Association between total dietary antioxidant capacity and food groups and incidence of depression in a cohort of Brazilian graduates (CUME Project).

This study aims to evaluate the association between Dietary Total Antioxidant Capacity (dTAC) and Total Antioxidant Capacity of food groups (fgTAC) with the incidence of depression in Brazilian graduates participating in the Cohort of Universities of Minas Gerais (CUME Study). The sample consisted of 2572 participants without a medical diagnosis of depression at baseline who responded to at least one follow-up questionnaire from the CUME Project. The Ferric Reducing Antioxidant Power assay was used to determine dTAC. Incidence of depression was estimated by self-reported medical diagnosis of depression during the years of cohort follow-up. Cox regression models were used to relate dTAC and fgTAC to the incidence of depression. The mean follow-up time was 2·96 (1·00) years, and 246 cases of depression were observed (32·3/1000 person-years). The mean dTAC was 11·03 (4·84) mmol/d. We found no associations between higher dTAC and lower risk of developing depression after adjusting for possible confounders. The incidence of depression was inversely associated with fgTAC of the beans and lentils group (hazard ratio (HR): 0·61; 95 % CI 0·41, 0·90). The fgTAC of the junk food group was positively associated with higher incidence of depression after all adjustments (HR: 1·57; 95 % CI 1·08, 2·26). Our findings do not support an association between dTAC and the incidence of depression in a highly educated Brazilian population. However, associations of fgTAC show the importance of analysing the food matrix in which these antioxidants are inserted. We highlight the need for more prospective studies with different nationalities to confirm these results.