The effects of isolated soy protein, isolated soy isoflavones and soy protein containing isoflavones on serum lipids in postmenopausal women: A systematic review and meta-analysis

BMI gain and dietary characteristics are risk factors of MASLD in non-obese individuals

This longitudinal observational study aimed to evaluate whether cardiometabolic factors and dietary characteristics are determinants of metabolic dysfunction-associated steatotic liver disease (MASLD) in non-obese individuals (body mass index [BMI] < 25 kg/m²). The study was conducted at the Japanese Red Cross Society Kyoto Daiichi Hospital. Clinical data were longitudinally recorded at annual health checks. The diagnosis of MASLD was based on the results of abdominal ultrasonography and cardiometabolic criteria. Lifestyle behaviors and dietary characteristics were assessed using a self-administered questionnaire. A total of 4,100 non-obese middle-aged and older participants (1,636 men and 2,464 women) were followed up for an average of 6.44 ± 4.16 years. During the follow-up period, there were 410 new cases of MASLD in men (25.1%) and 484 in women (19.6%). The incidence rate was higher for men (39.7 per 1,000 person-years) than for women (30.1 per 1,000 person-years). Multivariable-adjusted logistic regression analyses using the rate of change per year with standardized values found that BMI gain was strongly associated with the onset of MASLD for both men (OR: 1.90, 95% CI: 1.64-2.19) and women (OR: 1.95, 95% CI: 1.72-2.21). Increased waist circumference and triglycerides were also associated with MASLD onset for both men and women. Lowering of high-density lipoprotein cholesterol was identified as a risk factor for MASLD in both men and women. Regarding dietary characteristics, the onset of MASLD was significantly and negatively associated with "often eating vegetables" for men (OR: 0.73, 95% CI: 0.57-0.93) and "often eating soy products" for women (OR: 0.71, 95% CI: 0.58-0.88), even after adjusting for BMI change and other covariates. These findings suggest that maintaining body weight and favorable dietary characteristics are key factors in the prevention of MASLD in non-obese individuals.

Deciphering the influence of gut and oral microbiomes on menopause for healthy aging

Menopause is characterized by the cessation of menstruation and a decline in reproductive function, which is an intrinsic component of the aging process. However, it has been a frequently overlooked field of women's health. The oral and gut microbiota, constituting the largest ecosystem within the human body, are important for maintaining human health and notably contribute to the healthy aging of menopausal women. Therefore, a comprehensive review elucidating the impact of the gut and oral microbiota on menopause for healthy aging is of paramount importance. This paper presents the current understanding of the microbiome during menopause, with a particular focus on alterations in the oral and gut microbiota. Our study elucidates the complex interplay between the microbiome and sex hormone levels, explores microbial crosstalk dynamics, and investigates the associations between the microbiome and diseases linked to menopause. Additionally, this review explores the potential of microbiome-targeting therapies for managing menopause-related diseases. Given that menopause can last for approximately 30 years, gaining insights into how the microbiome and menopause interact could pave the way for innovative interventions, which may result in symptomatic relief from menopause and an increase in quality of life in women.

Functional Foods and Nutraceuticals for the Management of Cardiovascular Disease Risk in Postmenopausal Women

Cardiovascular disease (CVD) is a leading cause of death in women and risk of development is greatly increased following menopause. Menopause occurs over several years and is associated with hormonal changes, including a reduction in estradiol and an increase in follicle-stimulating hormone. This hormonal shift may result in an increased risk of developing abdominal adiposity, insulin resistance, dyslipidemia, vascular dysfunction, hypertension, type 2 diabetes mellitus (T2DM), metabolic dysfunction-associated fatty liver disease (MAFLD), and metabolic syndrome (MetS). Furthermore, with the onset of menopause, there is an increase in oxidative stress that is associated with impaired vascular function, inflammation, and thrombosis, further increasing the risk of CVD development. Despite the harmful consequences of the menopause transition being well known, women in premenopausal, perimenopausal, and postmenopausal stages are unlikely to be enrolled in research studies. Therefore, investigations on the prevention and treatment of cardiovascular and metabolic disease in middle-aged women are still relatively limited. Whilst lifestyle interventions are associated with reduced CVD risk in this population sample, the evidence still remains inconclusive. Therefore, it is important to explore the effectiveness of early intervention and potential therapeutic approaches to maintain cellular redox balance, preserve endothelium, and reduce inflammation. Glycine, N-acetylcysteine, and L-theanine are amino acids with potential antioxidant and anti-inflammatory activity and are identified as therapeutic interventions in the management of age-related and metabolic diseases. The benefits of the intake of these amino acids for improving factors associated with cardiovascular health are discussed in this review. Future studies using these amino acids are warranted to investigate their effect on maintaining the vascular health and cardiovascular outcomes of postmenopausal women.

