study.
“To explain a biologically elevated body weight ‘set-point,’ investigators in the field have speculated about the existence of fundamental changes to brain neurocircuits that control energy balance.”
“Our findings are the first to offer direct evidence of such a structural change, and they include evidence in humans, as well as in mice and rats.”
Schwartz noted that the researchers did not prove cause and effect between the hypothalamic neuron injury and defense of elevated body weight.
“That comes next,” he said. “But this amounts to solid evidence of a change affecting the key hypothalamic area for body weight control with the potential to explain the problem.”
The paper, “Obesity Is Associated with Hypothalamic Injury in Rodents and Humans,” will be published in the Jan. 3 issue of the Journal of Clinical Investigation.
Source: University of Washington