Soy Consumption Research Articles

Association between Dietary Factors and Breast Cancer Risk among Chinese Females: Systematic Review and Meta-analysis

Evidence for associations between dietary factors and breast cancer risk is inconclusive among Chinese females. To evaluate this question, we conducted a systematic review of relevant case-control and cohort studies. Studies were systematically searched among 5 English databases (PudMed, ScienceDirect, Wiley, Clinicaltrials.gov, and Cochrane) and 3 Chinese databases (CNKI, WanFang, and VIP) until November 2012. Random effects models were used to estimate summary odds ratios (ORs) and the corresponding 95% confidence intervals (CIs). Thirty one case-control studies and two cohort studies involving 9,299 cases and 11,413 controls were included. Consumption of both soy and fruit was significantly associated with decreased risk of breast cancer, with summary ORs of 0.65 (95% CIs: 0.43-0.99; I2=88.9%, P<0.001; N=13) and 0.66 (95% CIs: 0.47-0.91; I2=76.7%, P<0.001; N=7), respectively. Consumption of fat was significantly associated with increased risk of breast cancer (OR=1.36; 95% CIs: 1.13-1.63; I2=47.9%, P=0.088; N=6). There was non- significant association between consumption of vegetables and breast cancer risk (OR=0.72; 95% CIs: 0.51-1.02; I2= 74.4%, P<0.001; N=9). However, sensitivity analysis based on adjusted ORs showed decreased risk of breast cancer was also associated with consumption of vegetables (OR=0.49; 95% CIs: 0.30-0.67). Both soy food and fruit are significantly associated with decreased risk of breast cancer among Chinese females, and vegetables also seems to be protective while dietary fatexerts a promoting influence.

Soy consumption and its relation with heart diseases and cancer prevention

Soybean is a subtropical annual plant, a species of legumes native to Southeast Asia. It is considered as a member of a pea family that is widely grown due to its edible beans that are processed to be used in in making foods and food additives. There are many categories of soy protein which can be divided into different types according to the production methods to isolate, concentrate, and texture soy protein. Soy is one of those wonder foods; the issue of whether soybean has negative of positive effects on the health has been a continuing question; the potential effects of soybean, the health detriments or benefits of it remain a controversial issue. Extensive researches have been conducted to investigate the health effects of using soybean products, some of them admitted the soybean products ability in preventing a wide range of many diseases especially heart diseases and different types of cancer, while others found that soy products have no effect or negative effects on health. Despite all pro-soy studies, a controversy about soy products positive and negative effects still exist, and people are left with a choice whether they should consume soybean or not.

A possible cause of Alzheimer’s dementia – Industrial soy foods

Alzheimer’s data indicate that at present, approximately one new case of this form of dementia is identified in the USA every 68s and that by 2050 the incidence will be about every 33s, with projections from the Alzheimer Association (USA) indicating that nearly 25% of Americans will be affected by Alzheimer’s dementia by 2031. Despite the numerous advances in medical science and neurological research, the causes are still unknown and the incidence is not decreasing or levelling out. Most research on the causes of Alzheimer’s dementia indicates the possible roles of viruses, obesity, physical inactivity, diabetes, psychological depression, high blood pressure, frequent inflammation, environmental or domestic chemicals and toxins, or inescapable genetic factors. Alzheimer’s, being the degeneration of parts of the neural pathways in the brain, may indeed involve neuro-toxic compounds that can bypass the blood–brain barrier. Therefore, it is necessary to examine what is prolific in the environment and, in particular, the food supply. One of the many suggestions in the literature is the ingestion of food items derived from unfermented soybean products; the anti-thyroid, anti-nutrient, and endocrine disruption properties of soy can have a deleterious effect in many individuals. Among the many theories and different factors that may be involved in dementiae, soy consumption may be a significant contributor to Alzheimer’s dementia, and it cannot be excluded as a possible contributing cause. Our hypothesis argues that consumption of soy food products may contribute to the increasing incidence of Alzheimer’s dementia and other dementiae.