Dietary isoflavone intake is inversely associated with remnant cholesterol in US adults: A cross-sectional study

BACKGROUND

Several studies have shown that dietary isoflavones are negatively correlated with total cholesterol and low-density lipoprotein cholesterol. However, few studies have investigated the link between dietary isoflavones and remnant cholesterol (RC).

OBJECTIVES

We used the National Health and Nutrition Examination Survey (NHANES) database to explore the association between dietary isoflavone intake and RC.

METHODS

A cross-sectional study was conducted with 4731 participants aged ≥ 20 years from the 2007-2008, 2009-2010, and 2017-2018 NHANES databases. We adopted univariate and multiple linear regression analysis and restricted cubic spline (RCS) to assess the relationship between dietary isoflavone intake and RC. Moreover, we conducted stratified and interaction analyses to ensure the stability of the results and identify specific populations.

RESULTS

The weighted multifactor linear regression model showed a negative correlation between dietary isoflavone intake and remnant cholesterol (Model 2, β = -0.049, 95% CI: (-0.096, -0.002), P = 0.040). The RCS analysis indicated that there was an L-shaped negative correlation between dietary isoflavone intake and RC (P-value for non-linearity was 0.0464). Stratified analyses showed the inverse relationship between dietary isoflavone intake and RC persisted in most subgroups and there was no interaction except for the recreational activity group.

CONCLUSIONS

Our study found a non-linear and negative association between dietary isoflavone intake and RC in US adults, so we hypothesized that consuming an isoflavone-rich diet may help reduce blood RC and further reduce the risk of cardiovascular disease.

The effect of soy isoflavones supplementation on metabolic status in patients with non-alcoholic fatty liver disease: a randomized placebo controlled clinical trial

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) accounts as a crucial health concern with a huge burden on health and economic systems. The aim of this study is to evaluate the effect of soy isoflavones supplementation on metabolic status in patients with NAFLD.

METHODS

In this randomized clinical trial, 50 patients with NAFLD were randomly allocated to either soy isoflavone or placebo groups for 12 weeks. The soy isoflavone group took 100 mg/d soy isoflavone and the placebo group took the similar tablets containing starch. Anthropometric indices, blood lipids, glycemic parameters and blood pressure were measured at the beginning and at the end of the study.

RESULTS

At the end of week 12 the level of serum triglyceride (TG), low density lipoprotein (LDL) and total cholesterol (TC) was significantly decreased only in soy isoflavone group compared to baseline (P < 0.05). Although waist circumference (WC) decreased significantly in both groups after 12 weeks of intervention (P < 0.05), hip circumference (HC) decreased significantly only in soy isoflavone group (P = 0.001). No significant changes observed regarding high density lipoprotein (HDL) and blood pressure in both groups. At the end of the study, serum glucose level was significantly decreased in the placebo group compared to baseline (P = 0.047). No significant changes demonstrated in the soy isoflavone group in regard to glycemic parameters (P > 0.05).

CONCLUSIONS

This study revealed that soy isoflavones could significantly reduce TG, LDL TC, WC and HC in NAFLD patients.

TRIAL REGISTRATION

The Ethics committee of Ahvaz Jundishapur University of Medical Sciences approved the protocol of the present clinical research (IR.AJUMS.REC.1401.155). The study was in accordance with the Declaration of Helsinki. This study's registered number and date are IRCT20220801055597N1 and 20.09.2022, respectively at https://fa.irct.ir .

Are oilseeds a new alternative protein source for human nutrition?

This review focuses on the potential use, nutritional value and beneficial health effects of oilseeds as a source of food protein. The process of extracting oil from oilseeds produces a by-product that is rich in proteins and other valuable nutritional and bioactive components. This product is primarily used for animal feed. However, as the demand for proteins continues to rise, plant-based proteins have a real success in food applications. Among the different plant protein sources, oilseeds could be used as an alternative protein source for human diet. The data we have so far show that oilseeds present a protein content of up to 40% and a relatively well-balanced profile of amino acids with sulphur-containing amino acids. Nevertheless, they tend to be deficient in lysine and rich in anti-nutritional factors (ANFs), which therefore means they have lower anabolic potential than animal proteins. To enhance their nutritional value, oilseed proteins can be combined with other protein sources and subjected to processes such as dehulling, heating, soaking, germination or fermentation to reduce their ANFs and improve protein digestibility. Furthermore, due to their bioactive peptides, oilseeds can also bring health benefits, particularly in the prevention and treatment of diabetes, obesity and cardiovascular diseases. However, additional nutritional data are needed before oilseeds can be endorsed as a protein source for humans.

