The effect of nigella supplementation on blood pressure: A systematic review and dose-response meta-analysis.

This study was performed to assess the effect of nigella supplementation on blood pressure levels among the adult population. A comprehensive search was carried out through PubMed, Scopus, Web of Science, and Cochrane Library by using relevant keywords to find out the randomized clinical trials evaluating the effect of nigella administration on systolic blood pressure (SBP) and diastolic blood pressure (DBP). A random-effect model was applied to achieve the overall effect size. Subgroup analysis and meta-regression were used to explore the source of heterogeneity and the effects of the possible moderators. Of the twenty-two trials that were eligible for the present study, seventeen studies consisting of 1048 participants were included in the meta-analysis. The results indicated that nigella administration could significantly reduce both SBP (-4.58 mmHg; 95%CI: -6.22, -2.94) and DBP (-3.08 mmHg; 95%CI: -4.62, -1.55). Subgroup analysis did not show any superiority between subgroups of variables. Dose-response analysis detected a nonlinear association between dose and duration of administration and change in blood pressure outcomes, highlighting that maximum SBP and DBP reduction was experienced at 2000 mg/day and 8 weeks of nigella administration, respectively. The present study suggests that nigella supplementation can be beneficial for managing blood pressure.

Efficacy of synbiotic interventions on blood pressure: a systematic review and meta-analysis of clinical trials.

PURPOSE: The present systematic review and meta-analysis aimed to evaluate the effect of synbiotic interventions on blood pressure levels in adults. METHODS: A systematic literature search was conducted in the databases of MEDLINE, Scopus, Web of Science, and Cochrane through March 2020 to identify all randomized control trials (RCTs) investigating the effects of synbiotic interventions on blood pressure parameter, including systolic (SBP) and diastolic blood pressure (DBP). Grading of Recommendations Assessment, Development and Evaluation (GRADE) scale was used to assess the certainty of evaluated outcomes and determine the strength of recommendations. RESULTS: Eleven RCTs were included in the meta-analysis. Synbiotic interventions significantly reduced SBP (-3.02 mmHg; 95% CI: -4.84, -1.21; I2 = 55%) without changing DBP levels (-0.57 mmHg; 95% CI: -1.78, 0.64; I2 = 50%). Subgroup analyses revealed that the SBP-lowering effects of synbiotic interventions were more pronounced wherein trials were longer (≥12 weeks), synbiotic interventions were administrated as a supplement, and participants were younger (<50 years old). Also, a significant improvement in both SBP and DBP levels was evident in subgroups with a lower (<30 kg/m2) body mass index. CONCLUSIONS: Synbiotic interventions may significantly improve SBP levels in adults.

The effect of spirulina on type 2 diabetes: a systematic review and meta-analysis.

PURPOSE: The aim of the present study was to investigate the effect of spirulina on lipid profiles and glycemic related markers in type 2 diabetes patients. METHODS: PubMed, Scopus, Cochrane Library, ISI Web of Science, and Google Scholar were searched from inception to August 2020. All clinical trials which investigated the effect of spirulina supplementation on glycemic related markers and lipid profile among type 2 diabetes patients were included. Random effects modeling was utilized for pooling analysis to compensate for the between-study heterogeneity. RESULTS: Eight studies (9 arms) were included in the meta-analysis. We found a significant reduction in fasting blood glucose (-17.88 mg/dl; 95% CI: -26.99, -8.78; I 2 : 25%), triglyceride (-30.99 mg/dl; 95% CI: -45.20, -16.77; I 2 : 50%), total-cholesterol (-18.47 mg/dl; 95% CI: -33.54, -3.39; I 2 : 73%), LDL-C (-20.04 mg/dl; 95% CI: -34.06, -6.02; I 2 : 75%), VLDL (-6.96 mg/dl; 95% CI: -9.71, -4.22; I 2 : 33%), in addition to a significant increase in HDL-C (-6.96 mg/dl; 95% CI: -9.71, -4.22; I 2 : 33%), after spirulina administration. No significant effect was observed on HbA1C or post prandial blood sugar following spirulina consumption. CONCLUSION: The present study suggests that spirulina supplementation can elicit beneficial effects on fasting blood glucose and blood lipid profiles. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40200-021-00760-z.

