The effect of soy-derived isoflavones over hot flushes, menopausal symptoms and mood in climacteric women with increased body mass index

Investigating the Role of 17β-Estradiol on the Serotonergic System, Targeting Soy Isoflavones as a Strategy to Reduce Menopausal Depression: A Mechanistic Review

Low serotonin is one factor implicated in the development of depression. 17β-estradiol (E2) has been shown to modulate gene expression regulating the neurotransmission of serotonin. Sex hormone levels fluctuate dramatically during the menopausal transition, coinciding with a 14-fold increased risk of depression. This review aimed to examine the effect of soy isoflavones to support decreased and variable E2 levels before and after menopause, linked to an investigation of the pathophysiological mechanisms underlying the protective influence of E2 on the serotonin pathway. The overall aim of this review is to assess the potential of soy isoflavones to reduce depression in middle-aged women. A systematic literature search was performed in three stages. 1,421 papers were screened for relevance to the research aims and objectives. 63 papers were selected based on pre-defined inclusion/exclusion criteria (13 reviews, 24 mechanistic and 26 intervention studies) and critically appraised. Available research supported the hypotheses that E2 increases serotonin synthesis and availability through stimulation of tryptophan hydroxylase-2 (TPH-2) and decreased degradation by monoamine oxidase-A (MAO-A). There was less scientific agreement on the effects of E2 on serotonin transporter (SERT) and serotonin receptors 1 A and 2 A. Studies varied widely on the effectiveness of soy isoflavones in reducing depressive symptoms in (peri)menopausal women. Animal and human studies acknowledge women's increased risk of depression linked to fluctuating E2 rather than absolute levels. However, mechanisms linking E2 variability with depression remain an underrepresented area of research. Study limitations and heterogeneity may contribute to varying results for soy isoflavones and some effects of E2 on the serotonin pathway.

Royal Jelly and Fermented Soy Extracts-A Holistic Approach to Menopausal Symptoms That Increase the Quality of Life in Pre- and Post-menopausal Women: An Observational Study

BACKGROUND

The objective of this study was to determine the effects of royal jelly and fermented soy extracts on menopausal symptoms and on quality of life in pre- and post-menopausal women.

MATERIALS AND METHOD

This prospective observational study was carried out in a Clinical Hospital of Brasov, Romania, during June 2020 and December 2021. Eighty pre- and post-menopausal women, aged between 45 and 60 years, were included in two groups. The first group (40 women) received a dietary supplement with fermented soy extract twice a day for eight weeks and the second group (40 women) received the same dietary supplement with fermented soy extracts and 1500 mg of royal jelly capsules for eight weeks. After the treatment, the MENQOL score, DASS-21 score, and the mean number and intensity of daily hot flushes were recorded and compared with baseline values.

RESULTS

After eight weeks of treatment, the score of the MENQOL questionnaire and all its domains' scores decreased in comparison with the baseline in both groups (p < 0.001). Also, the DASS-21 score (p < 0.001), depression score (p < 0.001), anxiety score (p < 0.001), and stress score (p < 0.001) improved. The mean number and the intensity of hot flushes decreased in both groups (p < 0.001). Comparing these variables after the treatment in both groups, we observed that the women who received dietary supplements with fermented soy extracts and royal jelly capsules recorded better scores for MENQOL (vasomotor, physical, and psychosocial domains) and a more reduced mean number of daily hot flushes.

CONCLUSIONS

This observational study suggests that both dietary fermented soy supplements and royal jelly capsules possess beneficial effects against menopausal symptoms, increase the quality of life in pre- and post-menopausal women, and that the effects might be significantly improved if those dietary supplements are administered in association.

