Send to

Choose Destination
Health Psychol. 2017 Aug;36(8):760-769. doi: 10.1037/hea0000514. Epub 2017 May 29.

The Dietary Inflammatory Index, shift work, and depression: Results from NHANES.

Author information

Cancer Prevention and Control Program, Department of Epidemiology and Biostatistics, University of South Carolina.
Cancer Prevention and Control Program, University of South Carolina.



Abnormal physiology (e.g., inflammation), brought on by environmental exposures (e.g., diet or shift work [SW]), can affect numerous bodily systems, including the brain, and may be associated with depressive symptomatology. The study examined the associations between SW and depressive symptoms and diet-related inflammation (estimated by the Dietary Inflammatory Index [DII]) and depressive symptoms. Additionally, diet was examined as a mediator between SW and depressive symptoms.


Data were obtained from the U.S. National Health and Nutrition Examination Survey (Centers for Disease Control and Prevention, 2013). SW data were based on self-report. Dietary data were collected using 24-hr dietary recalls for DII calculation. Depressive symptoms were defined using a cut-point of 10 (moderate) on the Patient Health Questionnaire-9 (PHQ-9). Logistic regression was used to estimate odds ratios and 95% confidence intervals (95% CI) for depressive symptoms by SW and DII quartiles.


DII scores were associated with depressive symptoms among women. Women in DII quartile 4 were 30% more likely to report depressive symptoms than women in quartile 1 (95% CI [1.00-1.68]). There was no association between symptoms and SW when using a PHQ-9 cut-point of 10. When using a cut-point of 5 (mild depressive symptoms), those working any form of SW were more likely to suffer from mild symptoms than day workers (odds ratio = 1.22; 95% CI [1.04-1.43]). There was some evidence for mediation by the DII between SW and depressive symptoms.


Future longitudinal studies should examine effects of reductions in inflammation through diet on depressive symptoms, especially among shift workers, to elucidate the role of diet on depression among these groups. (PsycINFO Database Record

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for American Psychological Association Icon for PubMed Central
Loading ...
Support Center