Association between dietary total antioxidant capacity and breast cancer: a case-control study in a Middle Eastern country

Objective: The aim of this study was to determine the relationship between dietary total antioxidant capacity (dTAC) and risk of breast cancer among Iranian women. Design: In this hospital-based case-control study, dietary intake of participants was collected using a 168-item validated FFQ. Dietary TAC was assessed using FRAP assay considering. Logistic regression was used to obtain ORs for breast cancer across quartiles of dTAC. Setting: Cancer Institute, Iran. Participants: We included 412 women with pathologically confirmed breast cancer and 456 apparently healthy controls. Results: Mean dTAC was 11 center dot 3 +/- 5 center dot 8 for cases and 12 center dot 1 +/- 7 center dot 9 for controls. A trend towards significant inverse association was seen between dTAC and odds of breast cancer in the whole population; such that after controlling for several potential confounders, individuals in the highest quartile of dTAC were 0 center dot 39 times less likely to have breast cancer than those in the lowest quartile (0 center dot 61; 95 % CI: 0 center dot 38, 0 center dot 99, P < 0 center dot 05). In the stratified analysis by menopausal status, we found that postmenopausal women with the greatest dTAC had lower odds for breast cancer, compared with those with the lowest dTAC (0 center dot 47; 95 % CI: 0 center dot 24, 0 center dot 93, P < 0 center dot 05). This association strengthened after additional adjustment for BMI (0 center dot 28; 95 % CI: 0 center dot 11, 0 center dot 72, P < 0 center dot 05). No significant association was seen between dTAC and odds of breast cancer in premenopausal women. Conclusions: We found that dietary TAC was inversely associated with risk of breast cancer, in particular among postmenopausal women. Prospective cohort studies are needed to confirm these findings.