Metabolic effect of berberine–silymarin association: A meta‐analysis of randomized,double‐blind,placebo‐controlled clinical trials

The aim of this study is to assess the impact of a combination of berberine and silymarin on serum lipids and fasting plasma glucose (FPG) through a systematic review of literature and meta‐analysis of the available randomized, double‐blind, placebo‐controlled clinical trials (RCTs). A systematic literature search in SCOPUS, PubMed‐Medline, ISI Web of Science, and Google Scholar databases was conducted up to October 2, 2018, in order to identify RCTs assessing changes in plasma concentrations of total cholesterol (TC), triglycerides (TG), high‐density lipoprotein cholesterol (HDL‐C), low‐density lipoprotein cholesterol (LDL‐C) and FPG during treatment with berberine and silymarin in combination. Two review authors independently extracted data on study characteristics, methods, and outcomes. Quantitative data synthesis was performed using a random‐effects model. We identified five eligible RCTs, with 497 subjects overall included. Berberine and silymarin combination treatment exerted a positive effect on TC (mean difference [MD]: ?25.3, 95% CI [?39.2, ?11.4] mg/dl; p < 0.001), TG (MD: ?28, 95% CI [?35.3, ?20.6] mg/dl; p < 0.001), HDL‐C [MD: 6, 95% CI [3.2, 8.8] mg/dl; p < 0.001), LDL‐C (MD: ?29.1, 95% CI [?39.7, ?18.6] mg/dl; p < 0.001), and FPG (MD: ?7.5, 95% CI [?13, ?1.9] mg/dl; p = 0.008). The present findings suggest that the coadministration of berberine and silymarin is associated with an advantageous improvement in lipid and glucose profile, suggesting the possible use of this nutraceutical combination in order to promote the cardiometabolic health.     

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.     

The effects of curcumin‐containing supplements on biomarkers of inflammation and oxidative stress: A systematic review and meta‐analysis of randomized controlled trials

Besides other benefits, curcumin is getting more recognized for its antioxidant and anti‐inflammatory properties, highlighting the importance of curcumin application for chronic disease prevention. This systematic review and meta‐analysis of randomized controlled trials (RCTs) was conducted to assess the influence of curcumin‐containing supplements on biomarkers of inflammation and oxidative stress. MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials were searched till January 2018 for eligible studies. The selected studies were evaluated for their quality using the Cochrane risk of bias tool and relevant data were extracted from included studies. Data were pooled using the inverse variance method and expressed as standardized mean difference (SMD) with 95% confidence intervals (95% CI). Fifteen RCTs were included in the final analysis. The meta‐analysis indicated that curcumin supplementation significantly decreased interleukin 6 (IL‐6) (SMD ?2.08; 95% CI [?3.90, ?0.25]; p = 0.02), high‐sensitivity C‐reactive protein (hs‐CRP) (SMD ?0.65; 95% CI [?1.20, ?0.10], p = 0.02), and malondialdehyde (MDA) concentrations (SMD ?3.14; 95% CI [‐4.76, ?1.53], p < 0.001). Though, curcumin supplementation had no significant effect on tumor necrosis factor‐alpha (SMD ?1.62; 95% CI [?3.60, 0.36]; p = 0.10) and superoxide dismutase levels (SMD 0.34; 95% CI [?1.06, 1.74], p = 0.63). Overall, this meta‐analysis suggests that taking curcumin‐containing supplements may exert anti‐inflammatory and antioxidant properties through a significant reduction in IL‐6, hs‐CRP, and MDA levels.     

The impact of argan oil on plasma lipids in humans: Systematic review and meta‐analysis of randomized controlled trials

The study aims to investigate the effect of argan oil on plasma lipid concentrations through a systematic review of the literature and a meta‐analysis of available randomized controlled trials. Randomized controlled trials that investigated the impact of at least 2 weeks of supplementation with argan oil on plasma/serum concentrations of at least 1 of the main lipid parameters were eligible for inclusion. Effect size was expressed as the weighted mean difference (WMD) and 95% confidence interval (95% CI). Meta‐analysis of data from 5 eligible trials with 292 participants showed a significant reduction in plasma concentrations of total cholesterol (WMD: ?16.85 mg/dl, 95% CI [?25.10, ?8.60], p < .001), low‐density lipoprotein cholesterol (WMD: ?11.67 mg/dl, 95% CI [?17.32, ?6.01], p < .001), and triglycerides (WMD: ?13.69 mg/dl, 95% CI [?25.80, ?1.58], p = .027) after supplementation with argan oil compared with control treatment, and plasma concentrations of high‐density lipoprotein cholesterol (WMD: 4.14 mg/dl, 95% CI [0.86, 7.41], p = .013) were found to be increased. Argan oil supplementation reduces total cholesterol, low‐density lipoprotein cholesterol, and triglycerides and increases high‐density lipoprotein cholesterol levels. Additionally, larger clinical trials are needed to assess the impact of argan oil supplementation on other indices of cardiometabolic risk and on the risk of cardiovascular outcomes.     

