Association between dietary flavonoid intake and depressive symptoms: A cross-sectional research

Objective: To investigate the relationship between dietary flavonoid intake and depression symptoms in American adults. Methods: Data sets were obtained from the National Health and Nutrition Examination Survey (NHANES) 2007-2008, 2009-2010, and 2017-2018 survey cycles. Both males and females aged 18 years and older with complete information about dietary flavonoid intake (isoflavones, anthocyanidins, flavan-3-ols, flavanones, flavones, and flavonols), depression symptoms, and covariates were included. Logistic regression models were conducted to calculate the odds ratio (OR) of single dietary flavonoid subclass intake on depression, and the restricted cubic spline (RCS) models were utilized to explore the corresponding dose-response relationships. Additionally, we implemented the weighted quantile sum (WQS) regression and quantile g-computation (qgcomp) models to estimate the mixed effects of six flavonoid subclasses and identify the predominant types. Results: After multivariable adjustments, people with higher consumption of flavanones (OR: 0.68, 95% CI: 0.52-0.90, p = 0.008), flavones (OR: 0.63, 95% CI: 0.46-0.87, p = 0.007), flavonols (OR: 0.66, 95% CI: 0.49-0.89, p = 0.008), and total flavonoids (OR: 0.69, 95% CI: 0.50-0.95, p = 0.024) had lower odds of depression symptoms. Meanwhile, significant dose-response relationships were supported by the RCS models. However, no obvious associations between isoflavones, anthocyanidins, flavan-3-ols, and the odds of suffering from depression symptoms were found by the logistic regression models and RCS models. As for the mixed effect, the WQS and qgcomp models both demonstrated that the mixture of six flavonoid subclasses was inversely related to the odds ratios of depression symptoms, and flavones, flavanones, and anthocyanidins were the top 3 contributors. Conclusion: Our study implied dietary flavonoid intake was associated with the decreased probability of depression symptoms in U.S. adults, among which flavones, flavanones, and anthocyanidins may occupy the predominant roles.