Effects of soy intake on sex hormone metabolism in premenopausal women

Studies suggest that phytoestrogens in soy products may impart hormonal effects that protect women against breast cancer. Limited research suggests that intake of soy products high in isoflavonoid phytoestrogens affects sex hormone metabolism, but it is unknown whether phytoestrogens in soy have any effect on menstrual function or serum sex hormones in women on common hormone therapies, such as oral contraceptives (OC). We studied the effects of soy in 36 premenopausal women, 20 of whom used OC. Subjects consumed their normal diet for two menstrual cycles and added a soy beverage containing 20 g of protein and 38 mg of total isoflavones to their usual diet for another two menstrual cycles. No significant differences were observed in serum estrone, estradiol, sex hormone-binding globulin, dehydroepiandrosterone sulfate, prolactin, or progesterone concentrations with soy feeding in the non-OC or the OC group. No changes in menstrual cycle length or the urinary estrogen metabolite ratio of 2-hydroxyestrone to 16 alpha-hydroxyestrone were seen with soy feeding in the non-OC or the OC group. Levels of urinary estrogen metabolites were significantly different between the non-OC and the OC group. Thus soy consumption had no significant effect on the menstrual cycle, serum sex hormones, or urinary estrogen metabolite ratio in premenopausal OC or non-OC users.     

Effects of soy protein and soy phytochemicals on mammary tumor development in female transgenic mice overexpressing human pituitary growth hormone

The objective of this study was to determine the effect of soy-based diets on mammary tumors in female cancer- prone mice. Transgenic virgin female mice expressing human pituitary growth hormone and their respective phenotypically normal littermates were fed a diet containing either casein (C), low-isoflavone soy protein (LIS), or high-isoflavone soy protein (HIS). Indices of tumor development were measured throughout the study. Both days from birth until death and days on diet until death were increased [by 20% (P = .01) and 19% (P = .02), respectively] in the LIS group when compared with the C group. Both intervals were increased also (by 16% and 17%, respectively; P < .05) in the HIS group when compared with the C group. Days from birth to first tumor were increased by 7% (P < .05), as was days on diet to first tumor by 5% (P < .05), in the LIS group when compared with the C group. First-onset number of tumors was decreased (P = .02) by 41% and 34% in the LIS and C groups, respectively, when compared with the HIS group. Final onset of tumors was decreased (P < .05) by 44% and 9% in the LIS and HIS groups, respectively, when compared with the C group. Total area of final tumors was decreased (P < .05) by 30% in the LIS group when compared with the C group. Taken cumulatively, these data suggest that a diet rich in soy protein may provide protective benefits regarding tumor development in female cancer-prone mice. Furthermore, some bioactive compounds in the HIS diet appeared to confound the soy protein-induced beneficial effects.     

A clinician's guide to the use of gonadotropin-releasing hormone analogues in women

Gonadotropin-releasing hormone (GnRH) and its analogues have been extensively used in clinical medicine since they were identified and synthesized in 1971. Native GnRH stimulates gonadotrophs of the anterior pituitary and has been used for induction of ovulation. The GnRH agonists, which have greater potency and a longer half-life than native GnRH, produce an initial stimulation of pituitary gonadotrophs that results in secretion of follicle-stimulating hormone and luteinizing hormone and the expected gonadal response. This response is followed by downregulation and inhibition of the pituitary-gonadal axis. The GnRH antagonists promptly suppress pituitary gonadotropin by GnRH-receptor competition, thereby avoiding the initial stimulatory phase of the agonists. Discontinuation of GnRH antagonist treatment leads to a rapid and predictable recovery of the pituitary-gonadal axis. The GnRH analogues are potent therapeutic agents that are considerably useful in a variety of clinical indications. These indications include management of endometriosis, uterine leiomyomas, hirsutism, dysfunctional uterine bleeding, premenstrual syndrome, assisted reproduction, and some hormone-dependent tumors.     