Heart Failure in Menopause: Treatment and New Approaches

Aging is an important risk factor for the development of heart failure (HF) and half of patients with HF have preserved ejection fraction (HFpEF) which is more common in elderly women. In general, sex differences that lead to discrepancies in risk factors and to the development of cardiovascular disease (CVD) have been attributed to the reduced level of circulating estrogen during menopause. Estrogen receptors adaptively modulate fibrotic, apoptotic, inflammatory processes and calcium homeostasis, factors that are directly involved in the HFpEF. Therefore, during menopause, estrogen depletion reduces the cardioprotection. Preclinical menopause models demonstrated that several signaling pathways and organ systems are closely involved in the development of HFpEF, including dysregulation of the renin-angiotensin system (RAS), chronic inflammatory process and alteration in the sympathetic nervous system. Thus, this review explores thealterations observed in the condition of HFpEF induced by menopause and the therapeutic targets with potential to interfere with the disease progress.

Hypolipidemic Effects of Soy Protein and Isoflavones in the Prevention of Non-Alcoholic Fatty Liver Disease- A Review

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease and affects about 25% of the population globally. Obesity and diabetes are the main causes of the disease characterized by excessive accumulation of lipids in the liver. There is currently no direct pharmacological treatments for NAFLD. Dietary intervention and lifestyle modification are the key strategies in the prevention and treatment of the disease. Soy consumption is associated with many health benefits such as decreased incidence of coronary heart disease, type-2 diabetes, atherosclerosis and obesity. The hypolipidemic functions of soy components have been shown in both animal studies and human clinical trials. Dietary soy proteins and associated isoflavones suppressed the formation and accumulation of lipid droplets in the liver and improved NAFLD-associated metabolic syndrome. The molecular mechanism(s) underlying the effects of soy components are mainly through modulation of transcription factors, sterol regulatory element-binding protein-1 and peroxisome proliferator-activated receptor-γ2, and expressions of their target genes involved in lipogenesis and lipolysis as well as lipid droplet-promoting protein, fat-specific protein-27. Inclusion of appropriate amounts of soy protein and isoflavones in the diets might be a useful approach to decrease the prevalence of NAFLD and mitigate disease burden.

Food protein-derived bioactive peptides for the management of nutrition related chronic diseases

Dietary intervention via modifications of dietary pattern or supplementations of naturally derived bioactive compounds has been considered as an efficient approach in management of nutrition related chronic diseases. Food protein-derived bioactive peptide is representative of natural compounds which show the potential to prevent or mitigate nutrition related chronic diseases. In the past decades, substantial research has been conducted concentrating on the characterization, bioavailability, and activity assessment of bioactive peptides. Although various activities of bioactive peptides have been reported, the activity testes of most peptides were only conducted in cells and animal models. Some clinical trials of bioactive peptides were also reported but only limited to antihypertensive peptides, antidiabetic peptides and peptides modulating blood lipid profile. Hereby, clinical evidence of bioactive peptides in management of nutrition-related chronic diseases is summarized in this chapter, which aims at providing implications for the clinical studies of bioactive peptides in the future.

Influences of Dietary Vitamin E, Selenium-Enriched Yeast, and Soy Isoflavone Supplementation on Growth Performance, Antioxidant Capacity, Carcass Traits, Meat Quality and Gut Microbiota in Finishing Pigs

