A double-blind randomized study on the effects of red clover isoflavones on the endometrium

Role of Phytoestrogen-Rich Bioactive Substances (Linum usitatissimum L., Glycine max L., Trifolium pratense L.) in Cardiovascular Disease Prevention in Postmenopausal Women: A Systematic Review and Meta-Analysis

The aim of this report was to determine the impact of flaxseed, soy and red clover, and their bioactive substances on the lipid profile in postmenopausal women in cardiovascular diseases prevention. We used the following databases: MEDLINE (PubMed), EMBASE and the Cochrane Library. Meta-analysis indicates that the intake of flaxseed by postmenopausal women is associated with a statistically significant reduction in total cholesterol (TC) levels (weighted-mean difference (WMD) = -0.26; 95% confidence interval (95% CI): -0.38 to -0.13; p = 0.0001), low-density lipoprotein cholesterol (LDL-C) levels (WMD = -0.19; 95% CI: -0.30 to -0.08; p = 0.0006), and high-density lipoprotein cholesterol (HDL-C) levels (WMD = -0.06; 95% CI: -0.11 to -0.01; p = 0.0150). The effect of soy protein on the lipid profile showed a significant decrease in TC levels: WMD = -0.15; 95% CI: -0.25-0.05; p = 0.0048, LDL-C levels: WMD = -0.15; 95% CI: -0.25-0.05; p = 0.0067, as well as a significant increase in HDL-C levels: WMD = 0.05; 95% CI: 0.02-0.08; p = 0.0034. Changes in the lipid profile showed a significant reduction in TC levels after the use of red clover (WMD = -0.11; 95% CI: -0.18--0.04; p = 0.0017) and a significant increase in HDL-C levels (WMD = 0.04; 95% CI: 0.01 to 0.07; p = 0.0165). This meta-analysis provides evidence that consuming flaxseed, soy and red clover can have a beneficial effect on lipids in postmenopausal women and suggest a favorable effect in preventing cardiovascular diseases.

Phytoestrogens for the Management of Endometriosis: Findings and Issues

Endometriosis, a chronic disease characterized by recurrent pelvic pain and infertility, severely impacts the health and life quality of many women worldwide. Since phytoestrogens are commonly found in a variety of foods, and estrogen is a major pathological factor for the pathogenesis of endometriosis, their possible involvement cannot be ignored. This review summarizes data on the relationship between phytoestrogen intake and endometriosis risk, and analyzes the findings from in vitro experiments, rodent endometriotic models, and human intervention trials. While favorable results were often obtained from endometrial primary cultures and animal models for resveratrol, isoflavones and puerarin, only resveratrol showed promising results in human intervention trials. Critical issues concerning the current study efforts are discussed: the possible reasons beneath the discrepant observations of estrogenic/anti-estrogenic effects by phytoestrogens; the complicated interplays between phytoestrogens and endogenous estrogens; the shortage of currently used animal models; the necessity to apply reasonable doses of phytoestrogens in experiments. It is expected that the analyses would help to more properly assess the phytoestrogens' effects on the endometriosis pathogenesis and their potential values for preventive or therapeutic applications.

Effects of red clover on perimenopausal and postmenopausal women's blood lipid profile: A meta-analysis

The study aimed to perform a systematic review with meta-analysis of randomized controlled trials (RCTs) to access the effects of red clover isoflavones on the blood lipid profile of both perimenopausal and postmenopausal women. PubMed, Web of Science, Scopus, SciELO, and Cochrane Library were searched for the terms 'red clover', 'Trifolium pratense', and 'randomized controlled trial' during November 2017. Summary measures were reported as weighted mean differences (WMD) with 95% confidence interval (CI). Fixed or random effects models were used for meta-analyses, according to heterogeneity. Risk of bias was measured with the Cochrane tool. Twelve RCTs (totalizing 1284 perimenopausal and postmenopausal women receiving red clover isoflavones for 4 weeks-18 months) resulted in a significant decrease in total cholesterol (WMD = -12.34 mg/dl; 95% CI: -18.21, -6.48), low-density lipoprotein cholesterol (WMD = -10.61 mg/dl; 95% CI: -15.51, -5.72), and triglycerides (WMD = -10.18 mg/dl; 95% CI: -16.23, -4.13) together with a significant increase in high-density lipoprotein cholesterol (WMD = 1.60 mg/dl; 95% CI: 0.17, 3.03). In conclusion, the results demonstrate that the ingestion of red clover may have a beneficial effect on the lipid profile of perimenopausal and postmenopausal women.

Irilone from Red Clover ( Trifolium pratense) Potentiates Progesterone Signaling

The use of botanical dietary supplements is becoming increasingly popular for the alleviation of hormonal-based conditions such as hot flashes, premenstrual syndrome, and fertility. Estrogen and progesterone receptors (ER and PR) play an essential role in these processes. However, despite the fact that many therapies used to alleviate gynecological conditions act through PR-mediated mechanisms, few studies have investigated or identified any herbal natural product components that act on this receptor. In the current study, we used a progesterone response element (PRE)-luciferase (Luc) reporter assay to identify four phytoprogestins present in a standardized red clover ( Trifolium pratense) extract. We found that the component irilone (1) potentiated the effect of progesterone in both endometrial and ovarian cancer cell lines. In these cancers, progesterone action is generally associated with positive outcomes; thus the potentiating effect of 1 may provide entirely new strategies for enhancing progesterone signaling as a means of mitigating conditions such as fibroids and endometriosis. Formononetin (3) and biochanin A (4) exhibited mixed agonist activity, while prunetin (2) acted only as an antagonist. Collectively, these results suggest that the effects of red clover extract repeatedly observed in cultured cells and the inverse correlation between risk of various cancers and flavonoid intake may be due, in part, to altered progesterone signaling.

Oral isoflavone supplementation on endometrial thickness: a meta-analysis of randomized placebo-controlled trials

Background

Isoflavone from soy and other plants modulate hormonal effects in women, and the hormone disorder might result in different caners including endometrial cancer. However, it's effect on the risk of endometrial cancer is still inconclusive. We aimed to assess the effects of isoflavone on endometrial thickness, a risk factor of endometrial cancer in peri- and post-menopausal women.

Methods

A meta-analysis of randomized controlled trials was conducted to evaluate the effect of oral isoflavone supplementation on endometrial thickness in peri- and post-menopausal women. Electronic searches were performed on the PubMed, Embase, the Cochrane Library, web of science, CINAHL, and WHO ICTRP to August 1^st, 2015. Reviews and reference lists of relevant articles were also searched to identify more studies. Summary estimates of standard mean differences (SMD's) and 95%CIs were obtained with random-effects models. Heterogeneity was evaluated with meta-regression and stratified analyses.