Anemia and Iron Deficiency in Children

The aim of this study was to study the relative contribution of dietary sources of iron in children with high prevalence of anemia and iron deficiency (ID). A cross-sectional study in 263 healthy, 1.5- to 6-year-old children in the Jewish sector of Jerusalem, Israel. Venous blood samples and a qualitative Food Frequency Questionnaire on iron-rich foods were obtained. Anemia was defined as hemoglobin <11 g/dL for children younger than 4 years and <11.5 g/dL for children older than 4 years; ID was defined as ferritin <12 μg/L. Anemia was found in 11.2%, ID in 22%, and iron-deficiency anemia in 3.7%. The prevalence of anemia was higher in toddlers ages 1.5 to 3 years compared with children ages 3 to 6 years (17.7% vs 7.3%, P = 0.01). Children with extremely low red meat consumption (seldom) had 4-fold higher rates of ID than those who consumed ≥2 times per week (odds ratio 3.98; 95% confidence interval 1.21-13.03; P = 0.023), whereas poultry consumption was not associated with ID. Soy consumption was inversely associated with ferritin (marginally significant, r = -0.134, P = 0.057). The high prevalence of anemia and ID found in this study, mainly in children 1.5 to 3 years old, is related to low red meat consumption. The characteristically high poultry consumption in the Israeli population was not protective. The shift toward reduced red meat consumption and higher poultry consumption in developed countries may result in increasing the risk of ID.

Soy, Red Clover, and Isoflavones and Breast Cancer: A Systematic Review

BackgroundSoy and red clover isoflavones are controversial due to purported estrogenic activity and possible effects on breast cancer. We conducted a systematic review of soy and red clover for efficacy in improving menopausal symptoms in women with breast cancer, and for potential impact on risk of breast cancer incidence or recurrence.MethodsWe searched MEDLINE, Embase, the Cochrane Library, and AMED from inception to March 2013 for human interventional or observational data pertaining to the safety and efficacy of soy and red clover isoflavones in patients with or at risk of breast cancer. ResultsOf 4179 records, we included a total of 131 articles: 40 RCTs, 11 uncontrolled trials, and 80 observational studies. Five RCTs reported on the efficacy of soy for hot flashes, showing no significant reductions in hot flashes compared to placebo. There is lack of evidence showing harm from use of soy with respect to risk of breast cancer or recurrence, based on long term observational data. Soy intake consistent with that of a traditional Japanese diet (2-3 servings daily, containing 25-50mg isoflavones) may be protective against breast cancer and recurrence. Human trials show that soy does not increase circulating estradiol or affect estrogen-responsive target tissues. Prospective data of soy use in women taking tamoxifen does not indicate increased risk of recurrence. Evidence on red clover is limited, however existing studies suggest that it may not possess breast cancer-promoting effects. ConclusionSoy consumption may be associated with reduced risk of breast cancer incidence, recurrence, and mortality. Soy does not have estrogenic effects in humans. Soy intake consistent with a traditional Japanese diet appears safe for breast cancer survivors. While there is no clear evidence of harm, better evidence confirming safety is required before use of high dose (≥100mg) isoflavones can be recommended for breast cancer patients.

Intake of Specific Nonfermented Soy Foods May Be Inversely Associated with Risk of Distal Gastric Cancer in a Chinese Population

Because the association between soy consumption and gastric cancer is inconsistent, we evaluated the putative preventive effect of soy food on gastric cancer risk in the Shanghai Women's and Men's Health Studies, comprising a total of 128,687 participants. Intake of nonfermented soy foods was estimated using 2 validated food-frequency questionnaires. HRs were calculated with 95% CIs for intake amounts of total nonfermented soy food intake, soy protein, and isoflavones as well as individual soy food groups using Cox proportional hazards regression. A total of 493 distal gastric cancer cases were identified by 2010. Although all risk estimates for summary measures of soy food intake above the lowest quartile (quartile 1) were suggestive of a protective effect, no statistically significant associations with risk of distal gastric cancer were found. Among the separate soy food groups, significant reductions in risk of distal gastric cancer by increasing intake of tofu were found in men in quartile 2 (HR: 0.59; 95% CI: 0.40, 0.86), quartile 3 (HR: 0.62; 95% CI: 0.44, 0.88), and quartile 4 (HR: 0.64; 95% CI: 0.42, 0.99), resulting in a significant trend (P-trend = 0.02). Dry bean intake was also inversely associated with decreased risk of gastric cancer, but in postmenopausal women only [quartile 2 (HR: 0.54; 95% CI: 0.30, 0.96); quartile 3 (HR: 0.90; 95% CI: 0.64, 1.27); and quartile 4 (HR: 0.63; 95% CI: 0.43, 0.91)], resulting in a significant trend (P-trend = 0.03). Overall, our study found no statistically significant association between nonfermented soy food intake and distal gastric cancer risk, though the data supported the hypothesis that tofu may protect against distal gastric cancer in men and dry bean consumption may decrease the risk of gastric cancer in postmenopausal women.