This study investigated the effects of dietary compound antioxidants on growth performance, antioxidant capacity, carcass traits, meat quality, and gut microbiota in finishing pigs. A total of 36 barrows were randomly assigned to 2 treatments with 6 replicates. The pigs were fed with a basal diet (control) or the basal diet supplemented with 200 mg/kg vitamin E, 0.3 mg/kg selenium-enriched yeast, and 20 mg/kg soy isoflavone. Dietary compound antioxidants decreased the average daily feed intake (ADFI) and feed to gain ratio (F/G) at d 14−28 in finishing pigs (p < 0.05). The plasma total protein, urea nitrogen, triglyceride, and malondialdehyde (MDA) concentrations were decreased while the plasma glutathione (GSH) to glutathione oxidized (GSSG) ratio (GSH/GSSG) was increased by compound antioxidants (p < 0.05). Dietary compound antioxidants increased loin area and b* value at 45 min, decreased backfat thickness at last rib, and drip loss at 48 h (p < 0.05). The relative abundance of colonic Peptococcus at the genus level was increased and ileal Turicibacter_sp_H121 abundance at the species level was decreased by dietary compound antioxidants. Spearman analysis showed a significant negative correlation between the relative abundance of colonic Peptococcus and plasma MDA concentration and meat drip loss at 48 h. Collectively, dietary supplementation with compound antioxidants of vitamin E, selenium-enrich yeast, and soy isoflavone could improve feed efficiency and antioxidant capacity, and modify the backfat thickness and meat quality through modulation of the gut microbiota community.

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.

Dietary isoflavones intake is inversely associated with non-alcoholic fatty liver disease, hyperlipidaemia and hypertension

This study investigated associations between total isoflavones and their categories (daidzein, genistein, glycitein) intake and the risks for metabolic disorders. We used the data of 6786 Chinese adults from the Nutrition Health Atlas Project. We performed multiple logistic regression and restricted cubic spline models assessing the risks for metabolic disorders (non-alcoholic fatty liver disease (NAFLD), hyperlipidaemia, hypertension, diabetes and overweight/obesity) in each category of isoflavones. Higher total isoflavones, daidzein and genistein intake were inversely associated with NAFLD (p < .05). Higher total isoflavones, daidzein, genistein and glycitein intake were also inversely associated with hyperlipidaemia (p < .01) and hypertension (p < .01). Dose-response analyses revealed that total isoflavones, daidzein, genistein and glycitein intakes were associated with the risks of metabolic disorders in a nonlinear trend. In conclusion, total isoflavones, daidzein and genistein intake were inversely associated with NAFLD, hyperlipidaemia and hypertension. Glycitein was inversely associated with hyperlipidaemia and hypertension.

Association between functional foods and cardiometabolic health in a real-life setting: a longitudinal observational study using objective diet records from an electronic purchase system

The effects of the regular consumption of soy, barley, and green tea in a real-life setting are unclear. This longitudinal observational study showed the associations of their intake with cardiometabolic health when employees freely selected these foods in the workplace cafeteria of an industrial company in Japan. The consumption was objectively assessed by an electronic purchase system using integrated circuit chip-equipped tableware and personal identification cards. The associations between the cumulative number of servings of each food during the 12 weeks prior to a health examination and changes in cardiometabolic measurements were examined among Japanese male workers (n = 890). Higher total intake of soy products was associated with significant lower levels in low-density lipoprotein cholesterol. Higher total intake of rice with barley was marginally associated with lower levels in systolic blood pressure and glycated hemoglobin. These associations were attenuated after adjustment for the baseline values of the dependent variables. Serving soy and barley products in the workplace cafeteria possibly promotes real-life benefits to employees' cardiometabolic health.

Maximizing the Estrogenic Potential of Soy Isoflavones through the Gut Microbiome: Implication for Cardiometabolic Health in Postmenopausal Women

Soy isoflavones have been suggested as an alternative treatment for managing postmenopausal symptoms and promoting long-term health due to their structural similarity to mammalian estrogen and ability to bind to estrogen receptors. Among all soy isoflavones and their metabolites, (S)-equol is known for having the strongest estrogenic activity. Equol is a metabolite of the soy isoflavone daidzein produced through intestinal bacterial metabolism. However, more than half of the human population is not able to produce equol due to the lack of equol-producing bacteria in their gastrointestinal tract. The interpersonal variations in the gut microbiome complicate the interpretation of data collected from humans. Furthermore, because rodents are efficient equol-producers, translatability between rodent models and humans is challenging. Herein, we first summarized the current knowledge of the microbial conversion of daidzein to equol, its relation to health, and proposed the need for developing model systems by which equol production can be manipulated while controlling other known confounding factors. Determining the necessity of equol-producing capacity within a gut microbial community when consuming soy as a functional ingredient, and identifying strategies to maximize equol production by modulating the gut microbiome, may provide future therapeutic approaches to improve the health of postmenopausal women.

Whole-diet interventions and cardiovascular risk factors in postmenopausal women: A systematic review of controlled clinical trials

OBJECTIVES

Menopause is accompanied by many metabolic changes, increasing the risk of cardiometabolic diseases. The impact of diet, as a modifiable lifestyle factor, on cardiovascular health in general populations has been well established. The purpose of this systematic review is to summarize the evidence on the effects of whole diet on lipid profile, glycemic indices, and blood pressure in postmenopausal women.