Results

A total of 23 trials were included in the current analysis. The overall results did not show significant change of endometrial thickness after oral isoflavone supplementation (23 studies, 2167subjects; SMD:-0.05; 95%CI:-0.23, 0.13; P=0.60). Stratified analysis suggested that a daily dose of more than 54mg could decrease the endometrial thickness for 0.26mm (10 trials, 984subjects; SMD:-0.26; 95%CI:-0.45, −0.07; P=0.007). Furthermore, isoflavone supplementation significantly decrease the endometrial thickness for 0.23mm in North American studies (7 trials, 726 subjects; SMD:-0.23; 95%CI:-0.44, −0.01; P=0.04), but it suggested an increase for 0.23mm in Asian studies (3 trials, 224 subjects; SMD: 0.23; 95%CI:-0.04, 0.50; P=0.10).

Conclusion

Oral isoflavone supplementation might have different effects in different populations and at different daily doses. Multiple-centre, larger, and long-term trials are deserved to further evaluate its effect.

Urinary Phytoestrogen Concentrations Are Not Associated with Incident Endometriosis in Premenopausal Women

BACKGROUND

Phytoestrogens have been associated with subtle hormonal changes, but their effects on endometriosis are largely unknown.

OBJECTIVE

We assessed the association between urinary concentrations of phytoestrogens and incident endometriosis.

METHODS

We included an operative sample of 495 premenopausal women aged 18-44 y undergoing laparoscopies and laparotomies at 14 clinical sites between 2007 and 2009 and a general population sample of 131 women from the same geographic area who were matched on age and menstruation status. Endometriosis in the surgical sample was assessed by surgical visualization (clinical gold standard), whereas disease in the general population sample was assessed with the use of a pelvic MRI. Urine concentrations of genistein, daidzen, O-desmethylangolensin, equol, enterodiol, and enterolactone were measured at baseline. Poisson regression with robust error variance was used to estimate the risk of an endometriosis diagnosis for each sample after adjusting for age and body mass index (in kg/m²). Separate models were run for each phytoestrogen.

RESULTS

Overall geometric mean urine concentrations of phytoestrogens were as follows: genistein [88 nmol/L (95% CI: 72, 108 nmol/L)], daidzein [194 nmol/L (95% CI: 160, 236 nmol/L)], O-desmethylangolensin [4 nmol/L (95% CI: 3, 6 nmol/L)], equol [4 nmol/L (95% CI: 4, 6 nmol/L)], enterodiol [29 nmol/L (95% CI: 22, 38 nmol/L)], and enterolactone [355 nmol/L (95% CI: 395, 544 nmol/L)]. Geometric mean concentrations of phytoestrogens did not significantly differ by endometriosis status in either sample. Adjusted RRs for endometriosis ranged from 0.87 to 1.09 for the 6 phytoestrogens measured, with all CIs including a value ≥1. Phytoestrogens were not associated with the severity of endometriosis when restricting the analysis to women with moderate-to-severe disease per the revised American Society for Reproductive Medicine criteria. Furthermore, no associations were observed between self-reported high soy intake and endometriosis.

CONCLUSIONS

Despite endometriosis being an estrogen-dependent disease, we found no evidence that urinary phytoestrogens were associated with a higher risk of an endometriosis diagnosis in either a sample of premenopausal women or in a surgical sample.

Phytoestrogens in Botanical Dietary Supplements: Implications for Cancer

Phytoestrogens are plant constituents that possess either estrogenic or antiestrogenic activity. Although their activities are weak as compared with human endogenous estrogens, the consumption of phytoestrogens may have clinically significant consequences. A number of botanicals, or the compounds contained therein, have been identified as putative estrogenic agents, but consensus in the biomedical community has been hampered by conflicting data from various in vitro and in vivo models of estrogenic activity. Phytoestrogens may serve as chemopreventive agents while at the same time being capable of promoting growth in estrogen receptor positive cancer cell lines. Furthermore, they may exert their estrogenic influence through receptor-dependent and/or receptor-independent mechanisms. These findings have led to speculation that phytoestrogen intake might be ill advised for patients at an increased risk for hormone-dependent cancers, cancer patients, or cancer survivors. This article will attempt to sort out discrepancies between various experimental models and establish whether certain herbs possess estrogenic activity. The review will focus on 5 popular botanical dietary supplements: Trifolium pratense (red clover), Cimicifuga racemosa (black cohosh), Humulus lupulus (hops), Angelica sinensis (dong quai), and Glycyrrhiza glabra (licorice). It will address their mechanisms of action, clinical evidence bases, and implications for use in cancer.

Phytoestrogens for menopausal vasomotor symptoms

BACKGROUND

Vasomotor symptoms, such as hot flushes and night sweats, are very common during the menopausal transition. Hormone therapy has traditionally been used as a highly effective treatment, but concerns about increased risk of some chronic diseases have markedly increased the interest of women in alternative treatments. Some of the most popular of these treatments are foods or supplements enriched with phytoestrogens-plant-derived chemicals that have estrogenic action.

OBJECTIVES

To assess the efficacy, safety and acceptability of food products, extracts and dietary supplements containing high levels of phytoestrogens when compared with no treatment, placebo or hormone therapy for the amelioration of vasomotor menopausal symptoms (such as hot flushes and night sweats) in perimenopausal and postmenopausal women.

SEARCH METHODS

Searches targeted the following electronic databases: the Cochrane Menstrual Disorders and Subfertility Group Specialised Register of randomised trials (29 July 2013), the Cochrane Register of Controlled Trials (CENTRAL; 29 July 2013), MEDLINE (inception to 29 July 2013), EMBASE (inception to 29 July 2013), AMED (1985 to 29 July 2013), PsycINFO (inception to 29 July 2013) and CINAHL (inception to 29 July 2013). Attempts were made to access grey literature by sending letters to pharmaceutical companies and performing searches of ongoing trial registers. Reference lists of included trials were also searched.

SELECTION CRITERIA

Studies were included if they were randomised, included perimenopausal or postmenopausal participants with vasomotor symptoms (hot flushes or night sweats), lasted at least 12 weeks and provided interventions such as foods or supplements with high levels of phytoestrogens (not combined with other herbal treatments). Trials that included women who had breast cancer or a history of breast cancer were excluded.

DATA COLLECTION AND ANALYSIS

Selection of trials, extraction of data and assessment of quality were undertaken by at least two review authors. Most trials were too dissimilar for their results to be combined in a meta-analysis, so these findings are provided in narrative 'Summary of results' tables. Studies were grouped into broad categories: dietary soy, soy extracts, red clover extracts, genistein extracts and other types of phytoestrogens. Five trials used Promensil, a red clover extract; results of these trials were combined in a meta-analysis, and summary effect measures were calculated.