Model of gonadotropin-releasing hormone and gonadotropin-releasing hormone complex

Gonadotropin-releasing hormone (GnRH) neurons provide the primary driving force upon the other levels of the reproductive axis. Similar to other hormone, GnRH receptor can be identified. The main intracellular pathway activated by stimulation of GnRH receptors (GnRHRs) is related to Gq protein which induces a cytoplasmic metabolic cascade. The structures of both GnRH and GnRHR have been documented inn the recent year. However, the knowledge on the complex, recombination, between GnRH and GnRHR is limited. Here, the author performs an analysis to study the molecular structure of human GnRH and GnRHR complex. To reach the target, a computer-based study for protein recombination modeling is performed.     

Effects of danazol on gonadotropin secretion after ovariectomy in rats.

The effects of Danazol on the elevated levels of serum gonadotropins and on the pituitary response to LH-RH in ovariectomized rats pretreated or not pretreated with estradiol and progesterone, were studied. Danazol depresses significantly the elevated serum levels of LH, but not those of FSH. The LH and FSH response to LH-RH in ovariectomized rats was increased by Danazol. This compound partially modified the inhibitory action of estradiol and progesterone on the serum levels of LH and nullified the depression of FSH. The results indicate that the effects of Danazol on the gonadotropic function of the pituitary depend on the functional state of the gland and/or the duration of the treatment.     

Urinary isoflavonoid excretion and soy consumption in three generations of Japanese women in Hawaii

OBJECTIVE: To explore soy intake and urinary isoflavonoid excretion within several generations of American-Japanese women based on the hypothesis that earlier generations excrete higher levels of urinary isoflavonoids, in particular the metabolite equol, than later generations. SUBJECTS: A convenience sample of 43 women from 19 families aged 18-78 years, all of whom reported at least 50% Japanese ancestry. INTERVENTIONS: Each woman collected overnight urine samples at baseline and after consuming one serving of soymilk, both samples were analyzed for the isoflavonoids daidzein, genistein and equol using liquid chromatography-mass spectrometry. RESULTS: Median isoflavone intakes during the last year were 7.2 mg/day for the first generation, 7.3 mg/day for the second generation and 6.3 mg/day for the third generation (P=0.36). At baseline, the median isoflavonoid excretion for the first generation was nonsignificantly higher than for later generations (190, 86 and 42 nmol/h; P=0.20) but after intervention, the median urinary isoflavonoid excretion was very similar for the three groups: 2465, 1895 and 2775 nmol/h (P=0.70). Following intervention, a nonsignificantly higher proportion of older than younger women (53 vs 32 and 33%; P=0.41) excreted the metabolite equol. The respective median equol excretion rates by generation following intervention were 39.5, 4.2 and 3.5 nmol/h (P=0.04). CONCLUSIONS: This small investigation among three generations of Japanese-Americans detected a higher equol production among older women after a soy challenge, but no difference in the excretion of total isoflavonoids after a standardized dose of soymilk was observed.     

Correlates of soy food consumption in women at increased risk for breast cancer

OBJECTIVES: The objectives of the present study were to examine sociodemographic correlates of soy food consumption among women at increased risk of breast cancer, describe factors influencing soy food consumption or nonconsumption, and identify women's sources of information about soy foods. DESIGN: A cross-sectional, self-report survey was used to assess frequency of and factors influencing soy food consumption. 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 consumers and nonconsumers of soy foods were performed using multivariate logistic regression and chi(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 nonconsumption. Both consumers and nonconsumers reported obtaining information about soy foods from magazines, friends, and newspapers. Consumers also indicated using the Internet to seek information. CONCLUSIONS: These findings contribute to our understanding 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 consumption. Women, particularly in this vulnerable population, would benefit from clear messages regarding the health effects of soy.     

