TURKU, Finland — For most of us, partaking in our favorite activities or being around loved ones trigger a release of endorphins in our brains, which brings about feelings of pleasure and satisfaction. Now a recent study finds that a more unassuming activity that we do regularly each day also stimulates our happiness hormones: eating.
Researchers from the University of Turku say that eating causes a significant opioid release in the brain. There’s two sides to the coin here, though: the worse you eat (junk food, fast food), the more pleasure you feel. The healthier you eat (salads, smoothies), the less pleasure. But the authors found that larger amounts of opioid were released even when the meal wasn’t so pleasurable.
For the study, 10 healthy men were given two different meals — an appetizing pizza on one night, and a tasteless nutritional drink that contained the same amount of calories as the pizza on another night. They were also instructed to fast for a third night.
Using a PET scan, the researchers found that significant levels of endorphins were released after the participants ate the pizza. More unexpectedly, they noticed that even more were released following consumption of the bland drink. The finding led the authors to conclude that the brain’s opioid system signals feelings of both pleasure and fullness.
“It was a surprise that endorphins are released in the entire brain and that the nutritional drink had a larger impact,” says Dr. Jetro Tuulari, one of the study’s researchers, in a news release.
The authors also believe that when the brain’s pleasure center is overstimulated from eating, one’s risk of obesity rises too.
“The opioid system regulates eating and appetite, and we have previously found that its dysfunctions are a hallmark of morbid obesity,” says study co-author Lauri Nummenmaa. “The present results suggest that overeating may continuously overstimulate the opioid system, thus directly contributing to development of obesity. These findings open new opportunities for treating overeating and the development of obesity.”
Adds Tuulari: “This creates a basis for future research and hopefully we will find ways to study and describe the development and predictors of addiction, obesity and eating disorders.”
This study’s findings were published in The Journal of Neuroscience.