Molecular Pathways: Estrogen Pathway in Colorectal Cancer

Worldwide, colorectal cancer has a higher incidence rate in men than in women, suggesting a protective role for sex hormones in the development of the disease. Preclinical data support a role for estrogen and its receptors in the initiation and progression of colorectal cancer and establishes that protective effects of estrogen are exerted through ERβ. Hormone replacement therapy (HRT) in postmenopausal women as well as consumption of soy reduces the incidence of colorectal cancer. In the Women's Health Initiative trial, use of HRT in postmenopausal women reduced the risk of colon cancer by 56% [95% confidence interval (CI), 0.38-0.81; P = 0.003]. A recent meta-analysis showed that in women, consumption of soy reduced the risk of colon cancer by 21% (95% CI, 0.03-0.35; P = 0.026). In this review, using the preclinical data, we translate the findings in the clinical trials and observational studies to define the role of estrogen in the prevention of colorectal cancer. We hypothesize that sometime during the tumorigenesis process ERβ expression in colonocytes is lost and the estrogen ligand, HRT, or soy products, exerts its effects through preventing this loss. Thus, in the adenoma-to-carcinoma continuum, timing of HRT is a significant determinant of the observed benefit from this intervention. We further argue that the protective effects of estrogen are limited to certain molecular subtypes. Successful development of estrogen modulators for prevention of colorectal cancer depends on identification of susceptible colorectal cancer population(s). Thus, research to better understand the estrogen pathway is fundamental for clinical delivery of these agents.

Habitual Consumption of Soy Products and Risk of Nasopharyngeal Carcinoma in Chinese Adults: A Case-Control Study

Background and ObjectivesMany studies have shown a negative association between the consumption of soy products and the risk of some cancers, but little is known about the effect of soy consumption on nasopharyngeal carcinoma. We assessed the association between the consumption of soy products on nasopharyngeal carcinoma risk in Chinese individuals.MethodsThis case-control study included 600 (448 males and 152 females) incident cases of nasopharyngeal carcinoma, and an equal number of controls, matched according to gender, age (± 3 y) and household type to the nasopharyngeal carcinoma cases. All subjects were recruited from hospitals in Guangzhou, China. A face-to-face interview was conducted with each study individual to collect general information and habitual dietary intake using a 78-item quantitative food-frequency questionnaire. Odds ratios and their 95% confidence intervals were estimated using conditional logistic regression analyses.ResultsThe median intakes of soy foods (in protein) were 0.5/0.5, 1.4/1.7, 2.7/3.3 and 6.1/7.7 (male/female) g/d in the quartiles 1 to 4. Both univariate and multivariate analyses showed no significant association between the consumption of soy proteins or soy isoflavones and the risk of nasopharyngeal carcinoma. The adjusted odds ratios (95% confidence intervals) between extreme quartiles were 0.97 (0.66-1.45) for soy proteins and 0.97 (0.66-1.42) for total isoflavones. Null associations were also observed between intake of the individual isoflavones daidzein, genistein and glycitein and NPC risk, with adjusted odds ratios for the extreme quartiles ranging between 0.73 and 1.23.ConclusionHabitual consumption of soy products had no significant effect on the risk of nasopharyngeal carcinoma in Chinese adults with a relatively low intake.

Versatile and cheap: a global history of soy in the first half of the twentieth century

AbstractThis article traces the complex and shifting organization of soy's production and consumption from Northeast China to Europe and the United States. It focuses on a set of national and transnational actors with differing interests in the global and national spread of soybeans. The combination of these actors in certain spatiotemporal contexts enabled a fundamental change in soy from an Asian to an American cash crop. At the beginning of the twentieth century, soy rapidly became Northeast China's cash crop, owing to steadily increasing Western demand. However, the versatility of soy – and soy oil in particular – offered a highly successful response to the agricultural and industrial challenges that the United States faced during the Great Depression and the Second World War. By the end of the war, American farmers in the Midwest cultivated more soybeans than their Chinese counterparts.