METHODS

Embase, Medline, Cochrane Central Register of Controlled Trials, and Google Scholar were searched from inception to February 2021. We included controlled clinical trials in postmenopausal women that assessed the effect of a whole-diet intervention on lipid profile, glycemic indices, and/or blood pressure. The risk of bias in individual studies was assessed using RoB 2 and ROBINS-I tools.

SUMMARY OF EVIDENCE

Among 2,134 references, 21 trials met all eligibility criteria. Overall, results were heterogenuous and inconsistent. Compared to control diets, some studies showed that participants experienced improvements in total cholesterol (TC), low-density lipoprotein cholesterol (LDL), systolic blood pressure (SBP), fasting blood sugar (FBS), and apolipoprotein A (Apo-A) after following fat-modified diets, but some adverse effects on triglycerides (TG), very low-density lipoprotein cholesterol (VLDL), lipoprotein(a) (Lp(a)), and high-density lipoprotein cholesterol (HDL) concentrations were also observed. A limited number of trials found some effects of the Paleolithic, weight-loss, plant-based, or energy-restricted diets, or of following American Heart Association recommendations on TG, TC, HDL, insulin, FBS, or insulin resistance.

CONCLUSION

Current evidence suggests that diet may affect levels of some lipid profile markers, glycemic indices, and blood pressure among postmenopausal women. However, due to the large heterogeneity in intervention diets, comparison groups, intervention durations, and population characteristics, findings are inconclusive. Further well-designed clinical trials are needed on dietary interventions to reduce cardiovascular risk in postmenopausal women.

Consumption of soy products and cardiovascular mortality in people with and without cardiovascular disease: a prospective cohort study of 0.5 million individuals

PURPOSE

We sought to examine the association of soy product consumption with risk of cardiovascular death in Chinese individuals with and without a history of cardiovascular disease (CVD).

METHODS

The current analysis included 487,034 individuals free of CVD and 22,923 individuals with a history of CVD at study baseline. Data on consumption of soy products were collected by a food frequency questionnaire. The Cox regression was used to obtain the hazard ratios (HRs) of cardiovascular mortality associated with soy product consumption among people with and without a history of CVD at baseline.

RESULTS

During the period of follow-up, 12,582 and 2860 cardiovascular deaths were recorded among people without and with a history of CVD. Compared with those who never or rarely ate soy products, the multivariable HRs (95% CIs) were 1.02 (0.96, 1.08) for those who ate soy products monthly, 1.01 (0.95, 1.07) for those who ate soy products 1-3 days per week, 0.95 (0.88, 1.04) for those who ate soy products ≥ 4 days per week. For cause-specific mortality, soy product consumption was inversely associated with mortality from acute myocardial infarction (HR [95% CI] = 0.75 [0.61, 0.92]). Among people with a history of CVD, higher soy product consumption was not associated with cardiovascular mortality.

CONCLUSIONS

Soy consumption ≥ 4 days per week was associated with a significantly lower risk of mortality from acute myocardial infarction in comparison with never or rarely consumption among people without a history of CVD. Among people with a history of CVD, higher soy product consumption was not associated with cardiovascular mortality.

Effects of Isolated Soy Protein Supplementation Combined with Aerobic Exercise Training on Improving Body Composition, Anthropometric Characteristics and Cardiopulmonary Endurance in Women: A Pilot Study

Today, women are concerned with health promotion but also with improvements in body weight and shape. The purpose of this study was to investigate the effects of aerobic exercise training (AET) combined with isolated soy protein (ISP) supplementation on the body composition, anthropometric characteristics, and cardiopulmonary endurance of women. The qualified subjects were randomly assigned to AET or AET + ISP groups. Women in the AET + ISP group were given an ISP-rich supplement (40 g/day) 5 days a week for 8 weeks; those in the AET group were given the same amount of water in an identical manner. All women received 60 min of AET twice a week for 8 weeks at an intensity of 40–65% heart rate reserve (HRR) and their body composition, anthropometric characteristics, and physical fitness were measured one week before and after the 8-week AET class. A total of 16 subjects (age: 36.13 ± 5.76 years) completed the study and were included in the dataset. The results of this study show that the AET + ISP group obtained greater reductions in body weight (effect size = 0.99), body mass index (BMI, effect size = 1.04), percentage body fat (PBF, effect size = 1.18), circumferences (waist and hip, all effect sizes > 0.8), and greater gains in the percentage lean body mass (PLBM, effect size = 0.89), compared with the AET group, without significant differences in 20 m multi-stage shuttle run test (20 m MST). We conclude that there is a trend for the consumption of ISP following AET to improve the body composition and anthropometric characteristics in women, compared with those who received the same AET without ISP supplementation.

