Dietary diversity and Depression: Cross-sectional and longitudinal analyses in Spanish adult population with Metabolic Syndrome. Findings from PREDIMED-PLUS Trial

Objective: To examine the cross-sectional and longitudinal (2-year follow-up) associations between Dietary Diversity (DD) and depressive symptoms. Design: An energy-adjusted Dietary Diversity Score (DDS) was assessed using a validated food-frequency questionnaire and was categorized into quartiles (Q). The variety in each food group was classified into 4 categories of diversity (C). Depressive symptoms were assessed with Beck Depression Inventory-II (Beck II) questionnaire and depression cases defined as physician-diagnosed or Beck II>=18. Linear and logistic regression models were used. Setting: Spanish older adults with Metabolic Syndrome. Participants: A total of 6625 adults aged (55-75 years) from the PREDIMED-Plus study with overweight or obesity and MetS. Results: Total DDS was inversely and statistically significantly associated with depression in the cross-sectional analysis conducted; Odds Ratio (OR) Q4 vs Q1= 0.76 (95% confidence interval (CI): 0.64, 0.90). This was driven by high diversity compared to low diversity (C3 vs. C1) of vegetables [OR (95%CI) = 0.75 (0.57, 0.93)], cereals [OR (95%CI) = 0.72 (0.56-0.94)] and proteins [OR (95%CI) = 0.27 (0.11, 0.62)]. In the longitudinal analysis, there was no significant association between the baseline DDS and changes in depressive symptoms after 2 y- of follow-up, except for DD in vegetables C4 vs C1= [β (95%CI) = 0.70 (0.05, 1.35)]. Conclusions: According to our results, DD is associated with the presence of depressive symptoms but eating more diverse does not seem to reduce the risk of future depression. Additional longitudinal studies (with longer follow-up period) are needed to confirm these findings.