Phytoestrogens and Thyroid Cancer Risk: A Population-Based Case-Control Study in Connecticut.

BACKGROUND: Very few previous studies have examined the relationship between thyroid cancer risk and intake of phytoestrogens (PE); furthermore, these studies have reached inconsistent results. METHODS: We analyzed data from a population-based case-control study in Connecticut from 2010 to 2011, including 387 histologically confirmed thyroid cancer cases and 433 population-based controls, with compound data available concerning specific PEs. Multivariate unconditional logistic regression models were used to estimate the associations between specific PEs and the risk of thyroid cancer, adjusting for potential confounders. RESULTS: An elevated risk of thyroid cancer was associated with moderate to high levels of coumestrol intake [OR = 2.48, 95% confidence interval (CI), 1.39-4.43 for 40-80 µg/day; OR = 2.41, 95% CI, 1.32-4.40 for 80-130 µg/day; and OR = 2.38, 95% CI, 1.26-4.50 for >200 µg/day compared with <40 µg/day], and the main elevation in risk appeared among microcarcinomas (≤1 cm). A decreased risk of papillary macrocarcinomas (>1 cm; OR = 0.26, 95% CI, 0.08-0.85 for 1,860-3,110 µg/day compared with <760 µg/day) was associated with moderate genistein intake among women. CONCLUSIONS: Our study suggests that high coumestrol intake increases the risk of thyroid cancer, especially microcarcinomas, whereas moderate amounts of genistein intake appear to be protective for females with thyroid macrocarcinomas. IMPACT: The study highlights the importance of distinguishing between microcarcinomas and macrocarcinomas in future research on the etiology of thyroid cancer.

Coumestrol/hydroxypropyl-ß-cyclodextrin association incorporated in hydroxypropyl methylcellulose hydrogel exhibits wound healing effect: in vitro and in vivo study.

Several beneficial effects on the skin have been reported for coumestrol (COU), such as protection against photoaging and improvement of skin elasticity and thickness in postmenopausal women. However no reports on the effect of COU on wound healing were found. Nevertheless, COU has low aqueous solubility, which is a crucial limitation for biological tests. The present study was designed as a two-step experiment to evaluate the wound healing effect of COU. First, we used fibroblasts and the experimental in vitro artificial wound model, scratch assay, to compare the effects of COU free, dissolved in dimethyl sulfoxide (DMSO) or Dulbecco's modified Eagle's medium (DMEM), or associated with hydroxypropyl-ß-cyclodextrin (HPßCD). The 50 µM (66.1%) and 10 µM (56.3%) COU/HPßCD association induced cell proliferation and migration in inflicted wounds. Subsequently, the in vivo wound healing experimental model (Wistar rats) revealed that COU/HPßCD incorporated into hypromellose (HPMC) hydrogel had similar efficacy in wound healing in comparison to the positive control (Dersani®), with the advantage that 50% wound healing was achieved within a shorter period. In summary, the results successfully demonstrated, for the first time, the wound healing effect of COU/HPßCD incorporated into HPMC hydrogel and describe the feasibility of the biological tests with the use of HPßCD instead DMSO.

Effects of neonatal treatment with two phytoestrogens on male rat sexual behavior and partner preference.

The aim of this work was to compare the effect of neonatal treatment with the phytoestrogens coumestrol (COU) and genistein (GEN), administered in equimolecular doses, on the sexual behavior and partner preference of male rats. Four groups of male rats were injected daily from day 1 to 5 with 150 µg of GEN, an equivalent amount of COU, 1 µg of ß-estradiol 3-benzoato (EB), or olive oil (VEH) (control). A fifth group remained intact. In the GEN group, intromission and ejaculation latencies decreased, whereas ejaculatory frequency increased. Contrasting results were observed in COU males. EB males could not ejaculate and their mount and intromission latencies increased significantly. To determine sexual-partner preferences, a multiple partner preference arena was used and two types of tests were performed, the first one without allowing contact test (CT) with the stimulus animals, followed by a CT. COU and GEN groups did not show preference for any stimulus animal, whereas the EB males preferred the expert male. When CT with the stimulus animals was allowed, GEN-males preferred the receptive female, unlike the COU and EB groups. It is concluded that neonatal treatment with COU and GEN induced opposite effects, the effects of COU being more estrogenic.