The effect of apple cider vinegar on lipid profiles and glycemic parameters: a systematic review and meta-analysis of randomized clinical trials.

BACKGROUND: Elevated lipid profiles and impaired glucose homeostasis are risk factors for several cardiovascular diseases (CVDs), which, subsequently, represent a leading cause of early mortality, worldwide. The aim of the current study was to conduct a systematic review and meta-analysis of the effect of apple cider vinegar (ACV) on lipid profiles and glycemic parameters in adults. METHODS: A systematic search was conducted in electronic databases, including Medline, Scopus, Cochrane Library, and Web of Knowledge, from database inception to January 2020. All clinical trials which investigated the effect of ACV on lipid profiles and glycemic indicators were included. Studies were excluded if ACV was used in combination with other interventions or when the duration of intervention was < 2 weeks. To account for between-study heterogeneity, we performed meta-analysis using a random-effects model. RESULTS: Overall, nine studies, including 10 study arms, were included in this meta-analysis. We found that ACV consumption significantly decreased serum total cholesterol (- 6.06 mg/dL; 95% CI: - 10.95, - 1.17; I2: 39%), fasting plasma glucose (- 7.97 mg/dL; 95% CI: - 13.74, - 2.21; I2: 75%), and HbA1C concentrations (- 0.50; 95% CI: - 0.90, - 0.09; I2: 91%). No significant effect of ACV consumption was found on serum LDL-C, HDL-C, fasting insulin concentrations, or HOMA-IR. The stratified analysis revealed a significant reduction of serum TC and TG in a subgroup of patients with type 2 diabetes, those who took ≤15 mL/day of ACV, and those who consumed ACV for > 8-weeks, respectively. Furthermore, ACV consumption significantly decreased FPG levels in a subgroup of studies that administered ACV for > 8-weeks. Further, ACV intake appeared to elicit an increase in FPG and HDL-C concentrations in apparently healthy participants. CONCLUSION: We found a significant favorable effect of ACV consumption on FPG and blood lipid levels.

The Effect of Green Coffee Bean Extract on Cardiovascular Risk Factors: A Systematic Review and Meta-analysis.

BACKGROUND AND AIM: Cardiovascular disease remains the primary cause of noncommunicable disease- related death. The present systematic review and meta-analysis was performed to assess the possible benefit of the green coffee bean extract on cardio-metabolic markers. METHODS: PubMed, Scopus, Web of Science, and Cochrane Library were systematically searched to identify clinical trials that examined the effect of green coffee bean extract on cardio-metabolic risk factors including serum lipid profiles, glycemic status-related markers, blood pressure, and anthropometric indices. Since the included RCTs were carried out in different settings, random effect models were used to conduct all meta-analyses. RESULTS: Fifteen studies (19 arms) consisting of 637 participants were included. The results indicated that green coffee bean extract significantly reduced levels of total cholesterol (-5.93 mg/dl; 95% CI: -9.21, -2.65; I2: 0%), fasting plasma glucose (-2.21 mg/dl; 95% CI: -3.94, -0.48; I2: 32%), systolic blood pressure (-3.08 mmHg; 95% CI: -4.41, -1.75; I2: 26%), diastolic blood pressure (-2.27 mmHg; 95% CI: -3.82, -0.72; I2: 61%), body weight (-1.24 kg; 95% CI: -1.82, -0.66; I2: 15%), and BMI (-0.55 kg/m2; 95% CI: -0.88, -0.22; I2: 73%). Although the pooled effect size of LDL-C, fasting insulin, and waist circumstance were significant, the results were significantly influenced by individual studies. No significant effect was detected for triglycerides, HDL-C, HbA1C, and HOMA-IR. However, the nonsignificant pooled effect size for triglyceride levels was influenced by one individual study. CONCLUSION: The present study suggests that green coffee been extract consumption can improve total cholesterol, triglycerides, body weight, blood pressure, and fasting plasma glucose.

