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The effect of soy isoflavone combined with calcium on bone mineral density in perimenopausal Chinese women: a 6-month randomised double-blind placebo-controlled study.
Zhang, X, Liu, Y, Xu, Q, Zhang, Y, Liu, L, Li, H, Li, F, Liu, Z, Yang, X, Yu, X, et al
International journal of food sciences and nutrition. 2020;(4):473-481
Abstract
This study was a prospective, randomised, double-blind, placebo-controlled clinical trial and aimed to compare the effect of placebo, soy isoflavone, calcium and soy isoflavone combined with calcium on bone mineral density (BMD). One hundred and sixty perimenopausal women with osteoporosis or osteopenia were enrolled and randomised into four groups: control, soy isoflavone, calcium and soy isoflavone combined with calcium groups. After intervention, compared with control, isoflavone and calcium groups, mean changes from their corresponding baseline values of BMD, calcium/phosphorus, vitamin D and glutathione peroxidase (GSH-pX) activity were significantly increased, however, those of phosphorus, osteocalcin, luteinizing hormone (LH) and follicle stimulating hormone (FSH) were significantly decreased in isoflavone combined with calcium group. The results showed that soy isoflavone, calcium and isoflavone combined with calcium therapy were effective and safe on attenuating BMD loss in perimenopausal women and isoflavone combined with calcium therapy was better than soy isoflavone and calcium alone.
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Effects of soy isoflavones on cognitive function: a systematic review and meta-analysis of randomized controlled trials.
Cui, C, Birru, RL, Snitz, BE, Ihara, M, Kakuta, C, Lopresti, BJ, Aizenstein, HJ, Lopez, OL, Mathis, CA, Miyamoto, Y, et al
Nutrition reviews. 2020;(2):134-144
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Abstract
CONTEXT The results of preclinical and observational studies support the beneficial effect of soy isoflavones on cognition. OBJECTIVE This review aimed to evaluate the effects of soy isoflavones on cognition in adults. DATA SOURCES The PUBMED, EMBASE, Ovid Medline, Cochrane Library, and clinicaltrials.gov databases were searched. STUDY SELECTION Two researchers independently screened 1955 records, using the PICOS criteria: participants were adults; intervention was dietary sources with soy isoflavones or isolated soy isoflavones; comparator was any comparator; outcome was cognitive function; study type was randomized controlled trials (RCTs). A third researcher was consulted to resolve any discrepancies. Sixteen RCTs were included and their quality assessed. DATA EXTRACTION Information on study design, characteristics of participants, and outcomes was extracted. PRISMA guidelines were followed. DATA ANALYSIS A random-effects meta-analysis was used to pool estimates across studies. In the 16 RCTs (1386 participants, mean age = 60 y), soy isoflavones were found to improve overall cognitive function (standardized mean difference [SMD], 0.19; 95% confidence interval [CI], 0.07-0.32) and memory (SMD, 0.15; 95%CI, 0.03-0.26). CONCLUSION The results showed that soy isoflavones may improve cognitive function in adults. SYSTEMATIC REVIEW REGISTRATION PROSPERO registration no. CRD42018082070.
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Metabolic tracking of isoflavones in soybean products and biosamples from healthy adults after fermented soybean consumption.
Jang, HH, Noh, H, Kim, HW, Cho, SY, Kim, HJ, Lee, SH, Lee, SH, Gunter, MJ, Ferrari, P, Scalbert, A, et al
Food chemistry. 2020;:127317
Abstract
Fermentation may enhance the nutritional properties of foods by increasing metabolite bioactivity or bioavailability. This study explored the effect of fermentation on isoflavone bioavailability and metabolism. Isoflavone metabolites were tracked in foods and biospecimens of healthy adults after fermented soybean (FS) or non-fermented soybean (NFS) consumption in a randomized, controlled, crossover intervention study. The change in soybean isoflavones caused by fermentation resulted in faster absorption and higher bioavailability after consumption of FS. Although the urinary level of total isoflavone metabolites was similar after the consumption of the two diets, urinary genistein 7-O-sulfate was derived as a discriminant metabolite for the FS diet by partial least squares discriminant analysis. This study suggests that an isoflavone conjugate profile might be a more appropriate marker than total isoflavone levels for discriminating between the consumption of FS and NFS diets.
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Haplotype diversity underlying quantitative traits in Canadian soybean breeding germplasm.
