Associations Between Flavonoid Consumption And Depressive Symptoms In Adults

Objective: Depression,which is one of the most prevalent mental illnesses globally,is a leading cause of disability worldwide and a significant contributor to the global burden of disease.With the advancement of nutritional psychiatry,dietary intervention and nutritional support have emerged as new approaches to treating depression.Flavonoids,a type of polyphenols derived from plants,have been demonstrated to enhance cognitive function,reduce inflammation,and have a protective effect against various illnesses.The impact of flavonoid intake on depression symptoms remains uncertain.This study aims to examine the relationship between the intake of six subclasses of flavonoids by American adults and depression,and to explore possible mechanisms,providing a foundation for further research.Methods: This study used data from the National Health and Nutrition Examination Survey(NHANES)conducted during 2007-2010 and 2017-2018,a total of 6 years of publicly available data in the United States.A total of 10,959 individuals(5,684 males and 5,275 females)with ages ranging from 18-80 were included in the study.Flavonoids intake data were obtained from the Food and Nutrient Database for Dietary Studies(FNDDS)in the United States,with data for six subclasses of flavonoids(mg)extracted.The mean value obtained from two dietary surveys was used as the independent variable.The intake of the six subclasses of flavonoids was divided into four groups based on quartile distribution from low to high levels: low-level intake group(Q1),moderate-level intake group(Q2),high-level intake group(Q3),and highest level intake group(Q4).The low-level intake group was set as the reference group.The Patient Health Questionnaire-9(PHQ-9)was used to screen the presence of depression with a critical value of 10.Demographic data were obtained from structured information interviews.A weighted logistic regression model was used to analyze the correlation between the six subclasses of flavonoids and the risk of depression.This study further explored the doseresponse relationship between the six subclasses of flavonoids and depressive symptoms through a three-node weighted restricted cubic spline model.Results:(1)In this study,a total of 10959 subjects were included,among which 993(8.05%)were diagnosed with depression.(2)It was found that there was a statistically significant difference between the median intake of six types of flavonoids compounds,including isoflavones,anthocyanins,flavan-3-ols,flavones,flavanones,and flavonols,between the non-depression group and the depression group,and the median intake of the depression group was lower than that of the non-depression group.(3)The results of the multivariate weighted logistic model 2 showed that only flavones were negatively correlated with the risk of depression(odd ratio,0.66;95% confidence interval,0.46-0.95;the P for trend,0.0119).(4)Stratified analysis by gender showed that in male subjects,flavones were negatively correlated with the risk of depression(odd ratio,0.65;95%confidence interval,0.47-0.89;the P for trend<0.01).In female subjects,flavones and flavanones were negatively correlated with the risk of depression(flavones: odd ratio = 0.68,95% confidence interval = 0.52-0.87,the P for trend<0.001;flavanones: odd ratio = 0.61,95% confidence interval = 0.47-0.77,the P for trend<0.01).(5)Nonlinear relationship analysis based on a three-node weighted restricted cubic spline model showed that there was no nonlinear relationship between isoflavones,flavanones,flavan-3-ols,and depression symptoms(nonlinear P value >0.05).For anthocyanins,flavones,and flavonols,a nonlinear relationship with depression was found(nonlinear P value <0.05).Among them,anthocyanins and flavones were negatively correlated with the risk of depression,showing a “L-shaped” nonlinear relationship.And flavonols showed a “V-shaped” nonlinear relationship with the risk of depression.Conclusion: Based on a cross-sectional design,this research explores the correlation between the intake level of six subclasses of flavonoid compounds and depressive symptoms in American adults.Logistic regression analysis found a negative correlation between the intake level of flavones and depression.Gender-stratified analysis showed that the intake level of flavones in males was negatively correlated with depression,while the intake level of flavones and flavanones in females was negatively correlated with depression.Nonlinear relationship analysis showed an "Lshaped" nonlinear relationship between anthocyanins and flavonoids and depressive symptoms,and a "V-shaped" non-linear relationship between flavanols and depression.These results indicate that dietary intake of flavonoid compounds,especially flavones,may have a therapeutic or preventive effect on depressive symptoms.This study provides an epidemiological investigation basis for the following studies,and the causal relationship between flavonoids intake and depressive symptoms needs to be explored by larger-scale prospective cohort studies.