Dietary Total Antioxidant Capacity and Odds of Breast Cancer: A Case-Control Study.

Breast cancer (BC) is the most frequently diagnosed female cancer worldwide. It has been shown that oxidative stress can contribute to cancer development. Therefore, we investigated the association between dietary total antioxidant capacity (TAC) and breast cancer risk in a case-control study. This study was conducted on 136 newly diagnosed breast cancer patients and 272 hospitalized controls in Tehran, Iran. Participant habitual diet was obtained using a 168-item validated food frequency questionnaire. Dietary TAC scores were computed using two different methods: the dietary ferric reducing antioxidant potential (FRAP) method and oxygen radical scavenging capacity (ORAC). The association between dietary TAC and breast cancer risk was estimated by logistic regression. The score of DTAC calculated by ORAC method was associated with lower odds of BC, especially among premenopausal women. However, this association was not significant after controlling potential confounders (ORAC: OR Q4-Q1 = 1.01, 95% CI = 0.42-2.44, p-trend = 0.96). Estimation of DTAC by FRAP method was not associated with the risk of BC (FRAP: OR Q4-Q1 = 1.04, 95% CI = 0.53-2.05, p-trend = 0.8). There were no association detected based on menopausal status. In this study, dietary TAC was not significantly related to the odds of breast cancer.