The effects of cranberry on cardiovascular metabolic risk factors: A systematic review and meta-analysis.

BACKGROUND & AIMS: The impetus for the current study was to evaluate the efficacy of cranberry supplementation on cardiovascular disease metabolic risk factors in adult populations. METHODS: A systematic review was conducted on PubMed, Scopus, Web of Science and Google Scholar up to June 2018, to identify randomized controlled trials investigating the effect of cranberry supplementation on cardiovascular metabolic risk factors. RESULTS: The results of the pooled effect size indicated that cranberry administration significantly reduced systolic blood pressure and body mass index. No statistically significant change was observed in triacylglycerol, total cholesterol, low-density lipoprotein, high-density lipoprotein, fasting plasma glucose, fasting insulin, homeostasis model assessment of insulin resistance, diastolic blood pressure, waist circumference, C-reactive protein, and intercellular adhesion molecule. Stratified analysis showed that SBP reduction was more pronounced in studies with ≥50 mean age participants. Also, subgroup analysis suggested a significant increase in high-density lipoprotein concentrations in subgroups with subjects <50 mean age, and triacylglycerol levels in subsets with cranberry administered in juice form. CONCLUSIONS: This systematic review and meta-analysis suggests cranberry supplementation may be effective in managing systolic blood pressure, body mass index and high-density lipoprotein in younger adults. Further high-quality studies are needed to confirm these results.

The effect of synbiotics in improving Helicobacter pylori eradication: A systematic review and meta-analysis.

BACKGROUND: Helicobacter pylori is a common human infection, presenting in half of the world's population. The failure of the Helicobacter pylori eradication rate necessitates the assessment of new options. The aim of the present meta-analysis was therefore to assess the role of synbiotics in Helicobacter pylori eradication therapy. METHODS: A comprehensive literature search was conducted using PubMed, Google Scholar, Scopus, and Web of Knowledge up to June 2018 to identify all randomized controlled trials assessing the effect of synbiotics on the treatment of Helicobacter pylori. A random-effects model was applied for pooling analysis to compensate for the heterogeneity of included studies. The Cochrane Risk of Bias Tool was applied to assess potential bias risks. RESULTS: A total of 6 randomized controlled trials were found which assessed the effect of synbiotics on Helicobacter pylori eradication rate. The pooled effect size of the intention-to-treat showed that synbiotics can improve eradication rate (RR: 1.28; 95% CI: 1.15-1.43; I2 = 0%). Also, common adverse events resulting from antibiotics therapy were significantly reduced by adding synbiotics to conventional antibiotics treatments (RR: 0.47; 95% CI: 0.25-0.90; I2 = 36%). However, no difference in eradication rate was observed from per-protocol treatment between intervention and control groups (RR: 0.90; 95% CI: 0.69-1.16; I2 = 88%). CONCLUSION: The present systematic review and meta-analysis suggested synbiotics might improve Helicobacter pylori eradication rates, and reduce adverse effects. However, these findings assessed a low number of studies, and further high-quality studies are needed to confirm these results.

The efficacy of propolis on markers of glycemic control in adults with type 2 diabetes mellitus: A systematic review and meta-analysis.