MAIN RESULTS

A total of 43 randomised controlled trials (4,364 participants) were included in this review. Very few trials provided data suitable for inclusion in a meta-analysis. Among the five trials that yielded data assessing the daily frequency of hot flushes suitable for pooling, no significant difference overall was noted in the incidence of hot flushes between participants taking Promensil (a red clover extract) and those given placebo (mean difference (MD) -0.93, 95% confidence interval (CI) -1.95 to 0.10, I(2) = 31%). No evidence indicated a difference in percentage reduction in hot flushes in two trials between Promensil and placebo (MD 20.15, 95% CI -12.08 to 52.38, I(2) = 82%). Four trials that were not combined in meta-analyses suggested that extracts with high (> 30 mg/d) levels of genistein consistently reduced the frequency of hot flushes. Individual results from the remaining trials were compared in broad subgroups such as dietary soy, soy extracts and other types of phytoestrogens that could not be combined. Some of these trials found that phytoestrogen treatments alleviated the frequency and severity of hot flushes and night sweats when compared with placebo, but many trials were small and were determined to be at high risk of bias. A strong placebo effect was noted in most trials, with a reduction in frequency ranging from 1% to 59% with placebo. No indication suggested that discrepant results were due to the amount of isoflavone in the active treatment arm, the severity of vasomotor symptoms or trial quality factors. Also, no evidence indicated that these treatments caused oestrogenic stimulation of the endometrium or the vagina or other adverse effects when used for up to two years.

AUTHORS' CONCLUSIONS

No conclusive evidence shows that phytoestrogen supplements effectively reduce the frequency or severity of hot flushes and night sweats in perimenopausal or postmenopausal women, although benefits derived from concentrates of genistein should be further investigated.

Alternative and complementary therapies for the menopause

Despite a re-evaluation of risks in recent years, hormone replacement therapy is still surrounded by controversy. Almost 30% of women in a recent survey sought a natural approach to combat climacteric symptoms. Nevertheless, a large proportion of patients felt that they wanted a good safety profile and strong evidence base for treatment. This article seeks to review the evidence supporting non-hormonal approaches to treatment. There is only conflicting evidence at best to support alpha-2 agonists, e.g. clonidine and limited evidence for dihydroepiandrosterone and natural progesterones. There is limited randomized controlled trial data for gabapentin, selective norepinephrine re-uptake inhibitors (SNRIs) and selective serotonin re-uptake inhibitors (SSRIs), many of these studies being related to breast cancer patients. Of the herbal medicinal products, the largest evidence base rests with phytoestrogens. A Cochrane Database review looking at all types of phytoestrogens, e.g. red clover extracts, dietary soya and soya extracts concluded that there was no evidence to support improvement in climacteric symptoms and the meta-analysis of a 178 studies on soy products was inconsistent. Nevertheless, other studies disagree. Mammographic density is not affected by soy or phytoestrogen products and recent in vitro work shows only a weakly proliferative effect of soy isoflavone on breast cancer cells and evidence that soy isoflavone blocks the proliferative effect of estradiol on these cells. There are no studies looking at clinical outcome measures for cardiovascular disease but a number of studies looking at biochemical markers including arterial wall stiffness and apolipo protein B. Recent studies have also looked at the effects of red clover isoflavone on mood and depression, using specific depression rating scales. Finally, it is important to note that herbal medicinal products should not be used without caution. Some may produce quite marked side-effects in high doses and others can interact with pre-existing medication. A strategy for which patients are suitable for herbal medicinal products is reviewed.

Taking an integrated approach: managing women with phytoestrogens

An integrated approach can be employed when counselling women about menopausal management options, where lifestyle, complementary therapies and hormone replacement therapy (HRT) are discussed. Women might opt to use an alternative approach to HRT for a variety of reasons, e.g. fear of side-effects and risks or contraindications to HRT. There are many choices of dietary and herbal approaches for menopausal symptoms, which essentially divide into food supplements and herbal medicines. The choice can often be overwhelming and confusing for the woman. Of concern, the evidence for efficacy and safety of some of these complementary therapies can be extremely limited or non-existent. In order to enable women to make a fully informed choice, it is important that, when a recommendation is made regarding a specific complementary therapy, it should focus on preparations for which a significant dataset exists for efficacy and safety and in which there is ongoing research and development. One of the most extensively studied food supplements has been the phytoestrogenic preparation containing red clover isoflavones. There have been six randomized trials thus far studying the impact on vasomotor symptoms, three of which have shown a significant benefit compared to placebo. There are also data from small randomized and observational trials showing positive outcomes for surrogate markers of osteoporosis and cardiovascular disease. A recent study using validated depression scales has shown that women using red clover isoflavones may also derive psychological benefits. Safety data are reassuring for the endometrium and breast, although further studies would be welcome, particularly in women with significant medical risks.

Dietary phyto-oestrogens: molecular mechanisms, bioavailability and importance to menopausal health

Following the high-profile studies on hormone replacement therapy which provided little evidence in support of the drug therapy improving future health, there remains a growing demand for dietary solutions for maintaining health and preventing disease as women age. Although interest in the relative importance of phyto-oestrogens to human health has increased dramatically over the last decade, the effective dose for health benefits and hypothetical issues on safety remain to be resolved. Plausible mechanisms and epidemiological data are available to support the concept that phyto-oestrogen-rich diets exert physiological effects, but optimal doses and sources of these compounds have still not been elucidated for specific health benefits. In addition, much of the current mechanistic data are difficult to interpret as the experiments have incorporated levels of phyto-oestrogens that may not be achievable in vivo and have to date only used aglycones and glycosides of the pure compounds rather than examining the biological effects of gut and liver metabolites. The present review will concentrate on the isoflavone subclass of phyto-oestrogens, as, to date, these compounds have received most attention from both a commercial and research perspective.

Red clover isoflavones are safe and well tolerated in women with a family history of breast cancer

OBJECTIVE

To assess the safety and tolerability of a standardized 40 mg red clover isoflavone dietary supplement (Promensil, Novogen) in women with a family history of breast cancer to evaluate the feasibility of using the supplement for prevention of breast cancer in healthy women.

STUDY DESIGN

Healthy women aged 35-70 years (n = 401) with at least one first-degree relative with breast cancer received red clover isoflavones or placebo for three years in a randomized, double-blind, placebo-controlled pilot trial. Participants were assessed clinically and blood samples taken for biochemical analysis every six months. In addition, study participants underwent mammography, bone density and transvaginal ultrasound (postmenopausal women only) once per year.

RESULTS

No significant differences in breast density, endometrial thickness, serum cholesterol, follicle stimulating hormone levels and bone mineral density were detected between those taking red clover isoflavones and placebo. In postmenopausal women, some significant differences in bone marker levels were seen between active and placebo groups, at six months and at 12 months. The adverse event profile was similar across all red clover isoflavone and placebo groups.

