Dietary Antioxidant Vitamins and Minerals and Breast Cancer Risk: Prospective Results from the SUN Cohort

Cesar I. Fernandez-Lazaro,Alfredo Gea,Andrea Romanos-Nanclares,Inmaculada Aguilera-Buenosvinos,Miguel Ruiz-Canela,Miguel Ángel Martínez-González,Estefanía Toledo

doi:10.3390/antiox10030340

Abstract

There is growing interest in natural antioxidants and their potential effects on breast cancer (BC). Epidemiological evidence, however, is inconsistent. We prospectively evaluated the association between dietary intake of vitamins A, C, and E, selenium, and zinc and BC among 9983 female participants from the SUN Project, a Mediterranean cohort of university graduates. Participants completed a food frequency questionnaire at baseline, and biennial follow-up information about incident BC diagnosis was collected. Cases were ascertained through revision of medical charts and consultation of the National Death Index. Cox proportional hazards models were used to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CI). During an average follow-up of 11.3 years, 107 incident BC cases were confirmed. The multivariable HRs (95% CI) for BC comparing extreme tertiles of energy-adjusted dietary intakes were 1.07 (0.64–1.77; Ptrend = 0.673) for vitamin A, 1.00 (0.58–1.71; Ptrend = 0.846) for vitamin C, 0.92 (0.55–1.54; Ptrend = 0.728) for vitamin E, 1.37 (0.85–2.20; Ptrend = 0.135) for selenium, and 1.01 (0.61–1.69; Ptrend = 0.939) for zinc. Stratified analyses showed an inverse association between vitamin E intake and postmenopausal BC (HRT3 vs. T1 = 0.35; 95% CI, 0.14–0.86; Ptrend = 0.027). Our results did not suggest significant protective associations between dietary vitamins A, C, and E, selenium, or zinc and BC risk.

Highlights

Cancer is currently the most common cause of premature mortality in most developed countries and ranks second in terms of global mortality, accounting for 9.6 million deaths in 2018 [1,2]
Pearson correlations between dietary intake of antioxidants and energy intake were moderate for selenium (r = 0.58), vitamin E (r = 0.57), and weaker for zinc (r = 0.36), vitamin C (r = 0.36), and vitamin A (r = 0.29)
Models were adjusted for time since recruitment until the beginning of the time at risk. -Model 2: model 1 adjusted for calcium intake, coffee consumption, fat intake (E%, continuous), When we considered luminal breast cancer (BC) as outcome, we did not find associations between levels of antioxidant vitamin or mineral intake and BC risk (Supplemental Table S2)

Summary

Introduction

Cancer is currently the most common cause of premature mortality in most developed countries and ranks second in terms of global mortality, accounting for 9.6 million deaths in 2018 [1,2]. The incidence of cancer is expected to increase as the population ages [3]. Genetic predisposition is a well-known risk factor but it is estimated that the contribution of genetic factors on cancer risk is approximately between 5% and 10%, whereas environmental and lifestyle factors may account for the remaining 90–95% of cases [5]. Cumulative lifetime exposure to oxidative damage has been suggested to be involved in both cancer initiation and progression [6]. A potentially modifiable lifestyle risk factor, may contribute up to 35% of cancer cases, which highlights opportunities for cancer incidence prevention [5]

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