Furthermore, considering soy as a mere source of isoflavones is extremely reductive. Microbial alpha diversity and glucose homeostasis improved in PCOS group after isoflavone intervention, resembling the control group profile at baseline. A weak, not clinically relevant effect has been highlighted on cycle length and hormonal status. However, levels of progesterone, estradiol, free estradiol, estrone and SHBG did not show significant differences. 3 Department of Human Sciences and Promotion of the Quality of Life, San Raffaele Roma Open University, 00166 Rome, Italy. The possible correlation between menstrual cycle length and soy does not seem convincing either. In two studies, women having fertility treatment took part in research looking at the amount of soya they ate, and whether that affected the success of their treatment. Get the latest business insights from Dun & Bradstreet. For this reason, they are classified as phytoestrogensplant-derived compounds with estrogenic activity (1). The concomitant treatment with soybean phytoestrogens significantly increased the implantation rate (254% v. 202%; P<005), the pregnancy rate (393% v. 209%; P<005) and the pregnancy-to-delivery rate (303% v. 162%; P<005) compared with placebo. Independent Researcher, Via Venezuela 66, 98121Messina, Italy, Laboratory of Cardiovascular Endocrinology, IRCCS San Raffaele Roma, 00166Rome, Italy, Department of Human Sciences and Promotion of the Quality of Life, San Raffaele Roma Open University, 00166Rome, Italy, Center for Complementary Medicine, Department of Internal Medicine II, Faculty of Medicine, University of Freiburg, Freiburg, Germany, Reference Mosallanezhad, Mahmoodi and Ranjbar, Reference Setchell, Brown and Lydeking-Olsen, Reference Hamilton-Reeves, Vazquez and Duval, Reference Reed, Camargo and Hamilton-Reeves, Reference Oyawoye, Abdel Gadir and Garner, Reference Mumford, Sundaram and Schisterman, Reference Jacobsen, Jaceldo-Siegl and Knutsen, Reference Crawford, Pritchard and Herring, Reference Andrews, Schliep and Wactawski-Wende, Reference Sdergrd, Bckstrm and Shanbhag, Reference Escobar-Morreale, Luque-Ramrez and Gonzlez, Reference Showell, Mackenzie-Proctor and Jordan, Reference Romualdi, Costantini and Campagna, Reference Chavarro, Mnguez-Alarcn and Chiu, Reference Sinai, Ben-Avraham and Guelmann-Mizrahi, Reference Ropero, Alonso-Magdalena and Ripoll, Reference Valles, Dolz-Gaiton and Gambini, Reference Gunnarsson, Ahnstrm and Kirschner, Soy, soy foods and their role in vegetarian diets, Consumption of soy foods and isoflavones and risk of type 2 diabetes: a pooled analysis of three US cohorts, Cumulative meta-analysis of the soy effect over time, Soy, soy isoflavones, and protein intake in relation to mortality from all causes, cancers, and cardiovascular diseases: a systematic review and dose-response meta-analysis of prospective cohort studies, Consensus: soy isoflavones as a first-line approach to the treatment of menopausal vasomotor complaints, Soy isoflavones for osteoporosis: an evidence-based approach, Soy and isoflavone consumption and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational studies and randomized trials in humans, Soy intake is associated with lowering blood pressure in adults: a systematic review and meta-analysis of randomized double-blind placebo-controlled trials, The antioxidant role of soy and soy foods in human health, Non-isoflavone phytochemicals in soy and their health effects. In October 1999, the US Food and Drug Administration (FDA) approved labeling for foods containing soy protein as protective against coronary heart disease. Soya Isoflavones and Vitamins The Group for those Using, Abusing and thinking about taking over the counter items to boost fertility. The two observational studies also show different limitations, in particular, one of these studies uses a follow-up of only 2 months. The clinical trial was limited to a small sample size, lacking of control/placebo group and there was no characterisation of equol-competence. This could be due to the scarcity of studies on the topic and the presence of few clinical trials, adequately designed to evaluate soy effect on fertility with consistent timing, with an adequate number of participants, blinding, and randomisation for physiological conditions and the presence of equol-producer individuals. Furthermore, the type of dietary survey carried out in the proposed environmental questionnaire was not clear. (As part of this process, a group of eggs matures so that one will be ready for release during ovulation .) It helps you to ovulate and they quality. Go. Patients showed plasma androgens levels above or at the upper limit the normal range, at baseline. The same amount of genistein was used in a parallel clinical trial on 137 Iranian women with PCOS with a 3-month follow-up(Reference Khani, Mehrabian and Khalesi35). Pending further confirmation, soy and its components do not appear to have a clinically relevant influence on menstrual cycle in healthy women. 