Flaxseed consumption influences endogenous hormone concentrations in postmenopausal women

Lignans, similar in structure to endogenous sex steroid hormones, may act in vivo to alter hormone metabolism and subsequent cancer risk. The objective of this study was to examine effects of dietary intake of a lignan-rich plant food (flaxseed) on serum concentrations of endogenous hormones and binding proteins (estrone, estrone sulfate, 17 beta-estradiol, sex hormone-binding globulin, progesterone, prolactin, dehydroepiandrosterone sulfate, dehydroepiandrosterone, androstenedione, testosterone, and free testosterone) in postmenopausal women. This randomized, crossover trial consisted of three seven-week feeding periods, during which 28 postmenopausal women, aged 52-82 yr, consumed their habitual diets plus 0, 5, or 10 g of ground flaxseed. Serum samples collected during the last week of each feeding period were analyzed for serum hormones using standard diagnostic kits. The flaxseed diets significantly reduced serum concentrations of 17 beta-estradiol by 3.26 pg/ml (12.06 pmol/l) and estrone sulfate by 0.09 ng/ml (0.42 nmol/l) and increased prolactin by 1.92 micrograms/l (0.05 IU/ml). Serum concentrations of androstenedione, estrone, sex hormone-binding globulin, progesterone, testosterone, free testosterone, dehydroepiandrosterone, and dehydroepiandrosterone sulfate were not altered with flaxseed feeding. In this group of postmenopausal women, consuming flaxseed in addition to their habitual diets influenced their endogenous hormone metabolism by decreasing serum 17 beta-estradiol and estrone sulfate and increasing serum prolactin concentrations.     

Lipid responses in mildly hypertriglyceridemic men and women to consumption of docosahexaenoic acid-enriched eggs

This randomized, double-blind, controlled clinical trial assessed lipid responses in mildly hyper-triglyceridemic men and women to consumption of docosahexaenoic acid (DHA)-enriched eggs or ordinary chicken eggs. The study included 153 subjects aged 21-80 years, with serum triglyceride concentrations between 140 and 450 mg/dL, inclusive, and serum total cholesterol concentrations < 300 mg/dL. Subjects were randomly assigned to receive either DHA-enriched (147 mg DHA/egg) or ordinary eggs (20 mg DHA/egg), added to their usual diets for six weeks (10 eggs/week). Both treatments significantly lowered triglycerides and increased high-density lipoprotein (HDL) cholesterol levels from baseline; however, these changes were not significantly different between treatments. Low-density lipoprotein (LDL) cholesterol concentrations increased significantly in subjects who consumed DHA-enriched eggs (p = 0.047 vs. control). This increase was significantly higher than that observed with ordinary eggs. However, there was no significant increase in cholesterol carried by small, dense LDL particles, as determined by nuclear magnetic resonance analysis. Results of exploratory analyses suggest favorable effects of the DHA-enriched eggs over ordinary eggs on triglyceride and HDL cholesterol levels in subjects with body mass index > or = 30 kg/m2; the DHA treatment produced a larger reduction in serum triglyceride concentration vs. ordinary eggs (-12.3 vs. 2.1%; p = 0.027), and there was a greater increase for HDL cholesterol in the DHA-enriched vs. ordinary egg group (5.0 vs. 1.1%; p = 0.040).     

Probiotic consumption does not enhance the cholesterol-lowering effect of soy in postmenopausal women

Numerous studies report that soy lowers cholesterol. Probiotic bacteria were also reported to lower total cholesterol (TC) and LDL cholesterol (LDL-C). We hypothesized that by altering intestinal microflora, probiotic consumption may also change phytoestrogen metabolism and enhance the effects of soy. To evaluate the independent and interactive effects of probiotic bacteria and soy on plasma TC, LDL-C, HDL cholesterol (HDL-C), and triglycerides (TG), 37 women with a baseline TC of 5.24 mmol/L were given the following 4 treatments for 6 wk each in a randomized crossover design: soy protein isolate (26 +/- 5 g soy protein containing 44 +/- 8 mg isoflavones/d); soy protein isolate + probiotic capsules (10(9) colony-forming units Lactobacillus acidophilus DDS-1 and Bifidobacterium longum); milk protein isolate (26 +/- 5 g milk protein/d); and milk protein isolate + probiotic. Soy consumption decreased plasma TC by 2.2% (P = 0.02) and LDL-C by 3.5% (P = 0.005), increased HDL-C by 4.2% (P = 0.006) and tended to decrease TG (P = 0.07) compared with milk protein intake. When divided according to initial TC concentration, soy effects were observed only in hypercholesterolemic women (TC > 5.17 mmol/L). In this subgroup, soy treatments decreased plasma TC by 3.3% (P = 0.01), LDL-C by 4.5% (P = 0.004), and TG by 10.6% (P = 0.02), and increased HDL-C by 4.2% (P = 0.02). When subjects were divided on the basis of plasma and urine concentrations of the isoflavone metabolite, equol, equol producers and nonproducers did not differ in baseline lipids or in the effects of soy. Probiotics did not lower cholesterol or enhance the effects of soy. These results confirm a beneficial effect of soy on plasma cholesterol in mildly hypercholesterolemic postmenopausal women independent of equol production status, but do not support an independent or additive effect of these particular probiotic bacteria.     

