via AFP |
Stress can drive cravings for sweets, but indulging isn’t any more pleasurable than it would be under stress-free conditions, according to a small new study from the University of Geneva in Switzerland.
“Most of us have experienced stress that increases our craving for rewarding experiences, such as eating a tasty bar of chocolate,” says lead author Eva Pool, MS, a doctoral student at UG, “and it can make us invest considerable effort in obtaining the object of our desire, such as running to a convenience store in the middle of the night.”
In the study, Pool and her colleagues recruited 36 university students, all self-described chocolate lovers, of whom 19 were men.
They induced stress by asking participants to keep one hand in a bowl of ice-cold water while under observation and being filmed, and another group underwent the same experience but using lukewarm water.
The research team collected saliva samples from all participants ten minutes before and 30 minutes after the assignment to assess their levels of the stress hormone cortisol.
Next, participants were offered the chance to smell chocolate under the condition that they press a handgrip until a signal appeared, indicating the comforting aroma was on its way.
This way researchers were able to measure the lengths to which participants would go to get a whiff, then ask them just how pleasing it was when the chocolate bouquet wafted through their surroundings.
Results of the experiment, called a Pavlovian-Instrumental Transfer test (PIT), showed that those who had undergone the more stressful experience of keeping their hand in the ice-cold water made a greater effort to attain the chocolate scent.
“Stress seems to flip a switch in our functioning,” says co-author Tobias Brosch, PhD, also of UG. “If a stressed person encounters an image or a sound associated with a pleasant object, this may drive them to invest an inordinate amount of effort to obtain it.”
Curiously, those who had undergone the more stressful circumstance did not report the reward as being any more pleasurable than did those who attained it under less stressful conditions and who hadn’t worked as hard for it.
“Stress plays a critical role in many psychological disorders and is one of the most important factors determining relapses in addiction, gambling and binge eating,” says Dr. Brosch.
In light of the findings and the significant problem of stress eating, the authors, whose study waspublished in the Journal of Experimental Psychology: Animal Learning and Cognition, recommend further research.