Phthalates and the diets of US children and adolescents

BackgroundDi-2-ethylhexylphthalate (DEHP) is an ester of phthalic acid commonly found in processed foods. DEHP may contribute to obesity and insulin resistance in children and adolescents, yet dietary exposures have been not been studied in this vulnerable subpopulation. ObjectiveTo assess diet and its relation to urinary phthalates in a nationally representative sample of US children and adolescents. DesignCross-sectional analysis of 24-h dietary recall and urinary phthalate metabolites from 2743 6–19 year olds participating in the 2003–8 National Health and Nutrition Examination Surveys. Regression analyses examined relationships of food consumption with log-transformed metabolite concentrations, examined as low-molecular weight, high molecular weight and di-2-ethylhexylphthalate categories, controlling for urinary creatinine, age group, body mass index category, race/ethnicity, caloric intake and gender. ResultsWe identified a −0.04% (95% CI: −0.08, −0.01) increment in di-2-ethylhexylphthalate metabolite concentration/additional gram fruit consumption, a +0.01% increment/additional calorie dietary intake (95% CI: +0.003, +0.02), and a +0.09% (95% CI: +0.02, +0.17) increment/additional gram meat/poultry/fish consumption. Soy consumption (−0.40% increment/additional gram consumed, 95% CI: −0.66, −0.14) was inversely associated with di-2-ethylhexylphthalate, while poultry (+0.23% increment/additional gram consumed, 95% CI: +0.12, +0.35) was positively associated. Findings were robust to examination of metabolite concentrations per unit body mass index and weight, and inclusion of fasting time. ConclusionsDiet contributes to urinary phthalate concentrations in children and adolescents. Further study is needed to examine the implications of di-2-ethylhexylphthalate exposure, especially earlier in life, when more permanent metabolic changes may occur.

Soy and Its Isoflavones: The Truth Behind the Science in Breast Cancer

Epidemiological and migratory evidence suggests that dietary soy consumption can lower the risk for breast cancer. The role of soy isoflavones in cancer prevention and promotion is somewhat unclear. There are two views in terms of soy isoflavones and breast cancer. One line of evidence suggests that soy and its isoflavones have exhibited cancer-preventive properties including lengthening the menstrual cycle, altering estrogen metabolism away from cancerous compounds, and demonstrating anti-proliferative properties in vivo. On the contrary, isoflavones found in soy products are suggested to behave as weak estrogens and as such, much speculation surrounds the influence of soy and/or its isoflavones on hormone-receptor-positive cancers. The objective of this review is to present the latest knowledge regarding the role of soy and its isoflavones with the development and advancement of breast cancer, the safety of soy isoflavones for breast cancer survivors, and a comparison of the carcinogenic effects in animal models following soy isoflavone and estrogen administration. This review compares and contrasts literature in terms of the anti-cancer and cancer-promoting effects of soy isoflavones and estrogen in humans and animal models. In conclusion, current human and animal data provide evidence for several anticancer properties of soy and/or its isoflavones. Although the specific quantities and constituents responsible for the observed anti-cancer effects have not been elucidated, it appears that soy isoflavones do not function as an estrogen, but rather exhibit anti-estrogenic properties. However, their metabolism differs between humans and animals and therefore the outcomes of animal studies may not be applicable to humans. The majority of breast cancer cases are hormone-receptor-positive; therefore, soy isoflavones should be considered a potential anti-cancer therapeutic agent and warrant further investigation.

Consumption of Soy Improves Blood Lipid and Calcium Profile of Post-menopausal Women

This was a purposive randomized intervention trial carried out to examine the effect of soy protein isolate and calcium supplementation on blood profiles of post-menopausal women. A total of 100 post-menopausal women were selected and randomly divided in to two groups. Group I was given intervention of 40 gm soy protein isolate and Group II was given 500mg of calcium per day for 100 days. Results of soy protein intervention showed a significant decrease in total cholesterol (15.65%), triglyceride (13.33%), low density lipoprotein (19.90%), and very low density lipoprotein (13.09%). There was a significant decline in the high density lipoprotein level too (5.40%). A significant improvement was also observed in blood calcium (9.90%) and alkaline phosphatase level (11.50%). Calcium supplementation showed significant improvement in blood calcium (12.20%) and alkaline phosphatase (8.37%) level. The study reveals that soy protein isolate and calcium supplementation is beneficial for improving lipid profiles and bone health of post-menopausal women.