CONCLUSION

This three-year study supports the growing body of evidence that treatment with red clover isoflavones is safe and well tolerated in healthy women. Supplements containing red clover isoflavones did not adversely affect breast density, skeletal strength or cardiovascular status. In postmenopausal women, endometrial status was not adversely affected. The adverse event profile was similar between red clover isoflavones, and placebo and endocrine status did not differ.

Clinical studies of red clover (Trifolium pratense) dietary supplements in menopause: a literature review

Red clover (Trifolium pratense L., Fabaceae) botanical dietary supplements have received much attention recently for their potential use in the treatment of menopause symptoms, maintenance/improvement of bone and cardiovascular health, and reported benign effects on the breast and endometrium. Literature searches of four computerized databases were run to identify clinical studies of red clover botanical dietary supplements. The manufacturer of the red clover products used in the majority of the studies was contacted for unpublished information and/or clarification regarding the chemical content of their products. Red clover studies were reviewed that pertained to women's health or menopause. Clinical evidence is presently lacking to support the efficacy of semipurified red clover isoflavone extracts for alleviation of climacteric vasomotor symptoms or reduction of low-density lipoprotein levels in the blood. Furthermore, the safety of use of red clover isoflavone supplements in patients with breast or endometrial cancer has not been established. Limited evidence suggests possible efficacy in maintenance of bone health and improvement of arterial compliance, a risk factor for atherosclerosis. This literature review covers red clover botanical dietary supplement clinical studies having a possible impact on the health care of mature and menopausal women, and provides historical perspective regarding the traditional uses of red clover.

Uterotropic effects of dietary equol administration in ovariectomized Sprague-Dawley rats

AIM

The aim of the present study was to evaluate the uterotropic effects of the administration of dietary equol, a metabolite of soy-derived daidzein or formononetin present in red clover, in an ovariectomized rat model of menopause.

METHOD

Two doses of racemic equol were used (50 mg/kg of chow and 400 mg/kg of chow) and the results were compared with two doses of estradiol-3 benzoate (E2B) (4.3 mg/kg of chow and 17.3 mg/kg of chow). After 3 months, animals were sacrificed and the uteri were removed, weighed and paraffin-embedded for morphometrical and immunohistochemical evaluation. The expression of selected uterine estrogen-responsive genes was also measured using real-time reverse transcription-polymerase chain reaction.

RESULTS

Compared to controls, uterine weights in animals treated with high-dose equol were significantly higher, presented histologic features of mild estrogenic stimulation and had greater epithelial height and thickness of the uterine stroma and myometrium. Staining for the presence of the proliferating cell nuclear antigen (PCNA) also showed a greater prevalence of the PCNA-positive cells in the uterine stroma in animals treated with high-dose equol. Conversely, the percentage of PCNA-positive cells in the uterine epithelium was lower compared to the controls. Dietary high-dose equol treatment also increased significantly levels of uterine insulin-like growth factor 1, progesterone receptor and complement protein 3 mRNA. Although statistically significant, all these effects were, however, lower in magnitude compared to the effects of low- and high-dose E2B treatment. Low-dose equol did not have any effects on the above-studied parameters.

CONCLUSION

Long-term high-dose dietary equol administration to ovariectomized rats exerts uterotropic effects at the cellular and molecular level which question the safety of uncontrolled and unlimited consumption of soy or red clover supplements by postmenopausal women with intact uteri.

Integrated healthcare: herbal remedies for menopausal symptoms

Women approaching the menopause frequently resort to complementary therapies and natural remedies, especially herbal medicines. Nurses working with mature women, both in the community and in hospital, may find themselves drawn into a debate about these remedies, yet may feel unable to answer women's questions, or be unsure where to find information. However, with the increased use of complementary therapies generally, it is imperative that nurses recognize the parameters of their personal practice and appreciate the possible problems which may arise from ill-informed use of natural remedies, such as herb-drug interactions. This article provides an overview of herbal remedies popularly self-administered by women in the peri-menopausal period. The effects and safety of several remedies are explored to facilitate nurses to offer accurate, comprehensive and evidence-based information to patients. The issue of integration of herbal medicine into mainstream management of menopausal symptoms is also debated as a means of providing optimum and safe care to women at this time.

Phytoestrogens for vasomotor menopausal symptoms

BACKGROUND

Vasomotor symptoms, such as hot flushes and night sweats, are very common during the menopausal transition. Hormone replacement therapy has traditionally been used as a very effective treatment but concerns over increased risks of some chronic diseases have markedly increased the interest of women in alternatives. Some of the most popular of these are treatments based on foods or supplements enriched with phytoestrogens, plant-derived chemicals that have oestrogenic action.

OBJECTIVES

To assess the efficacy, safety and acceptability of foods and supplements based on high levels of phytoestrogens for reducing hot flushes and night sweats in postmenopausal women.

SEARCH STRATEGY

Searches were undertaken of the following electronic databases: the Cochrane Menstrual Disorders and Subfertility Group Specialised Register of randomised trials, Cochrane Register of Controlled Trials (CENTRAL) (March 2007), MEDLINE (1966 to March 2007), EMBASE (1980 to March 2007), AMED (1985 to March 2007), PsycINFO (1986 to March 2007) and CINAHL (1982 to March 2007). Attempts were made to access grey literature by letters to pharmaceutical companies and searches of ongoing trial registers. Reference lists of included trials were also searched.

SELECTION CRITERIA

Studies were included if they were randomised, had peri- or postmenopausal participants with vasomotor symptoms, a duration of at least 12 weeks and where the intervention was a food or supplement with high levels of phytoestrogens (and not combined with other herbal treatments). Trials of women who had breast cancer or a history of breast cancer were excluded.

DATA COLLECTION AND ANALYSIS

Selection of trials, data extraction and quality assessment were undertaken by at least two authors. Most of the trials were too dissimilar to combine in meta-analysis and their results are provided in table format. Studies were grouped into broad categories: dietary soy, soy extracts, red clover extracts and other types of phytoestrogen. Five trials used Promensil, a red clover extract; these trials were combined in a meta-analysis and summary effect measures were calculated.

