Overeating Explained: My Genes Made Me Do It

This study, reported in the October 17^th issue of Science, focuses on the brain’s neurotransmitter, dopamine and its link to obesity.

Cells in the brain release dopamine when you eat, eventually registering a feeling of pleasure that you are full.   

So blame being overweight on sluggish dopamine receptors. 

In this study, 43 female college students and 33 teenagers were observed as they drank a chocolate milkshake and a drink with no taste.   Their brain activity was monitored using an MRI scanner.

While drinking the chocolate milkshake, the brain triggered activity in the dorsal striatum, where the dopamine receptors are found, while the no-flavor drink did not trigger anything.

The women whose brains were less activated by the pleasure chemical dopamine, were more likely to be obese and more likely to gain weight over time.

Previous studies have shown that some people have fewer brain cell receptors for dopamine. But there’s also the problem of a variant gene linked to weight gain. 

Lead author, Eric Stice from the Oregon Research Institute in Portland, along with researchers from Yale, and the University of Texas, have identified the D2 dopamine receptor gene. 

Women with the lowest pleasure response had one form of the D2 dopamine gene. When drinking the milkshake they had to drink more to get a pleasure response. That could translate to weight gain over time. 

Want to overcome your weight gain?  Eat less and find other pleasurable activities, the researchers conclude.   Switching to a healthy diet may reset the pleasure circuitry, Dr. Stice believes. 

Dopamine is similar to adrenalin. It affects the brain controlling movement, emotions and experience pleasure and pain.  A person with an overactive dopamine system can have schizophrenia.

The authors say that a drug could be developed to correct the dopamine variations.   #