Dietary Soy Effects on Mammary Gland Development during the Pubertal Transition in Nonhuman Primates

While epidemiologic studies suggest that soy intake early in life may reduce breast cancer risk, there are also concerns that exposure to soy isoflavones during childhood may alter pubertal development and hormonal profiles. Here, we assessed the effect of a high-soy diet on pubertal breast development, sex hormones, and growth in a nonhuman primate model. Pubertal female cynomolgus monkeys were randomized to receive a diet modeled on a typical North American diet with one of two protein sources for approximately 4.5 years: (i) casein/lactalbumin (CL, n = 12, as control) or (ii) soy protein isolate with a human equivalent dose of 120 mg/d isoflavones (SOY, n = 17), which is comparable to approximately four servings of soy foods. Pubertal exposure to the SOY diet did not alter onset of menarche, indicators of growth and pubertal progression, or circulating estradiol and progesterone concentrations. Greater endometrial area was seen in the SOY group on the first of four postmenarchal ultrasound measurements (P < 0.05). There was a subtle effect of diet on breast differentiation whereby the SOY group showed higher numbers of differentiated large-sized lobular units and a lower proportion with immature ducts following menarche (P < 0.05). Numbers of small lobules and terminal end buds and mammary epithelial cell proliferation did not differ by diet. Expression of progesterone receptor was lower in immature lobules of soy-fed animals (P < 0.05). Our findings suggest that consumption of soy starting before menarche may result in modest effects consistent with a more differentiated breast phenotype in adulthood.

Consumption of Soy Improves Blood Lipid and Calcium Profile of Post-menopausal Women

Consumption of Soy Improves Blood Lipid and Calcium Profile of Post-menopausal Women

Effect of Soy Protein Isolate Supplementation on Biochemical Recurrence of Prostate Cancer After Radical Prostatectomy

Soy consumption has been suggested to reduce risk or recurrence of prostate cancer, but this has not been tested in a randomized trial with prostate cancer as the end point. To determine whether daily consumption of a soy protein isolate supplement for 2 years reduces the rate of biochemical recurrence of prostate cancer after radical prostatectomy or delays such recurrence. Randomized, double-blind trial conducted from July 1997 to May 2010 at 7 US centers comparing daily consumption of a soy protein supplement vs placebo in 177 men at high risk of recurrence after radical prostatectomy for prostate cancer. Supplement intervention was started within 4 months after surgery and continued for up to 2 years, with prostate-specific antigen (PSA) measurements made at 2-month intervals in the first year and every 3 months thereafter. Participants were randomized to receive a daily serving of a beverage powder containing 20 g of protein in the form of either soy protein isolate (n=87) or, as placebo, calcium caseinate (n=90). Biochemical recurrence rate of prostate cancer (defined as development of a PSA level of ≥0.07 ng/mL) over the first 2 years following randomization and time to recurrence. The trial was stopped early for lack of treatment effects at a planned interim analysis with 81 evaluable participants in the intervention group and 78 in the placebo group. Overall, 28.3% of participants developed biochemical recurrence within 2 years of entering the trial (close to the a priori predicted recurrence rate of 30%). Among these, 22 (27.2%) occurred in the intervention group and 23 (29.5%) in the placebo group. The resulting hazard ratio for active treatment was 0.96 (95% CI, 0.53-1.72; log-rank P = .89). Adherence was greater than 90% and there were no apparent adverse events related to supplementation. Daily consumption of a beverage powder supplement containing soy protein isolate for 2 years following radical prostatectomy did not reduce biochemical recurrence of prostate cancer in men at high risk of PSA failure. clinicaltrials.gov Identifier: NCT00765479.