MAIN RESULTS

Thirty trials comparing phytoestrogens with control met the inclusion criteria. Very few trials had data suitable for combining in meta-analysis. Of the five trials with data suitable for pooling that assessed daily frequency of hot flushes, there was no significant difference overall in the frequency of hot flushes between Promensil (a red clover extract) and placebo (WMD=-0.6, 95% CI -1.8 to 0.6). There was no evidence of a difference in percentage reduction in hot flushes in two trials between Promensil and placebo (WMD=20.2, 95% CI -12.1 to 52.4). Individual results from the remaining trials were compared. Some of the trials found that phytoestrogen treatments alleviated the frequency and severity of hot flushes and night sweats when compared to placebo but many of the trials were of low quality and were underpowered. There was a strong placebo effect in most trials with a reduction in frequency ranging from 1% to 59% with placebo. There was no indication that the discrepant results were due to the amount of isoflavone in the active treatment arm, the severity of vasomotor symptoms or trial quality factors. There was also no evidence that the treatments caused oestrogenic stimulation of the endometrium (an adverse effect) when used for up to two years.

AUTHORS' CONCLUSIONS

There is no evidence of effectiveness in the alleviation of menopausal symptoms with the use of phytoestrogen treatments.

Dietary daidzein and puerarin do not affect pituitary LH expression but exert uterotropic effects in ovariectomized rats

OBJECTIVE

To investigate the potency of LH suppression, as an indirect measure of alleviation of postmenopausal vasomotor symptoms, as well as the uterotropic effects of two isoflavones: daidzein and puerarin in an ovariectomized (ovx) rat model and compare them with the effects of 17beta-estradiol benzoate (E2B).

DESIGN

Eighty female Sprague-Dawley rats were ovx and divided into six different treatment groups and one control group (11-12 animals per group). Daidzein, puerarin and E2B were added to the soy free rodent chow in low and high doses (250 mg and 1000 mg per kg, 600 mg and 3000 mg per kg and 4.3 mg and 17.3 mg per kg, respectively). After 3 months of treatment, animals were sacrificed and using real time RT-PCR, pituitary LHbeta and uterine IGF-1, PR and C3 mRNA levels were measured. Additionally serum LH levels were measured in a radioimmunoassay.

RESULTS

Both of our tested isoflavones at low and high doses had no effect on the expression of the pituitary LH at the mRNA and protein level. Only E2B at both doses significantly decreased pituitary LHbeta gene expression and serum LH levels. Daidzein and puerarin at high dose increased significantly uterine weights. Uterine IGF-1 gene expression was only upregulated in puerarin high group. Uterine PR mRNA levels were higher in animals fed with low dose daidzein and high dose puerarin. Uterine C3 gene expression was upregulated in animals fed with daidzein and puerarin at high doses. Although statistically significant, all these effects were however very discrete compared to those of E2B at low and high doses.

CONCLUSION

We speculate that due to the lack of LH suppressing effects in our model, it is very unlikely for daidzein and puerarin to alleviate vasomotor symptoms in postmenopausal women. In contrast, due to their uterotropic effects, high dose consumption of commercially available preparations containing daidzein or puerarin may expose women with an intact uterus to the risk of endometrial hyperplasia.

Phytoestrogens and Coronary Microvascular Function in Women with Suspected Myocardial Ischemia: A Report from the Women's Ischemia Syndrome Evaluation (WISE) Study

AIMS

Soy phytoestrogens are popular, but information on their coronary effects in patients with suspected ischemic heart disease is limited. Accordingly, we investigated the relationship between blood phytoestrogen levels and coronary reactivity in women with suspected myocardial ischemia referred for coronary angiography.

METHODS

Coronary flow velocity reserve (CFVR) and volumetric flow reserve (VFR) to adenosine (ADO) and nitroglycerin (NTG) (nonendothelial-dependent responses) and acetylcholine (ACH) (endothelial-dependent response) were assessed in 106 women from the Women's Ischemia Syndrome Evaluation (WISE). Blood phytoestrogen (daidzein and genistein) and estrogen (estradiol) levels were correlated with coronary reactivity measures.

RESULTS

Participants were mostly postmenopausal (79%), mean age 56 years, and 24% had obstructive coronary artery disease (CAD) at angiography. Genistein blood levels were negatively correlated with nonendothelial-dependent coronary flow responses. The highest genistein tertile (>6.1 ng/mL) had a CFVR of 2.1 +/- 0.5 (mean +/- SD) and VFRADO of 1.0 +/- 0.6, and both were significantly (p= 0.0001) lower compared with the other genistein tertiles combined. Similar associations were noted for CFVR(NTG) and VFR(NTG) (p = 0.03 and p = 0.01, respectively). The highest genistein tertile was associated with lower CFVR(ACH) compared with the other tertiles (p = 0.03). In multivariable modeling, blood genistein levels were significant independent predictors of coronary flow responses to ADO. There were no significant correlations between coronary reactivity variables and daidzein or endogenous estrogen.

CONCLUSIONS

In women with suspected myocardial ischemia, higher genistein blood levels are associated with impaired nonendothelial-dependent and endothelial-dependent coronary microvascular function.

Integrating phytoestrogens with prescription medicines--a conservative clinical approach to vasomotor symptom management

There is a growing body of scientific evidence that complementary therapies such as isoflavone containing phytoestrogens might help menopausal symptoms. Women are now using them, believing them to be safer and "more natural" especially following the current controversies regarding HRT. However, the choice of treatments is confusing and with some preparations, little is known about their active ingredients, safety or side effects or how they may interact with other therapies. This paper examines the available evidence for management of menopause symptoms with isoflavone containing phytoestrogens, both in terms of efficacy and safety. An algorithm is suggested to demonstrate how these preparations may be integrated with conventional therapies to effectively manage menopause symptoms.

Trifolium pratense isoflavones in the treatment of menopausal hot flushes: a systematic review and meta-analysis

OBJECTIVE

To critically assess the evidence of supplements containing Trifolium pratense (red clover) isoflavones in the reduction of hot flush frequency in menopausal women.

DATA SOURCES

Systematic literature searches were performed in (Medline (1951 - April 2006), Embase (1974 - April 2006), CINAHL (1982 - April 2006), Amed (1985 - April 2006) and The Cochrane Library (Issue 2, 2006). Reference lists located were checked for further relevant publications. Experts in the field and manufacturers of identified products were contacted for unpublished material. No language restrictions were imposed.

REVIEW METHODS

Studies were selected according to predefined inclusion and exclusion criteria. All randomized clinical trials of monopreparations containing T. pratense isoflavones for treating hot flushes were included. Study selection, data extraction and validation were performed by at least two reviewers with disagreements being settled by discussion. Weighted means and 95% confidence intervals were calculated and sensitivity analyses were performed.

RESULTS

Seventeen potentially relevant articles were retrieved for further evaluation. Five were suitable for inclusion in the meta-analysis. The meta-analysis indicates a reduction in hot flush frequency in the active treatment group (40-82 mg daily) compared with the placebo group (weighted mean difference -1.5 hot flushes daily; 95% CI -2.94 to 0.03; p=0.05).