Bruce, RW, Torkamaneh, D, Grainger, CM, Belzile, F, Eskandari, M, Rajcan, I
TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik. 2020;(6):1967-1976
Abstract
Identification of marker-trait associations and trait-associated haplotypes in breeding germplasm identifies regions under selection and highlights changes in haplotype diversity over decades of soybean improvement in Canada. Understanding marker-trait associations using genome-wide association in soybean is typically carried out in diverse germplasm groups where identified loci are often not applicable to soybean breeding efforts. To address this challenge, this study focuses on defining marker-trait associations in breeding germplasm and studying the underlying haplotypes in these regions to assess genetic change through decades of selection. Phenotype data were generated for 175 accessions across multiple environments in Ontario, Canada. A set of 76,549 SNPs were used in the association analysis. A total of 23 genomic regions were identified as significantly associated with yield (5), days to maturity (5), seed oil (3), seed protein (5) and 100-seed weight (5), of which 14 are novel. Each significant region was haplotyped to assess haplotype diversity of the underlying genomic region, identifying ten regions with trait-associated haplotypes in the breeding germplasm. The range of genomic length for these regions (7.2 kb to 6.8 Mb) indicates variation in regional LD for the trait-associated regions. Six of these regions showed changes between eras of breeding, from historical to modern and experimental soybean accessions. Continued selection on these regions may necessitate introgression of novel parental genetic diversity as some haplotypes were fixed within the breeding germplasm. This finding highlights the importance of studying associations and haplotype diversity at a breeding program scale to understand breeders' selections and trends in soybean improvement over time. The haplotypes may also be used as a tool for selection of parental germplasm to inform breeder's decisions on further soybean improvement.
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Effect of whole soy and purified daidzein on androgenic hormones in chinese equol-producing post-menopausal women: a six-month randomised, double-blinded and Placebo-Controlled trial.
Liu, ZM, Li, G, Zhang, D, Ho, SC, Chen, YM, Ma, J, Huang, Q, Li, S, Ling, WH
International journal of food sciences and nutrition. 2020;(5):644-652
Abstract
A randomised, double-blind and placebo-controlled trial was performed to examine the effects of whole soy and isoflavone daidzein on serum androgenic hormones in Chinese equol-producing post-menopausal women. A total of 270 eligible women aged 45-70 years were randomised to either one of the three iso-caloric supplements: 40 g soy flour (whole soy group), 40 g low-fat milk powder +63 mg daidzein (daidzein group) or 40 g low-fat milk powder (placebo group) daily for 6 months. Fasting venous samples were tested for serum androstenedione (AD), testosterone (T), prolactin, sex hormone binding globulin and dehydroepiandrosterone sulphate. Intention-to-treat analysis indicated that serum T (p = .022) and AD (p = .05) levels modestly but significantly decreased after 6-month daidzein treatment in comparison with placebo, with a mean difference of -0.057 nmol/L (95%CI: -0.185 to 0.070, p = .018) and -0.118 ng/mL (95%CI: -0.240-0.004, p = .045), respectively. This 6-month trial suggested that purified daidzein may exhibit less androgenic effect.Trial registration: The trial was registered in ClinicalTrials.gov with identifier of NCT01270737. (URL: http://clinicaltrials.gov/ct2/show/NCT01270737.).
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Legume and soy intake and risk of type 2 diabetes: a systematic review and meta-analysis of prospective cohort studies.