Probiotic Beverage with Soy Isoflavone Consumption for Breast Cancer Prevention: A Case-control Study

The purpose of this study is to evaluate how beverages containing Lactobacillus casei Shirota (BLS) and soy isoflavone consumption since adolescence affected the incidence of breast cancer. In a population-based case-control study, three hundred and six cases with breast cancer and 662 controls aged 40 to 55 were matched for age and residential area and included in the analyses. Diet, lifestyle and other breast cancer risk factors were investigated using the self-administered questionnaire and interview. Odds ratios (ORs) of BLS and soy isoflavone consumption for breast cancer incidence were independently and jointly estimated using a conditional logistic regression. The ORs of BLS consumption (≥ four times a week against < four times a week) was 0.65 and statistically significant (p = 0.048). The analysis of association between soy consumption and breast cancer incidence showed the more the isoflavone consumption is, the lower the odds of breast cancer becomes. Adjusted ORs for breast cancer in the second, the third and the fourth quartiles of soy consumption against the first quartile were 0.76, 0.53 and 0.48, respectively (trend test, p = 0.0002). The BLS-isoflavone interaction was not statistically significant; however, a biological interaction was suggested. Regular consumption of BLS and isoflavones since adolescence was inversely associated with the incidence of breast cancer in Japanese women.

Soy extracts suppressed iodine uptake and stimulated the production of autoimmunogen in rat thyrocytes

Soy consumption is associated with thyroid disorders such as hypothyroidism, goiter, and autoimmune thyroid disease (ATD) as well as increased iodine requirement in certain cases. However, the anti-thyroid component(s) in soy are yet to be identified and the molecular mechanism(s) involved remain unclear. This study examined the effects of soy isoflavones (ISF) on iodide uptake and expression of thyroglobulin (Tg) and sodium/iodide symporter (NIS) in thyrocytes. Fischer rat thyroid cells (FRTL) were treated with Novasoy (a soy alcohol extract containing 30% ISF) or major ISF aglycones or glycosides for 24 h. Iodide uptake was measured by a colorimetric assay. The protein level of Tg and NIS was measured by Western blotting. Cytotoxicity of tested compounds was determined by the MTT cell proliferation assay. Iodide uptake in FRTL cells was dose-dependently suppressed by Novasoy added into the cell culture (10, 25, or 50 µg/mL, P < 0.05). However, neither the major ISF aglycones nor glycosides alone or in combination had similar effects. Novasoy (up to 200 µg/mL) had no cytotoxic effect. Novasoy (1, 10, and 50 µg/mL) and genistein (1 and 10 µM) markedly increased the protein content of a 40 kDa Tg fragment (P40, a known autoimmunogen) and non-glycosylated NIS in the FRTL cells (P < 0.05). Overall, this study demonstrated that the alcohol soluble component(s) other than the major ISF in soy remarkably inhibited iodide uptake in the FRTL cells. Soy ISF, particularly genistein, induced the production of P40, which might be responsible for the higher incidence of ATD reported in soy infant formula-fed children.

The Effects of Soy Consumption before Diagnosis on Breast Cancer Survival: The Multiethnic Cohort Study

This study tested the hypothesis that prediagnostic soy intake was inversely associated with all-cause and breast cancer-specific mortality. The analyses included 3842 women in the Multiethnic Cohort (MEC) study of African Americans, Native Hawaiians, Japanese Americans, Latinos, and Caucasians, who completed a quantitative food frequency questionnaire, aged ≥50 yr at cohort entry, and diagnosed with primary invasive breast cancer following cohort entry (1993–2007). Hazard ratios (HR) and 95% confidence intervals (CI) were estimated from Cox proportional hazards regression with adjustment for known clinical and lifestyle factors. During a mean follow-up after diagnosis of invasive breast cancer of 6.2 ± 3.8 yr, there were 804 deaths including 376 breast cancer-specific deaths. The HR (95%CI) for all-cause and breast cancer-specific morality comparing the highest versus lowest tertiles were 1.03 (0.81–1.33) and 1.03 (0.71–1.50) for soy products and 0.99 (0.82–1.20) and 0.95 (0.71–1.28) for total isoflavones, respectively (Ptrend > 0.60 for all). There was limited evidence of differences by hormone receptor status, tumor stage, or ethnic group. Prediagnostic soy intake was unrelated to mortality in postmenopausal women. Our findings are consistent with the literature that soy consumption does not adversely affect breast cancer survival in women.

Abstract LB-188: Isoflavone pharmacokinetics and metabolism after consumption of soy and soy-almond bread in men with asymptomatic prostate cancer.