Coumestrol inhibits autoantibody production through modulating Th1 response in experimental autoimmune thyroiditis.

Coumestrol is a common phytoestrogen found in plants and Chinese medicinal herbs. Its influences on experimental autoimmune thyroiditis (EAT) were investigated in this study. Female adult CBA/J mice were fed with drinking water containing 1% Tween80 only (Control group), 0.8 mg/l (L group) and 8 mg/l coumestrol (H group) from 6 to 15 weeks of age, respectively. Their serum coumestrol concentrations were determined by high performance liquid chromatography, which were undetectable, 43.70 ± 21.74 ng/ml and 135.07 ± 70.40 ng/ml, respectively. In addition, the mice (n = 14-16/group) were immunized twice with thyroglobulin (Tg) and Freund's adjuvant to induce EAT during the meantime. Although no overt changes in the extent of intrathyroidal mononuclear cell infiltration were shown in the two coumestrol-treated groups as compared with the controls, serum anti-Tg IgG2a, IgG3 and IgG1 titers, ratio of IgG2a to IgG1 and the percentage of T helper (Th)1 cells in the splenocytes were significantly reduced in the L group. Another consistent change was the significantly decreased expression of splenic IFN-γ mRNA after low dose of coumestrol exposure. Uterine weight was also markedly reduced in the mice of L group. These findings suggest that coumestrol treatment may have some beneficial actions against thyroid-specific autoantibody production in the development of autoimmune thyroiditis through suppression of Th1 response due to its anti-estrogenic activity.

Effects of coumestrol administration to maternal mice during pregnancy and lactation on immunoblogulin A-secreting cells in mammary glands.

Mortality and morbidity of neonates continue to be major problems in humans and animals, and immunoblogulin A (IgA) provides protection against microbial antigens at mucosal surfaces. The present study was conducted to clarify the effects of coumestrol administration to maternal mice during pregnancy and lactation on IgA antibody-secreting cells (ASC) in mammary glands in lactating mice. From 6.5 to 16.5 days post coitus and 1 to 13 days post partum (dpp), maternal mice were administered coumestrol at 200 µg/kg body weight/day. Coumestrol administration increased the number of IgA ASC and the messenger RNA expression of IgA C-region and vascular cell adhesion molecule-1 in mammary glands of maternal mice at 14 dpp, but coumestrol administration had no effect on the number of IgA ASC in the ileum. Coumestrol administration increased serum IgA concentration in maternal mice at 14 dpp, but IgA concentrations in serum, stomach contents, intestine and feces of neonatal mice were not affected by treatment. These results imply that coumestrol administration to maternal mice during pregnancy and lactation is effective in increasing the numbers of IgA ASC in mammary glands during lactation owing to the activated messenger RNA expressions of IgA C-region and vascular cell adhesion molecule-1 in mammary gland.

Phytoestrogen and fiber intakes in relation to incident vasomotor symptoms: results from the Study of Women's Health Across the Nation.

OBJECTIVE: Although reduction of vasomotor symptoms (VMS; hot flashes and night sweats) has been reported in postmenopausal women who used isoflavones, a clear dose response has not been shown, has largely not been reported for perimenopausal women, and has largely only been reported for reducing prevalent VMS, not preventing newly developing VMS. We analyzed longitudinal data from the Study of Women's Health Across the Nation for the relation of dietary phytoestrogen and fiber intake to incident VMS in this multiracial/ethnic cohort. METHODS: The Study of Women's Health Across the Nation included 3,302 premenopausal and early perimenopausal women, 1,651 of whom reported no VMS at baseline and were followed with annual visits for 10 years. Dietary intakes of isoflavones, coumestrol, lignans, and fiber were assessed by a food frequency questionnaire at baseline and in annual visits 5 and 9 and interpolated for intervening years. The number of days experiencing VMS in the past 2 weeks was self-reported annually. Using multinomial logistic regression with generalized estimating equations, we modeled incident VMS in relation to isoflavones, lignans, fiber, coumestrol, or total phytoestrogen intake and covariates. RESULTS: No consistent monotonic relations were observed between any dietary phytoestrogen or fiber and incident VMS, although adjusted odds ratios for some individual quartiles were statistically significant. CONCLUSIONS: For certainty of any effect of dietary phytoestrogens or fiber on the prevention of incident VMS, a randomized, placebo-controlled, double-masked trial with sufficient numbers of women in different racial/ethnic, menopausal status, and metabolic groups over years of follow-up is required, but our results suggest that a clinically significant or large effect is improbable.