Social marketing improved the consumption of iron-fortified soy sauce among women in China

OBJECTIVE: To test the feasibility and effectiveness of social marketing on the improvement of women's knowledge, attitudes, and behaviors regarding iron-fortified soy sauce (FeSS). DESIGN: A community-based intervention was conducted among 4 groups, experimental rural (E(R)), control rural (C(R)), experimental urban (E(U)), and control urban (C(U)). SETTING: Urban and rural areas in Guizhou province, China. PARTICIPANTS: Women 19 to 70 years old (n = 193 in rural areas and n = 179 in urban areas). INTERVENTION: A mass-media campaign to promote use of FeSS was conducted throughout Guizhou province. In the intervention areas, social marketing strategies using integrated 6 Ps (product, price, place, promotion, policy, and partnership) were implemented from December 2004 to February 2006. MAIN OUTCOME MEASURES: Knowledge of FeSS; benefits, barriers, and intention to purchase; availability of FeSS; behaviors regarding purchase and use of FeSS. ANALYSIS: Analysis of covariance, paired T test and cross-tabulations were used. The alpha level was set at .05. RESULTS: Compared with the baseline, perceived benefits of FeSS, barriers (BARRI) and intention to buy (INTEN) significantly improved within both experimental groups (P < .01 or .001). The only improvement in control groups was for BARRI in C(R) (P < .001). Availability of FeSS increased in all areas. Purchase and use of FeSS in rural and urban intervention groups increased by nearly 30% more than those in control groups. CONCLUSION AND IMPLICATION: Social marketing of FeSS is feasible and effective to improve knowledge, perception (perceived benefits and overcoming barriers), intention to purchase, and consumption of FeSS among women in Guizhou, China.     

锌对AtT-20垂体细胞系分泌促肾上腺皮质激素的影响

为探讨锌对 At T- 2 0细胞系分泌促肾上腺皮质激素 (ACTH)的影响 ,用放射免疫法 (RIA)观察添加不同浓度的锌和 0 .5μm ol/ L促肾上腺皮质激素释放激素对分泌 ACTH的影响。结果显示 ,当锌浓度为10 - 7～ 10 - 4 mm ol/ L时 ,对 At T- 2 0细胞分泌 ACTH有依次增强的促进作用。提示在一定剂量范围内 ,锌可促进 At T- 2 0细胞分泌 ACTH,有类似促肾上腺皮质激素释放激素的作用。     

