Investigating the relationship between Dietary total antioxidant capacity and depression and anxiety in Iranian adults

Background & Objective: Although several studies are available linking individual dietary antioxidants to the risk of psychological disorders, data about the association of dietary total antioxidant capacity (TAC) with depression and anxiety are scarce. This study was conducted to investigate the association between dietary TAC and odds of depression and anxiety among Iranian adults. Material & Methods: In this cross-sectional study, dietary intakes of 3297 apparently healthy adults in Isfahan province, Iran, were assessed using a validated detailed food frequency questionnaire. Dietary TAC was estimated using the ferric-reducing antioxidant power (FRAP) international databases. Depression and anxiety were assessed using a validated Persian translated version of Hospital Anxiety and Depression Scale (HADS) questionnaire. Having the scores 0-7 in either subscales was considered as “normal” and the scores of 8 or more as the presence of depression or anxiety. Results: Overall, 28.6% (n= 943) of study participants were depressed or at the borderline level, and 13.6% (n= 448) had anxiety or were at the borderline level. After controlling for potential confounders, including dietary intakes of omega-3 fatty acids, we found that those in the top quintile of dietary TAC were 43% less likely to be depressed than those in the bottom category (OR: 0.57; 95% CI: 0.40-0.82, Ptrend= 0.001). Regarding anxiety, there was a significant inverse association between dietary TAC and anxiety comparing extreme quintiles (OR: 0.62; 95% CI: 0.39-0.99, Ptrend= 0.06). Conclusion: A significant inverse association between dietary TAC and odds of depression and anxiety was found among adults. Further prospective studies are required to confirm these findings.