Effects of daidzein and genistein on markers of cardiovascular disease risk among women with impaired glucose regulation: a double-blind, randomized, placebo-controlled trial

BACKGROUND AND OBJECTIVE

soy protein and soy isoflavones have been suggested to be associated with improved cardiovascular risk factors (e.g., lipid profiles and uric acid (UA)), but few studies have been conducted among women with impaired glucose regulation (IGR). This study is aimed to evaluate the effect of isolated daidzein and genistein on lipid profiles, high sensitive C-reactive protein (hs-CRP), and uric acid (UA) among Chinese women with IGR.

METHODS AND RESULTS

this randomized, double-blind, and placebo-controlled trial was conducted in 165 Chinese women aged 30-70 years with IGR. Participants were randomly assigned to one of the three groups: 0 mg of daidzein and genistein with 10 g soy protein (placebo group), 50 mg of daidzein with 10 g soy protein (daidzein group), or 50 mg of genistein with 10 g soy protein (genistein group) supplementation for 24 weeks. Fasting serum total cholesterol (TC), triacylglycerol (TG), high-density lipoprotein (HDL-C), low-density lipoprotein (LDL-C), lipoprotein a (LP (a)), hs-CRP, and UA were assessed at baseline, 12, and 24 weeks after intervention. The results showed no significant differences in the changes (%) of TC, TG, HDL-C, LDL-C, LP (a), hs-CRP, and UA between the three treatment groups at weeks 12 or 24 (all P > 0.05).

CONCLUSION

neither isolated daidzein nor genistein had a significant effect on cardiovascular health in Chinese women with IGR.

Effects of soy isoflavone supplementation on patients with diabetic nephropathy: a systematic review and meta-analysis of randomized controlled trials

Diabetic nephropathy (DN) is a microvascular complication that is becoming a worldwide public health concern. The aim of this study was to assess the effects of dietary soy isoflavone intervention on renal function and metabolic syndrome markers in DN patients. Seven databases including Medline, the Cochrane Central Register of Controlled Trials, Science Direct, Web of Science, Embase, China National Knowledge Infrastructure, and WanFang were searched for controlled trials that assessed the effects of soy isoflavone treatment in DN patients. Finally, a total of 141 patients from 7 randomized controlled trials were included. The meta-analysis showed that dietary soy isoflavones significantly decreased 24-hour urine protein, C-reactive protein (CRP), blood urea nitrogen (BUN), total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and fasting blood glucose (FBG) in DN patients. The standard mean difference was -2.58 (95% CI: -3.94, -1.22; P = 0.0002) for 24-hour urine protein, -0.67 (95% CI: -0.94, -0.41; P < 0.00001) for BUN, -6.16 (95% CI: -9.02, -3.31; P < 0.0001) for CRP, -0.58 (95% CI: -0.83, -0.33; P < 0.00001) for TC, -0.41 (95% CI: -0.66, -0.16; P < 0.00001) for TG, -0.68 (95% CI: -0.94, -0.42; P < 0.00001) for LDL-C, and -0.39 (95% CI: -0.68, -0.10; P = 0.008) for FBG. Therefore, soy isoflavones may ameliorate DN by significantly decreasing 24-hour urine protein, BUN, CRP, TC, TG, LDL-C, and FBG.

Isoflavone biomarkers are inversely associated with atherosclerosis progression in adults: a prospective study

BACKGROUND

Many studies have examined associations between dietary isoflavones and atherosclerosis, but few used objective biomarkers.

OBJECTIVES

We examined the associations of isoflavone biomarkers (primary analyses) and equol production (secondary analyses) with the progression of carotid intima-media thickness (cIMT), and whether inflammation, systolic blood pressure (SBP), blood lipids, and sex hormone-binding globulin (SHBG) mediated these associations, in Chinese adults.

