Dietary phytoestrogen intake—lignans and isoflavones—and breast cancer risk (Canada)

Abstract

Lignan intake may be associated with reduced breast cancer risk among pre-menopausal women, and our data suggest BMI modifies this association.

Dietary intakes and food sources of phytoestrogens in the European Prospective Investigation into Cancer and Nutrition (EPIC) 24-hour dietary recall cohort

“…Non-MED countries had slightly higher, though still relatively low levels of estimated isoflavone intake (0.76 mg/day), which is comparable to other reported data (from 0.23 to 0.96 mg/day). 4,34,35,43 These low intakes are consistent with estimates for other Western countries such as Canada (0.31 mg/day) 20 and US (around 1.1 mg/day). 37,44 In the UK general population, the isoflavone intake was also higher (2.34 mg/day) compared with other European countries because of the addition of soy flour to regular flour used in baking.…”

“…51 In other Western countries such as Mexico, US and Canada, lignan intakes were much lower than our results (from 0.35 to 0.86 mg/day). 20,37,52 To our knowledge, there are not descriptive data on dietary lignan intake in Asian populations, but probably their contribution to the total phytoestrogen intake would be low like in our UK health-conscious group (o16%). Several papers have reported on intakes of secoisolariciresinol and matairesinol, 34,60 but most of them did not consider lariciresinol and pinoresinol, which contributed 470% to the total lignans in our cohort.…”

“…MED countries had the lowest phytoestrogen intake (1.52 mg/day), followed by non-MED countries (2.11 mg/day) and UK general population (4.04 mg/day), showing similar results as those published in individual European countries, such as The Netherlands, 34 Sweden 35,36 and UK 4 (0.58-3.17 mg/day), and in the US (1.11-2.02 mg/day) 37 or Canada (1.17 mg/day). 20 The UK health-conscious cohort is made up predominantly of lacto-ovo vegetarians and vegans; therefore they consume more plant foods, especially soy products that are the most abundant food sources of phytoestrogens. 33 Despite this, phytoestrogen intake was not statistically associated with healthy lifestyle characteristics, such as be active physical activity or never smoker, in the whole cohort.…”

“…[14][15][16][17][18] Few descriptive articles exist on lignans, 19,20 and even fewer are available to date on coumestans, enterolignans and equol intakes, especially in Europe. 4 Moreover, the assessment methods used in these studies have been quite heterogeneous and some used old food composition databases (FCDB), so it is straightforward comparing phytoestrogen intakes.…”

Clinical and Ultrasonographic Changes of the Breast after Use of Soy Isoflavones

“…However, most studies have showed a lowering effect of PEs over breast carcinogenesis. Significantly reduced tumor growth after consumption of genistein and soy extracts in the mouse (Kim et al, 2008), better prognosis in breast cancer patients with higher plasma genistein levels (Iwasaki et al, 2008), higher frequency of ER and PR positivity, resulting probably in better cancer prognosis (Zhang et al, 2010), overall decrease in premenopausal breast cancer (Morimoto et al, 2012) -merely in overweight women (Cotterchio et al, 2008)-or postmenopausal disease (Goodman et al, 2009;Buck et al, 2010;Anderson et al, 2012;Zaineddin et al, 2012) -especially ER+PR+ tumors (Anderson et al, 2012) with more frequent use of PE, have all been detected in different valuable studies.…”