Positive Association Found Between Depression and Inflammatory Foods

Researchers found a positive, J-shaped association between the Dietary Inflammatory Index (DII) and depression, according to a study published in the Journal of Affective Disorders.

“Our findings have major implications for clinical practice as well as public health,” lead author, Leiyong Zhao, Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China, noted. “Because diet is a factor that can be changed, depression can be prevented and reduced by restricting a pro-inflammatory diet or encouraging an anti-inflammatory diet.”

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Overall, 30,627 people in the United States participated. Subjects were pulled from the National Health and Nutrition Examination Survey (NHANES). Participants answered questions on their diet and lifestyle and were given scores based on dietary inflammation as well as evaluated for depression. Researchers used weighted multivariable logistic regression models with subgroup analysis to investigate the connection between DII and depression and a 2-piece linear regression model and recursive algorithm to calculate inflection points. Nonlinear associations were examined using generalized additive models.

A positive association was found between DII and depression, even after adjustments for lifestyle habits, common comorbidities, and body mass index (BMI). This positive association indicated that high bodily inflammation correlated with a higher risk of depression. The odds ratio (OR) for the association was 1.05, and the J-shaped connection found between the 2 factors had a turning point of 2.74. After that point, the OR was 1.60 and the only statistically significant interaction was in cardiovascular disease analysis. 


Zhao L, Sun Y, Liu Y, et al. A J-shaped association between Dietary Inflammatory Index (DII) and depression: A cross-sectional study from NHANES 2007–2018. Journ Affect Disord. 2023;323:257-263.

High inflammatory diet found to increase likelihood of depression, new study finds. News release. CTV News; January 23, 2023. Accessed February 3, 2023.