Hesperidin,a major flavonoid in orange juice,might not affect lipid profile and blood pressure: A systematic review and meta‐analysis of randomized controlled clinical trials

Previous studies have led to conflicting results regarding the effect of hesperidin supplementation on cardiometabolic markers. This study aimed to evaluate the efficacy of hesperidin supplementation on lipid profile and blood pressure through a systematic review and meta‐analysis of randomized controlled trials (RCTs). PubMed, Web of Science, Scopus, and Google Scholar, as well as the reference lists of the identified relevant RCTs, were searched up to May 2018. Effect sizes were pooled by using the random effects model. Ten RCTs (577 participants) were eligible to be included in the systematic review. The meta‐analysis revealed that hesperidin supplementation had no effect on serum total cholesterol (weighted mean difference [WMD] = ?1.04 mg/dl; 95% confidence interval [CI]: ?5.65, 3.57), low‐density lipoprotein cholesterol (WMD = ?1.96 mg/dl; 95% CI [?7.56, 3.64]), high‐density lipoprotein cholesterol (WMD = 0.16 mg/dl; 95% CI [?1.94, 2.28]), and triglyceride (WMD = 0.69 mg/dl; 95% CI [?5.91, 7.30]), with no significant between‐study heterogeneity. Hesperidin supplement also had no effect on systolic (WMD = ?0.85 mmHg; 95% CI [?3.07, 1.36]) and diastolic blood pressure (WMD = ?0.48 mmHg; 95% CI [?2.39, 1.42]). Hesperidin supplementation might not improve lipid profile and blood pressure. Future well‐designed trials are still needed to confirm these results.     

The efficacy of sour tea (Hibiscus sabdariffa L.) on selected cardiovascular disease risk factors: A systematic review and meta‐analysis of randomized clinical trials

This study sought to summarize clinical evidence of sour tea (Hibiscus sabdariffa L.) administration on cardiovascular disease risk factors. PubMed, Scopus, Institute for Scientific Information Web of Science, and Google Scholar were systematically searched from inception to June 2019 to identify randomized clinical trials, which assessed the effect of sour tea consumption on lipid profiles, fasting plasma glucose, and blood pressure in adult populations. Mean and standard deviation for each parameter were extracted to calculate effect size. Cochrane Collaboration tools were used to evaluate risk of bias assessment. A total of seven randomized clinical trials consisting 362 participants were included in the meta‐analysis. Pooled effect size demonstrated that sour tea consumption significantly reduces fasting plasma glucose (?3.67 mg/dl, 95% confidence interval, CI [?7.07, ?0.27]; I² = 37%), systolic blood pressure (?4.71 mmHg, 95% CI [?7.87, ?1.55]; I² = 53%), and diastolic blood pressure (?4.08 mmHg, 95% CI [?6.48, ?1.67]; I² = 14%). Although no significant effect was observed on triacylglycerol, total cholesterol, and high‐density lipoprotein cholesterol following sour tea consumption, a trend toward a significant reduction was found in low‐density lipoprotein cholesterol serum concentrations (p = 0.08). This systematic review and meta‐analysis suggests that sour tea consumption could have beneficial effect in controlling glycemic status and blood pressure among adult population.     

