Feb. 23, 2012 at 8:26 AM ET
Sure, Stephen Colbert’s Americone Dream tastes so good it’s addictive, but is it, you know, addictive? Could Ben and Jerry, Häagen Dazs, or Blue Bell really be pushers of a substance akin to nicotine?
Baskin-Robbins-as-crack-house might seem ridiculous, and the idea that any food can be addictive in the scientific sense is still controversial. But, broadly speaking, as far as the brain’s circuitry is concerned, pleasure is pleasure. Activation patterns often look about the same.
Now new research shows that ice cream and drugs may share something else in common.
With drugs, over time, addicts feel less and less pleasure, though they crave more and more. This effect has been linked to a lowered density of specific versions of cellular receptors for the brain chemical dopamine. It’s as if constant stimulation has blunted the ability to enjoy.
When researchers Kyle S. Burger and Eric Stice, of the Oregon Research Institute, fed kids real chocolate milkshakes (made with Häagen Dazs) while the kids’ brains were being scanned, they found a similar effect.
In a study published online last week by the American Journal of Clinical Nutrition, Burger and Stice first surveyed the 151 adolescents, all of them of healthy weight, about their recent eating habits and how much they craved certain foods. Then they scanned them in an fMRI machine while showing them a cartoon of a milkshake, to measure craving, followed by the real shake.
All the kids wanted the shake, but those who ate the most ice cream over the previous few weeks enjoyed it less, as reflected in lowered activity in reward centers.
It’s as if the brains of big ice cream eaters had been changed, Burger said. "Over consumption of these foods down regulates reward processes," he explained. "That may, in turn, make you eat more," in an effort to feel the same pleasure you once did. "You could be continually tying to match the earlier experience," he said, taking bigger and bigger portions, and gaining more and more weight.
Importantly, these kids weren’t fat. That means that the brain changes Burger believes are at work happen before obesity sets in.
"Hyper-rewarding foods cause changes in the brain akin to what we see with tobacco and alcohol. ... That is food addiction,"insisted Ashley Gearhardt, a Yale psychology PhD candidate who has also conducted research using milkshakes. (Solid ice cream can’t be fed to a subject in an fMRI.) She admitted the case for food addiction "is not open and shut," but, she said, "our food environment preys on people" by manufacturing food "designed to amp up reward" and vulnerable people can become addicts.
Burger isn’t so sure. "I personally do not say food is addictive. I say energy-dense food, high sugar food, can elicit neural responses during consumption that parallel those seen in drug addiction. So it has addictive-like properties."
That may seem a difference without a purpose, but true addiction is more complicated than diminished reward in the face of high craving. Until more is learned, enjoy -- a little -- of that Super Fudge Chunk.