Effects of a supplement containing isoflavones and Actaea racemosa L. on asymmetric dimethylarginine, lipids, and C-reactive protein in menopausal women

The effects of soy supplementation on inflammatory biomarkers: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Soy products contain several compounds with anti-inflammatory properties like genistein and daidzein which reported to act through different pathways. Present study conducted considering the inconsistent results and lack of any comprehensive review regarding randomized controlled trials which assess the effect of soy products on inflammatory markers.

METHODS

Following electronic databases were searched up to March 2020: PubMed, Scopus, ISI web of science, and Cochrane Library All randomized trials which assessed the effect of soy product supplementation on c-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) were included for last analysis. Treatment effects were expressed as mean difference (MD) and the standard deviation (SD) of outcomes. To estimate the overall effect the random-effects model was employed.

RESULTS

Finally, 51 randomized trial were included for present study. Last analysis showed that soy product supplementation lead to significant reduction in CRP (MD -0.27 mg/L; 95% CI: -0.51, -0.02, p = 0.028) but it did not affect IL-6 (MD 0.0 pg/ml; 95% CI: -0.06, 0.06, p = 0.970) and TNF-α (MD = -0.04 pg/ml; 95% CI: -0.11, 0.03, p = 0.252). Subgroup analysis showed that soy supplementation had a significant impact on decreasing IL-6 and TNF-α levels when studies had a long-term intervention (≥12 weeks) and used low dose isoflavone (<100 mg/day).

CONCLUSION

In conclusion, present systematic review and meta-analysis found a significant reduction in CRP levels after soy supplementation whiles IL-6 and TNF-α did not affect.

A systematic review and meta-analysis of the effects of soy on serum hs-CRP

BACKGROUND & AIM

The results of studies about the effect of soy products on serum highly sensitive C-reactive protein (hs-CRP) are inconsistent. The aim of this systematic review and meta-analysis of randomized clinical trials (RCTs) was to investigate the effect of soy products intake on serum hs-CRP concentration.

METHODS

We searched PubMed, EMBASE, Science Direct, ISI Web of Science, Google Scholar and Cochrane Central Register of Controlled Trials up to December 2016 without language restrictions. Random-effect model was used for quantitative data synthesis.

RESULTS

Thirty-six studies were included in our analyses. A meta-analysis revealed a non-significant reduction in serum hs-CRP concentrations following soy products consumption, -0.19 (mg/L) (95% CI: -0.49 to 0.09; I2 = 95.6%). Subgroup analyses suggested that natural soya products may reduce plasma levels of CRP by -0.18 mg/L (95% CI: -0.28 to -0.08; I2: 11.6) in comparison to other source of isoflavones (soya extracts, supplements). Moreover, the effect was stronger among subjects with baseline hs-CRP concentrations of less than 2.52 mg/L, -0.15 (95% CI: -0.27 to -0.02; I2: 34.6). A meta-regression analysis revealed that dosage of isoflavones seems to be a strong predictor of the effect of soya on serum hs-CRP levels.

CONCLUSION

Present review of RCTs published up to December 2016 did not provide strong evidence regarding the beneficial effect of soya products consumption on blood hs-CRP concentrations. However, it appears that natural soya products may reduce plasma levels of hs-CRP in comparison to other source of isoflavones. Large and well-designed studies are recommended to confirm this conclusion.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018069371.

Soya products and serum lipids: a meta-analysis of randomised controlled trials

Soya proteins and isoflavones have been reported to exert beneficial effects on the serum lipid profile. More recently, this claim is being challenged. The objective of this study was to comprehensively examine the effects of soya consumption on the lipid profile using published trials. A detailed literature search was conducted via MEDLINE (from 2004 through February 2014), CENTRAL (The Cochrane Controlled Clinical Trials Register) and ClinicalTrials.gov for randomised controlled trials assessing the effects of soya on the lipid profile. The primary effect measure was the difference in means of the final measurements between the intervention and control groups. In all, thirty-five studies (fifty comparisons) were included in our analyses. Treatment duration ranged from 4 weeks to 1 year. Intake of soya products resulted in a significant reduction in serum LDL-cholesterol concentration, -4.83 (95% CI -7.34, -2.31) mg/dl, TAG, -4.92 (95% CI -7.79, -2.04) mg/dl, and total cholesterol (TC) concentrations, -5.33 (95% CI -8.35, -2.30) mg/dl. There was also a significant increase in serum HDL-cholesterol concentration, 1.40 (95% CI 0.58, 2.23) mg/dl. The I² statistic ranged from 92 to 99%, indicating significant heterogeneity. LDL reductions were more marked in hypercholesterolaemic patients, -7.47 (95% CI -11.79, -3.16) mg/dl, than in healthy subjects, -2.96 (95% CI -5.28, -0.65) mg/dl. LDL reduction was stronger when whole soya products (soya milk, soyabeans and nuts) were used as the test regimen, -11.06 (95% CI -15.74, -6.37) mg/dl, as opposed to when 'processed' soya extracts, -3.17 (95% CI -5.75, -0.58) mg/dl, were used. These data are consistent with the beneficial effects of soya proteins on serum LDL, HDL, TAG and TC concentrations. The effect was stronger in hypercholesterolaemic subjects. Whole soya foods appeared to be more beneficial than soya supplementation, whereas isoflavone supplementation had no effects on the lipid profile.