METHODS

This 8.8-y prospective study included 2572 subjects (40-75 y old) from the GNHS (Guangzhou Nutrition and Health Study; 2008-2019). The concentrations of daidzein, genistein, and equol were assayed by an HPLC-tandem MS in serum (n = 2572) at baseline and in urine (n = 2220) at 3-y intervals. The cIMT of the common carotid artery (CCA) and bifurcation segment were measured by B-mode ultrasound every 3 y, and the progressions of cIMT ( ∆cIMT) were estimated using the regression method.

RESULTS

Multivariable linear mixed-effects models (LMEMs) and ANCOVA revealed that subjects with higher serum isoflavones tended to have lower increases of CCA-cIMT. The mean ± SEM differences in 8.8-y ∆CCA-cIMT between extreme tertiles of serum isoflavones were -17.1 ± 8.4, -20.6 ± 8.3, and -23.3 ± 10.4 μm for daidzein, total isoflavone, and equol (P-trends < 0.05), respectively. LMEMs showed that the estimated yearly changes (95% CIs) (μm/y) in CCA-IMT were -2.0 (-3.8, -0.3), -1.9 (-3.6, -0.1), and -2.1 (-3.8, -0.3) in the highest (compared with the lowest) tertile of daidzein, genistein, and total isoflavones, respectively (P-interaction < 0.05). Path analyses indicated that the serum equol-atherosclerosis association was mediated by increased SHBG and decreased SBP. Similar beneficial associations were observed in the secondary analyses.

CONCLUSIONS

Serum isoflavones and equol exposure were associated with reduced cIMT progression, mediated by SHBG and SBP.

Physiologically Active Molecules and Functional Properties of Soybeans in Human Health-A Current Perspective

In addition to providing nutrients, food can help prevent and treat certain diseases. In particular, research on soy products has increased dramatically following their emergence as functional foods capable of improving blood circulation and intestinal regulation. In addition to their nutritional value, soybeans contain specific phytochemical substances that promote health and are a source of dietary fiber, phospholipids, isoflavones (e.g., genistein and daidzein), phenolic acids, saponins, and phytic acid, while serving as a trypsin inhibitor. These individual substances have demonstrated effectiveness in preventing chronic diseases, such as arteriosclerosis, cardiac diseases, diabetes, and senile dementia, as well as in treating cancer and suppressing osteoporosis. Furthermore, soybean can affect fibrinolytic activity, control blood pressure, and improve lipid metabolism, while eliciting antimutagenic, anticarcinogenic, and antibacterial effects. In this review, rather than to improve on the established studies on the reported nutritional qualities of soybeans, we intend to examine the physiological activities of soybeans that have recently been studied and confirm their potential as a high-functional, well-being food.

Beneficial effect of soy isoflavones and soy isoflavones plus soy protein on serum concentration of C-reactive protein among postmenopausal women: An updated systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Scientists suggest that soy isoflavones or the combination of soy isoflavones and soy protein may have beneficial effects on inflammation. Thus, the present study aims at conducting a systematic review and meta-analysis on randomized controlled trials (RCTs) in which the effect of soy isoflavones and the combination of soy isoflavones and soy protein on serum concentration of C-reactive protein (CRP) among postmenopausal women is assessed.

METHODS AND MATERIALS

A literature searching was done to identify a breadth of related references in PubMed, Scopus, ISI Web of Science, Cochrane Library, and Clinicaltrials.gov up to December 2020. The mean change from baseline in the CRP concentrations and its standard deviation (SD) for both intervention and comparison groups were used to calculate the effect size. The summary of the overall effects and heterogeneity was estimated by using the DerSimonian and Laird random effects model. The protocol was registered in PROSPERO (No. CRD42020166053).

RESULTS

This study considered 23 articles for systematic review and 19 articles for meta-analysis. The overall effect presented a non-significant effect of soy isoflavones on serum CRP concentrations (WMD = 0.08 mg/L, 95 % CI: -0.08, 0.24; p = 0.302) and the overall effect of the combination of soy isoflavones and soy protein indicated non-significant effect in serum levels of CRP (WMD= -0.02 mg/L 95 % CI: -0.12, 0.08; p = 0.715).

CONCLUSION

Published RCTs did not provide strong evidence regarding beneficial effect of soy isoflavones or the combination of soy isoflavones and soy protein on serum CRP concentration among postmenopausal women.

