OVEREATING CAUSED BY A HORMONE DEFICIENCY IN THE BRAIN?

OVEREATING CAUSED BY A HORMONE DEFICIENCY IN THE BRAIN?

By sciencedaily.com

If you find yourself downing that extra piece of chocolate fudge cake even though you're not hungry, it might be the absence of a hormone in your brain that's causing you to overeat purely for pleasure.

In a new Rutgers Robert Wood Johnson Medical School study published in Cell Reports, researchers found that when the hormone glucagon like peptide-1 (GLP-1) was reduced in the central nervous system of laboratory mice, they overate and consumed more high fat food.

"The mice in which the GLP-1 deficiency was induced ate beyond the need for calories and showed an increase preference for high fat food," says Vincent Mirabella, a medical school and doctoral student who co-authored the study. "Conversely when we enhanced GLP-1 signaling in the brains of mice we were able to block the preference of high fat foods."

GLP-1 peptides are small sequences of amino acids that have many functions, including how our bodies regulate eating behaviors. They are secreted from cells in both the small intestine and the brain and are supposed to let our brain know when we are satisfied and should put down the fork.

Rutgers scientists say it has been unclear how the GLP-1 released in the brain contributes to appetite regulation. Although this is not the only reason why people overeat, the study provides new evidence that targeting neurons in the mesolimbic dopamine system -a reward circuit in the brain -- rather than targeting the whole body might be a better way to control overeating and obesity with fewer side effects.

In the study, the authors found that activating the GLP-1 hormone in the mesolimbic system hindered communication between neurons which communicate to control reward behaviours, including eating. The result was that mice consumed less food altogether and, more important, lost the preference for high fat food.

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