When you eat a cookie, your brain sparkles. That’s a scientific description of how cookies work. An MRI can see those sparkles as dopamine neurons light up in response to the reward of eating a delicious treat. Typically, high-calorie foods like chocolaty, buttery cookies activate the brain’s reward system more than low-calorie foods like broccoli. This is true also of the anticipatory reward system, so when faced with the bounty of the grocery store’s produce section, which is almost always inexplicably next to the bakery, you’ll often be more likely to be drawn to the cookies.
How much easier would it be if brains sparkled for the broccoli? A small study published recently in Nutrition & Diabetes suggests that could at least be a possibility.
The study followed 13 overweight and obese adults over six months as they took part in a behavioral intervention weight loss program. The program offered “high-satiety menu plans, recipes, and tip sheets.” The researchers scanned participants’ brains before and after the six-month program using an fMRI, and focused on activity in the striatum, a region of the brain associated with reward processing.
While participants were having their brains scanned, researchers showed them pictures of high-calorie foods (fries, Froot Loops, a chicken leg) and low-calorie foods (a grilled chicken breast, a sweet potato). They also rated the desirability of these foods.
People who participated in the weight-loss program not only lost more weight than those who didn’t (so far, so good), but they also showed significantly more reward system activity for low-calorie foods after the program was over, and significantly less activity for high-calorie foods.
“While the regulation of food intake via reward systems is clearly complicated,” the study reads, “[this] suggests that broad changes occurred in reward system responsiveness that potentially can impact the valuation of different foods both at the level of anticipation of consumption and at the level of actual consumption.”
Other research has shown that certain procedures like gastric bypass surgery could lead to healthier eating, they tend to generally decrease people's enjoyment of food, rather than shifting their enjoyment to foods that are better for them, said Dr. Thilo Deckersbach, lead study author and psychologist at Massachusetts General Hospital in a press release. "We show here that it is possible to shift preferences from unhealthy food to healthy food without surgery, and that MRI is an important technique for exploring the brain's role in food cues," he said.
There’s a lot we don’t know here. It was a small study, first of all, and who knows if a sparkling brain translated to a healthier grocery list. While the healthy foods may have activated participants’ brains, we can’t know if they activated their hearts. But as a first step, it’s promising. It shows there’s a chance. So look out cookies, broccoli’s coming for you.