Dietary Total Antioxidant Capacity and Colorectal Cancer in the Italian EPIC Cohort.

Marilena Monica Vece,Claudia Agnoli,Rosario Tumino,Fulvio Ricceri,Nicoletta Pellegrini,Valeria Pala,Benedetta Bendinelli,Carlotta Sacerdote,Sara Grioni,Vittorio Krogh,Graziella Frasca,Sabina Sieri,Amalia Mattiello,Salvatore Panico,Giovanna Masala,Giovanna Bermano

doi:10.1371/journal.pone.0142995

Abstract

BackgroundColorectal cancer is the third most common cancer worldwide. Diet has been hypothesized as involved in colorectal cancer etiology, but few studies on the influence of total dietary antioxidant intake on colorectal cancer risk have been performed.MethodsWe investigated the association between colorectal cancer risk and the total antioxidant capacity (TAC) of the diet, and also of intake of selected antioxidants, in 45,194 persons enrolled in 5 centers (Florence, Naples, Ragusa, Turin and Varese) of the European Prospective Investigation into Cancer and Nutrition (EPIC) Italy study. TAC was estimated by the Trolox equivalent antioxidant capacity (TEAC) assay. Hazard ratios (HRs) for developing colorectal cancer, and colon and rectal cancers separately, adjusted for confounders, were estimated for tertiles of TAC by Cox modeling, stratifying by center.ResultsFour hundred thirty-six colorectal cancers were diagnosed over a mean follow-up of 11.28 years. No significant association between dietary TAC and colorectal cancer incidence was found. However for the highest category of TAC compared to the lowest, risk of developing colon cancer was lower (HR: 0.63; 95% CI: 0.44–0.89, P trend: 0.008). By contrast, increasing TAC intake was associated with significantly increasing risks of rectal cancer (2nd tertile HR: 2.09; 95%CI: 1.19–3.66; 3rd tertile 2.48 95%CI: 1.32–4.66; P trend 0.007). Intakes of vitamin C, vitamin E, and ß-carotene were not significantly associated with colorectal cancer risk.ConclusionsFurther prospective studies are needed to confirm the contrasting effects of high total antioxidant intake on risk of colon and rectal cancers.

Highlights

In 2012, colorectal cancer was the third most common cancer worldwide in men, with about 746,000 cases diagnosed, and the second most common cancer in women with about 614,000 cases diagnosed [1]
We investigated the association between colorectal cancer risk and the total antioxidant capacity (TAC) of the diet, and of intake of selected antioxidants, in 45,194 persons enrolled in 5 centers (Florence, Naples, Ragusa, Turin and Varese) of the European Prospective Investigation into Cancer and Nutrition (EPIC) Italy study
For the highest category of TAC compared to the lowest, risk of developing colon cancer was lower (HR: 0.63; 95% confidence interval (CI): 0.44–0.89, P trend: 0.008)

Summary

Introduction

In 2012, colorectal cancer was the third most common cancer worldwide in men, with about 746,000 cases diagnosed, and the second most common cancer in women with about 614,000 cases diagnosed [1]. The panel of the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) [2] reported that there is ‘convincing’ evidence that foods high in dietary fiber protect against colorectal cancer, and that consumption of red meat, processed meat and alcohol (especially in men) increase the risk of developing colorectal cancer. Foods of plant origin contain various antioxidants [5, 6] Those with high antioxidant content include coffee, chocolate, berries, vegetables of the brassica family, red wine, and wholegrain cereals [7,8,9]; and these have been proposed as protective against cancer, in part because antioxidants counteract free radicals in the body [10, 11]. Diet has been hypothesized as involved in colorectal cancer etiology, but few studies on the influence of total dietary antioxidant intake on colorectal cancer risk have been performed

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Results

Conclusion