The effect of saffron on weight and lipid profile: A systematic review,meta‐analysis,and dose–response of randomized clinical trials

Plant derivatives such as carotenoids and phytosterols enrich foods have been shown to reduce plasma triglyceride (TG), low‐density lipoprotein (LDL) cholesterol, and cholesterol concentrations. The aim of this systematic review and meta‐analyses study was to investigate the effects of saffron on lipid profiles, reported in randomized controlled trials (RCTs). We performed a systematic electronic search in PubMed/MEDLINE, Cochrane, and SCOPUS to identify RCTs and screening of relevant articles references up to October 12, 2018. There were no language restrictions. We performed this systematic review and meta‐analysis according to the Preferred Items for Reporting of Systematic Reviews and Meta‐Analyses guidelines. We identified and analyzed 14 eligible studies in this meta‐analysis. Our study found a significant reduction in cholesterol and TG following saffron intervention (weighted mean difference [WMD]: ?6.36 mg/dl, 95% confidence interval, CI, [?10.58, ?2.18] and WMD: ?5.37 mg/dl, 95% CI [?10.25, ?0.48], respectively). There was no significant effect on weight and LDL concentration. A meta‐regression analysis showed that long‐term saffron intervention can increase the high‐density lipoprotein (HDL) levels. In conclusions, our study findings indicate some benefits of saffron on cholesterol, HDL, and TG compared with placebo. However, we recommend the conduct of adequately powered, high‐quality RCTs with short‐ and long‐term follow‐up, evaluating relevant clinical outcomes to allow for making definitive recommendations.     

The effects of spirulina on glycemic control and serum lipoproteins in patients with metabolic syndrome and related disorders: A systematic review and meta‐analysis of randomized controlled trials

The aim of this systematic review and meta‐analysis was to evaluate the effects of spirulina on glycemic control and serum lipoproteins in patients with metabolic syndrome (MetS) and related disorders. Two independent authors systematically searched online database including EMBASE, Scopus, PubMed, Cochrane Library, and Web of Science from inception until April 30, 2019. The Cochrane Collaboration's risk of bias tool was applied to assess the methodological quality of included trials. The heterogeneity among the included studies was assessed using Cochrane's Q test and I‐square (I²) statistic. Pooling effect sizes from studies showed a significant reduction in fasting plasma glucose (FPG; weighted mean difference [WMD]: ?10.31; 95% confidence interval, CI [?16.21, ?4.42]) and insulin concentrations (WMD: ?0.53; 95% CI [?0.62, ?0.44]) following the administration of spirulina. Pooled analysis showed also a significant reduction in total cholesterol (WMD: ?20.50; 95% CI [?38.25, ?2.74]), low‐density lipoprotein cholesterol (LDL‐C; WMD: ?19.02; 95% CI [?36.27, ?1.78]), and very low‐density lipoprotein cholesterol (VLDL‐C) concentrations (WMD: ?6.72; 95% CI [?9.19, ?4.26]) and a significant increase in high‐density lipoprotein cholesterol (HDL‐C) levels (WMD: 1.42; 95% CI [0.16, 2.68]) following spirulina therapy. This meta‐analysis demonstrated the beneficial effects of spirulina supplementation on improving FPG, insulin, total cholesterol, LDL‐C, VLDL‐C, and HDL‐C levels in patients with MetS and related disorders.     

Possible anti‐obesity effects of phytosterols and phytostanols supplementation in humans: A systematic review and dose–response meta‐analysis of randomized controlled trials

Present meta‐analysis investigates the effects of phytosterols and phytostanol (PS) supplementation on anthropometric indices, using data from randomized controlled trials. We performed a systematic search in the databases: PubMed, Scopus, Cochran, and Web of Science. Weighted mean difference (WMD) with 95% confidence intervals (CIs) were presented. Overall, 79 randomized controlled trials investigated the effects of PS on anthropometric indices. Meta‐analysis results did not reveal any significant effect of PS supplementation on weight (66 trials‐WMD: ?0.083 kg; CI [?0.233, 0.066]; I² = 42.5%), percentage fat mass (6 trials‐WMD: ?0.090%; CI [?0.789, 0.610]; I² = 0.0%), and waist circumference (WC; 5 trials‐WMD: ?0.039 cm; CI [?0.452, 0.374]; I² = 0.0%). However, body mass index (BMI) significantly decreased after PS supplementation (39 trials‐WMD: ?0.063 kg/m2, p = 0.024, I² = 25.1%). Subgroup analyses showed that PS supplementation in subjects with baseline BMI ≥25 and hyperlipidemic significantly decreased body weight and BMI. The overall results showed that although PS supplementation did not affect anthropometric indices (except BMI), baseline status regarding BMI and hyperlipidemia and also dose and duration could be contributing factors for favorable effects.     

