Ask the Brain: Why Do We Crave Sugar When We're Stressed?

In America, uncontrolled sugar consumption is a concern because of its contributions to obesity and diabetes. A recent study investigated the psychological basis of sugar cravings during times of stress. Researchers proposed that sugar turns down the stress response in the human brain. As a result, we may be consuming sugar as a quick way to hold back feelings of stress.

To test this hypothesis, scientists conducted stress tests in two groups of women. For two weeks, one group was asked to drink beverages containing sugar three times a day, while the other was asked to drink beverages with a substitute, aspartame. The women took the stress test before and after the treatment, and measurements of the brain’s responses to stress were made: 1) the production of a stress compound, cortisol, and 2) activity in a certain region of the brain, the hippocampus. Their results suggest that sugar consumption somehow changes cortisol levels and hippocampus activity during stress, and perhaps how the brain perceives and responds to stressful events.

Unfortunately, we still do not have a complete explanation for how sugar affects the response to stress. Hippocampus activity is regulated by many factors, not just stress. How changes in activity in the hippocampus relate to the stress response remains vague. Also, how cortisol production and brain activity are coordinated to bring about the brain’s response to stress in response to sugar is unclear. More work is required to understand how sugar consumption affects the brain during times of stress.

Managing Correspondent: Emily Low

Acknowledgments: Special thanks to contributing correspondent Anna Leshinskaya, a Graduate Student in the Psychology Department at Harvard, for providing expert advice on MRI brain imaging and neuroscience.

Original journal article: The Journal of Clinical Endocrinology and Metabolism

Media coverage: reuters.com