Can foods be addictive? So many of us ask exactly that question when a sugary doughnut or a gooey cheese pizza call to us so insistently. Scientists have debated the question, too. Some hold that certain foods really do behave like addictive drugs, while others give foods a not-guilty verdict, saying that overeating is simply an emotional problem. But once we gained the ability to understand what is actually happening inside the brain, we gained a whole new perspective.
Here’s what we’ve learned: When sugar hits your tongue, it triggers the release of feel-good chemicals in the brain in the same way that intense exercise triggers the “runner’s high.” Like weak versions of heroin or morphine, these natural opiates can get you hooked on whatever food triggered them. That’s exactly what sugar does. As sugar touches your taste buds, it sends nerve impulses to the brain, triggers the release of opiates, and makes you want to come back for more. And more powerful than pure sugar is the combination of sugar and fat. Think of the mixture of sugar and butter or shortening in a cookie, cake or pie. They tend to call to us much more than sugar itself.
Chocolate is similar, as University of Michigan researchers proved, using the medication naloxone. Normally, this drug is used to treat heroin overdose, because it stops heroin from attaching to receptors on brain cells. The research team gave naloxone, not to heroin addicts, but to chocolate lovers – people who really tended to binge on chocolate. After infusing the drug intravenously, the researchers offered a tray of chocolate candies. It turned out that chocolate had lost much of its appeal, showing that the lure of chocolate is not all taste and mouth-feel. Rather, chocolate hijacks your brain chemistry, triggering the same receptors that heroin affects, and when researchers block that brain effect with naloxone, much of chocolate’s attraction is gone.