1. However, only 106 individuals provided information on soy intake. Nevertheless, a reduction in FSH levels was confirmed (SMD: 087IU/l, 95% CI 172, 002). To our knowledge, this is the first comprehensive review on soy effect on women's fertility. Soy can contain numerous other phytochemicals such as saponins, phytosterols, phytic acid, non-isoflavone flavonoids, peptides, protease inhibitors and other bioactive substances. . Presumably, treatment with pharmacological concentrations of soy phytoestrogens allows mitigating the negative effect of clomiphene citrate on endometrial tissue, thus facilitating embryo implantation. In addition, non-English papers could have provided relevant data on the topic, especially those from countries with a more consistent history of soy consumption. Polycystic ovary syndrome (PCOS) is a major endocrine and metabolic disorder in women(Reference Meier62,Reference Liu, Zhang and Shi63) . Green, Eulalee Currently, data are insufficient to assess the effect of early-stage soy exposure on fertility-related outcomes. A total number of twenty-two experimental articles plus a meta-analysis was used for the final synthesis. was a pilot study without a characterisation of diet among participants and without data on soy composition (isoflavone or antioxidant contents). Similarly, the stratification by ethnicity and equol-producers may suggest the nature of interactions between soy and fertility. Soy is a very popular food and its consumption is part of the traditional cuisine of South-East Asian countries. However, there were also limitations: the duration of the study which was limited to two menstrual cycles and an evaluation of equol-producers among individuals was lacking. Furthermore, no characterisation was made on the possible presence of equol-producers among the participants. However, the sampling during the various days of the cycle allowed a detailed characterisation of serum LH surge day. The influence on SHBG levels can have a beneficial effect from an endocrine point of view, without negative effects on ovulation. Participants recruited were seeking for pregnancy and this could have been a source of confounders. The ethnicity assessment of participants was useful in identifying, as might be expected, a greater consumption of soy foods by Asian individuals. This latter aspect suggests a differential capacity for metabolising isoflavones even if these differences were no longer significant when corrected for the intake of isoflavones and estradiol levels were not significantly associated with urinary excretion of isoflavones. Soy consumption is supposed to have protective effects against cardiovascular disease by cholesterol-lowering and blood pressure improvement action and in the prevention of cancer or diabetes and it also supports bone health and the management of menopause symptoms(Reference Ding, Pan and Manson2Reference Mosallanezhad, Mahmoodi and Ranjbar8). Moreover, urinary concentrations seem to reflect the isoflavone intakes in a short time window. Furthermore, there was no evaluation of metabolic utilisation capacity of isoflavones and their absorption by measuring serum and urinary levels. The mice were then switched to an isoflavone-free diet - and their tumours regressed over the following nine weeks.. In addition, equol acts on incretins levels in endocrine L cell line GLUTag cells at concentration ranging from 50 to 300M, with long-term metabolic consequences(Reference Harada, Sada and Sakaguchi79). Isoflavone genistein inhibited the enzyme tyrosine kinase in human A431 cell membranes at 07g/ml, a very high, non-physiological concentration(Reference Akiyama, Ishida and Nakagawa77) and act as a ligand for peroxisome proliferator-activated receptors (PPARs) in cultured astrocytes at 500nM(Reference Valles, Dolz-Gaiton and Gambini78). This, in turn, stimulates ovulation and can make you ready for pregnancy. In addition, full-text bibliographic lists from selected papers were screened to retrieve further relevant articles. Recently, Haudum and colleagues conducted a longitudinal case-control clinical trial on forty-four Australian patients (twenty-four PCOS and twenty healthy controls) using 400ml/d of soy milk (containing approximately 50mg of isoflavones, 132g protein) for a 3-d pilot study(Reference Haudum, Lindheim and Ascani46). For the remaining papers, the full texts were retrieved for the final evaluation and inclusion in the summary. However, in the work of Filiberto and colleagues(Reference Filiberto, Mumford and Pollack37), even if the correlation between isoflavones and the increase in SHBG was highlighted, the dosage of estradiol and free estradiol did not show significant correlations, although the estimate of free estradiol was done through Sodergard's formula(Reference Sdergrd, Bckstrm and Shanbhag61), so a