Abstract Background: Soy phytochemicals, particularly isoflavones, are hypothesized to have anti-prostate cancer activity. Soy isoflavones are present predominantly as glucosides but when combined with β-glucosidase activity in almond meal, a greater conversion to aglycones has been observed. We hypothesized that soy bread will serve as an excellent source of soy polyphenols and that an aglycone-rich soy-almond bread (SAB) compared to a glycoside-rich soy bread (SB) will demonstrate greater bioavailability of soy isoflavones. Methods: SB and SAB were fed in a 20 week randomized phase II cross-over trial involving 32 men with asymptomatic metastatic prostate cancer and escalating prostate specific antigen (PSA). Isoflavones were quantitated by HPLC in soy breads and isoflavone metabolites in 24h urine. HPLC-tandem mass spectrometry evaluated isoflavone pharmacokinetics in plasma. Biomarkers were determined by chemiluminescence-based assays. Results: The aglycone composition in the SB and SAB was 18% and 78%, respectively. Compliance was 95±14%, toxicity rare and limited to grade I GI complaints (NIH_NCI criteria). Urinary isoflavone patterns over 24hours revealed that isoflavonoid metabolites were significantly greater with soy bread consumption. Plasma pharmacokinetics following a test meal showed that daidzein (p=0.028) and genistein (p=0.010) absorption was significantly faster from the aglycone-rich SAB. Interestingly, PSA doubling time was prolonged compared to pre-enrollment, in 60% of men (n=30) with soy intervention. Conclusions: Bread is an excellent vehicle for the delivery of soy phytochemicals with outstanding compliance. Modification of soy bread with a source of β-glucosidase may enhance the initial absorption rates of isoflavones. Food products, such as SAB, with consistent and stable composition of phytochemicals can be developed that are appropriate for long-term chemoprevention studies in humans or as an adjunct to therapy. Citation Format: Jennifer H. Ahn-Jarvis, Steven K. Clinton, Elizabeth M. Grainger, Kenneth M. Riedl, Steven J. Schwartz, Yael Vodovotz. Isoflavone pharmacokinetics and metabolism after consumption of soy and soy-almond bread in men with asymptomatic prostate cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-188. doi:10.1158/1538-7445.AM2013-LB-188

Abstract 3700: Prepubertal dietary genistein intake reduces ovarian cancer risk in BRCA+/- mice.

Abstract Genistein, a soy-derived isoflavone, is thought to play a key role in the cancer-preventive activity of soy consumption. Germline mutations in BRCA1 and BRCA2 genes are known risk factors for both ovarian and breast cancers. Previously, our lab has discovered that prepubertal dietary exposure to genistein reduced 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary incidence (P = 0.029) and aggressiveness of the tumors (P &amp;lt; 0.001) in the WT mice, and upregulated the expression of BRCA1 in their mammary glands (P = 0.04). In this study, we investigated whether prepubertal dietary exposure to genistein reduces ovarian tumors in heterozygous BRCA+/- mice and their wild type littermates. Mice were fed a control diet AIN93G or 500 ppm genistein-supplemented diet from postnatal day (PND) 15 to PND 30, and thereafter mice received the control AIN93G diet. On PND42, control and genistein mice were primed with medroxyprogesterone acetate and, starting at PND50, administered 7,12-dimethylbenz(a)anthracene (DMBA) once a week for four weeks. Ovarian tissues were harvested at 5 months of age. Histopathology assessment shows that mice developed granulosa cell tumors. Ovarian tumor incidence in control diet fed wildtype mice was 80% and in the BRCA+/- mice 100%. The incidence dropped to 33% in the wildtype and to 50% in the BRCA+/- mice following prepubertal genistein intake. Thus, the exposure to prepubertal genistein in both BRCA+/- and WT mice significantly reduced ovarian tumor incidence, compared with their control diet fed littermates (P=0.001). The mechanisms mediating the protective effect of prepubertal genistein intake on ovarian cancer risk are being investigated. Citation Format: E Carney, L. Hilakivi-Clarke, A. Warri, S. de Assis. Prepubertal dietary genistein intake reduces ovarian cancer risk in BRCA+/- mice. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3700. doi:10.1158/1538-7445.AM2013-3700