Polyphenols as novel interventions for depression: exploring the efficacy, mechanisms of action, and implications for future research

Numerous animal and human studies have assessed the relationship between polyphenols and outcomes related to depression. However, no comprehensive synthesis of the main findings has been conducted. The aim of this manuscript was to systematically review the available evidence from animal and human studies on the association and the effects of dietary polyphenols on depression and provide recommendations for future research. We based our review on 163 preclinical animal, 16 observational and 44 intervention articles assessing the relationship between polyphenols and outcomes related to depression. Most animal studies demonstrated that exposure to polyphenols alleviated behaviours reported to be associated with depression. However, human studies are less clear, with some studies reporting and inverse relationship between the intake of some polyphenols, and polyphenol rich foods and depression risk and symptoms, while others reporting no association or effect. Hence, while there has been extensive research conducted in animals and there is some supporting evidence in humans, further human studies are required, particularly in younger and clinical populations.

Meal-Based Intervention on Health Promotion in Middle-Aged Women: A Pilot Study

Middle-aged women belong to a risk group for metabolic dysregulation and menopausal symptoms, mainly due to a dramatic hormonal shift. Supplementation with functional compounds or a single nutrient has been dominantly explored as a nutritional approach for improving aging-related health parameters. However, a meal-based approach might be another strategy for promoting the overall health of the target population. This pilot study aimed to develop a meal-based intervention for middle-aged women and to evaluate its potential health benefits. Considering the nutrient intake status of Korean middle-aged women, diets enriched with four major nutrients (isoflavone, omega-3, fiber, and calcium) were designed and provided to forty-nine women aged 50 to 65 with mild levels of menopausal symptoms for 8 weeks. In the post-intervention phase, they showed reduced body weight and body fat, and improved biochemical metabolic parameters with decreased levels of cholesterol, low-density lipoprotein-cholesterol, ApoB, and fasting insulin. Moreover, bone resorption markers and menopause symptoms were lower in the post-intervention phase. In conclusion, the meal-based intervention might be a prominent strategy for overall health promotion in relatively healthy middle-aged women and further investigation is needed to test its efficacy with a randomized controlled study.

Soy product consumption and the risk of major depressive disorder in older adults: Evidence from a cohort study

Background

To explore the association between soy product consumption and the risk of depression in the community.

Methods

In 2014, a total of 10,901 older people were recruited from Zhejiang province, China, and completed food frequency interviews. Participants were followed up over the next 6 years, and depression was assessed at each visit. Finally, 6,253 participants were included in the present study. Mixed effects models were performed to analyze the association by multivariate adjustments for potential confounders.

Results

Over four-fifths of the eligible participants took soy food at least one day per week. The mixed effects model has shown the adjusted odds ratios (95% CI) of high-frequency consumers (4-7 days per week) were 0.46 (0.39-0.54) for depression with a cut-off score of 5, compared with non-consumers.

Conclusions

More frequent soy product consumption was associated with a lower risk of depression.

Exploring the Impact of Flavonoids on Symptoms of Depression: A Systematic Review and Meta-Analysis

Recent evidence suggests that diet modifies key biological factors associated with the development of depression. It has been suggested that this could be due to the high flavonoid content commonly found in many plant foods, beverages and dietary supplements. Our aim was to conduct a systematic review to evaluate the effects of dietary flavonoids on the symptoms of depression. A total of 46 studies met the eligibility criteria. Of these, 36 were intervention trials and 10 were observational studies. A meta-analysis of 36 clinical trials involving a total of 2788 participants was performed. The results showed a statistically significant effect of flavonoids on depressive symptoms (mean difference = −1.65; 95% C.I., −2.54, −0.77; p < 0.01). Five of the 10 observational studies included in the systematic review reported significant results, suggesting that a higher flavonoid intake may improve symptoms of depression. Further studies are urgently required to elucidate whether causal and mechanistic links exist, along with substantiation of functional brain changes associated with flavonoid consumption.

Evaluation of the potential antidepressant effects of soybean isoflavones

OBJECTIVE

The aim of the study was to determine whether isoflavones affect depressive symptoms in women.

