Intakes of plant foods, fibre and fat and risk of breast cancer – a prospective study in the Malmö Diet and Cancer cohort

Abstract

The objective of this study was to investigate prospectively the associations between intakes of plant foods, fibre and relative fat and risk of breast cancer in a subsample of 11 726 postmenopausal women in the Malmö Diet and Cancer cohort. Data were obtained by an interview-based diet history method, a structured questionnaire, anthropometrical measurements and national and regional cancer registries. During 89 602 person-years of follow-up, 342 incident cases were documented. Cox regression analysis examined breast cancer risks adjusted for potential confounders. High fibre intakes were associated with a lower risk of postmenopausal breast cancer, incidence rate ratio ¼ 0.58, 95% CI: 0.40, 0.84, for the highest quintile of fibre intake compared to the lowest quintile. The combination high fibre -low fat had the lowest risk when examining the effect in each cell of cross-classified tertiles of fibre and fat intakes. An interaction (P ¼ 0.049) was found between fibre-and fat-tertiles. There was no significant association between breast cancer risk and intakes of any of the plant food subgroups. These findings support the hypothesis that a dietary pattern characterised by high fibre and low fat intakes is associated with a lower risk of postmenopausal breast cancer.

Dietary Carbohydrate, Fiber and Sugar and Risk of Breast Cancer According to Menopausal Status in Malaysia

“…Protective effects of dietary fiber towards breast cancer shown in our study were in line with previous findings among premenopausal (Cade et al, 2007) and postmenopausal women (Mattisson et al, 2004;Park et al, 2009). A significant 69% reduction in premenopausal breast cancer risk and 77% reduction in postmenopausal breast cancer risk were observed with an intake more than 17 g/day of dietary fiber.…”

“…The same pattern was also observed in a case control study in USA among premenopausal women (Li et al, 2013). Among postmenopausal women, the Malmo Diet and Cancer Cohort found that 25 g/day of dietary fiber can lower breast cancer risk by 42% (IRR=0.58; 95%CI: 0.40-0.84) (Mattisson et al, 2004). Consistently, the NIH-AARP Diet and Health Study found that dietary fiber intake in the highest quintiles can lower postmenopausal breast cancer risk by 13% (RR=0.87; 95%CI: 0.77-0.98) (Park et al, 2009).…”

“…Concurrently, there have been striking changes in mortality rates of breast cancer among other cancers which lagged around 10 years from the beginning of the nutrition transition towards a westernized diet in selected geographical location in East Asia (Zhang et al, 2012). In the past decade, dietary carbohydrate, fiber and sugar has gained much attention in relation towards breast cancer risk according to menopausal status, but studies have been limited in developed countries (Cho et al, 2003;Holmes et al, 2004;Romieu et al, 2004;Mattisson et al, 2004;Nielsen et al, 2005;Giles et al, 2006;Cade et al, 2007;Lajous et al, 2008;Suzuki et al, 2008;Larsson et al, 2009;Wen et al, 2009;Park et al, 2009;Shikany et al, 2011;Zaineddin et al, 2012;Ferrari et al, 2013;Li et al, 2013;Woo et al, 2013). A few studies have appeared from South-East Asia and Eastern Europe (Kruk and Marchlewicz, 2013;Sangrajrang et al, 2013).…”

Maternal dietary exposure to fiber during pregnancy and mammary tumorigenesis among rat offspring

“…8,9 However, most prospective human studies have not shown an association between dietary fiber intake and risk of developing breast cancer, 10 with few exceptions. 11 Animal studies suggest that the type of fiber may be critical 12 : these studies have reported a reduction in carcinogenesis (including in the breast) in animals fed wheat bran. [12][13][14][15] Fiber originating from flaxseed also has been associated with reduced carcinogenesis.…”

Nutrients and nipple aspirate fluid composition: the breast microenvironment regulates protein expression and cancer aetiology

“…Recently, it was reported that dietary fibre intake may reduce the probability of yielding NAF enriched of epithelial cells, limiting the breast ductal cell proliferation and its turnover [25]. Likewise, an inverse association between dietary fibre intake and BC risk was observed in some cohorts and case-control studies (reviewed in [34]); dietary fibre has been postulated to inhibit intestinal reabsorption of excreted biliary estrogens, limiting the increased stimulation of NAF prolactin and steroids due to increased dietary fat intake [28]. Such hormonal stimulation of the breast may also affect mammary epithelial cells, because supplementation of foods with compounds displaying weak estrogenic properties (such as the isoflavones genistein and daidzein from soy proteins) was shown to increase not only breast fluid secretion but also the appearance of hyperplastic epithelial cells in NAF, as well as plasma estradiol levels, suggesting that plant isoflavones may act directly on breast epithelial cells lining ducts [33,45].…”