Higher anthocyanin intake is associated with lower depressive symptoms in adults with and without major depressive disorder

Background: Major depressive disorder (MDD) is a significant cause of disability globally and an emerging body of evidence suggests that dietary components, including flavonoids, may impact depression-related biochemical pathways. Further research that characterizes dietary intake of flavonoids in diverse population groups, including people with MDD and explores the relationship between flavonoid intake and depression is needed. This study aimed to determine dietary flavonoid and subclass intake and assess the association with depressive symptomatology in a sample of adults with and without MDD. Methodology: Participants with and without MDD (determined using DSM 5) completed the Depression, Anxiety, and Stress Scale-21 (DASS-21). Diet history interviews were analyzed using PhenolExplorer to quantify flavonoid subclasses (flavan-3-ols, flavonols, anthocyanins, flavones, flavanones, isoflavones), and total flavonoid intake. Independent t-tests and linear regression, adjusting for age, sex, and BMI were performed. Results: Participants (n = 93; 75% female) had a mean age of 26.0 +/- 8.2 years. Participants with MDD had significantly higher DASS-depression scores (n = 44; DASS-depression 27.3 +/- 9.8) compared to participants without MDD (n = 49; DASS-depression 3.1 +/- 4.4; p < .001). Intakes of total flavonoids and subclasses were similar between groups, except for anthocyanins where participants with MDD reported lower intakes of anthocyanins compared to participants without MDD (median intake: 0.08 mg/day and 11.6 mg/day, respectively; p = .02). In the total sample, higher anthocyanin intake was associated with lower DASS-depression score (B = -4.1; SE = 1.8; 95% CI [-7.7, -0.4]; p = .029). Conclusion: Intake of total flavonoids and most subclasses were similar between people with and without MDD. However, a dietary deficit of anthocyanins (found in purple/red fruits and vegetables) was evident in participants with MDD, and higher anthocyanin intake was associated with lower depressive symptomatology in the total sample. Further research in larger samples is warranted to explore if the documented association is independent of MDD status.