METHODS

Literature searches were conducted to identify clinical and epidemiologic studies that evaluated the impact of soy intake and isoflavone exposure on depressive symptoms. References from identified studies were also evaluated to identify eligible studies.

RESULTS

Only limited epidemiologic research has evaluated the impact of soy or isoflavone intake on depression although several studies from China and Japan did find soy product intake was inversely related to risk of depression. Often times, soy was, however, evaluated only as a component of a summative dietary pattern (eg, a "Japanese" or "Healthy" diet). Of the 20 intervention studies identified, roughly half found statistically significant reductions in depressive symptoms in response to isoflavones although several had design weakness. Of those studies reporting a lack of antidepressant effects of isoflavones, design limitations likely contributed to the lack of efficacy. In all but two trials, assessment of depression was, however, a secondary outcome. It is notable that both trials in which depression was a primary outcome found isoflavones significantly improved symptoms.

CONCLUSIONS

Although the data are inconsistent and limited, the clinical and epidemiologic evidence suggests that isoflavones may offer a safe, well-tolerated option for management of depression. Furthermore, the intervention doses used in the clinical studies fall well within the dietary range. The extant literature reveals key design features for future studies, which based upon the results of this review, are clearly warranted.

Multidimensional Effects of Soy Isoflavone by Food or Supplements in Menopause Women: A Systematic Review and Bibliometric Analysis

Isoflavones can exert their action on various levels: on cardiovascular system, bone and muscle health, on cancer, on menopausal symptoms, on obesity, on thyroid and on cognitive function. The aim of this systematic review is to evaluate the multidimensional effects of phytoestrogens in postmenopausal woman, and specifically to explore the impact on scientific literature. A research strategy was planned on PubMed and Scopus by defining the following key words:: menopause, climacteric, soy, isoflavone, phytoestrogens, cardiovascular system, bone mineral density, muscle mass, cancer, thyroid, obesity, cognitive. A total of 43 studies (in humans) were retrieved. The majority (12) describe the applications of soy isoflavones on cardiovascular disease, followed by effects on bone and muscle health (9), and studies concerning their action on menopausal symptoms (7), on cancer (6), on obesity (4), on cognitive function (3) and on thyroid function (2). The citation analysis revealed a growing interest for this topic and the papers on thyroid function are the most cited. Citation trends of the articles regarding the action on cardiovascular disease and on obesity are growing in the last years. Concerning the research areas, this review has assessed the effectiveness of various activities of isoflavones on welfare of menopausal women. In particular, literature show that a specific dosage of isoflavones reduces cardiovascular disease (from 20 to 100 mg/die), may be protective in osteoporosis and muscular fatigue (from 20 to 80 mg/die), may be useful for cancer prevention on endometrium, mammary glands and liver (from 50 to 100 mg/die), might improve menopausal symptoms, particularly in reducing the frequency of hot flashes (from 50 to 120 mg/die), can reduce abdominal fat and circulating inflammatory markers (from 80 to 160 mg/die), may ameliorate the possible interaction between endogenous estrogen and thyroid function (75 mg/die) and improve visual memory (from 50 to 100 mg/die).

Short-Term Isoflavone Intervention in the Treatment of Severe Vasomotor Symptoms after Surgical Menopause: A Case Report and Literature Review

Isoflavones are soy phytoestrogens that potentially exert various favorable effects in postmenopausal women, for example, alleviating vasomotor episodes, attenuating bone loss, and stimulating vaginal epithelial maturation. There has, however, been lack of consensus regarding those therapeutic effects. Most clinical studies of isoflavones have been conducted with women who had undergone natural menopause, but not those who had undergone surgical menopause. This study reports on a 51-year-old woman who presented with severe vasomotor episodes after undergoing a hysterectomy and a bilateral oophorectomy due to hypermenorrhea secondary to myoma uteri. She refused hormone therapy due to fear of adverse drug reactions so was treated with oral soy isoflavones (two capsules twice daily, equivalent to at least 100 mg daily dose) for 8 weeks. The number and severity of hot flushes and her menopause-specific quality of life dramatically improved from baseline values. The serum bone resorption marker (beta C-telopeptide) decreased markedly, while vaginal epithelial maturation improved slightly, suggesting the potential of isoflavones in attenuating bone loss and stimulating vaginal maturation. The intervention did not adversely affect the hormonal profile (FSH, LH, and estradiol) and liver or renal functions. Thus, isoflavones could be an option for women experiencing severe vasomotor episodes after surgical menopause.