BACKGROUND AND OBJECTIVES: The impetus for the current study was to evaluate the efficacy of propolis supplementation on markers of glycemic status in adults with type 2 diabetes mellitus (T2DM). METHODS: A comprehensive search was conducted in PubMed, Scopus, Cochrane Library, Web of Science, and Google Scholar up to August 2018, identifying randomized controlled trials investigating the effect of propolis supplementation on glycemic markers in adults with T2DM. Cochrane Collaboration tool was used to evaluate the risk of bias assessment. A random-effects model was applied in the meta-analysis to compensate for potential heterogeneity among the included studies. RESULTS: Six randomized controlled trials comprising 373 participants were included in the systematic review and meta-analysis. The results of the meta-analysis revealed significant reductions in fasting plasma glucose (-13.51 mg/dl; 95% CI [-24.98, -2.04]) and hemoglobin A1C (-0.52%; 95% CI [-0.94, -0.10]) concentrations following propolis supplementation. However, no significant lowering effect was observed in fasting insulin levels (-0.53 pmol/L; 95% CI [-1.69, 0.63]) or homeostasis model assessment of insulin resistance (-0.543; 95% CI [-1.72, 0.64]). CONCLUSION: This systematic review and meta-analysis suggested that propolis supplementation may be effective in controlling glycemic levels for T2DM patients. Further studies are needed to confirm these results.

Clinical evidence on the effects of saffron (Crocus sativus L.) on cardiovascular risk factors: A systematic review meta-analysis.

Cardiovascular disease is a one of most common causes of mortality around the world. This meta-analysis aims to summarize and conclude the clinical evidence regarding the use of saffron and its constituents, in particular crocin, on cardiovascular risk factors. A systematic review was conducted with PubMed, Scopus, Web of Science, Cochrane library and Google Scholar up to 24 May 2018. Randomized controlled trials (RCTs) that assessed the clinical effects of saffron and/or its constituents on blood lipid profile, glycemic parameters, blood pressure and anthropometric indices in human subjects were included. Eleven publication from ten studies comprising 622 participants included in quantitative analysis. Pooling of results showed significant effect of saffron on diastolic blood pressure (-1.24 mmHg; 95% CI: -1.51 to -0.96; I2 = 0%), body weight (-1.29 kg; 95% CI: -2.14 to -0.44; I2 = 70%) and waist circumstance (-1.68 cm; 95% CI: -3.31 to -0.04; I2 = 51%). When subgroup analysis was performed based on quality of studies, a significant reduction in fasting plasma glucose levels was observed in subgroup with high quality studies (-10.14 mg/dl; 95% CI: -13.80 to -6.48; I2 = 0%). Meta-analysis did not reveal any significant change in lipid profile, fasting insulin, systolic blood pressure and body mass index following saffron consumption. Present meta-analysis suggests that saffron might be beneficial in several outcomes related with cardiovascular disease. However, further RCTs with long term intervention with different dose of administration are needed.

Effect of purslane on blood lipids and glucose: A systematic review and meta-analysis of randomized controlled trials.

Despite a history of purslane usage as a herbal treatment for dyslipidemia and hyperglycemia management, existing evidence from clinical trials is controversial. The aim for the current study was to evaluate the efficacy of purslane supplementation on lipid parameters and glycemic status in adult populations. A systematic review was conducted in PubMed, Scopus, ISI Web of Science, and Google Scholar up to January 15, 2018, searching for randomized controlled trials that assessed the impact of purslane on fasting blood glucose (FBG), triglycerides, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C). Based on the detected heterogeneity between studies, a random- or fixed-effect model was applied in the meta-analysis. The findings from six randomized controlled trials, comprising 352 participants, indicated that purslane can reduce FBG (-4.54 mg/dl, 95% CI [-7.54, -1.53]; I2  = 0.53%) and triglycerides (-19.16 mg/dl, 95% CI [-38.17, -0.15]; I2  = 0%) levels. Changes in TC, LDL-C, and HDL-C concentrations did not reach a statistically significant level. Subgroup analysis showed a favorable effects of purslane on FBG, triglycerides, TC, and LDL-C in a subset of studies in which purslane was administered >1.5 g/day. Categorization based on gender showed that purslane was more effective in improving FBG, TC and LDL-C in females compared with males. This systematic review and meta-analysis suggested that the purslane might be effective on the improvement of blood lipid and glucose levels. Further robust studies with sufficient durations and dosages of supplementation are needed to confirm these results.

