Association of Dietary Total Antioxidant Capacity with Cancer Recurrence and Mortality among Breast Cancer Survivors: A Prospective Cohort Study

Abstract

Antioxidants decrease the risk of breast cancer by reducing oxidative stress, but the association between dietary total antioxidant capacity (DTAC) and cancer recurrence has not yet been investigated. The present study aimed to test the hypothesis that DTAC is inversely associated with cancer recurrence and mortality in breast cancer patients. Breast cancer patients (n = 603) who underwent breast cancer surgery and a dietary survey within 5 years after surgery were recruited. This study observed disease-free survival (DFS) and mortality in breast cancer patients according to DTAC calculated based on 24-hr dietary recall. Total DTAC was significantly lower in patients with cancer recurrence than in those without. DFS was positively associated with the total DTAC (p = 0.005) and DTAC of vegetables and legumes (p = 0.001 and p = 0.010), respectively. However, total DTAC was not associated with mortality. Cox proportional hazards regression analysis showed that total DTAC (HR: 0.44, 95% CI 0.26-0.94) and DTAC of vegetables (HR: 0.30, 95% CI 0.14-0.65) and legumes (HR: 0.38, 95% CI 0.18-0.73) were inversely associated with cancer recurrence after adjusting for confounding factors. This study was the first to indicate that total DTAC and DTAC of vegetables and legumes could be beneficial in decreasing breast cancer recurrence.