The effect of Aronia consumption on lipid profile,blood pressure,and biomarkers of inflammation: A systematic review and meta‐analysis of randomized controlled trials

Plant derivatives, such as anthocyanin‐rich phytochemicals, have been reported to elicit a positive effect on lipid profile. Therefore, the aim of this study was to systematically review and meta‐analyze the effects of Aronia consumption on lipid profiles, blood pressure, and biomarkers of inflammation in randomized controlled trials. A systematic search was performed in PubMed/MEDLINE, Cochrane, and SCOPUS up to December 2018. Seven studies were identified and analyzed in this meta‐analysis. Our study found a significant increase in high‐density lipoprotein (HDL; weighted mean difference [WMD]: 1.48 mg/dl, 95% confidence interval, CI, [1.29, 1.68]) and diastolic blood pressure (WMD: 2.55 mmHg, 95% CI [0.63, 4.47]) following Aronia consumption. There was no significant effect on systolic blood pressure and C‐reactive protein, tumor necrosis factor, and interleukin‐1. Furthermore, subgroup analysis showed that cholesterol (WMD: ?7.18, 95% CI [?13.90, ?0.46]) and low‐density lipoprotein (LDL; WMD: ?5.84, 95% CI [?6.91, ?4.77]) decreased more significantly in interventions less than 10 weeks in duration. Dose–response analysis demonstrated a significant reduction in triglyceride levels when dose of Aronia was increased to 300 mg/day. In conclusion, the results demonstrated a significant increase in HDL and reduction in total cholesterol and LDL among patients supplementing with Aronia.     

Effects of ginseng supplementation on selected markers of inflammation: A systematic review and meta‐analysis

The present meta‐analysis was performed to evaluate the efficacy of ginseng administration on serum level of inflammatory biomarkers. We performed a systematic search of all available randomized controlled trials (RCTs) conducted up to June 2018 in the following electronic databases: PubMed, Scopus, Cochrane, and Google Scholar. RCTs that investigated the effect ginseng supplementation on high‐sensitivity C‐reactive protein (hs‐CRP), tumor necrosis factor‐α (TNF‐α), and interleukin‐6 (IL‐6) were included for final analysis. A total of seven RCTs were included in the meta‐analysis. Results indicated significant reduction in IL‐6 (mean difference [MD]: ?0.265 pg/ml, 95% CI [?0.396, ?0.135], p < .001) and TNF‐α (MD: ?2.471 pg/ml, 95% CI [?2.904, ?2.039], p < .001) and no significant change in hs‐CRP (MD: ?0.125 mg/L, 95% CI [?0.597, 0.347], p = .604). Although there was publication bias across studies, trim and fill analysis showed that results from unpublished studies could not change the results for CRP. However, removing one study in sensitivity analysis did reveal a significant reduction in CRP. We conclude that ginseng supplementation significantly lowered IL‐6 and TNF‐α but did not significantly lower CRP. However, these findings were not robust, because they showed sensitivity for CRP and IL‐6, and future long‐term well‐designed dose‐escalating trials are required.     

Effect of garlic supplementation on serum C‐reactive protein level: A systematic review and meta‐analysis of randomized controlled trials

The present study was designed to systematically review randomized controlled trials (RCTs) that report on the effects of garlic supplementation on serum C‐reactive protein (CRP) levels. We conducted a literature search of Scopus, PubMed, Cochrane Library, and Google Scholar up to January 2018. Weighted mean differences (WMD) were estimated for net change in serum CRP. Subgroup analyses were also performed by duration of study, dose of supplementation, baseline CRP level, and the quality of studies. From 438 articles found and screened in our initial search, nine RCTs with the sum of total sample size of 363 were included in the meta‐analysis. Compared with the controls, garlic intake significantly reduced the concentrations of serum CRP by 0.8 mg/L (95% CI [?1.5, ?0.1], p = 0.02) with the evidence of heterogeneity among studies. Subgroup analyses showed that garlic significantly lowered CRP by 0.82 mg/L (95% CI [?1.02, ?0.62], p < 0.001) among studies with a daily garlic dose ≥1,200 mg/day and by 2.44 mg/L (95% CI [?4.02, ?0.87], p = 0.002) among studies with baseline CRP ≥2 mg/L. Current data confirmed that garlic supplementation would reduce serum CRP levels. However, the changes were related to the supplemental doses and baseline levels of serum CRP.     

