Magazine article Nutrition Action Healthletter

Food & Addiction: Can Some Foods Hijack the Brain?

Magazine article Nutrition Action Healthletter

Food & Addiction: Can Some Foods Hijack the Brain?

Article excerpt

Picture three random American adults in a room. Odds are, one is obese, one is overweight, and one is normal weight.

If the three were children, one would be overweight or obese. And obesity rates in children are still rising.

Clearly, there's no single cause of the obesity epidemic. Our 24/7 exposure to calorie-dense food and long hours at a desk or dashboard play a role. But new evidence suggests that some foods may keep us eating by hijacking the brain like an addictive drug.

"How much overeating in the population is attributable to these foods working on the brain so people keep coming back for more?" asks Kelly Brownell, professor of psychology at Yale University.

"It's possible that once people start consuming these foods, the brain changes in ways that make it very difficult to stop."

Here's what we're learning about food and addiction.

"The food industry obviously manipulates the qualities of its foods to maximize desirability," says Kelly Brownell, who directs Yale University's Rudd Center for Food Policy & Obesity. "That's what they're in business to do."

"But if some foods start taking over the brain to create a biological demand, that's a problem," he adds. "Both animal and human studies suggest that an addictive process is profoundly possible."

Here's the evidence that some foods may alter the brain like an addictive drug.

SIGNS OF ADDICTION

What is food addiction?

"There is no clinically recognized definition," says Marcia Pelchat of the Monell Chemical Senses Center in Philadelphia. In other words, you won't find food addiction in the Diagnostic and Statistical Manual of Mental Disorders (DSM) that's used by mental health professionals.

"However, the DSM does have a definition of substance dependence," notes Pelchat. (Dependence is the clinical term for addiction.) "There's a list of seven criteria, and you have to meet three of them within a year."

In 2009, Brownell and his colleague Ashley Gearhardt adapted those criteria to food.

"We wanted to see if traditional criteria for substance abuse could be applied to the eating and obesity arena," says Brownell. "And it's pretty clear that the answer is yes."

In a survey of roughly 350 Yale undergraduates, 11 percent of respondents met the criteria for "food dependence." In particular, many reported a loss of control when eating, a persistent desire or effort to cut back, and heavy use despite deleterious consequences. (1)

"Once the Yale Food Addiction Scale starts getting administered to large populations, we'll know more about how common addictive eating is, its relationship to obesity, and its health consequences," says Brownell.

However, relatively few people fall into that category, he notes. And although those people need help, they're not his main worry.

"We're not as concerned about extreme cases, but the everyday cases of people eating an unhealthy diet," says Brownell. "I'm less interested in the person who sits down and eats 15 doughnuts than the person who gets up in the morning and needs a sugared beverage to get the day going."

The bigger question: "Can you make a case that the brain is being hijacked enough by certain foods that you've got a public health crisis?"

To find answers, some scientists have zeroed in on how the brain's response to some foods can parallel its response to drugs.

DOPAMINE

In 2001, Nora Volkow and her colleagues at the Brookhaven National Laboratory published a groundbreaking study called "Brain Dopamine and Obesity."

The results were stunning. Very obese people had lower levels of dopamine in the "reward" areas of their brains than did people who were normal weight (see illustration, p. 4). (2)

"These brain scans were game-changers," says Pamela Peeke, assistant clinical professor of medicine at the University of Maryland School of Medicine. …

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