Q. A friend jokes she is a "chocoholic." Can you really become addicted to chocolate or other foods?
A. With so many Americans overweight or obese, public health experts are also asking this question. Since it is so difficult to follow the simple advice to "eat a healthy diet" and "exercise more," they realize that food might have addictive properties. Yet common sense demands that food — even chocolate — be placed in a different category from substances like heroin or alcohol.
Addiction involves three essential components: intense craving, loss of control over the object of that craving, and continuing involvement despite bad consequences. Preliminary evidence demonstrates that people can exhibit all three elements when it comes to food.
Consider the phenomenon of craving, for example. For individuals addicted to substances, environmental cues — such as a neighborhood bar or the smoking area at work — can trigger craving. Similarly, many people find that seeing or smelling food can trigger their appetite, even if they have just eaten a satisfying meal.
But your friend's joke about being a chocoholic is a reminder that not all foods induce cravings. The midnight run for a pint of ice cream is familiar, but I've never heard of anyone trolling for celery at that hour. This observation is consistent with research that demonstrates what we might expect if food were addicting — high-fat and high-carbohydrate foods trigger reward pathways in animal brains, and restricting these foods can induce a stress-like response in some of the animals studied.
Chocolate, which contains both sugar and fat, is often used in studies of food addiction. In a study published in Archives of General Psychiatry, for example, researchers at Yale University asked volunteers to fill out questionnaires to assess addictive behavior. The volunteers then underwent brain imaging while being able to see and smell, and then finally drink, a chocolate milkshake. Participants who scored higher on the food addiction scale experienced a surge of activity in the part of the brain that regulates cravings and rewards when presented with the chocolate milkshake. Once they started drinking it, they showed markedly reduced activity in areas of the brain that we use to control the impulse to seek rewards. A similar pattern of brain activity is found in people addicted to drugs.
In another study, this one involving candy, researchers at Drexel University concluded that people experienced psychological reactions while eating chocolate — such as intense pleasure and craving for more — that were similar to those experienced on drugs.
The epidemic of obesity may at once epitomize all of the key components of addiction. Many people who are overweight crave food, lose control over eating, and experience negative health effects that should, but don't, serve as a deterrent. And the influence of stress on eating provides another link between food and addictive behavior. Those who have broken free of an addiction tend to relapse when they are under stress — partly because they begin craving the comfort they experienced while using alcohol, cigarettes, or drugs. In the same way, stress is often what prompts people to go off a diet.
Despite intriguing parallels, however, there are also significant differences between drugs of addiction and food. The most obvious one is that food is necessary for survival, while addictive drugs are not. And this makes treatment more of a challenge too. It's not possible to go off food, as it were, cold turkey.
Moreover, researchers have yet to identify the addictive component of foods. We know that nicotine in cigarettes causes addiction, for example. But what exactly is it about chocolate that causes addiction? The studies showing how the animal brain responds to sugar and fat are interesting, but far from conclusive.
Whether "chocoholism" exists or not, most of us are stuck with the simple, if frustrating, advice to moderate our consumption. Health depends less on what we call our behavior than on paying attention to the hundreds of small but important choices we have to make every day.