People with eating behaviors that resemble addiction appear to have greater neural activity in certain regions of the brain similar to that of substance abusers, including a heightened response in reward circuitry to food cues — more powerful cravings, in other words.
In a study posted online that will appear in the August print issue of Archives of General Psychiatry, researchers used functional magnetic resonance imaging (fMRI) to study the response of 48 healthy young women in response to cues signaling impending delivery of a highly palatable food (chocolate milkshake) vs. a tasteless control solution; and consumption of a chocolate milkshake vs. a tasteless solution.
The women ranged from lean to obese and had been recruited for a healthy weight maintenance trial. Their eating behavior was assessed using a food addiction scale developed by lead author Ashley Gearhardt, a doctoral student at Yale University.
“Similar patterns of neural activation are implicated in addictive-like eating behavior and substance abuse and dependence,” Gearhardt noted in the study.”Food and drug use both result in dopamine release in mesolimbic regions [of the brain] and the degree of release correlates with subjective reward from both food and drug use.”
Gearhardt and colleagues found that participants with higher food addiction scores showed more activity in brain areas linked with craving. “These findings support the theory that compulsive food consumption may be driven in part by an enhanced anticipation of the rewarding properties of food,” the authors write. “Similarly, addicted individuals are more likely to be physiologically, psychologically, and behaviorally reactive to substance-related cues.”
The researchers said that if certain foods are addictive for some people, that could explain in part why they find it so hard to lose weight and keep it off.
While researchers have speculated that an addictive process may be involved in obesity, the authors said that this is the first study to identify distinctive neural or brain activity in people with addictive eating behavior.
In addition, Gearhardt said, “If food cues take on enhanced motivational properties in a manner analogous to drug cues, efforts to change the current food environment may be critical to successful weight loss and prevention efforts. Ubiquitous food advertising and the availability of inexpensive palatable foods may make it extremely difficult to adhere to healthier food choices because the omnipresent food cues trigger the reward system.”
Source: American Medical Association