Prospective association between dietary fiber intake and breast cancer risk.

Mélanie Deschasaux,Mathilde His,Pilar Galan,Paule Latino-Martel,Serge Hercberg,Camille Pouchieu,Mathilde Touvier,Laurent Zelek,Aamir Ahmad

doi:10.1371/journal.pone.0079718

Mélanie Deschasaux, Mathilde His + Show 7 more

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https://doi.org/10.1371/journal.pone.0079718

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Abstract

BackgroundMechanistic hypotheses suggest a potential effect of dietary fiber on breast carcinogenesis through the modulation of insulin-like growth factor bioactivity, estrogen metabolism and inflammation. An association between dietary fiber intake and breast cancer risk has been suggested in epidemiological studies but remains inconclusive. In particular, data is lacking regarding the different types of dietary fibers.ObjectiveThe objective was to investigate the prospective relationship between dietary fiber intake and breast cancer risk, taking into account different types of dietary fiber (overall, insoluble, soluble and from different food sources: cereals, vegetables, fruits and legumes).Design4684 women from the SU.VI.MAX cohort were included in this analysis as they completed at least three 24h-dietary records within the first two years of follow-up. Among them, 167 incident invasive breast cancers were diagnosed during a median follow-up of 12.6 years (between 1994 and 2007). The associations between quartiles of dietary fiber intake and breast cancer risk were characterized using multivariate Cox proportional hazards models.ResultsTotal fiber intake was not associated with breast cancer risk (HRQuartile4vs.Quartile1 = 1.29 (95%CI 0.66–2.50), P-trend = 0.5), nor was fiber intake from cereals (P-trend = 0.1), fruits (P-trend = 0.9) and legumes (P-trend = 0.3). In contrast, vegetable fiber intake was related to a decreased risk of breast cancer (HRQ4vs.Q1 = 0.50 (0.29-0.88), P-trend = 0.03). Overall vegetable intake (in g/day) was not associated with breast cancer risk (P-trend = 0.2).ConclusionThis prospective study suggests that vegetable fiber intake may contribute to reduce breast cancer risk, in line with experimental mechanistic data.

Highlights

Several mechanisms are involved in breast cancer development
Overall vegetable intake was not associated with breast cancer risk (P-trend = 0.2). This prospective study suggests that vegetable fiber intake may contribute to reduce breast cancer risk, in line with experimental mechanistic data
Insulin-resistance and its consequences such as higher insulin-like growth factor (IGFs) bioactivity [1,2] or lower sexhormone binding globulin (SHBG) [3] concentration have been associated with increased breast cancer risk in experimental [3,4] and epidemiological [5,6,7] studies

Summary

Introduction

Several mechanisms are involved in breast cancer development. First, insulin-resistance and its consequences such as higher insulin-like growth factor (IGFs) bioactivity [1,2] or lower sexhormone binding globulin (SHBG) [3] concentration have been associated with increased breast cancer risk in experimental [3,4] and epidemiological [5,6,7] studies. Mechanistic hypotheses support a role for dietary fiber in the prevention of breast cancer through a reduction of IGFs bioactivity, notably by increasing insulin-like growth factor binding protein 3 (IGFBP3) concentration [14,15]; an influence on steroid hormone concentrations by decreasing circulating estrogens [16] and upregulating SHBG concentrations [17] and a reduction of inflammation, thanks to the production of short-chain fatty acid (SCFA) by colonic fermentation [18,19,20,21]. Two meta-analyses of prospective studies have been published, suggesting a decreased breast cancer risk associated with dietary fiber intake [23,24]. Mechanistic hypotheses suggest a potential effect of dietary fiber on breast carcinogenesis through the modulation of insulin-like growth factor bioactivity, estrogen metabolism and inflammation. Data is lacking regarding the different types of dietary fibers

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