Green tea as a safe alternative approach for nonalcoholic fatty liver treatment: A systematic review and meta-analysis of clinical trials.

This study aimed to evaluate the efficacy of green tea supplementation on nonalcoholic fatty liver disease treatment. Electronic databases, including PubMed, Scopus, Web of Science, and Google Scholar, were systematically searched up to October 30, 2017, to identify eligible trials based on the inclusion criteria. The effect size was presented as mean difference with 95% confidence intervals (CI). The meta-analysis of data from four studies indicated significant effects of green tea supplementation in altering alanine aminotransferases (-12.81 U/L; 95% CI: -18.17 to -7.45) and aspartate aminotransferases (-10.91 U/L; 95% CI: -19.66 to -2.17) blood concentrations. Likewise, a favorable effect of green tea administration was observed on body mass index (-2.08 kg/cm2 ; 95% CI: -2.81 to -1.36), triacylglycerol (-31.87 mg/dl; 95% CI: -40.62 to -23.12), total cholesterol (-27.57 mg/dl; 95% CI: -36.17 to -18.98), and low-density lipoprotein cholesterol (-14.15 mg/dl; 95% CI: -23.69 to -4.60), whereas no significant effect was detected on high-density lipoprotein cholesterol concentrations (7.41 mg/dl; 95% CI: -1.49 to 16.30) and homeostasis model assessment of insulin resistance (-4.06; 95% CI: -10.22 to 2.09). This systematic review and meta-analysis of available trials suggests that there  are potential benefits of green tea supplementation on nonalcoholic fatty liver disease.

The effect of ginger supplementation on lipid profile: A systematic review and meta-analysis of clinical trials.

BACKGROUND: Elevated levels of blood lipids are a major cause of atherosclerosis and consequently cardiovascular disease. Several studies used ginger as a lipid lowering agent. PURPOSE: The aim of the present systematic review and meta-analysis was to clarify the effect of ginger supplementation on lipid parameters. METHODS: PubMed, Scopus, Science Direct, ISI Web of Science and Google Scholar were systematically searched until May 2017 to find clinical trials which examined effect of ginger supplementation on level of lipid parameters in adult participants. Means for blood lipids and potential sources of heterogeneity were extracted. A subgroup analysis was applied to find out potential sources of inter-study heterogeneity. RESULTS: A total of 12 trials (586 participants) were included in the meta-analysis. Pooled analysis suggested that ginger supplementation reduced triacylglycerol (TAG) (-17.59 mg/dl; 95% CI: -29.32 to -5.87) and low density lipoprotein cholesterol (LDL-C) (-4.90 mg/dl; 95% CI: -22.30 to -6.17). Ginger had no significant effect on total cholesterol (TC) (-5.13 mg/dl, 95% CI: -11.05 to 0.78; P = 0.089) and high density lipoprotein cholesterol (HDL-C) (2.18 mg/dl, 95% CI: -0.08 to 4.45; P = 0.059). As inter-study heterogeneity was high, studies were classified by ginger dosage. Stratified analysis showed a significant reduction in TC (-12.26 mg/dl; 95% CI: -22.37 to -2.16) and TAG (-38.42 mg/dl; 95% CI: -57.01 to -19.82) in studies which used ≤2 g/day of ginger. However, a similar significant effect was not observed in trials with >2 g/day of ginger. Neither studies which used ≤2 g/day nor trials which used >2 g/day of ginger showed significant changes in LDL-C or HDL-C. CONCLUSION: The present systematic review and meta-analysis suggests that ginger had a favorable effect on TAG and LDL-C. Also, the result revealed that low dose of ginger (≤2 g/day) had greater lowering impact on TAG and TC. Further studies with large-scale and better design are needed to confirm this result.