direct dosage would be more reliable. For these reasons, results should be interpreted with caution. Even if serum AMH concentrations appear as a useful tool for predicting female fertility, only one study from our selection used them(Reference Haudum, Lindheim and Ascani46). Fertility is closely associated with menstrual cycle functions and a longer time to pregnancy is associated with shorter menstrual cycles(Reference Crawford, Pritchard and Herring56Reference Wise, Mikkelsen and Rothman58). However, the work had several strengths: the real evaluation of luteal and follicular phase through the dosage of urinary LH:creatinine ratio, the characterisation of sampling according to the cycle; the evaluation of isoflavone content in foods used for the intervention and quantification of urinary isoflavones to check compliance; the use of soy foods and not supplements or extracts to approach a real-life pattern; the characterisation of diet at various steps of clinical trial to avoid confounding mechanisms; the stratification by ethnicity which indirectly showed the effect on equol-producer individuals. The standard guidelines for Clomid are to take it either on cycle days 3-7 or 5-9. Isoflavones are non-steroidal compounds with a chemical structure similar to endogenous estrogens and for this reason, they are defined as phytoestrogens: a functional classification that also includes lignans, coumestans and stilbenes(Reference Basu and Maier12). Many of its components show an antioxidant activity that can at least partially explain its effectiveness(Reference Rizzo9). Similarly, a significant correlation between isoflavone intake and nulligravidity emerged (P=003) with a 13% higher risk but with a wide range of confidence interval (95% CI 2, 26) in women with intake 40mg/d compared with lower intakes (<10mg/d). Participants were divided into four categories: non-consumers and tertiles of soy intake. (Reference Wu, Stanczyk and Hendrich28). Unfortunately, the work of Kohama et al. Even if the exact conversion mechanism has not been characterised yet, a limited conversion capacity in Western populations (about 25%) has been highlighted, as opposed to the greater competence of Asian populations (50%), estimated through urinary equol excretion(Reference Setchell, Brown and Lydeking-Olsen17). However, even in the West, it is currently widely used, especially due to its versatility in plant-based products for health purposes and vegetarian diets (Reference Rizzo and Baroni 1).Interest in soy is particularly driven by its possible beneficial effects on human . The authors highlighted a marginal reduction of luteal phase in the adjusted multivariable model for an increase of 10mg/d of dietary isoflavones (aOR: 138, 95% CI 099, 192, P=006), identified by monitoring LH levels in urine by a fertility monitor and 4-d per cycle 24-h dietary recalls. Feature Flags: { The detailed selection process is highlighted in Fig. From the sub-analysis by ethnic stratification, follicular SHBG levels were higher in non-Asians. Among the studies discussed to evaluate menstrual cycle length, three interventional studies also evaluated the levels of circulating hormones following soy intake in healthy women(Reference Lu, Anderson and Grady26,Reference Wu, Stanczyk and Hendrich28,Reference Lu, Anderson and Grady29) . These conclusions cover several physiological aspects, including those concerning women's fertility, consistently with the conclusions of this review that highlighted nine additional articles compared with Messina's selection about the topic. Genistein treatment reduced LDL cholesterol and triglycerides levels. In another clinical trial already discussed, although no changes in cycle length were found following soy foods intervention in twenty women with a follow-up of at least seven menstrual cycles, a significant reduction in follicular phase by 93% (P<005) in estradiol concentrations was observed, but not in luteal phase(Reference Wu, Stanczyk and Hendrich28). These aspects considerably reduce the reliability of results, favouring data misinterpretation. Moreover, significant improvement of oxidative markers such as total glutathione and malondialdehyde levels was observed. However, even in the West, it is currently widely used, especially due to its versatility in plant-based products for health purposes and vegetarian diets(Reference Rizzo and Baroni1). In a logical perspective, the effect of soy cannot be attributed to the effect of its isoflavones alone. However, the difference became not significant after adjustment for isoflavone intake. However, the association between soy and isoflavones with the reduction of luteal phase seems weak. Sub-Analysis by ethnic stratification, follicular SHBG levels can have a beneficial from. Standard guidelines for Clomid are to take it either on cycle length and soy does not seem convincing.! 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