Tang, J, Wan, Y, Zhao, M, Zhong, H, Zheng, JS, Feng, F
The American journal of clinical nutrition. 2020;(3):677-688
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Abstract
BACKGROUND Previous findings on the associations of legume and soy intake with the risk of type 2 diabetes are conflicting. OBJECTIVE We aimed to summarize the longitudinal associations between legume and soy intake and risk of type 2 diabetes. METHODS We searched for relevant prospective cohort studies in PubMed, EMBASE, and Ovid up to August 2019. Study-specific, multivariable-adjusted RRs and 95% CIs were pooled by random-effects models. RESULTS We identified 15 unique cohorts including 565,810 individuals and 32,093 incident cases. The summary RRs (95% CIs) of incident type 2 diabetes were 0.95 (0.79, 1.14; NS) for total legumes, 0.83 (0.68, 1.01; NS) for total soy, 0.89 (0.71, 1.11; NS) for soy milk, 0.92 (0.84, 0.99) for tofu, 0.84 (0.75, 0.95) for soy protein, and 0.88 (0.81, 0.96) for soy isoflavones, respectively. High heterogeneity was found for total legumes (I2 = 84.8%), total soy (I2 = 90.8%), and soy milk (I2 = 91.7%). Potential sources of heterogeneity were not evident for total legumes or soy milk, whereas for total soy, geographic location (Asia, United States; P = 0.04) and study quality (high, moderate, or low; P = 0.02) significantly predicted heterogeneity. In dose-response analysis, significant linear inverse associations were observed for tofu, soy protein, and soy isoflavones (all P < 0.05). Overall quality of evidence was rated as moderate for total legumes and low for total soy and soy subtypes. CONCLUSIONS Dietary intakes of tofu, soy protein, and soy isoflavones, but not total legumes or total soy, are inversely associated with incident type 2 diabetes. Our findings support recommendations to increase intakes of certain soy products for the prevention of type 2 diabetes. However, the overall quality of evidence was low and more high-quality evidence from prospective studies is needed. This trial was registered as PROSPERO CRD42019126403 (https://www.crd.york.ac.uk/PROSPERO).
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Soy isoflavones prevent bone resorption and loss, a systematic review and meta-analysis of randomized controlled trials.
Akhlaghi, M, Ghasemi Nasab, M, Riasatian, M, Sadeghi, F
Critical reviews in food science and nutrition. 2020;(14):2327-2341
Abstract
BACKGROUND Osteoporosis is a common bone disease characterized by reduced bone mass resulting from continuous bone resorption. METHODS PubMed, Scopus, and Embase were searched to find published trials on the effect of soy isoflavones on bone mineral density (BMD) and bone turnover markers (bone-specific alkaline phosphatase, osteocalcin, osteoprotegerin, pyridinoline, deoxypyridinoline, C-telopeptide, and N-telopeptide). Random-effects inverse-variance model was used to calculate the pooled effects. RESULTS A total of 5313 articles were found, screened, and assessed for eligibility, and finally 52 trials were included in the meta-analysis. Consumption of soy isoflavones caused significant improvement in BMD of lumbar spine (mean difference (MD) = 0.76%; 95% CI: 0.09, 1.42%; p = 0.03), hip (MD = 0.22%; 95% CI: 0.02, 0.42%; p = 0.04), and femoral neck (MD = 2.27%; 95% CI: 1.22, 3.31%; p < 0.001). Subgroup analysis showed that in all 3 sites, the improvement was significant in normal weight subjects and interventions longer than a year, although trial location and dosage were also factors influencing isoflavones' impact on BMD. Among markers of bone turnover, osteoprotegerin (MD = 5.79; 95% CI: 3.08, 8.51 pg/ml; p < 0.001), pyridinoline (MD = -5.13; 95% CI: -7.76, -2.50 nmol/mmol; p < 0.001), and C-telopeptides (MD = -0.08; 95% CI: -0.16, -0.00 ng/ml; p = 0.04) were favorably affected by isoflavones while osteocalcin and bone alkaline phosphatase did not change. Subgroup analysis of bone markers showed that in overweight/obese individuals and dosages <90 mg/day, isoflavones are more effective. CONCLUSIONS Soy isoflavones prevent osteoporosis-related bone loss in any weight status or treatment duration. They increase BMD in normal weight subjects and diminish bone resorption in overweight/obese individuals. Although bone resorption may be decelerated over short-term isoflavone consumption, periods longer than a year are probably needed to affect BMD. Isoflavones also appear benefits on bone in any dose or subjects' ethnicity.
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Valorisation of By-Products from Soybean (Glycine max (L.) Merr.) Processing.
Colletti, A, Attrovio, A, Boffa, L, Mantegna, S, Cravotto, G
Molecules (Basel, Switzerland). 2020;(9)
Abstract
In recent years, increased awareness of the health benefits associated with consuming soy-based foods, knowledge of milk-related allergies and a move towards more sustainable food production have led to an increase in the number of available soy-based products. The biggest producers in the world, the USA, South America and China, are from the Pacific region. This enormous production is accompanied by the accumulation of related by-products, in particular, a substance that is known as okara. Okara is a paste that is rich in fibre (50%), protein (25%), fat (10%), vitamins and trace elements. Its proper use would lead to economic advantages and a reduction in the potential for polluting the environment. Its high fibre content and low production costs mean that it could also be used as a dietary supplement to prevent diabetes, obesity and hyperlipidaemia. Chemical or enzymatic treatment, fermentation, extrusion, high pressure and micronisation can all increase the soluble fibre content, and thus improve nutritional quality and processing properties. However, the product also degrades rapidly due to its high moisture content (70-80%), which makes it difficult to handle and expensive to dry by conventional means. The aim of this paper is therefore to thoroughly study the existing literature on this subject in order to develop a general protocol for okara exploitation and valorisation. A cost/benefit analysis could drive the design of eco-friendly, sustainable protocols for the preparation of high-value nutritional products.
