Depression associated with dietary intake of flavonoids: An analysis of data from the National Health and Nutrition Examination Survey, 2007-2010

Background: Flavonoids may have a protective effect against depression. The purpose of this study was to examine whether flavonoid intake was associated with depression. Methods: This is an observational cross-sectional study. We evaluated a sample of 8183 adults from the National Health and Nutrition Examination Survey (NHANES), 2007-2010. The participants had an average age of 46.7 years, and 48.4% of them were male. Flavonoid intake was obtained through dietary recall interviews, and it included six subclasses: isoflavones, anthocyanidins, flavan-3-ols, flavanones, flavones, and flavonols. Depression was identified using the Patient Health Questionnaire (PHQ-9). Logistic regression was utilized to evaluate the association between flavonoid intake and depression. Restricted cubic splines (RCS) were utilized to investigate nonlinear associations. Differences between subgroups were explored. Mediation analysis was used to explore confounding/mediating factors. These models were adjusted for age, sex, race/ethnicity, poverty status, education, smoking status, alcohol consumption, BMI, energy intake, physical activity, and chronic diseases. Results: There were 765 individuals with depression (PHQ-9 score >= 10) in the sample. After adjusting for covariates, flavanones, flavones, and total flavonoid intake were associated with a lower likelihood of depression (OR (95% CI): 0.73(0.64,0.84); 0.36(0.21,0.63); 0.86(0.74,0.99), respectively). A significant inverse correlation was observed between flavonoid consumption and the somatic symptom score of the PHQ-9. We observed a stronger association between flavonoids and depression in non-Hispanic white groups. The relationship between the total flavonoid intake and depression was explained to some extent by sleep duration (13.8%). Conclusions: Flavonoid intake was associated with lower odds of depression.