The Brain Circuit Controlling Overeating and Sugar Addiction Discovered

brain circuit controlling overeating

A new study finds the brain circuit controlling overeating and sugar addiction . This discovery might make it possible to treat compulsive overeating protecting many from obesity.

We’ve all heard about being “addicted” to sugar. Though this expression is commonly overused there is a real disorder called compulsive overeating that’s a better fit for the addiction moniker. This disorder involves binge-eating sessions as a reward-seeking behavior, not unlike drug addiction. The overeating can lead to both obesity and mental health problems causing sufferers feelings of shame and depression. Now new research have found the part of the brain, the neural circuit, responsible for compulsive overeating behavior.

The Brain Circuit Controlling Overeating and Sugar Addiction

These finds were published in the journal Cell, Jan 29th.

To treat compulsive overeating you first need something to target. Targeting circuits responsible for regular eating can cause problems since we tend to need food for survival. In this study researchers instead explored which specific brain circuits are involved in compulsive overeating and which are involved in normal feeding . They found a neural pathway from the lateral hypothalamus to the ventral tegmental area. A brain area known for its involvement in rewarding behavior like eating, sex and drug addiction.

To test if this was the brain circuit controlling overeating causing the disorder, researchers used the insanely cool technique optogenetics. This method involves modifying nerve cells making it possible for researchers to switch them on or off using nothing but light of a certain wavelength. When researchers activated the suspected neural circuit it changed the behavior of the mice. Fully fed mice spent more time feeding and were more interested in activating a reward switch in the cage delivering a sugar cube. They craved the sugar cube to such a degree they were willing to suffer electric shocks just to get the sugar reward. When researchers instead inhibited the same neural circuit mice stopped wanting the extra sugar reward while their normal feeding behavior remained unchanged.

According to senior study author Kay Tye this brain circuit controlling overeating probably evolved to make us binge-eat sugary food during the scarce time-period that type of food were available. This circuit is out of sync with modern society where sugary food is available all year round in abundance, which is why this is such a problem.

“However, in our modern day society, there is no scarcity of palatable foods, and high-sugar or high-fat foods are often even more available than fresh produce or proteins,” Tye says. “We have not yet adapted to a world where there is an overabundance of sugar, so these circuits that drive us to stuff ourselves with sweets are now serving to create a new health problem. The discovery of a specific neural circuit underlying compulsive sugar consumption could pave the way for the development of targeted drug therapies to effectively treat this widespread problem.”

 

Image credit: Lauren Lionheart via flickr.com, CC BY 2.0

Nieh EH, Matthews GA, Allsop SA, Presbrey KN, Leppla CA, Wichmann R, Neve R, Wildes CP, & Tye KM (2015). Decoding Neural Circuits that Control Compulsive Sucrose Seeking. Cell, 160 (3), 528-41 PMID: 25635460