CONCLUSION

There is evidence of a marginally significant effect of T. pratense isoflavones for treating hot flushes in menopausal women. Whether the size of this effect can be considered clinically relevant is unclear. Whereas there is no apparent evidence of adverse events during short-term use, there are no available data on the safety of long-term administration.

Soy and red clover for mid-life and aging

INTRODUCTION

Menopause is associated with mid-life, a time when many women begin to experience the signs and symptoms of aging, such as increases in blood pressure, changes in lipid profiles, loss of bone mass density, and diminished memory and cognition. Given the result of the Women's Health Initiative, many women no longer consider hormone therapy the first option for promoting healthy aging. Instead, they are turning to botanical and dietary supplement (BDS) products in place of hormone therapy. This paper reviews the evidence available for use of isoflavones from soy and red clover for the treatment or prevention of these health issues.

METHODS

The MEDLINE and EMBASE databases were searched for articles relating to soy or red clover supplement use for prevention and/or treatment of heart disease, hyperlipidemia, osteoporosis, mood disorders and cognitive abilities. Studies were included if they were randomized, controlled trials and included peri- or postmenopausal women.

RESULTS

Isoflavone products appear to be the most useful for improving lipid profiles; however, the evidence suggests that isoflavone extracts from soy are less effective than products containing soy protein or red clover isoflavones. Soy protein appears to reduce levels of total cholesterol and low density lipoprotein cholesterol, while red clover reduces levels of triglycerides and increases high density lipoprotein cholesterol. The data were somewhat less convincing, although promising, for increasing bone mass density and improving cognitive abilities.

CONCLUSIONS

Research suggests that isoflavones found in soy foods and red clover appear to have a small but positive health effect on plasma lipid concentrations, bone mass density, and cognitive abilities. Given the lack of serious safety concerns in the short term, it would appear that including soy and red clover in the diet of postmenopausal women, not withstanding a soy allergy, might be beneficial.

Effects of a red clover extract (MF11RCE) on endometrium and sex hormones in postmenopausal women

OBJECTIVE

To evaluate the effects of a non-prescription red clover extract (MF11 RCE, Melbrosin International, Vienna, Austria) on selected sex hormones and endometrium in postmenopausal women.

PATIENTS AND METHODS

One-hundred and nine postmenopausal women with an age > or =40 years were randomly assigned to one of two groups either two capsules of MF11RCE (80mg isoflavone) per day for a 90 day period, or placebo of equal design. After a 7 day washout period, medication was crossed-over for another 90 days.

RESULTS

Combined evaluation demonstrated that supplementation with MF11RCE (verum), in contrast to placebo, significantly increased plasma testosterone levels and decreased endometrial thickness.

CONCLUSION

MF11RCE exerts a moderate effect on testosterone levels in postmenopausal women, while estradiol levels remained unchanged. The observed reduction of endometrial thickness provides further support for a safe role for isoflavones in terms of endometrial hyperplasia.

Complementary and hormonal therapy for vasomotor symptom relief: a conservative clinical approach

Vasomotor symptoms are the most common menopausal symptom experienced by women and the leading reason menopausal women seek health care advice. The recent shift towards a more conservative use of hormone therapy (HT) during menopause has prompted the need for treatment regimens to be individualized according to symptom severity. Our objective was to develop a new algorithm that enables practitioners to customize treatment regimens according to symptom severity. In order to develop a comprehensive treatment algorithm, we conducted a literature review and considered the findings from recently published treatment guidelines from around the world. We also evaluated the results of systematic reviews investigating the efficacy and safety of complementary and alternative medicines. We found a growing trend away from prescription HT in women with mild to moderate symptoms and an increasing trend toward lifestyle modification and the use of complementary and alternative medicines. On the basis of these findings, we have developed an algorithm that accounts for symptom severity. The algorithm presented here provides treatment options based on symptom severity and a comprehensive approach for integrating lifestyle modifications and complementary therapies with prescription treatment regimens.

Soy protein, isoflavones, and cardiovascular health: an American Heart Association Science Advisory for professionals from the Nutrition Committee

Soy protein and isoflavones (phytoestrogens) have gained considerable attention for their potential role in improving risk factors for cardiovascular disease. This scientific advisory assesses the more recent work published on soy protein and its component isoflavones. In the majority of 22 randomized trials, isolated soy protein with isoflavones, as compared with milk or other proteins, decreased LDL cholesterol concentrations; the average effect was approximately 3%. This reduction is very small relative to the large amount of soy protein tested in these studies, averaging 50 g, about half the usual total daily protein intake. No significant effects on HDL cholesterol, triglycerides, lipoprotein(a), or blood pressure were evident. Among 19 studies of soy isoflavones, the average effect on LDL cholesterol and other lipid risk factors was nil. Soy protein and isoflavones have not been shown to lessen vasomotor symptoms of menopause, and results are mixed with regard to soy's ability to slow postmenopausal bone loss. The efficacy and safety of soy isoflavones for preventing or treating cancer of the breast, endometrium, and prostate are not established; evidence from clinical trials is meager and cautionary with regard to a possible adverse effect. For this reason, use of isoflavone supplements in food or pills is not recommended. Thus, earlier research indicating that soy protein has clinically important favorable effects as compared with other proteins has not been confirmed. In contrast, many soy products should be beneficial to cardiovascular and overall health because of their high content of polyunsaturated fats, fiber, vitamins, and minerals and low content of saturated fat.

Do soy isoflavones cause endometrial hyperplasia?

For many years, hormone replacement therapy (HRT) was considered the gold standard for the symptomatic treatment of menopause. Clinical trials have found that HRT reduces the symptoms of hot flashes and sweating, while also decreasing vaginal dryness and urinary tract infections. HRT has also been shown to be protective against colon cancer (37%) and hip fractures (34%). However, recent findings from the Women's Health Initiative (WHI) have revealed that long-term HRT may actually lead to an increase in heart disease (29%), breast cancer (26%) and other adverse events, such as stroke (41%). Consequently, many women in the United States and abroad are actively looking for alternative treatments for menopause, including botanical dietary supplements.

Isoflavones and postmenopausal women: a critical review

Isoflavonic phytoestrogens, or isoflavones, constitute a class of phytoestrogens that have properties similar to selective estrogen receptor modulators, and have attracted a substantial degree of attention in recent years, particularly as a possible alternative to the conventional hormone replacement therapy regimens used by postmenopausal women. Despite great promise, it is difficult to make many specific recommendations about their use at the current time, in light of the many outstanding questions that hopefully will be answered in the future by focused interventional studies involving humans. Studies to date indicate that the use of isoflavones to address vasomotor symptoms provides at most small benefits beyond a placebo effect, and no benefit for genital atrophy. As for postmenopausal women whose primary concern is cardiovascular disease, the recommendation of the American Heart Association to include soy protein foods as part of an otherwise healthy diet is well justified, and similarly the substitution of supplements containing soy protein for animal protein can also be recommended. The use of purified isoflavone supplements not containing soy protein may have some cardiovascular benefits, but these appear to be less substantial in degree than those provided by soy protein with isoflavones. In particular, more research is needed to assess the effects of isoflavones on osteoporosis, for which no recommendation regarding isoflavones can be made based on the current data. Also, isoflavones should not be taken by postmenopausal women for the specific purpose of decreasing their risk of breast or endometrial cancer, although, at least for those without pre-existing disease or at high risk, it seems quite unlikely that isoflavone use is harmful in this regard.

