Dietary flavonoid intake is associated with a lower risk of depressive symptoms in US adults: Data from NHANES 2007–2008, 2009–2010, and 2017–2018

Depressive symptoms is an important public health problem. The aim of the present study is to examine the association of dietary flavonoid intake with risk of depressive symptoms.In this study, we conducted an assessment to investigate the potential association between dietary flavonoid intake and the risk of depressive symptoms. Our analysis was based on a nationally representative sample of 9674 adults who participated in the 2007-2010 and 2017-2018 National Health and Nutrition Examination Surveys. Flavonoid intake was measured using a 24-hour dietary recall method, while depressive symptoms was evaluated using the Patient Health Questionnaire-9. To examine the relationship between dietary flavonoid intake and the risk of depressive symptoms, we employed logistic regression, subgroup and restricted cubic spline models.Following multivariate adjustment, the study found a negative association between total flavonoids, anthocyanidins, flavanones, flavones, isoflavones and the risk of depressive symptoms. In subgroup analysis, total flavonoid intake was inversely associated with risk of depressive symptoms among women whereas no association was found among man. Additionally, a non-linear relationship was observed between total flavonoid intake and depressive symptoms, with statistical significance (P for nonlinearity <0.001).The present study employed a cross-sectional design, which precludes the establishment of causality. Furthermore, the data relied on self-reported measures.In present study, moderate total flavonoids intake, but not high intake, was associated with lower odds of depressive symptoms suggesting a U-shaped association.