Therapeutic efficacy and safety of chamomile for state anxiety,generalized anxiety disorder,insomnia, and sleep quality: A systematic review and meta‐analysis of randomized trials and quasi‐randomized trials

This systematic review and meta‐analysis aimed to study the efficacy and safety of chamomile for the treatment of state anxiety, generalized anxiety disorders (GADs), sleep quality, and insomnia in human. Eleven databases including PubMed, Science Direct, Cochrane Central, and Scopus were searched to retrieve relevant randomized control trials (RCTs), and 12 RCTs were included. Random effect meta‐analysis was performed by meta package of R statistical software version 3.4.3 and RevMan version 5.3. Our meta‐analysis of three RCTs did not show any difference in case of anxiety (standardized mean difference = ?0.15, 95% CI [?0.46, 0.16], P = 0.4214). Moreover, there is only one RCT that evaluated the effect of chamomile on insomnia and it found no significant change in insomnia severity index (P > 0.05). By using HAM‐A scale, there was a significant improvement in GAD after 2 and 4 weeks of treatment (mean difference = ?1.43, 95% CI [?2.47, ?0.39], P = 0.007), (MD = ?1.79, 95% CI [?3.14, ?0.43], P = 0.0097), respectively. Noteworthy, our meta‐analysis showed a significant improvement in sleep quality after chamomile administration (standardized mean difference = ?0.73, 95% CI [?1.23, ?0.23], P < 0.005). Mild adverse events were only reported by three RCTs. Chamomile appears to be efficacious and safe for sleep quality and GAD. Little evidence is there to show its effect on anxiety and insomnia. Larger RCTs are needed to ascertain these findings.     

Effect of Hibiscus sabdariffa (Roselle) supplementation in regulating blood lipids among patients with metabolic syndrome and related disorders: A systematic review and meta‐analysis

This study aimed to assess the efficacy of Hibiscus sabdariffa (Roselle) in regulating blood lipids among patients with metabolic syndrome and related disorders. PubMed, the Cochrane Library, Embase, Web of Science, and Clinical Trials were searched to identify the randomised controlled trials meeting the inclusion criteria. Study selection, data extraction, and risk assessment were performed according to Cochrane handbook; available data were analysed using STATA 15.0 software. Eventually, nine trials involving 503 participants were included in this meta‐analysis. The results showed that compared with the control group, H. sabdariffa supplementation could reduce total cholesterol (WMD = ?14.66; 95% CI [?18.22, ?11.10]; p = .000; I² = 46.9%) and low‐density lipoprotein cholesterol (WMD = ?9.46; 95% CI [?14.93, ?3.99]; p = .001; I² = 50.1%) but could not effectively reduce triglyceride (WMD = ?0.77; 95% CI [?7.87, 6.33]; p = 0.832; I² = 0%). Meanwhile, there were no serious adverse reactions reported in the included studies. To summarise, current evidence suggests that the benefits of H. sabdariffa supplementation to patients with metabolic diseases are associated with its cholesterol‐lowering effects; however, more high‐quality clinical trials are needed to confirm these results.     

Does turmeric/curcumin supplementation improve serum alanine aminotransferase and aspartate aminotransferase levels in patients with nonalcoholic fatty liver disease? A systematic review and meta‐analysis of randomized controlled trials

We performed a meta‐analysis to evaluate the efficacy of turmeric/curcumin supplementation on serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in patients with nonalcoholic fatty liver disease (NAFLD). We searched PubMed, Scopus, Cochrane Library, ISI Web of Science, and Google Scholar up to November 20, 2018. Studies that examined the effect of turmeric/curcumin on serum concentrations of ALT and AST among patients with NAFLD were included. The mean difference and standard deviation (SD) of changes in ALT and AST between intervention and control groups were used as effect size for the meta‐analysis. A total of six randomized controlled trials (RCTs) were eligible for meta‐analysis. Results from pooled analysis revealed that turmeric/curcumin supplementation reduced ALT (MD: ?7.31 UL/L, 95% CI [?13.16, ?1.47], p = 0.014) and AST (MD: ?4.68 UL/L, 95% CI [?8.75 ?0.60], p = 0.026). When RCTs stratified on the basis of their treatment duration, the significant reduction in serum concentrations of ALT and AST was observed only in studies lasting less than 12 weeks. This review suggests that turmeric/curcumin might have a favorable effect on serum concentrations of ALT and AST in patients with NAFLD. However, further clinical trials are needed to confirm these findings.     

