Addiction to food, drugs similar in the brain (En)
Each of the women filled out a 25-item questionnaire, adapted from assessments for drug and alcohol dependence, in which they were asked how strongly they agreed with statements such as “I find myself continuing to consume certain foods even though I am no longer hungry” and “When certain foods are not available, I will go out of my way to obtain them.” They were also asked to identify any foods — from a list including ice cream, chocolate, chips, pasta, cheeseburgers, and pizza — that gave them “problems.”
Then the researchers brought on the milk shakes, made with four scoops of Häagen-Dazs ice cream and Hershey’s chocolate syrup. While their brains were being scanned, the women were shown a picture of the milk shake to whet their appetite; five seconds later, they got to taste it. (As a comparison, each of the women was also shown a picture of a glass of water followed by a tasteless beverage.)
In addition to exhibiting patterns of craving and tolerance similar to those seen in drug addiction, the brains of women who scored high on the food-addiction scale showed less activity in areas responsible for self-control, which suggests that their brain chemistry may prime them to overindulge, Gearhardt says.
“It’s a combination of intense wanting coupled with disinhibition,” she says. “The ability to use willpower goes offline.”
The junk foods that are most likely to trigger cravings may be part of the problem. Over the past several decades, many foods have become less natural and more heavily refined, as sugars and fats have been added to make them tastier and more satisfying, says Gene-Jack Wang, M.D., a senior scientist at Brookhaven National Laboratory, in Upton, New York, who studies the brain’s role in obesity and eating disorders.
“Natural foods take a long time for the body to absorb,” says Wang, who was not involved in the study. “But the added sugars hit the brain right away.”
Some people, Wang adds, might be especially vulnerable to developing a dependence on such foods. “They may be genetically hardwired to like certain foods and to absorb them faster,” he says.
Over time, however, a person’s food of choice becomes less important as the cycle of dependence takes over, Gearhardt says. “At first you want it because it tastes good,” she explains. “But as you go from use to abuse to dependence, you begin to crave it and liking it doesn’t play as much of a role.”