Many people consume sweets in response to stress. Now researchers may have discovered why. Sugar reduces levels of cortisol, the stress hormone.
Scientists recruited 19 female volunteers. For 12 days, eight of them consumed beverages sweetened with aspartame, an artificial sweetener. The rest drank an identical beverage containing 25 percent sucrose, or table sugar.
Before and after the experiment, researchers measured the volunteers’ saliva cortisol levels and performed functional M.R.I. scans while they took arithmetic tests designed to be just beyond their abilities — a procedure known to increase cortisol levels.
The study, in the Journal of Clinical Endocrinology and Metabolism, found no differences in the tests between the two groups before the 12-day diet. But in tests afterward, cortisol levels were lower in the sugar consumers and higher in the aspartame group.
The post-diet M.R.I. showed increased activity in the areas of the brain controlling fear and stress in the sugar group. The aspartame group showed decreased activity in those areas.
The senior author, Kevin D. Laugero, a nutritionist with the federal Department of Agriculture, said no one should conclude that sugar should be used as a stress reducer. But, he said, “the finding is intriguing because it suggests that there is a metabolic pathway sensitive to sugar outside the brain that may expose new targets for treating neurobehavioral and stress-related conditions.”
Credit Tony Cenicola/The New York Times