Phytoestrogens for menopausal symptoms

University of Auckland, O&G FMHS, Grafton Rd, Private Bag 92019, Auckland, New Zealand, 1142.
Cochrane database of systematic reviews (Online) (Impact Factor: 6.03). 02/2007; 12(4):CD001395. DOI: 10.1002/14651858.CD001395.pub3
Source: PubMed


Review question: This Cochrane review has evaluated whether phytoestrogen treatments reduce the number and severity of hot flushes and whether they are safe and acceptable. Background: Hormone therapy is an effective treatment for controlling the most common menopausal symptoms—hot flushes and night sweats. However, it is now recommended only in low doses given for the shortest possible time because of concerns about increased risk of some chronic diseases. Many women have started to use therapies that they perceive as 'natural' and safe, but they often do not have good information about the potential benefits and risks. Some of these therapies contain phytoestrogens—a group of plant-derived chemicals that are thought to prevent or treat disease. Phytoestrogens are found in a wide variety of plants, some of which are foods, particularly soy, alfalfa and red clover. Study characteristics: This review found 43 RCTs conducted up to July 2013 that included 4,084 participants with hot flushes who were close to the menopause or were menopausal. Evidence obtained is current to July 2013. Key results: Some trials reported a slight reduction in hot flushes and night sweats with phytoestrogen-based treatment. Extracts containing high levels of genistein (a substance derived from soy) appeared to reduce the number of daily hot flushes and need to be investigated further. Overall no indication suggested that other types of phytoestrogens work any better than no treatment. No evidence was found of harmful effects on the lining of the womb, stimulation of the vagina or other adverse effects with short-term use. Quality of the evidence: Many of the trials in this review were small, of short duration and of poor quality, and the types of phytoestrogens used varied substantially.

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    • "There has been a growing interest in red clover extract derived isoflavones among women according to scientific literature (Lipovac et al., 2011). The effect of red clover has been comprehensively assessed in several systematic reviews and showed a range from weak beneficial effect (Krebs et al., 2004, Lethaby et al., 2007, Nelson et al., 2006) to significant effect (Thompson Coon et al., 2007). Some animal studies have raised concern regarding high dose of red clover intake and an increased risk of estrogen-dependent cancers (Sites et al., 2014). "
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    ABSTRACT: Objective: To critically evaluate the effect of red clover on hot flash, endometrial thickness, and hormones status in postmenopausal and peri- and post-menopausal women. Materials and Methods: MEDLINE (1966 to July 2014), Scopus (1990 to July 2014), and the Cochrane Central Register of Controlled Trials (The Cochrane Library issue 1, 2014) were searched for published randomized controlled Trials (RCTs). Results: Of 183 relevant publication trials, 11 RCTs met the inclusion criteria. The mean hot flashes frequency in red clover was lower than the control groups (MD -1.99; p=0.067). There was larger decrease in FSH (SMD -0.812; CI: -1.93 to 0.312; p=0.157) and SHBG (SMD -0.128; CI-0.425 to 0.170; P=0.4) in red clover group, compared with placebo, which was not however statistically significant. LH (SMD 0.144; CI-0.097 to 0.384, p=0.242), estradiol (SMD 0.240; CI-0.001 to 0.482, p=0.051), testosterone (MD 0.083; CI: -0.560 to 0.726; p=0.901), and endometrial thickness (SDM 0.022; CI: -0.380 to 0.424, p=0.915) showed greater increase in red clover, compared with placebo, although the effect of estradiol was only significant. Conclusion: Red clover had a positive effect of alleviating hot flash in menopausal women. Our data, however, suggested very slight changes in FSH, LH, testosterone, and SHBG and significant effect in estrogen status by red clover consumption. However, the interpretation of results of the current study is limited due to methodological flaws of the included studies, menopause status, and large heterogeneity among them. Further trials are still needed to confirm the current finding.
    Avicenna Journal of Phytomedicine 11/2015; 5(6):498-511.
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    • "Cancer meta-analyses indicate that the consumption of soy or soy isoflavones is associated with reduced prostate cancer (11–14), gynecological cancers (15), and possibly breast cancer (16–21). There is no conclusive evidence that soy phytoestrogens reduce hot flashes associated with menopause (22–24). Overall, the literature contains many conflicting reports regarding the health benefits of consuming soy and phytoestrogen supplements. "
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    ABSTRACT: Numerous neurological disorders including fragile X syndrome, Down syndrome, autism, and Alzheimer's disease are co-morbid with epilepsy. We have observed elevated seizure propensity in mouse models of these disorders dependent on diet. Specifically, soy-based diets exacerbate audiogenic-induced seizures in juvenile mice. We have also found potential associations between the consumption of soy-based infant formula and seizure incidence, epilepsy comorbidity, and autism diagnostic scores in autistic children by retrospective analyses of medical record data. In total, these data suggest that consumption of high levels of soy protein during postnatal development may affect neuronal excitability. Herein, we present our theory regarding the molecular mechanism underlying soy-induced effects on seizure propensity. We hypothesize that soy phytoestrogens interfere with metabotropic glutamate receptor signaling through an estrogen receptor-dependent mechanism, which results in elevated production of key synaptic proteins and decreased seizure threshold.
    Frontiers in Neurology 09/2014; 5:169. DOI:10.3389/fneur.2014.00169
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    • "Meanwhile, it is claimed that the decreasing effect is at least partially related to subjects' initial cholesterol concentrations and isoflavones might account for at least 60% of the cholesterol-lowering effects of soy protein [111]. More than 50 trials since then, investigating health benefits of isoflavones, have been conducted [113, 114]. It has been further demonstrated that LDL reduction induced by soy protein without isoflavones is mild, indicating that isoflavones might be the main active compounds, contributing to the cholesterol-lowering effects [115, 116]. "
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    ABSTRACT: Interest in relationship between diet and ageing is growing. Research has shown that dietary calorie restriction and some antioxidants extend lifespan in various ageing models. On the one hand, oxygen is essential to aerobic organisms because it is a final electron acceptor in mitochondria. On the other hand, oxygen is harmful because it can continuously generate reactive oxygen species (ROS), which are believed to be the factors causing ageing of an organism. To remove these ROS in cells, aerobic organisms possess an antioxidant defense system which consists of a series of enzymes, namely, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR). In addition, dietary antioxidants including ascorbic acid, vitamin A, vitamin C, α -tocopherol, and plant flavonoids are also able to scavenge ROS in cells and therefore theoretically can extend the lifespan of organisms. In this connection, various antioxidants including tea catechins, theaflavins, apple polyphenols, black rice anthocyanins, and blueberry polyphenols have been shown to be capable of extending the lifespan of fruit flies. The purpose of this review is to brief the literature on modern biological theories of ageing and role of dietary antioxidants in ageing as well as underlying mechanisms by which antioxidants can prolong the lifespan with focus on fruit flies as an model.
    04/2014; 2014(6):831841. DOI:10.1155/2014/831841
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