Phytoestrogens derived from red clover: an alternative to estrogen replacement therapy?

The benefits of plant extracts from soy and red clover as alternatives to conventional hormone replacement therapy (HRT) have been debated in the past. Here, an attempt has been made to summarize the biochemical and pharmacological data in the light of clinical aspects. Red clover and soy extracts contain isoflavones, which have a high affinity to estrogen receptor alpha (ERalpha), estrogen receptor beta (ERbeta), progesterone receptor (PR) and androgen receptor (AR). The higher affinity to ERbeta compared to ERalpha has been used as an explanation why red clover extracts function as food additives to treat menopausal disorders and may reduce risk of breast cancer. Biochemical analysis shows that these representatives of phytoestrogens have multiple actions beside selective estrogen receptor modulator (SERM)-activity. They act as selective estrogen enzyme modulators (SEEMs), have antioxidant activity and interact with transcription factors such as NF-kappaB. Furthermore, it is indicated that they have protective effects on osteoporosis and the cardiovascular system. Currently 40-50mg of isoflavones (biochanin A, daidzein, formononetin and genistein) are recommended as daily dose. This recommendation is based on the daily intake of phytoestrogens in a traditional Japanese diet.

Lack of effect of isoflavonoids on the vagina and endometrium in postmenopausal women

OBJECTIVE

To determine the effects of soy-derived isoflavones on vaginal epithelium and the endometrium.

DESIGN

Double-blind, randomized, placebo-controlled crossover trial.

SETTING

Outpatient clinic of a university hospital.

PATIENT(S)

Sixty-four postmenopausal women with a history of breast cancer.

INTERVENTION(S)

The women took (in a randomized order) 114 mg of isolated isoflavonoids or placebo in tablets daily for 3 months; the treatment regimens were crossed over after a 2-month washout period. The subjects were studied before and on the last day of each treatment period.

MAIN OUTCOME MEASURE(S)

Vaginal dryness, maturation index (MI) of vaginal epithelium, endometrial thickness, histology, and expression of estrogen (E) and progesterone (P) receptors and the proliferation marker Ki-67 in the endometrium.

RESULT(S)

Isolated isoflavones did not relieve vaginal dryness. Maturation index values remained unchanged during the isoflavone regimen, but decreased during the placebo regimen. No changes were found in any of the variables measured in the endometrium.

CONCLUSION(S)

Daily administration of 114 mg of isolated isoflavones for 3 months had no effect on the subjective perception of vaginal dryness or on objective findings in the vagina or endometrium. This implies safety with regard to the endometrium.

Endometrial effects of long-term treatment with phytoestrogens: a randomized, double-blind, placebo-controlled study

OBJECTIVE

To determine the effects of 5 years of treatment with soy phytoestrogens on histological characteristics of endometrium in postmenopausal women.

DESIGN

Randomized, double-blind, placebo-controlled study.

SETTING

Centre of Perinatal and Reproductive Medicine, Department of Gynecological, Obstetrical, and Pediatric Sciences, University of Perugia, Italy.

PATIENT(S)

Three hundred seventy-six postmenopausal healthy women, all with intact uterus.

INTERVENTION(S)

Women were distributed in two different groups using randomized criteria: group A (n = 179) patients received soy tablets (150 mg of isoflavones per day) for 5 years; group B (n = 197) patients received identical appearing placebo tablets for 5 years.

MAIN OUTCOME MEASURE(S)

Results of endometrial histology from biopsies obtained at baseline, 30 months, and 5 years after the beginning of the treatment.

RESULT(S)

Two hundred ninety-eight women completed the 5-year treatment. No cases of malignancy were detected during biopsy. Seventy percent of women undergoing treatment with soy phytoestrogens had an endometrium classified as atrophic or nonassessable versus 81% receiving placebo. The occurrence of endometrial hyperplasia was significantly higher in group A (3.37% vs. 0%).

CONCLUSION(S)

Long-term treatment (up to 5 years) with soy phytoestrogens was associated with an increased occurrence of endometrial hyperplasia. These findings call into question the long-term safety of phytoestrogens with regard to the endometrium.

The effects of phytoestrogen isoflavones on bone density in women: a double-blind, randomized, placebo-controlled trial

BACKGROUND

Isoflavone phytoestrogen therapy has been proposed as a natural alternative to hormone replacement therapy (HRT). HRT has a beneficial effect on bone, but few trials in humans have investigated the effects of isoflavones on bone.

OBJECTIVE

The objective of the study was to determine the effect on bone density of a red clover-derived isoflavone supplement that provided a daily dose of 26 mg biochanin A, 16 mg formononetin, 1 mg genistein, and 0.5 mg daidzein for 1 y. Effects on biochemical markers of bone turnover and body composition were also studied.

DESIGN

Women aged 49-65 y (n = 205) were enrolled in a double-blind, randomized, placebo-controlled trial; 177 completed the trial. Bone density, body composition, bone turnover markers, and diet were measured at baseline and after 12 mo.

RESULTS

Loss of lumbar spine bone mineral content and bone mineral density was significantly (P = 0.04 and P = 0.03, respectively) lower in the women taking the isoflavone supplement than in those taking the placebo. There were no significant treatment effects on hip bone mineral content or bone mineral density, markers of bone resorption, or body composition, but bone formation markers were significantly increased (P = 0.04 and P = 0.01 for bone-specific alkaline phosphatase and N-propeptide of collagen type I, respectively) in the intervention group compared with placebo in postmenopausal women. Interactions between treatment group and menopausal status with respect to changes in other outcomes were not significant.

CONCLUSION

These data suggest that, through attenuation of bone loss, isoflavones have a potentially protective effect on the lumbar spine in women.