Intakes and sources of isoflavones, lignans, enterolignans, coumestrol and soya-containing foods in the Norfolk arm of the European Prospective Investigation into Cancer and Nutrition (EPIC-Norfolk), from 7 d food diaries, using a newly updated database.

OBJECTIVE: A diet rich in phyto-oestrogens has been suggested to protect against a variety of common diseases but UK intake data on phyto-oestrogens or their food sources are sparse. The present study estimates the average intakes of isoflavones, lignans, enterolignans and coumestrol from 7 d food diaries and provides data on total isoflavone, lignan and phyto-oestrogen consumption by food group. DESIGN: Development of a food composition database for twelve phyto-oestrogens and analysis of soya food and phyto-oestrogen consumption in a populationbased study. SETTING: Men and women, aged 40­79 years, from the general population participating in the Norfolk arm of the European Prospective Investigation into Cancer and Nutrition (EPIC-Norfolk) between 1993 and 1997, with nutrient and food data from 7 d food diaries. SUBJECTS: A subset of 20 437 participants. RESULTS: The median daily phyto-oestrogen intake for all men was 1199 mg (interquartile range 934­1537mg; mean 1504mg, SD 1502mg) and 888mg for all women (interquartile range 710­1135 mg; mean 1205 mg, SD 1701mg). In soya consumers, median daily intakes were higher: 2861 mg in men (interquartile range 1304­7269mg; mean 5051mg, SD 5031mg) and 3142 mg in women (interquartile range 1089­7327mg; mean 5396 mg, SD 6092 mg). In both men and women, bread made the greatest contribution to phyto-oestrogen intake ­ 40?8% and 35?6%, respectively. In soya consumers, vegetable dishes and soya/goat's/sheep's milks were the main contributors ­ 45?7% and 21?3% in men and 38?4% and 33?7% in women, respectively. CONCLUSIONS: The ability to estimate phyto-oestrogen intake in Western populations more accurately will aid investigations into their suggested effects on health.

Relationship between dietary phytoestrogens and development of urinary incontinence in midlife women.

OBJECTIVE: Because exogenous estrogen treatment has been associated with a higher risk of urinary incontinence, our objective was to evaluate the longitudinal relationships of dietary phytoestrogen intakes (isoflavones, coumestans, and lignans) and the development of incontinence in midlife women transitioning through menopause. METHODS: The Study of Women's Health Across the Nation (SWAN) Phytoestrogen Study was developed within SWAN, a community-based, multisite, multiracial/ethnic, prospective cohort study. SWAN interviewers administered a food consumption assessment at baseline and on follow-up visits 5 and 9. The SWAN Phytoestrogen Study created a phytonutrient database that allowed estimation of the usual daily intakes of four isoflavones, four lignans, and coumestrol. On an annual self-administered questionnaire, participants reported on the frequency and type of incontinence. We used discrete proportional hazards models to evaluate whether the estimated daily intake of each phytoestrogen class on the visit previous to the first report of incontinence was associated with the development of monthly or more incontinence versus remaining continent. RESULTS: We found no association or patterns of association between developing any, stress, or urge incontinence and the reported daily dietary intake of isoflavones, coumestrol, and lignans on the visit previous to the onset of incontinence. CONCLUSIONS: The results of this longitudinal study provide important information to better understand estrogenlike substances in the continence mechanism of midlife women. Our study shows that neither high nor low dietary intakes of isoflavones, coumestrol, and lignans prevent stress or urge incontinence. Future studies should evaluate whether serum levels of phytoestrogens or their metabolites impact incontinence symptoms.

