Dietary total anti-oxidant capacity is inversely related to the prevalence of depression in adolescent girls

BACKGROUND: Oxidative stress is considered to be a contributory factor for depression, and is affected by the dietary intake of pro-and anti-oxidants. Dietary total antioxidant capacity (DTAC) is an index which is applied to estimate the cumulative power of antioxidants in the whole diet. The aim of this study was to determine the relationship between DTAC and prevalence of depression in adolescent girls. METHODS: A total of 741 Iranian adolescent girls aged 12–18 years were recruited into this cross-sectional study. Dietary intake and depression severity score were assessed using a food frequency questionnaire and Beck's depression inventory, respectively. To estimate the DTAC, the oxygen radical absorbance capacity method was used for selected foods. To explore the associations between DTAC and depression, logistic regression was applied using crude and adjusted models. RESULTS: Individuals in the greatest adherence to high DTAC had more intakes of whole grains, legumes, fruits, dried fruits, low fat dairy products, cruciferous vegetables, fiber, magnesium, vitamin C, folate, potassium, zinc, β-carotene, lutein, thiamin, riboflavin, niacin and vitamin B-6 and lower consumption of refined grains. Subjects in the highest quartile of DTAC had a 39% lower odds of depression compared to those in the first quartile (OR = 0.61; 95% CI: 0.38–0.97, P for trend = 0.012); these associations remained significant after adjustments in first, second and third (OR = 0.5; 95% CI: 0.28–0.92, P for trend < 0.001) adjusted models. CONCLUSIONS: An inverse association was observed between the DTAC and the prevalence of depression in our population sample of adolescent girls. Further research needs to be conducted in different areas, including longitudinal studies with larger sample sizes.