Gene Linked to Stimulus-Seeking Behavior Common in Study Participants with Diabetes, May Cause Compulsive Overeating

WASHINGTON—A gene linked to stimulus-seeking behavior is surprisingly widespread among people with type 2 diabetes, according to a study published in the January issue of the journal Nutrition. Nutrition researcher Neal D. Barnard, M.D., and his co-authors believe this genetic variant, known as Taq1 A1, may cause compulsive overeating, which in turn may lead to overweight and greater risk of diabetes. The study was funded in part by the National Institutes of Health.

"People genetically predisposed to overeat seem to benefit from a simple approach to weight loss, such as entirely leaving aside meat and other high-fat foods," says Dr. Barnard, the lead researcher. "Following a low-fat vegan diet seemed to be easier for study participants with the stimulus-seeking gene, because you can eat as much as you like and still lose weight." In addition to weight loss, study participants saw improvements in blood sugar, kidney function, and cholesterol levels. 

In this clinical trial of 93 adults with type 2 diabetes, the Taq1 A1 gene was identified in about half the participants. That’s far more than in the general population and similar in prevalence to substance-abusing populations.

People with the Taq1 A1 genetic variant get less than the normal amount of dopamine, a brain chemical associated with pleasure. They tend to compensate with stimulus-seeking behavior such as smoking, drinking, gambling, and overeating. Overeating can lead to weight gain and greater risk of developing diabetes.

Founded in 1985, the Physicians Committee for Responsible Medicine is a nonprofit health organization that promotes preventive medicine, conducts clinical research,and encourages higher standards for ethics and effectiveness in research.