Coumestrol has neuroprotective effects before and after global cerebral ischemia in female rats.

Global ischemia arising during cardiac arrest or cardiac surgery causes highly selective, delayed death of hippocampal CA1 neurons. Phytoestrogens are naturally occurring plant-derived compounds that are present in the human diet and are considered selective estrogen receptor (ER) modulators. The phytoestrogen coumestrol is a potent isoflavonoid, with binding affinities for both ER-α and ER-ß that are comparable to those of 17 b-estradiol. The present study examined the hypothesis that coumestrol protects hippocampal neurons in ovariectomized rats in a model of cerebral global ischemia. Ovariectomized rats were subjected to global ischemia (10 min) or sham surgery and received a single intracerebroventricular or peripheral infusion of 20 µg of coumestrol, 20 µg of estradiol or vehicle 1h before ischemia or 0 h, 3h, 6h or 24h after reperfusion. Estradiol and coumestrol afforded significant neuroprotection in all times of administration, with the exception of estradiol given 24h after the ischemic insult. Animals received icv infusion of the broad-spectrum ER antagonist ICI 182,780 (50 µg) or vehicle into the lateral ventricle just before the E2 or coumestrol administration. The ER antagonist abolished estradiol protection, consistent with a role of classical ERs. In contrast, ICI 182,780 effected only partial reversal of the neuroprotective actions of coumestrol, suggesting that other cellular mediators in addition to classical ERs may be important. Additional research is needed to determine the molecular targets mediating the neuroprotective action of coumestrol and the therapeutic potential of this phytoestrogen in the mature nervous system.

Dietary phytoestrogen intakes and cognitive function during the menopausal transition: results from the Study of Women's Health Across the Nation Phytoestrogen Study.

OBJECTIVE: Phytoestrogens, which consist mainly of isoflavones, lignans, and coumestans have estrogenic and anti-inflammatory properties. Previous research suggests that higher dietary or supplemental intakes of isoflavones and lignans are related to better cognitive performance in middle-aged and older women. METHODS: We conducted longitudinal analysis of dietary phytoestrogens and cognitive performance in a cohort of African American, white, Chinese, and Japanese women undergoing the menopausal transition. The tests were Symbol Digit Modalities, East Boston Memory, and Digits Span Backward. Phytoestrogens were assessed using the Food Frequency Questionnaire. We modeled each cognitive score as a function of concurrent value of the primary predictors (highest tertile of isoflavones, lignans, or coumestrol) and covariates including the menopausal transition stage. RESULTS: Coumestrol and isoflavone intakes were 10 and 25 times greater, respectively, in Asian than in non-Asian participants. During late perimenopause and postmenopause, Asian women with high isoflavone intakes did better on processing speed, but during early perimenopause and postmenopause, high-isoflavone Asian consumers performed worse on verbal memory. The highest isoflavone consumers among non-Asians likewise posted lower verbal memory scores during early perimenopause. A verbal memory benefit of higher dietary lignan consumption was apparent only during late perimenopause, when women from all ethnic/racial groups who were in the highest tertile of intake demonstrated a small advantage. Coumestrol was unrelated to cognitive performance. CONCLUSIONS: The cognitive effects of dietary phytoestrogens are small, seem to be class-specific, vary by menopause stage and cognitive domain, and differ among ethnic/racial groups (but whether this is related to dose or to host factors cannot be discerned).

Development of an updated phytoestrogen database for use with the SWAN food frequency questionnaire: intakes and food sources in a community-based, multiethnic cohort study.

