Beyond Emotional EatingApril 18, 2018 /
The Effect of Sugar on Stress Hormones
Author: Elaine M. Hinzey, RD, LDN
Reviewed and updated by Anne Danahy, MS, RDN, LDN
Stress leads to overeating, and approximately 35% to 60% of people eat more when they are stressed. For most of these people, stress alters the type of foods they choose, with a tendency toward foods that are higher in fat, sugar, and other carbohydrates.1 In addition to contributing empty calories to one’s diet, excess sugar consumption, especially when it is related to stress, may wreak havoc with glucose, insulin, and stress hormone levels, especially cortisol.
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Cortisol is a hormone released by the adrenal glands, in response to fear or stress, and it is part of the fight-or-flight reaction. Cortisol is an adaptive hormone that is released whenever the body senses it is “in danger.” It raises blood glucose levels, raises blood pressure, and modulates immune function. If cortisol levels remain chronically high, it plays a part in the development of high blood pressure, prediabetes and diabetes, obesity, increased abdominal fat, decreased bone mass, brain changes, memory loss, depression, suicide, insomnia, and poor wound healing.
The relationship between stress, cortisol, and sugar cravings is complex, but researchers believe there may be some evidence that people can self-medicate with food. Animal studies have shown that stress conditions lead to elevated cortisol, which raises insulin levels, and activates a reward pathway in the brain. Palatable food satisfies this reward system, which in turn triggers opioid, dopamine, and endocannabinoid signaling to reinforce the behavior of eating more palatable foods. The natural feeling of reward, especially from sugary foods, has also been shown to reduce activity of the hypothalamus-pituitary-adrenal (HPA) axis, the hormonal stress-response system.2
A study published in the Journal of Clinical Endocrinology and Metabolism supports this theory. Researchers determined that sugar-sweetened beverages suppress the hormone cortisol and stress responses in the brain, but aspartame sweetened drinks do not alter hormone levels or brain responses. The researchers looked at the effects of sugar-sweetened and aspartame-sweetened beverages of 19 women between the ages of 18 and 40.
Eight of the women consumed aspartame-sweetened drinks, while 11 were given the sugar-sweetened drinks; the drinks were consumed at all 3 meals for 12 days. After the 12-day study, the women had functional magnetic resonance imaging (MRI) screening and performed math tests. They also provided saliva samples to measure levels of cortisol.
The researchers found that the women who received the sugar-sweetened drinks had a diminished cortisol response to the math test, but they also had more activity in the hippocampus, which is the part of the brain involved in memory that is sensitive to stress. The hippocampus is less active when the body is stressed.3
People might reach for sugary foods when they are psychologically or emotionally stressed for physical reasons, rather than or in addition to the emotional reasons that researchers have assumed. Considering that more than 1 in 3 adults and 17% of children are obese, this could be an important scientific finding. About half of all people consume sugar-sweetened drinks daily.
When working with patients and clients who are emotional or stress eaters, dietitians should address this and help clients identify healthier ways to manage stress and bring down cortisol levels. The following suggestions may help reduce stress and cortisol levels, and minimize cravings for less healthy foods:
- Do not drink alcohol—it elevates cortisol levels
- Avoid refined carbohydrate as much as possible
- Eat fatty fish, such as salmon, tuna, or lake trout, at least twice a week
- Include a serving of protein with each meal and snack
- Drink unsweetened black or green tea
- Chew sugarless gum
- Practice mindfulness and meditation
- Exercise regularly and consider yoga
- Consider rhodiola, an adaptogenic herb that is believed to decrease cortisol levels
- Maintain strong social connections, whether it be family, friends, or a romantic partner
- Have fun and laugh often
- Listen to music
- Aim for no less than 7 hours of sleep a night
References and recommended readings
- Ulrich-Lai YM, Fulton S, Wilson M, Petrovich G, Rinaman L. Stress exposure, food intake and emotional state. Stress. 2015;18(4):381-399.
- Adam TC, Epel ES. Stress, eating and the reward system. Physiol Behav. 2007;24;91(4):449-458.
- Tryon MS, Stanhope KL, Epel ES, et al. Excessive sugar consumption may be a difficult habit to break: a view from the brain and body. J Clin Endocrinol Metab. 2015;100(6):2239-2247.
Previous review date: 4/23/15
Current review date: 3/20/18