饮用奶粉对青年女性月经周期和尿中激素排泄水平的影响

目的观察长期持续饮用奶粉对健康育龄妇女生理周期、排卵时机以及晨尿中性激素排泄水平的影响。方法招募32名健康青年女性并随机分配到两个组,分别给予不同的饮奶量,进行为期3个月经周期的饮奶实验。第一个月经周期为对照周期,第二个月经周期为饮奶周期。受试者从第二个月经周期月经来潮第4d开始每日饮奶,每日一次饮用33g(低剂量组)或55g(高剂量组)市售奶粉冲调的复原奶,持续21 d;第三个月经周期为停止饮奶的对照周期。在全部三个月经周期内,记录受试者周期长度,采用基础体温和排卵试纸测定排卵日期,多时点(第一、三月经周期第4、7、10、13、16、19和24 d,第二月经周期第4、5、6、7、9、12、15、18、21和24 d)采集晨尿样本,测定尿雌二醇、孕二醇以及肌酐浓度;将尿激素浓度随时间描绘曲线,计算至24d时的曲线下面积。结果高剂量组的三个月经周期分别平均为(29.60±3.180)、(28.87±3.021)和(29.60±2.995)d,低剂量组分别为(30.40±4.014)、(29.67±3.266)和(29.47±3.021)d,两个组的三个月经周期差异均无统计学意义,每个周期两组间差异也无统计学意义。高剂量组排卵日时间分别平均为(15.47±2.295)、(15.40±1.882)和(15.73±2.404)d,低剂量组排卵日时间为(16.93±1.624)、(15.73±2.344)和(15.47±2.200)d,两组的三个周期间差异无统计学意义,每个周期两组间差异无统计学意义。分别将第一、三周期的周期长度、排卵日时间与第二周期进行比较,其差值在两个组间差异无统计学意义。高剂量组三个周期内肌酐校正的尿雌二醇的曲线下面积分别为(7160.28±2305.52)、(6700.26±2066.67)和(6676.24±2573.89);低剂量组为(6838.21±1447.25)、(6611.33±1648.21)和(5949.24±1437.54)。高剂量组三个周期内肌酐校正的尿孕二醇的曲线下面积分别为(51.93±18.80)、(44.55±14.62)和(46.49±22.44);低剂量组为(49.25±15.68)、(48.79±15.61)和(43.45±12.77)。肌酐校正的尿雌二醇、孕二醇浓度的曲线下面积在不同剂量组、不同周期间均无统计学意义。结论 21 d内每日连续饮用日常消费量的奶粉,没有观察到对女性生理周期的显著影响,也没观察到晨尿中雌二醇、孕二醇的排泄水平的变化。     

促性腺激素释放激素激动剂垂体降调节后多卵泡发育的病例分析及文献复习

目的:结合既往临床病例及文献复习,总结促性腺激素释放激素激动剂（gonadotropin-releasing hormone agonist,GnRH-a）垂体降调节后多卵泡发育的诊疗特征。方法:报道1例于本院应用GnRH-a垂体降调节后多卵泡发育的患者情况,并结合中外文献报道的16例个案的病例特点进行回顾性分析。结果...     

Comparison of hormone and glucose responses of overweight women to barley and oats

OBJECTIVE: To determine the effect of particle size (flour vs. flakes) on glycemic responses after oats and barley (Prowashonupana cultivar), which contain high amounts of soluble fiber, are consumed by overweight women. DESIGN: Ten women, average age 50 years and body mass index 30, consumed glucose (1 g/kg body weight) and four test meals (1 g carbohydrate/kg body weight; 2/3 of the carbohydrate from oat flour, oatmeal, barley flour, or barley flakes and 1/3 from pudding) in a Latin square design after consuming controlled diets for 2 days. Blood samples were collected at fasting and periodically after each meal. RESULTS: Peak glucose and insulin levels after barley were significantly lower than those after glucose or oats. Glucose areas under the curve (AUCs) after test meals compared with AUCs after glucose were reduced after both oats and barley (29-36% by oats and 59-65% by barley) (p < 0.002). Insulin AUCs after test meals compared with glucose AUCs were significantly reduced only by barley (44-56%) (p < 0.005). Indexes for insulin resistance (HOMA, MFFM, Cederholm) after the oat and barley meals were not different from indexes after the glucose meal. Glucagon and leptin responses did not significantly differ for the carbohydrates tested. CONCLUSIONS: Particle size of the oats or barley had little effect on the glycemic responses. Both oat and barley meals reduced glycemic responses; the high soluble fiber content of this barley appeared to be a factor in the greater reduction observed.     