Red clover for treatment of hot flashes and menopausal symptoms: A systematic review and meta-analysis

This study evaluated the efficacy of red clover to relieve hot flashes and menopausal symptoms in peri/postmenopausal women. Electronic databases (MEDLINE, Scopus and the Cochrane Library) were searched. The mean frequency of hot flashes in red clover groups was lower compared with that in the control groups (close to statistical significance). Difference in means (MD) of hot flashes frequency was - 1.99 (- 4.12-0.139; p = 0.067; heterogeneity P > 0.01; I(2) = 94.93%; Random effect model). Subjective (vaginal dryness) and objective (maturation value) symptoms of vaginal atrophy showed a significant improvement with 80-mg dose of red clover. Red clover showed less therapeutic effect on psychology status, sexual problems and sleeping disorders. Red clover consumption may decrease frequency of hot flashes, especially in women with severe hot flashes (≥ 5 per day). Red clover may reduce other menopausal symptoms. Further trials are needed to confirm the current systematic review findings.

The application of soy isoflavones for subjective symptoms and objective signs of vaginal atrophy in menopause: A systematic review of randomised controlled trials

Vaginal atrophy is a common complaint among many women in their menopause, presenting with a cluster of symptoms including dryness, itching, burning/soreness, discharge, irritation and painful intercourse. We searched for existing pertinent data in three chief registries. Specified time brackets included 1996-2013 for Medline, 1990-2013 for Scopus and 2013 for Cochrane Central Register of Controlled Trials (issue 1). Of 110 potentially relevant publications, 17 and 9 trials (7 on maturation value and 2 on vaginal dryness) were selected for qualitative and quantitative analysis, respectively. In general, soy isoflavones seem to improve vaginal symptoms as opposed to control arms. Soy isoflavones were also shown to be more efficacious in quantitative analysis, though this was statistically non-significant. Standardised difference in means of maturation value change was 0.072 (95% confidence interval [CI]: - 0.42 to 0.57), p = 0.777; heterogeneity P = 0.00; I(2) = 85.15%. Difference in means of vaginal dryness was - 0.204 (95% CI: - 0.28 to - 0.126), p < 0.001; heterogeneity P = 0.423; I(2) = 0.00. Soy isoflavones may relieve vaginal symptoms during menopause; nevertheless beneficial effects still remain uncertain due to possible publication bias or vast heterogeneity of the selected studies. Further studies with consistency in design as well as statistics are warranted.

Supercritical fluid chromatography for the separation of isoflavones

The first protocol for the analysis of isoflavones by supercritical fluid chromatography is reported. Optimum results were obtained on an Acquity UPC(2) BEH 1.7 μm column, using a solvent gradient of supercritical carbon dioxide and methanol (with phosphoric acid as additive) for elution. The method enables the baseline separation of nine isoflavones (aglyca and glycosides) in 8 min, and is suitable for their quantitative determination in dietary supplements containing soy (Glycine max), red glover (Trifolium pratense) and kudzu (Pueraria lobata). Method validation confirmed that the assay is selective, linear (R(2)≥0.9994), accurate (recovery rates from 97.6 to 102.4%), as well as precise on the short- and long-term level (intra-day precision ≤2.1%), and shows an on-column detection limit of 0.2 ng and below. This, together with an excellent performance shown in the analysis of real samples, indicates that SFC is well suited for the fast and accurate determination of isoflavones in complex matrices. Disadvantages compared to the established approaches were not observed, so that SFC has to be considered in this case as an (at least) equivalent analytical alternative.