Effect of fenugreek consumption on serum lipid profile: A systematic review and meta‐analysis

Various studies have shown that Trigonella foenum‐graecum (fenugreek) supplementation has lipid‐lowering activity. This meta‐analysis was performed to evaluate the effect of fenugreek supplementation on human serum lipid profile. Data sources were PubMed, EMBASE, Scopus, and Coherence library which were searched systematically from January 2000 up to December 2019. Inclusion criteria were randomized clinical trial (RCT) study design, at least one of lipid profile components (triglyceride [TG], total cholesterol [TC], low‐density lipoprotein cholesterol, and high‐density lipoprotein cholesterol) levels measured before fenugreek use and one of the lipid components level reported as result. The pooled weighted mean difference (MD) and its 95% confidence interval (CI) were calculated and pooled using a random‐effect model. Only articles published in English were considered. Fifteen RCTs involving 281 cases consumed fenugreek and 255 control cases in controlled group (11 articles) and 136 cases in uncontrolled group (4 articles) were analyzed in our study. Pooled data of indicated a significant impact of fenugreek supplementation on lowering TC (?1.13 [?1.88, ?0.37]; p = .003), low‐density lipoprotein (LDL) (?1.26 [?2.09, ?0.43]; p = .003), and TG (?1.07 [?1.82, ?0.33]; p = 0.005) and increasing the high‐density lipoprotein (HDL) level (0.70 [0.07, 1.34]; p = .03) compared with the control group. There were no significant differences in TC, TG, and LDL between pre‐ and post‐fenugreek studies in the noncontrolled studies however, the result of combination of four studies without control group showed a significant increase in mean HDL (0.81 [0.33,1.29]; p‐value = .001). The results of subgroup analysis showed that the fenugreek reduced the TG and LDL and increases HDL levels in diabetic subjects more effectively. Fenugreek supplementation significantly improved lipid profile (LDL, TG, TC, and HDL). It could be considered as an effective lipid‐lowering medicinal plant. Further high‐quality studies are needed to firmly establish the clinical efficacy of the plant.     

Effects of silymarin supplementation on blood lipids: A systematic review and meta‐analysis of clinical trials

Dyslipidemia is a leading cause of endothelial dysfunction and cardiovascular disease. Several studies used silymarin as an herbal supplement in hyperlipidemic subjects. The aim of the present systematic review and meta‐analysis was to examine the effect of silymarin supplementation on blood lipids. PubMed, Scopus, Ovid (Cochrane library), ISI Web of Science, and Google Scholar were systematically searched until March 2018 to find intervention studies that examined the impact of silymarin supplementation on blood lipids in adults. Changes in blood lipids and potential sources of between‐study variation were extracted. We run a subgroup analysis to determine potential sources of inter‐study heterogeneity. Ten clinical trials fulfilled the eligibility criteria. Meta‐analysis indicated that silymarin supplementation in combination with other treatments (not silymarin alone) reduced total cholesterol (change: ?25.45 mg/dl; 95% confidence interval [CI] [?47.89, ?3.01 mg/dl]) and low‐density lipoprotein (change: ?28.25 mg/dl; 95% CI [?53.09, ?3.42 mg/dl]). Also, silymarin increased high‐density lipoprotein concentration (change: 4.82 mg/dl; 95% CI [2.01, 7.63 mg/dl]). Blood concentration of triglyceride was significantly after silymarin supplementation in comparison with controls (change: ?22.55 mg/dl; 95% CI [?44.32, ?0.78 mg/dl]). Present systematic review and meta‐analysis revealed that silymarin supplementation in combination with other treatments had a favorable effect on blood lipids.     