Blood lipid and oxidative stress responses to soy protein with isoflavones and phytic acid in postmenopausal women

BACKGROUND: Postmenopausal women are at risk of cardiovascular disease (CVD) as a result of unfavorable blood lipid profiles and increased oxidative stress. Soy protein consumption may help protect against these risk factors. OBJECTIVE: Our objective was to ascertain the effect of the soy protein components isoflavones and phytate on CVD risk in postmenopausal women. DESIGN: In a double-blind 6-wk study, 55 postmenopausal women were randomly assigned to 1 of 4 treatments with soy protein (40 g/d) isolate (SPI): low phytate/low isoflavone (LP/LI); normal phytate/low isoflavone (NP/LI); low phytate/normal isoflavone (LP/NI); or normal phytate/normal isoflavone (NP/NI). Blood lipids (total, LDL, and HDL cholesterol and triacylglycerol) and oxidative stress indexes (protein carbonyls, oxidized LDLs, and 8-iso-prostaglandin-F(2alpha)) were measured at baseline and 6 wk. RESULTS: The oxidative stress indexes were not significantly affected by either phytate or isoflavones. Phytate treatment had a minimal but nonsignificant effect in reducing protein carbonyls and 8-iso-prostaglandin-F(2alpha); the reductions were 6-8% and 4-6% in the NP/LI and NP/NI groups and 1-4% and 3-4% in the LP/LI and LP/NI groups, respectively. Similarly, circulating lipids were not significantly affected by either phytate or isoflavones. The decline in total (6%-7% compared with 2%-4%) and LDL (10%-11% compared with 3%-7%) cholesterol did not differ significantly between the normal- and low-isoflavone groups, respectively. CONCLUSION: In postmenopausal women, neither phytate nor isoflavones in SPI have a significant effect of reducing oxidative damage or favorably altering blood lipids.     

Effects of oral contraceptive steroids on pituitary prolactin secretion.

Serum prolactin (PRL) levels in 16 premenopausal subjects on synthetic estrogen and progestin were measured during 19 treatment cycles. The studies were performed during the estrogen segments of the treatment cycle (days 7–16) in 10 subjects receiving sequential contraceptives, and between days 9–20 in 6 subjects receiving combination type contraceptives. Because of the episodic nature of PRL release, the transverse mean of the frequent samples obtained over a period of four hours was used for quantitative comparison of subjects receiving the contraceptive steroids with normal subjects. Significant increases in prolactin concentrations were noted in both sequential (P < 0.001) and combination (P < 0.05) pill users as compared to normals. The mean serum PRL level of subjects on sequential type pill was significantly greater (P < 0.01) than that of subjects on combination type pill. This data suggests that the estrogen component of the pill exerts a positive effect on pituitary prolactin secretion.     

Effect of consumption of soy isoflavones on behavioural, somatic and affective symptoms in women with premenstrual syndrome

Up to 80 % of the Western female population experience premenstrual syndrome (PMS). Long-term pharmacological therapy is unacceptable to most women, and is not warranted for moderate symptoms. Nutritional therapies are popular, but lack a clear evidence base. Anecdotal evidence suggests beneficial effects of soy isoflavones because of their influence on endogenous oestrogen and actions on specific tissues. The effect of isolated soya protein (ISP) containing 68 mg/d (aglycone equivalents) soy isoflavones (IF) on premenstrual symptom severity was studied in a seven-menstrual cycle, double-blind, placebo-controlled, crossover intervention study in twenty-three women with prospectively confirmed PMS aged 18-35 years and BMI 19-30 kg/m(2). ISP containing IF or milk protein placebo was consumed for two complete menstrual cycles. ISP containing IF (genistein, daidzein, equol) were measured in 24 h urine samples. After two cycles of ISP containing IF intervention, total symptoms (F(2,36) 8.20, P=0.000) and physical symptoms (F(2,36) 8.18, P=0.000) were significantly reduced compared with baseline after both active and placebo treatments, although differences between active and placebo treatment were non-significant. Specific premenstrual symptoms, headache (F(2,32) 4.10, P=0.026) and breast tenderness (F(2,32) 4.59, P=0.018), were reduced from baseline after soy IF, but not milk protein placebo. Cramps (F(2,32) 4.15, P=0.025) and swelling (F(2,32) 4.64, P=0.017) were significantly lower after active treatment compared with placebo. Concentrations of genistein and daidzein were increased following soy IF consumption, but equol production did not enhance symptom reduction. The present study showed that ISP containing IF may have potential to reduce specific premenstrual symptoms via non-classical actions.