Effect of soy isoflavone supplementation on menopausal quality of life

OBJECTIVE

The purpose of this study was to assess the effect of soy isoflavone supplementation on quality of life in postmenopausal women.

METHODS

A multicenter, randomized, double-blind, placebo-controlled 24-month trial was conducted to assess the effect of 80 or 120 mg of daily aglycone hypocotyl soy isoflavone supplementation on quality of life in 403 postmenopausal women using a validated Menopause-Specific Quality of Life questionnaire.

RESULTS

Menopause-Specific Quality of Life domain scores at 1 year and 2 years were similar to baseline. There were no differences in domain scores among treatment groups.

CONCLUSIONS

Soy isoflavone supplementation offers no benefit to quality of life in postmenopausal women.

Efficacy of Cimicifuga racemosa, Hypericum perforatum and Agnus castus in the treatment of climacteric complaints: a systematic review

OBJECTIVE

The systematic review examines whether Cimicifuga racemosa (CR), Hypericum perforatum (HP), Agnus castus, vitamins and minerals, either as monotherapy or in combination, have an evidence-based impact on vasomotor, genital and psychological climacteric complaints. DATA SOURCES AND METHODS OF STUDY SELECTION: We searched in the databases EMBASE, OVID and PubMed using the keywords "vasomotor symptoms, hot flashes, vaginal atrophy, psychological problems, endometrium, sleep, concentration, cognition in combination with vitamins, multivitamins, minerals, multiminerals, black cohosh, Cimicifuga, Agnus castus, chasteberry, chaste tree, monk's pepper and menopause" for randomized controlled trials (RCT). Relevant studies were reviewed by four independent reviewers qualitatively.

RESULTS

Most of the studies with a comparison of CR vs. placebo do not show an evidence-based significant effect of CR on climacteric symptoms. The combination of CR and HP shows an improvement of climacteric complaints in comparison to placebo. In some RCTs, there was no significant difference between CR and hormone-replacement therapy. The combination of HP and Agnus castus showed no significant difference in the treatment of climacteric complaints.

CONCLUSION

CR monotherapy as well as HP and Agnus castus showed no better effect than placebo. The combination of CR with HP demonstrated a positive effect on climacteric complaints.

Pomegranate seed oil in women with menopausal symptoms: a prospective randomized, placebo-controlled, double-blinded trial

OBJECTIVE

The aim of this study was to investigate the potential effects of pomegranate seed oil (PGS) on menopausal symptoms.

METHODS

The prospective randomized, placebo-controlled, double-blinded trial was completed by 81 postmenopausal women, who received two daily doses of either 30 mg PGS containing 127 μg of steroidal phytoestrogens per dose or a placebo for 12 weeks. The participants reported their number of hot flashes and completed the Menopause Rating Scale II at baseline and at weeks 4, 8, 12, and 24. At baseline and after 12 weeks, hormonal status was determined.

RESULTS

After 12 weeks of treatment, PGS reduced the number of hot flashes per day by 4.3 (38.7%), whereas placebo reduced it by 2.5 (25.6%). Both groups were significant compared with baseline, but the treated group was not significant compared with the placebo group (P = 0.17). After 24 weeks, the treated group showed a mean of 7.1 (interquartile range, 4.0) hot flashes per day compared with the placebo group with a mean of 8.8 (interquartile range, 5.0; P = 0.02). Although the overall sum score of the Menopause Rating Scale II parameters at week 12 decreased in the treated group from 16.0 to 9.0 at week 12 and in the placebo group from 18.0 to 14.5 (P = 0.08), the sum score of the vegetative somatic symptoms subgroup decreased strongly versus placebo (P < 0.03), attributable mainly to an improvement in sleeping disorders. PGS did not affect the hormone status, and no adverse effects were reported.