Phytoestrogens, heterocyclic phenols found in plants, may benefit several health outcomes. However, epidemiologic studies of the health effects of dietary phytoestrogens have yielded mixed results, in part due to challenges inherent in estimating dietary intakes. The goal of this study was to improve the estimates of dietary phytoestrogen consumption using a modified Block Food Frequency Questionnaire (FFQ), a 137-item FFQ created for the Study of Women's Health Across the Nation (SWAN) in 1994. To expand the database of sources from which phytonutrient intakes were computed, we conducted a comprehensive PubMed/Medline search covering January 1994 through September 2008. The expanded database included 4 isoflavones, coumestrol, and 4 lignans. The new database estimated isoflavone content of 105 food items (76.6%) vs. 14 (10.2%) in the 1994 version and computed coumestrol content of 52 food items (38.0%), compared to 1 (0.7%) in the original version. Newly added were lignans; values for 104 FFQ food items (75.9%) were calculated. In addition, we report here the phytonutrient intakes for each racial and language group in the SWAN sample and present major food sources from which the phytonutrients came. This enhanced ascertainment of phytoestrogens will permit improved studies of their health effects.

Estimated dietary phytoestrogen intake and major food sources among women during the year before pregnancy.

BACKGROUND: Phytoestrogens may be associated with a variety of different health outcomes, including outcomes related to reproductive health. Recently published data on phytoestrogen content of a wide range of foods provide an opportunity to improve estimation of dietary phytoestrogen intake. METHODS: Using the recently published data, we estimated intake among a representative sample of 6,584 women of reproductive age from a multi-site, population-based case-control study, the National Birth Defects Prevention Study (NBDPS). The NBDPS uses a shortened version of the Willett food frequency questionnaire to estimate dietary intake during the year before pregnancy. We estimated intake among NBDPS control mothers. RESULTS: Lignans contributed 65% of total phytoestrogen intake; isoflavones, 29%; and coumestrol, 5%. Top contributors to total phytoestrogen intake were vegetables (31%) and fruit (29%); for isoflavones, dairy (33%) and fruit (21%); for lignans, vegetables (40%) and fruit (29%); and for coumestans, fruit (55%) and dairy (18%). Hispanic women had higher phytoestrogen intake than non-Hispanic white or black women. Associations with maternal age and folic acid-containing supplements were more modest but indicated that older mothers and mothers taking supplements had higher intake. CONCLUSIONS: The advantage of the approach used for the current analysis lies in its utilization of phytoestrogen values derived from a single laboratory that used state-of-the-art measurement techniques. The database we developed can be applied directly to other studies using food frequency questionnaires, especially the Willett questionnaire. The database, combined with consistent dietary intake assessment, provides an opportunity to improve our ability to understand potential associations of phytoestrogen intake with health outcomes.

Phytoestrogen consumption from foods and supplements and epithelial ovarian cancer risk: a population-based case control study.

BACKGROUND: While there is extensive literature evaluating the impact of phytoestrogen consumption on breast cancer risk, its role on ovarian cancer has received little attention. METHODS: We conducted a population-based case-control study to evaluate phytoestrogen intake from foods and supplements and epithelial ovarian cancer risk. Cases were identified in six counties in New Jersey through the New Jersey State Cancer Registry. Controls were identified by random digit dialing, CMS (Centers for Medicare and Medicaid Service) lists, and area sampling. A total of 205 cases and 390 controls were included in analyses. Unconditional logistic regression analyses were conducted to examine associations with total phytoestrogens, as well as isoflavones (daidzein, genistein, formononetin, and glycitein), lignans (matairesinol, lariciresinol, pinoresinol, secoisolariciresinol), and coumestrol. RESULTS: No statistically significant associations were found with any of the phytoestrogens under evaluation. However, there was a suggestion of an inverse association with total phytoestrogen consumption (from foods and supplements), with an odds ratio (OR) of 0.62 (95% CI: 0.38-1.00; p for trend: 0.04) for the highest vs. lowest tertile of consumption, after adjusting for reproductive covariates, age, race, education, BMI, and total energy. Further adjustment for smoking and physical activity attenuated risk estimates (OR: 0.66; 95% CI: 0.41-1.08). There was little evidence of an inverse association for isoflavones, lignans, or coumestrol. CONCLUSIONS: This study provided some suggestion that phytoestrogen consumption may decrease ovarian cancer risk, although results did not reach statistical significance.

Effects of coumestrol administration to pregnant and lactating mice on intestinal alkaline phosphatase activity.