Curcumin intervention for cognitive function in different types of people: A systematic review and meta‐analysis

Curcumin is a polyphenolic natural compound with diverse and attractive biological activities, which may prevent or ameliorate pathological processes underlying age‐related cognitive decline, dementia, or mood disorders. However, clinical trials and animal studies have yielded conflicting conclusions regarding its effectiveness for cognition in different individuals. The aim of this review is to meta‐analytically assess the effectiveness of curcumin for cognitive function in different types of people. A preliminary search on PubMed, Embase, Web of Science, ClinicalTrials.gov, Cochrane Library, Chinese National Knowledge Infrastructure, and Wanfang Data and China Biology Medicine disc was performed to identify randomized controlled trials investigating the effect of curcumin on cognition. Six clinical trials with a total of 289 subjects met inclusion criteria for this review. We used a random‐effects model to calculate the pooled standardized difference of means (SMD). For older adults who received curcumin, scores on measures of cognitive function (SMD = 0.33, 95% confidence interval [CI] [0.05, 0.62]; p = 0.02), occurrence of adverse events (odds ratio [OR] = 5.59, 95% CI [0.96, 36.80]; p = 0.05), and measures of depression (SMD = ?0.29, 95% CI [0.64, 0.05]; p = 0.09) indicated significant memory improvement. In patients with Alzheimer's disease (AD), scores in measures of cognition status (SMD = ?0.90, 95% CI [1.48, ?0.32]; p = 0.002) indicated that there was a trend for treated subjects to do worse than placebo‐treated subjects on the Mini‐Mental State Examination. The occurrence of adverse events (OR = 0.87, 95% CI [0.10, 7.51]; p = 0.90) was similar to those who received placebo. Due to insufficient data, it was impossible to provide a narrative account of only the outcomes for schizophrenia. Curcumin appears to be more effective in improving cognitive function in the elderly than in improving symptoms of AD and schizophrenia. Curcumin is also safe and tolerated among these individuals. Because of the small number of studies available, a funnel plot or sensitivity analysis was not possible. Further high‐quality trials with larger sample sizes or bioavailability‐improved curcumin formulations may be considered for reliable assessment.     

Does ginger supplementation lower blood pressure? A systematic review and meta‐analysis of clinical trials

The aim of the present systematic review and meta‐analysis was to determine the efficacy of ginger supplementation on blood pressure (BP). PubMed, Scopus, ISI Web of Science, Cochrane Library, and Google Scholar were comprehensively searched until September 2018. Human clinical trials, which reported the effect of ginger supplementation on aortic and/or brachial BP, were included. Mean differences were pooled using a random effects model. Standard methods were used for assessment of heterogeneity, sensitivity analysis, and publication bias. Total of six randomized clinical trials (345 participants) were included in the meta‐analysis . Pooled analysis suggested that ginger supplementation can reduced systolic BP (MD: ?6.36 mmHg, 95% confidence interval [?11.27, ?1.46]; I² = 89.8%; P = .011) and diastolic BP (MD: ?2.12 mmHg, 95% confidence interval [?3.92, ?0.31]; I² = 73.4%; P = .002). When studies were categorized based on participants' mean age, ginger dosage and duration of intervention, systolic BP and diastolic BP were significantly decreased only in the subset of studies with mean age ≤ 50 years, follow‐up duration of ≤8 weeks and ginger doses ≥3 g/d. Our findings revealed that ginger supplementation has favorable effects on BP. Nonetheless, further studies are warranted before definitive conclusions may be reached.     

Effects of quercetin supplementation on glycemic control among patients with metabolic syndrome and related disorders: A systematic review and meta‐analysis of randomized controlled trials

This systematic review and meta‐analysis of randomized controlled trials was performed to determine the effect of quercetin supplementation on glycemic control among patients with metabolic syndrome and related disorders. Databases including PubMed, MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials were searched until August 30, 2018. Nine studies with 10 effect sizes out of 357 selected reports were identified eligible to be included in current meta‐analysis. The pooled findings indicated that quercetin supplementation did not affect fasting plasma glucose (FPG), homeostasis model of assessment‐estimated insulin resistance, and hemoglobin A1c levels. In subgroup analysis, quercetin supplementation significantly reduced FPG in studies with a duration of ≥8 weeks (weighted mean difference [WMD]: ?0.94; 95% confidence interval [CI; ?1.81, ?0.07]) and used quercetin in dosages of ≥500 mg/day (WMD: ?1.08; 95% CI [?2.08, ?0.07]). In addition, subgroup analysis revealed a significant reduction in insulin concentrations following supplementation with quercetin in studies that enrolled individuals aged <45 years (WMD: ?1.36; 95% CI [?1.76, ?0.97]) and that used quercetin in dosages of ≥500 mg/day (WMD: ?1.57; 95% CI [?1.98, ?1.16]). In summary, subgroup analysis based on duration of ≥8 weeks and used quercetin in dosages of ≥500 mg/day significantly reduced FPG levels.