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Acute Soy Supplementation Improves 20-km Time Trial Performance, Power, and Speed.
Seeley, AD, Jacobs, KA, Signorile, JF
Medicine and science in sports and exercise. 2020;(1):170-177
Abstract
INTRODUCTION Isoflavones, a chemical class of phytoestrogens found in soybeans and soy products, may have biological functions similar to estradiol. After binding with ERβ or perhaps independently of estrogen receptors, isoflavones may augment vascular endothelial relaxation, contributing to improved limb blood flow. PURPOSE To determine if acute fermented soy extract supplementation influences 20-km time trial cycling performance and cardiac hemodynamics compared with a placebo. METHODS Subjects included 25 cyclists and triathletes (31 ± 8 yr, V˙O2peak: 55.1 ± 8.4 mL·kg·min). Each subject completed a V˙O2peak assessment, familiarization, and two 20-km time trials in randomized order after ingestion of a fermented soy extract supplement or placebo. The fermented soy extract consisted of 30 g powdered supplement in 16 fl. ounces of water. The placebo contained the same quantities of organic cocoa powder and water. Each trial consisted of 60 min of rest, 30 min at 55% Wpeak, and a self-paced 20-km time trial. RESULTS Soy supplementation elicited a faster time to 20-km completion (-0.22 ± 0.51 min; -13 s), lower average HR (-5 ± 7 bpm), and significantly greater power (7 ± 3 W) and speed (0.42 ± 0.16 km·h) during the last 5 km of the time trial compared with placebo. Analysis of the results by relative fitness level (<57 vs ≥ 57 mL⋅kg⋅min) indicated that those with a higher level of fitness reaped the largest performance improvement alongside a reduced HR (-5 ± 7 bpm). CONCLUSIONS Ingestion of a fermented soy extract supplement improved sprint-distance performance through improvements in both power and speed. For those with great aerobic fitness, soy supplementation may help to decrease cardiac demand alongside performance improvement.
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High soy isoflavone or soy-based food intake during infancy and in adulthood is associated with an increased risk of uterine fibroids in premenopausal women: a meta-analysis.
Qin, H, Lin, Z, Vásquez, E, Luan, X, Guo, F, Xu, L
Nutrition research (New York, N.Y.). 2019;:30-42
Abstract
Numerous studies have examined the association of soy isoflavones or soy-based food intake with the risk of uterine fibroids (UF), but the results are inconsistent. The purpose of this meta-analysis was to quantitatively assess whether high soy isoflavones intake is associated with an increased risk of UF. PUBMED and EMBASE databases were reviewed to screen for relevant published studies up to December 2018. Using key words of uterine fibroid and isoflavone, we identified 4 studies focusing on infancy intake and 7 studies evaluating intake during adulthood. The pooled odds ratio (OR) and corresponding 95% confidence interval (95% CI) were calculated using a random-effect model. In addition, subgroup analyses and 2-stage random-effect dose-response were also performed. When comparing high vs low intake of soy isoflavones, we found that there were positive associations of UF among patients being fed soy formula during infancy (OR, 1.19; 95% CI, 0.99-1.43; P = .06) and with high consumption of soy-based foods in adulthood (OR, 2.50; 95% CI, 1.09-5.74; P = .03), respectively. Additionally, dose-response analysis showed the pooled ORs (95% CIs) of UF risk for low, moderate, and high intake of soy isoflavones were 1.00 (0.87-1.14), 1.08 (0.94-1.24), and 1.23 (0.99-1.53) when compared to occasional intake, respectively. Our findings suggest that high soy isoflavones or soy-based food intake during infancy and in adulthood is associated with an increased risk of uterine fibroids in premenopausal women. There is a need for large-scale prospective cohort studies using more accurate measurements of soy isoflavones to further ascertain our study findings.