The present study was conducted to clarify the effects of coumestrol administration on Ca metabolism during pregnancy and in lactating mice. From 6.5 to 16.5 days post coitus (dpc), pregnant mice were administered coumestrol at 200 µg/kg body weight/day. The duodenum, jejunum and blood samples were obtained at 17.5 dpc or 10 days after parturition (dap). Coumestrol administration decreased alkaline phosphatase (ALP) activity and mRNA expression of IAP and estrogen responsive genes, c-fos and vascular endothelial growth factor (VEGF), in the duodenum and jejunum of pre-delivery mice. In lactating mice, the ALP activity and mRNA expression of IAP were not changed, although coumestrol administration decreased mRNA expression of c-fos in the duodeum and VEGF in the jejunum. Coumestrol did not affect serum Ca and the expression of vitamin D receptor protein in the duodenum and jejunum. Thus, coumestrol administration during pregnancy may decrease the mRNA expression of IAP and the ALP activity in the intestine of the pre-delivery mice through ERα, but coumestrol had little effect on intestinal ALP activity at 10 days after parturition.

Phytoestrogen consumption and endometrial cancer risk: a population-based case-control study in New Jersey.

Phytoestrogens have been shown to exert anti-estrogenic and estrogenic effects in some tissues, including the breast. However, only a few studies have evaluated their role in endometrial cancer risk. We evaluated this association in a population-based case-control study in New Jersey. A total of 424 cases and 398 controls completed an interview, including a food frequency questionnaire with supplemental questions for phytoestrogen foods. Risk estimates were derived using an unconditional logistic regression, adjusting for major risk factors for endometrial cancer. There was some suggestion of a decreased risk with quercetin intake (OR: 0.65; 95% CI: 0.41-1.01 for the highest compared to the lowest quartile; p for trend: 0.02). We found a limited evidence of an association with any of the lignans evaluated, total lignans, coumestrol, individual isoflavones, total isoflavones, or total phytoestrogens. However, there was some suggestion of an inverse association with total isoflavone intake limited to lean women (BMI <25; OR for the highest tertile: 0.50; 95% CI: 0.25-0.98) and those with a waist-to-hip ratio

Lactational coumestrol exposure increases ovarian apoptosis in adult rats.

This study is the first to examine the increased apoptosis in the adult rat ovary after lactational exposure to coumestrol (COU), a potent phytoestrogen. Lactating dams were gavaged at doses of 0.01, 0.1, 1, and 10 mg/kg COU during the lactation period and the reproductive effects of female pups were investigated in young adults. Rats were sacrificed at postnatal days (PND) 81-84. Ovarian weights were reduced significantly at 0.1 and 1.0 mg/kg COU. The reduction in the ovarian weight occurred in parallel with an increase in the apoptosis at PND 135-140. A marked dose-dependent increase in the expressions of active caspase-3 and -7 was observed in ovarian granulosa cells. Immunostaining for active caspase-3 and the TUNEL staining of apoptotic cells were also increased in ovaries exposed to COU in a dose-dependent manner. These results suggest new sights into the effect of lactational exposure to COU on the female reproductive health.

Phytoestrogen treatment induces testis alterations in dogs. Potential use in population control.

Dog overpopulation is considered a human health risk; they are the terrestrial vector of rabies and reservoirs for other human diseases. Surgical neutering and intratesticular injections have been used in male dogs. Physiological and morphological alterations in reproductive organs can be induced by phytoestrogens. Our goal was to evaluate the effect of oral coumestrol on dog ejaculates and testis histology. Two groups of 5 healthy adult dogs were used. One coumestrolcontaining biscuit was given once a week for a 4 week period to the experimental group. Ejaculates were obtained and evaluated. After treatment, testis were obtained and processed for histology. Compared to controls, treated dogs have reduced tubules (462 +/- 1.4 vs 336 +/- 2 micron(2)), spermatogenic epithelium (49.1 +/- 0.01 vs 13.3 +/- 0.01 micron(2)), and lumen opening (891 +/- 1.4 vs 530 +/- 26.9 micron). Ejaculates from treated animals have increased numbers of abnormal spermatozoa and reduced sperm concentration.

