The efficacy of soy isoflavones combined with soy protein on serum concentration of interleukin‐6 and tumour necrosis factor‐α among post‐menopausal women? A systematic review and meta‐analysis of randomized controlled trials

Abstract

The post-menopausal stage in women's life is associated with the enhancement of inflammation that may be reduced using soy isoflavones or soy protein. The present study aimed to summarize the effect of soy isoflavones plus soy protein on circulating interleukin-6 (IL-6) and tumour necrosis factorα (TNFα) in post-menopausal women.The English-language articles were identified from the databases such as Cochrane Library, clinicaltrials.gov, Web of Science, PubMed, and Scopus until December 2020.The mean change from baseline and its standard deviation (SD) for intervention and comparison groups were used to calculate the effect size. The statistical heterogeneity of the intervention effects was computing by Cochran's Q test and I 2 statistic. Nine and seven studies were selected for systematic review and meta-analysis, respectively. The results of our meta-analysis indicated a non-significant effect on the serum concentrations of IL-6 and TNFα (weighted mean differences [WMD] = 0.07 pg/mL; 95% confidence interval [CI] = −0.03, 0.17 pg/mL; P = 0.190; WMD =0.05 pg/mL; 95% CI = −0.01, 0.12 pg/mL; P = 0.092; respectively). In subgroup analysis, soy isoflavones plus soy protein could increase the serum concentration of IL-6 in studies with soy isoflavones dose ≤87 mg/days, cross-over design, weak quality, and studies on participants who had health risk factors or diseases. The serum concentration of TNFα increased in studies with cross-over design, intervention duration ≤56 days, and body mass index (BMI) >27, and in studies that were conducted on at-risk or sick participants. In conclusion, our meta-analysis did not confirm any significant effect on serum concentration of IL-6 and TNFα among post-menopausal women.

Soy Protein Containing Isoflavones Improves Facial Signs of Photoaging and Skin Hydration in Postmenopausal Women: Results of a Prospective Randomized Double-Blind Controlled Trial

“…As opposed to topical application, oral supplementation may have other benefits that could be considered an integrative and holistic approach to skin care. For example, soy protein supplementation may have an overall anti-inflammatory effect on the body with a reduction in the circulating IL-6 and TNF-alpha levels [62,63], although the impact on postmenopausal women remains unclear [64]. Furthermore, soy protein supplementation may improve bone health in post-menopausal women as well [65,66].…”

Effect of the Fermented Soy Q-CAN® Product on Biomarkers of Inflammation and Oxidation in Adults with Cardiovascular Risk, and Canonical Correlations between the Inflammation Biomarkers and Blood Lipids

“…Although it is unclear why IL-6 levels increased in participants consuming the fermented soy powder, the causes may be due either to participant characteristics or the soy supplement dose. In a recent subgroup analysis of trials with isoflavone containing soy products among women, serum IL-6 concentration increases occurred in studies where the isoflavone doses were ≤87 mg per day, in studies where participants had chronic disease risk factors and BMIs > 27 kg/m 2 , and in crossover studies [ 41 ]. The fermented soy supplement in the current study contained approximately 36 mg of isoflavones per daily dose and participants were obese with a mean BMI of 32 kg/m 2 .…”

Relationship of Inflammatory Markers and Metabolic Syndrome in Postmenopausal Women

“…Besides estrogen decrease in postmenopausal women, their elevation is associated with chronic diseases such as dyslipidemia, high blood pressure, and CVD. Moreover, estrogen stimulates the synthesis of IL-6 and TNF-α [36][37][38]. Zannas et al [39], advocating that cardiometabolic risks are augmented due to the psychosocial stress exposition and during the menopausal transition in women, investigated the role of IL-6 in predicting longitudinal cardiometabolic outcomes in women at perimenopause.…”