Effects of soy consumption on metabolic parameters in patients with metabolic syndrome: A systematic review and meta-analysis

Functional foods like soy have unique effects on health status. Although various dietary modifications have been recommended to ameliorate features of metabolic syndrome (MetS), no meta-analysis has summarized the effect of soy consumption in patients with MetS. PubMed, ISI Web of Science, and Scopus were searched for relevant articles until Jun 2020, resulting in six relevant publications that were included in our meta-analysis. Combining a total of 9 comparisons suggested a significant decrease in serum levels of triglyceride (WMD: -0.29; 95 % CI: -0.49, -0.09 mg/dL), total cholesterol (WMD: -1.46; 95 % CI: -1.70, -1.22 mg/dL), LDL-C (WMD: -0.73; 95 % CI: -0.93, -0.52 mg/dL) and no change in serum HDL-c levels. Combining a total of 7 effect sizes examining soy effects on glycemic parameters indicated that subjects who consumed soy products had lower levels of fasting blood sugar (WMD: -0.90; 95 % CI: -1.12, -0.68 mg/dL), insulin (WMD: -1.06; 95 % CI: -1.29, -0.84 pmol/ L) and HOMA-IR (WMD: -1.08; 95 % CI: -1.31, -0.85) compared with those in the control group. Soy consumption could not significantly change anthropometric measures and blood pressure. Consuming soy products in patients with MetS effectively improved lipid profile and glycemic parameters independent of affecting anthropometric measures.

Effects of soy isoflavones extract on the lipid profile and uterus in ovariectomized rats

AIM

Although soy isoflavones (ISO) have been shown to relief postmenopausal symptoms, it remains inconclusive whether ISO can improve lipid-profile without uterotrophic effects under estrogen-deficiency. Thus, we investigated the effects of ISO on lipid-profile and uterus of ovariectomized (Ovx) rats.

MATERIALS AND METHODS

Twenty-five adult rats were Ovx or Sham-operated (Sham) and assigned into five groups: Sham and Ovx groups, administered with vehicle solutions; Ovx-E, treated with 10 µg/kg of 17β-Estradiol; Ovx-ISO, treated with 200 mg/kg of ISO; Ovx-E + ISO, treated with estradiol + ISO combined. After fifty days of treatments, rats were euthanized and uterine horns were processed for histomorphometry or to collagen fibers and glycosaminoglycans evaluations. Blood samples were collected to evaluate levels of triglycerides, total cholesterol (TC) and its fractions (HDL/VLDL). Data were subjected to statistical analysis (p < .05).

RESULTS

Uterus weight was lower in Ovx group than the Sham and Ovx-E groups, whereas it was similar between Ovx and Ovx-ISO groups. Histomorphometry showed atrophic uterus in Ovx and Ovx-ISO groups, whereas uterotrophic effects were noticed in Ovx-E and Ovx-E + ISO groups. Collagen fibers-birefringence was higher in Sham, Ovx, and Ovx-ISO groups than in Ovx-E and Ovx-E + ISO groups. Sulfated glycosaminoglycans content was similar among Sham, Ovx, and Ovx-ISO groups, while it was higher in estrogen-treated groups; total glycosaminoglycans content was similar among groups. TC and HDL was higher in Ovx-ISO group, whereas VLDL and triglycerides levels was higher in Ovx-E + ISO group and similar among other groups.

CONCLUSION

Soy isoflavones at 200 mg/kg have slight beneficial effects on lipid-profile without uterotrophic effects in Ovx rats.

Impact of Short-Term Isoflavone Intervention in Polycystic Ovary Syndrome (PCOS) Patients on Microbiota Composition and Metagenomics

BACKGROUND

Polycystic ovary syndrome (PCOS) affects 5-20% of women of reproductive age worldwide and is associated with disorders of glucose metabolism. Hormone and metabolic signaling may be influenced by phytoestrogens, such as isoflavones. Their endocrine effects may modify symptom penetrance in PCOS. Equol is one of the most active isoflavone metabolites, produced by intestinal bacteria, and acts as a selective estrogen receptor modulator.

METHOD

In this interventional study of clinical and biochemical characterization, urine isoflavone levels were measured in PCOS and control women before and three days after a defined isoflavone intervention via soy milk. In this interventional study, bacterial equol production was evaluated using the log(equol: daidzein ratio) and microbiome, metabolic, and predicted metagenome analyses were performed.

RESULTS

After isoflavone intervention, predicted stool metagenomic pathways, microbial alpha diversity, and glucose homeostasis in PCOS improved resembling the profile of the control group at baseline. In the whole cohort, larger equol production was associated with lower androgen as well as fertility markers.

CONCLUSION

The dynamics in our metabolic, microbiome, and predicted metagenomic profiles underline the importance of external phytohormones on PCOS characteristics and a potential therapeutic approach or prebiotic in the future.