Fluorescence and inmunohistological detection of estrogen receptors in dog testis and epidydimis after oral coumestrol administration.

INTRODUCTION: Estrogens are well recognized as important hormones in male reproduction and act as ligands to alpha and beta estrogen receptors. Both estrogen receptors could interact with estrogen-mimicking compounds such as the fluorescent phytoestrogen coumestrol, which acts both in an agonist or antagonist fashion. OBJECTIVE: To investigate the presence of Coumestrol-Estrogen Receptor complexes by fluorescence in testis and epididymis, its effect in the ER expression by immunostain in the same tissues and the effect of this binding in the testis histological characteristics. DESIGN: Adult healthy and sexually active dogs were assigned to either the experimental or control group .Coumestrol impregnated dog biscuits were given to each animal from the experimental group once a week for a 4 week period. The control group received a biscuit with no Coumestrol, also once a week and for the same period. Testis morphology, ER immunodetection, and coumestrol-receptor binding were evaluated. SETTING: The experiment was done in the facilities of the Mexico City canine shelter. Animals were caged individually with food and water ad libitum and having at least two daily hours for exercise. RESULTS: Morphological alterations in testis after oral administration of coumestrol were detected. The main alterations include decreased germinal epithelium in tubule, and the loss of a continuous proliferation and differentiation gamete layer. Fluorescence signals in testis interstitial Leydig cells and epididymus indicating ER-coumestrol complexes were detected at the same points to those Immunohystochemically detected ER. CONCLUSIONS: Coumestrol administration induces testis alterations and coumestrol-ER complexes can be co-localized by binding-enhanced fluorescence and immunoprecipitation.

Dietary phytoestrogens are not associated with risk of overall breast cancer but diets rich in coumestrol are inversely associated with risk of estrogen receptor and progesterone receptor negative breast tumors in Swedish women.

Results from epidemiological and experimental studies indicate that phytoestrogens may protect against breast cancer. Because one of the biological effects of phytoestrogens is probably estrogenic, it's possible that the preventive effect on breast cancer differs by estrogen receptor (ER) or progesterone receptor (PR) status of the tumor. We evaluated the associations between dietary phytoestrogen (isoflavonoids, lignans, and coumestrol) intake and risk of breast cancer and whether the ER/PR statuses of the tumor influence this relationship. In 1991-2 a prospective population-based cohort study among Swedish pre- and postmenopausal women was performed, making questionnaire data available for 45,448 women. A total of 1014 invasive breast cancers were diagnosed until December 2004. Cox proportional hazards models were performed to estimate multivariate risk ratios, 95% CI for associations with risk of breast cancer. Intakes of lignan, isoflavonoid, or coumestrol were not associated with breast cancer risk overall or before or after 50 y of age. The effects of lignans or isoflavonoids were independent of receptor status. However, intake of coumestrol was associated with decreased risk of receptor negative tumors (ER-PR-) but not positive tumors. The risk of ER-PR- tumors was significantly lower (50%) in women with intermediate coumestrol intake compared with those who did not consume any. In conclusion, we found no association between intake of isoflavonoids or lignans and breast cancer risk. Our results of a decreased risk of ER-PR- tumors in women with intermediate intake of coumestrol could be due to chance because of the low intake. The results should be confirmed in other studies.

Dietary phytoestrogens, including isoflavones, lignans, and coumestrol, in nonvitamin, nonmineral supplements commonly consumed by women in Canada.

Twenty-one nonvitamin, nonmineral dietary supplements commonly consumed by women in Canada were analyzed for isoflavones (formononetin, daidzein, genistein, glycitein), lignans (pinoresinol, lariciresinol, secoisolariciresinol, matairesinol), and coumestrol to complement our previously published food phytoestrogen database. Supplements containing soy or red clover had the highest concentrations of total isoflavones (728.2-35,417.0 ug/g) and total phytoestrogens (1030.1-35,517.7 ug/g) followed by licorice and licorice-containing supplements (41.3-363.3 ug/g isoflavones; 56.5-370.0 ug/g total phytoestrogens). Other supplements had considerably less isoflavones (