The Interrelationship between Stress, Sugar Consumption and Depression.

Depression is a leading cause of disability in the United States. Previous research has shown that added sugar consumption and stress are both risk factors for depression. Despite evidence that stress predicts added sugar consumption, and both affect the HPA axis, no research has explored how stress, added sugar consumption and depression are related. In this study, we investigated the possible effects of total added sugar and sugar-sweetened beverage consumption on depression, as well as their potential interactions with chronic stress. Measures of sugar consumption, chronic stress and depression were taken in an adult community sample at two time points. We hypothesized that high sugar consumption would predict more depression even after stress was statistically adjusted for, but that stress would moderate the relationship between added sugar consumption and depressive symptoms, amplifying the effect. We found that both total sugar consumption and sugar-sweetened beverage consumption at baseline predicted depressive symptoms one month later. However, only sugar-sweetened beverage consumption was a significant predictor of depression after controlling for stress, possibly because stress is related to diet quality. Stress did not moderate the relationship between added sugar consumption and depressive symptoms. These results suggest that stress should be included in future research on sugar and depression.