Effect of soy isoflavones on circulating C-reactive protein in postmenopausal women: meta-analysis of randomized controlled trials

Strong evidence suggests that C-reactive protein (CRP) is a novel risk factor for cardiovascular disease. We aimed to examine the effect of soy isoflavones on circulating CRP concentrations in postmenopausal women by conducting a meta-analysis of randomized controlled trials. We performed a literature search using PubMed, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov databases in December 2010 for randomized controlled trials conducted in postmenopausal women, using soy foods with isoflavones or isoflavone extracts as treatment, and with a report of CRP change. A meta-analysis was performed using a fixed-effects model or a random-effects model to calculate the combined effect size. In addition, subgroup and metaregression analyses were carried out to examine the influences of study designs and participant characteristics on the effect estimates. A pooled analysis of 14 trials showed a slight, but not significant, reduction of 0.17 mg/L (95% CI, -0.38 to 0.04; P = 0.12) in CRP concentrations among postmenopausal women with soy isoflavone intervention compared with controls. No substantial heterogeneity was observed. Subgroup analyses showed that soy isoflavones significantly lowered CRP by 0.70 mg/L (95% CI, -1.17 to -0.23; P = 0.003) among women with baseline CRP concentrations greater than 2.2 mg/L. No significant changes in CRP were observed in the other subgroups. Metaregression analysis further revealed that baseline CRP was a potential effect modifier of isoflavone treatment in lowering CRP. The present meta-analysis found insufficient evidence that soy isoflavones significantly reduce CRP concentrations in postmenopausal women. However, soy isoflavones may produce a significant reduction in CRP among postmenopausal women with elevated CRP.

Combined effects of exercise and soy isoflavone diet on paraoxonase, nitric oxide and aortic apoptosis in ovariectomized rats

Menopause is associated with an increased risk of cardiovascular disease (CVD). Exercise and soy isoflavone diets have been suggested to reduce the risk of CVD in postmenopausal women. We investigated the effects of exercise, or combined exercise and soy isoflavone diet, on plasma lipid profiles, paraoxonase (PON), nitric oxide (NO) and apoptosis in the aorta of ovariectomized (OVX) rats. Thirty-two female Sprague-Dawley rats were divided into four groups: OVX with general diet (OVX-GD), OVX with isoflavone diet (OVX-ISO), OVX-GD with exercise training (OVX-ET) and OVX-ISO with exercise training (OVX-ISO+ET). The experimental rats undertook treadmill training (30 min/day, 4 days/week) and/or were supplied a soy isoflavone diet (added to the experimental diet at 2.39 mg/g protein) for 12 weeks. Body weight and levels of total cholesterol (TC), triglyceride (TG), LDL-cholesterol (LDL-C) increased in the OVX rats and HDL-C decreased. These effects were reduced by exercise and/or soy isoflavone supplementation. PON and NO activities were higher in the OVX-ISO+ET group than in the OVX-GD group. In addition, this group had lower caspase-9 and -3 and higher Bcl-2 expression, and there was less aortic apoptotic cell death. These results suggest that a combination of exercise and a soy isoflavone diet has beneficial effects in terms of protecting against cardiovascular risk factors by controlling lipid profiles and the related enzyme, PON, as well as NO activity and apoptosis of the aorta in OVX rats.

Black cohosh (Cimicifuga racemosa): a systematic review of adverse events

Black cohosh (Cimicifuga racemosa) is used most often to treat symptoms that can occur during menopause. However, in the last years, several concerns regarding its safety have been voiced. The aim of this systematic review was to evaluate the clinical evidence for or against the safety of black cohosh. Systematic literature searches were conducted in 5 computerized databases (Medline, Embase, Amed, Phytobase, and Cochrane Library). The references of all located articles were scanned for further relevant publications. Any type of clinical data that included case reports and observational studies was considered. No language restrictions were imposed. Thirteen clinical trials (all of which indicated relative safety), 3 postmarketing surveillance studies, 4 case series, and 8 single case reports were identified. Clinical studies suggest black cohosh to be safe. In most case reports, causal attribution is problematic. In conclusion, black cohosh has been associated with serious safety concerns that urgently require further investigation.