Effects of dietary isoflavone aglycones on the reproductive tract of male and female mice

We assessed the effects of dietary consumption of soy isoflavone aglycones on the reproductive tract of sexually mature male and female mice. Isoflavone concentrates with a ratio of 10:1, 2:1 or 1:10 genistein:daidzein (G:D) were added to provide 120 mg total isoflavones/1800 Calories (approximately 40 mg/kg body weight) to diets having either casein/lactalbumin or soy protein isolate as the source of protein. After 16 weeks, mice were necropsied and gross and histopathologic assessments of uterus, vagina, testes and accessory sex glands were completed. Effects of the 10G:1D isoflavone concentrates were absent or minimal in females but in males included atrophy of accessory sex glands. In contrast, the 2G:1D and 1G:10D concentrates caused dramatic estrogenic effects in both male and female mice. Effects in females included endometritis and effects typical of estrogenic stimulation (i.e., uterine enlargement, keratinization of vaginal epithelium, increased height of endometrial surface epithelial cells, and uterine squamous metaplasia). Effects in males included reduced plasma testosterone concentrations, atrophy of seminiferous epithelium, atrophy of accessory sex glands, and squamous metaplasia of seminal vesicles. Some effects varied with protein source. We conclude that a diet containing approximately 40 mg/kg soy isoflavone aglycones with a genistein:daidzein ratio of 2:1 or less has marked estrogenic effects on the reproductive system of male and female mice.

Soy protein isolate with isoflavones does not prevent estradiol-induced endometrial hyperplasia in postmenopausal women: a pilot trial

OBJECTIVE

To test the hypothesis that soy protein isolate (SPI) with isoflavones opposes the proliferative effects of exogenous estradiol (E2) on the endometrium after menopause.

DESIGN

Thirty-nine postmenopausal women were randomized to receive daily for 6 months either 0.5 mg E2 + placebo, 1.0 mg E2 + placebo, 0.5 mg E2 + 25 g SPI with 120 mg isoflavones, or 1.0 mg E2 + 25 g SPI with 120 mg isoflavones. Primary outcome measures were endometrial histology, ultrasound endometrial thickness, and Ki67 staining quantification, a marker of cellular proliferation. Secondary outcome measures were serum lipids and markers of bone resorption.

RESULTS

Endometrial hyperplasia, endometrial stromal and epithelial cellular proliferation, and sonographically measured endometrial thickness were similarly affected in all groups. SPI did not lessen the beneficial effects of E2 on lipids and markers of bone resorption.

CONCLUSION

In this pilot study, SPI with isoflavones did not protect the endometrium from E2-induced hyperplasia in postmenopausal women. If higher, long-term doses of isoflavone supplementation are found to be safe for postmenopausal women, then future studies combining E2 with isoflavones may be feasible as an alternative to traditional hormone replacement therapy.

Phytoestrogens: a review of the present state of research

Phytoestrogens are a diverse group of plant-derived compounds that structurally or functionally mimic mammalian estrogens and show potential benefits for human health. The number of articles published on phytoestrogens has risen dramatically in the past couple decades. Further research continues to demonstrate the biological complexity of phytoestrogens, which belong to several different chemical classes and act through diverse mechanisms. This paper discusses the classification of phytoestrogens, methods of identification, their proposed mechanisms of action and botanical sources for phytoestrogens. The effects of phytoestrogens on breast and prostate cancers, cardiovascular disease, menopausal symptoms and osteoporosis will also be examined including research on benefits and risks.

Phytoestrogens--mechanism of action and effect on bone markers and bone mineral density

Dietary supplements, especially those containing phytoestrogens, frequently are used to either promote health or prevent disease. An estimated 20 billion dollars was spent on dietary supplements in the year 2000. Approximately 40% to 55% of Americans use supplements on a regular basis and 24% of these supplements contain herbs. Phytoestrogens are defined as any compound that is structurally or functionally related to ovarian or placental estrogens and their active metabolites. These compounds are widely used for various disorders related to women's health.

Comparison of hormonal activity (estrogen, androgen and progestin) of standardized plant extracts for large scale use in hormone replacement therapy

Extracts from red clover (Trifolium pratense), soybean (Glycine max.) and black cohosh (Cimicifuga racemosa) are frequently used as alternative compounds for hormone replacement therapy (HRT) to treat menopausal disorders. Fifteen commercially available products made either from red clover, soybean or black cohosh were tested in in vitro assays in this study. The main polycyclic phenolic compounds of soy and red clover products were biochanin A, genistein, daidzein, formononetin, and glycitein. In red clover products glycitein was not abundant. All the compounds showed clear estrogenic activity through estrogen receptor alpha (ERalpha) and estrogen receptor beta (ERbeta) and affinity to progesterone receptor (PR) and androgen receptor (AR), whereas the compounds from black cohosh did not. This was corroborated by synthetic isoflavones such as biochanin A, daidzein, genistein and formononetin. They exerted affinity to PR and AR in the range of 0.39-110 mM. Statistical analysis applying principal component analysis (PCA) revealed that all red clover and soy products are grouped in different clusters. Red clover products showed a higher affinity to AR and PR than soy products, which is explained by the higher amount of isoflavones present. In vitro assays and chemical analysis showed that theoretical estrogenic activity expressed as equivalent E2 concentration is in the same range as recommended for synthetic estrogens. Broader spectrum of action and hypothesized lower side effects by action through ERbeta make them suitable for alternative hormone replacement therapy.

Management of the menopause in cancer survivors

The consequences of premature menopause are of great importance to cancer survivors. Oestrogen replacement therapy (with and without added progestins) is the most extensively researched agent for the treatment and prevention of menopausal problems. While this may be appropriate for symptom control in patients with tumours that are not hormone responsive, patients with hormone dependent tumours will require safe and effective alternative treatments for menopausal symptoms. This paper will discuss both the short-term and long-term consequences of the menopause in cancer survivors and will also offer various management strategies.

Isoflavones from red clover (Promensil) significantly reduce menopausal hot flush symptoms compared with placebo

OBJECTIVES

To investigate the effectiveness and safety of a red clover isoflavone dietary supplement (Promensil, Novogen Ltd., Australia) versus placebo on the change in hot flush frequency in postmenopausal women.

METHODS

In this randomized, double blind, placebo-controlled trial 30 women with more than 12 months amenorrhoea and experiencing more than five flushes per day were enrolled. All received single blind placebo tablets for 4 weeks and were subsequently randomized to either placebo or 80 mg isoflavones for a further 12 weeks. Efficacy was measured by the decrease in number of hot flushes per day and changes in Greene Climacteric Scale Score.

RESULTS

During the first 4 weeks of placebo the frequency of hot flushes decreased by 16%. During the subsequent double blind phase, a further, statistically significant decrease of 44% was seen in isoflavones group (P<0.01), whereas no further reduction occurred within the placebo group. The Greene score decreased in the active group by 13% and remained unchanged in the placebo group.

CONCLUSION

In this study, treatment with 80 mg isoflavones (Promensil) per day resulted in a significant reduction in hot flushes from baseline. At the end of the study there was a significant decrease in hot flushes of 44% between the active and placebo group, demonstrating the effectiveness of Promensil in the management of hot flushes.