Correlates of Soy Food Consumption in Women at Increased Risk for Breast Cancer

Abstract

ObjectivesThe objectives of the present study were to examine sociodemographic correlates of soy food con sumption among women at increased risk of breast can cer, describe factors influencing soy food consumption or nonconsumption, and identify women's sources of infor mation about soy foods. Design A cross-sectional, self-report survey was used to assess frequency of and factors influencing soy food con sumption. Soy food intake was reported for the past year. Subjects/setting Participants were 452 women with family histories of breast cancer who were enrolled in a cancer risk assessment program. Statistical analyses performed Comparisons between con sumers and nonconsumers of soy foods were performed using multivariate logistic regression and � 2 analyses. Results Thirty-two percent reported soy food consumption. Commonly consumed soy foods were vegetable burgers, tofu, and soymilk. Consumers of soy foods were more likely to have higher levels of education and report eating five or more daily servings of fruits and vegetables. The primary reason for consumption of soy foods was eating a healthful diet, whereas insufficient knowledge about soy food preparation was the primary reason stated for noncon sumption. Both consumers and nonconsumers reported ob taining information about soy foods from magazines, friends, and newspapers. Consumers also indicated using the Internet to seek information. Conclusions These findings contribute to our understand ing of the level of soy intake among women at increased risk for breast cancer and highlight potential factors that may influence women's decisions regarding soy food con sumption. Women, particularly in this vulnerable popu lation, would benefit from clear messages regarding the health effects of soy. C. Y. Fang is an associate member, M. Tseng is an asso The promise of health benefits from soy has contributed to the recent increase in the availability of soy-contain ing foods (1,2). Since 1995, sales of soy-based products have increased 20% per year, with a large boost in 1999 when the US Food and Drug Administration approved a health claim for soy's cardiovascular benefits (3). Largescale dietary trends toward vegetarianism and ready-to-eat meals are also driving an increase in the consumption of soy-based meat alternatives (4,5). As a result, soy foods are moving rapidly from a niche market to mainstream accep tance.Given recent studies reporting an inverse relationship between soy intake and breast cancer risk (6-8), awareness and use of soy foods may be particularly high among women at increased risk for breast cancer. Likewise, beliefs about the benefits of soy in reducing menopausal symptoms may motivate women at risk for breast cancer who are peri menopausal or postmenopausal to try alternatives to estro gen to treat menopausal symptoms (9). However, despite the widespread promotion of soy and evidence of its health benefits with respect to heart disease risk, its effects on breast health, especially in non-Asian women, are un known. Indeed, studie...

Food Frequency Questionnaires and Overnight Urines Are Valid Indicators of Daidzein and Genistein Intake in U.S. Women Relative to Multiple 24-h Urine Samples

“…In a previous analysis (12) we found that respondents to the SFQ were slightly older than nonrespondents (mean age = 42 vs. 41 yr) and more likely to be college educated (66% vs. 57%), but they were similar with respect to other demographic characteristics and health behaviors. We observed no significant differences in demographic characteristics or health behaviors, including isoflavone intake, between SFQ respondents (N = 451) and subsample subjects (N = 27).…”

“…Possibly, these women have controlled their soy intake as a result of concerns about the estrogenic effects of isoflavones. In a previous analysis, however, only 7% of nonconsumers wrote that they avoided soy foods for this reason (12). In our previous analysis, we found that not knowing how to prepare soy foods and disliking the taste of soy foods were the primary reasons for their nonconsumption (12).…”

“…In a previous analysis, however, only 7% of nonconsumers wrote that they avoided soy foods for this reason (12). In our previous analysis, we found that not knowing how to prepare soy foods and disliking the taste of soy foods were the primary reasons for their nonconsumption (12). These reasons are the most likely explanations for our subjects' generally low level of isoflavone intake and for their more frequent consumption of vegetable burgers in favor of richer but less familiar isoflavone sources such as tofu.…”

“…A detailed description of the SFQ has been provided previously (12). Briefly, the SFQ followed the format of the DAF.…”

Genistein-induced differentiation of breast cancer stem/progenitor cells through a paracrine mechanism

“…Generally, GEN is developed and used as a protein tyrosine kinase inhibitor and an ER agonist to block PI3K/Akt activation. Nevertheless, with treatment of GEN, the level of phospho-Akt 308/473 expression in soloculture mammosphere cells does not differ according to our study, which means the inhibition of PI3K/Akt signaling by GEN in breast cancer is probably mediated by ER (30) or the concentration of GEN is not appropriate for suppression (45). Given that mammosphere cells from MDA-MB-231 cells lack ER and PR expression (46,47), GEN as a kind of phytoestrogen could not bind to ER to have antiproliferative effects by reduction of PI3K/Akt signaling.…”