CONCLUSIONS

In postmenopausal women, PGS does not significantly reduce hot flashes within a 12-week observation period, but further studies are needed to investigate the long-term effect.

Soy germ isoflavones improve menopausal symptoms but have no effect on blood lipids in early postmenopausal Chinese women: a randomized placebo-controlled trial

OBJECTIVE

Estrogen therapy is, to date, the most effective treatment of menopausal syndrome and also has a favorable effect on lipid profiles. Because of its potential adverse effects, however, a more acceptable alternative therapy needs to be identified. This study examines the effect of soy germ isoflavones on menopausal symptoms and serum lipids.

METHODS

Ninety early postmenopausal Chinese women, aged 45 to 60 years, were randomly assigned to three treatment groups (30 each) receiving daily doses of 0 (placebo), 84, and 126 mg of soy germ isoflavones. Hot flush frequency, Kupperman scores, serum 17β-estradiol, follicle-stimulating hormone, luteinizing hormone, and serum lipids, including triglyceride, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, apolipoprotein A-I, and apolipoprotein B100, were assessed at baseline and at 12 and 24 weeks after treatment.

RESULTS

Both the frequency of hot flushes and the Kupperman index score decreased in all three treatment groups during the intervention period, but the percentage decreases in both were significantly greater in the two isoflavone groups (44.3 ± 19.1 and 57.8 ± 37.4 [84 mg isoflavones]; 48.5 ± 27.2 and 56.7 ± 26.7 [126 mg isoflavones]) than in the placebo group (27.8 ± 15.5 and 34.6 ± 46.2; p < 0.01). There was no significant difference in the changes in estradiol, follicle-stimulating hormone, and luteinizing hormone among the three treatment groups during the study, and no significant differences were observed in the lipid components.

CONCLUSIONS

A daily supplement of 84 or 126 mg soy germ isoflavones may improve menopausal symptoms, although neither dose was found to affect lipid profiles in early postmenopausal Chinese women after 24 weeks of treatment. The favorable effects are unlikely to be associated with female hormones.

Non-estrogen conventional and phytochemical treatments for vasomotor symptoms: what needs to be known for practice

OBJECTIVE

Non-hormonal treatment for menopausal vasomotor symptoms (VMS) is needed in women in whom there are medical or personal concerns on the use of hormone therapy. This paper reviews conventional and phytochemical therapies available for the relief of VMS, on their mechanisms of action, their efficacy and safety concerns.

METHODS

Medline was searched through Pubmed on the names of the diverse therapies analyzed, up to June 2011. The Cochrane Controlled Clinical Trials Register Database was searched for relevant trials that provided data on treatment of menopausal hot flushes.

RESULTS

All non-estrogen treatments for VMS are less efficacious than estrogen treatment. Randomized trials with neuroendocrine agents show globally modest to moderate reduction of VMS and frequent bothersome adverse events. The variability of effects makes it possible to undergo treatment in search for individual response where estrogen treatment is contraindicated. The antidepressants that interact with cytochrome P450, inhibiting tamoxifen metabolism to endoxifen, interfere with tamoxifen therapy in breast cancer patients. Otherwise, botanical products containing isoflavones from soy bean or red clover have great variability in bioavailability, have a broader spectrum of action than estradiol, and have predominant estrogen receptor-b activity. The efficacy of phytoestrogens on VMS is similar to placebo. They should be avoided in women with breast cancer and, in particular, in women being treated with tamoxifen or aromatase inhibitors due to possible antagonism. Cimicifuga racemosa is not a phytoestrogen, has partial serotonin agonist action and has a modest effect on VMS.

CONCLUSIONS

There are safe non-hormonal conventional treatments for menopausal VMS, although they are less efficacious than estrogens. The indication of phytochemicals is for women who make this choice on personal beliefs; long-term studies of larger groups of patients are needed to assess safety.