Drug use and eating may be connected in more ways than munchies.
Yale’s Rudd Center for Food Policy and Obesity released a study Monday that finds that the same brain activity signifies both compulsive eating and drug addiction. The study, led by clinical psychology doctoral student Ashley Gearhardt GRD ’12, showed that food addiction is triggered by strong reward activation and suppressed inhibitions, the same activity that accompanies drug abuse. Gearhardt said she hopes that her research will be used to address widespread health problems, especially those afflicting children.
“Think of alcoholics walking past their favorite bars,” Gearhardt said. “They crave the alcohol so much that they might stop in, even if they have other commitments. We thought something similar may be happening in the brains of food addicts and decided to perform this experiment.”
The study focused on 48 young women of a wide range of weights. The women were asked questions about their diets in order to separate them into high and low food addiction groups. Each group was then shown images of milkshakes. The high food addiction group exhibited stronger reward center stimulation than the low group, just as a cocaine addict’s brain would react to the image of the drug.
The questions used to divide the participants were provided by the Yale Food Addiction Scale (YFAS), a questionnaire used to diagnosis food addiction. Developed in 2009 at part by Gearhardt, the scale was a crucial instrument to the study’s methodology.
“Before the YFAS, there was no measurement of food addiction,” Gearhardt said. “The YFAS takes the questions asked to potential alcohol and cocaine addicts and applies them to food.”
The YFAS resolves various misconceptions about food addiction, Gearhardt said. It takes into account, for example, that thinness is not a guarantor against food addiction, as a fast metabolism or rigorous exercise regime can reduce the physical symptoms of overeating. The scale also provided a clear metric that defines precisely when eating habits become addictive and need to be treated.
The study, published in the Archive of General Psychology, notes that one-third of all Americans are obese, and obesity-related disease is the second leading cause of preventable death.
“Kids are in an especially dangerous position,” Gearhardt said. “From an early age, they are exposed to addictive food, and we would like to look into how those foods affect their bodies and brains.”
Dr. Jennifer Brout, founder of the Sensory Processing and Emotion Regulation Program at Duke University, pointed out that studies like this may allow food addicts to receive help instead of criticism.
“People often look at those who have weight problems as people who have bad habits or are careless,” Brout said. “We know that drug addiction is a sickness, but food has never been looked at that way — this study may help get rid of this ‘blame the victim’ mentality.”
Several recent advancements in brain scanning technology, including improved Functional Magnetic Resonance Imagery (fMRI), as well as Positron Emission Technology (PET) scans, greatly facilitated the study by enabling researchers to pinpoint active neurological mechanisms, Gearhardt said.
The study’s results also build on a growing trend in psychology to classify disorders within broader categories of illness, said Dr. M. Zachary Rosenthal, an assistant professor at Duke University Medical Center’s Department of Psychiatry and Behavioral Sciences.
“In the past few years, the dimensional approach to disorders, which searches for the underlying mechanisms of disease categories, has gained momentum among psychologists,” Rosenthal said. “This study seems to follow in that trend.”
Gearhardt intends to perform several follow-up experiments which will investigate different demographics, such as men and different age groups, and different stimuli, such as food advertisements.