As a society, we’ve come to recognize there’s more to substance abuse — like drug or alcohol addiction — than a simple lack of self-control. Neurochemical imbalances help drive compulsive behaviors — and vice versa. But when it comes to confronting obesity, food addiction usually gets left out of the equation. Emerging research, however, is starting to elucidate the role of brain chemistry in compulsive eating.

One recent study published in the Archives of General Psychiatry used functional magnetic resonance imaging (fMRI) technology to show that brain scans of compulsive eaters react to images of a milkshake similarly to the way the alcohol addicted brain might react to the mention of a martini. Yale University researchers administered a questionnaire to 48 healthy young women. Of these women, 15 were classified as food addicted, exhibiting classic signs of dependency such as withdrawal, out-of-control consumption, interference with work, social life, etc. These women had markedly different neurological reactions upon viewing the milkshake — triggering increased activity in specific, dopamine-regulated areas of the brain that are also shown to light up in drug and alcohol addicts.

Previous research has associated certain brain chemicals, such as galanin, with both alcoholism and overeating. Sugar, particularly when combined with fat and salt (hello, junk food!), especially engages the brain’s reward centers. Indeed, one study using rats found sugar to be even more addictive than cocaine. A taste sensitivity to fat has been linked to lower fat and calorie intake, possibly suggesting that over-consumption of fat eventually desensitizes the tongue.

Published June 1, 2011