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 Although there was publication bias across studies, trim and fill analysis showed that results from unpublished studies could not change the results for CRP.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.     

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.     

Effects of saffron (Crocus sativus L.) supplementation on inflammatory biomarkers: A systematic review and meta‐analysis

The effect of saffron supplementation on subclinical inflammation remains inconclusive. We performed a systematic review and meta‐analysis to summarize available findings on the effect of saffron supplementation on inflammatory biomarkers (C‐reactive protein [CRP], tumor necrosis factor‐α [TNF‐α], and interleukin‐6 [IL‐6]) in adults. We searched PubMed/Medline, Scopus, Web of Science, and Google Scholar databases up to November 2019 using relevant keywords to identify eligible trials. All randomized controlled trials (RCTs) that examined the effect of oral saffron supplementation on plasma concentrations of CRP, TNF‐α, and IL‐6 were included. For each outcome, mean differences and SDs were pooled using a random‐effects model. Overall, eight RCTs were included in this meta‐analysis. The pooled results showed that saffron supplementation did not result in significant changes in serum CRP (weighted mean difference [WMD]: ?0.43 mg/L; 95% confidence interval [CI]: ?1.04 to 0.17; p = .16), serum TNF‐α (WMD: ?1.29 pg/mL; 95% CI: ?4.13 to 1.55; p = .37), and IL‐6 concentrations (WMD: 0.11 pg/mL; 95% CI: ?0.79 to 1.00; p = .81). Subgroup analysis indicated a significant reduction in serum CRP levels in studies with baseline CRP of ≥3 mg/L, saffron dosage of ≤30 mg/day, and intervention duration of <12 weeks, as well as trials that used crocin. Similarly, saffron was found to decrease TNF‐α in studies that recruited non‐diabetic subjects, subjects with baseline levels of ≥15 pg/mL, and participants with <50 years old, as well as trials that administered saffron at the dosage of ≤30 mg/day. We also found a significant non‐linear effect of saffron dosage on serum CRP concentrations (p_{non‐linearity} = .03). The overall results indicated that saffron supplementation did not affect inflammatory cytokines. Further high‐quality studies are needed to firmly establish the clinical efficacy of supplemental saffron on inflammatory biomarkers.     

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.     

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.     

Effects of cardamom supplementation on lipid profile: A systematic review and meta‐analysis of randomized controlled clinical trials

Cardiovascular disease is a highly prevalent issue worldwide and one of its main manifestations, dyslipidemia, needs more attention. Recent studies have suggested that cardamom has favorable effects beyond lipid lowering, but the result are contradictory. Our objective was to conduct a systematic review and meta‐analysis on randomized controlled trials (RCTs) that assessed the effect of cardamom on lipids. The search included PubMed, Scopus, ISI Web of Science, Google Scholar, and the Cochrane library (up to March, 2019) to identify RCTs investigating the effects of cardamom supplementation on serum lipid parameters. Weighted mean differences (WMDs) were pooled using a random‐effect model. Meta‐analysis of data from five eligible RCTs showed that cardamom supplementation did not significantly change the concentrations of total cholesterol (WMD: ?6.11 mg/dl, 95% CI [?13.06, 0.83], I² = 0.0%), low‐density lipoprotein cholesterol (WMD: ?4.31 mg/dl, 95% CI [?9.75, 1.13], I² = 0.0%), or high‐density lipoprotein cholesterol (WMD: 1.75 mg/dl, 95% CI [?1.95 to 5.46], I² = 71.4%). However, a significant reduction was observed in serum triglyceride (TG; WMD: ?20.55 mg/dl, 95% CI [?32.48, ?8.63], I² = 0.0%) levels after cardamom supplementation. Cardamom might be able to change TG, but for confirming the results, more studies exclusively on dyslipidemia patients and considering the intake of lipid lowering agents as exclusion criteria are necessary.     

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 effect of l‐carnitine supplementation on serum levels of omentin‐1, visfatin and SFRP5 and glycemic indices in patients with pemphigus vulgaris: A randomized,double‐blind,placebo‐controlled clinical trial

Pemphigus vulgaris (PV) is a chronic autoimmune disorder with potentially fatal outcomes. The aim of this study was to investigate the effect of l ‐carnitine (LC) on secreted frizzled‐related protein‐5 (SFRP5), omentin, visfatin, and glycemic indices in PV patients under corticosteroid treatment. In this randomized, double‐blind, placebo‐controlled clinical trial, 52 patients with PV were divided randomly into two groups to receive 2 g of LC or a placebo for 8 weeks. Serum levels of SFRP5, omentin, visfatin, and also glycemic indices were evaluated at the baseline and end of the study. LC supplementation significantly decreased the serum level of visfatin (95% CI [?14.718, ?0.877], p = .05) and increased the serum levels of SFRP5 (95%CI [1.637, 11.380], p < .006) and omentin (95% CI [9.014, 65.286], p < .01). However, LC supplementation had no significant effects on the serum levels of glycemic factors such as insulin (95% CI [?1.125, 3.056], p = .426), fasting blood sugar (95% CI [?4.743, 3.642], p = .894), homeostatic model assessment of insulin resistance (95% CI [?0.305, 0.528], p = .729), and quantitative insulin‐sensitivity check index (95% CI [?0.016, ?0.010], p = .81). LC supplementation decreased visfatin serum level and increased omentin‐1 and SFRP5 serum levels in patients with PV. However, it has no significant effect on the serum levels of insulin and glycemic indices.     

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.     

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 impact of pycnogenol supplementation on plasma lipids in humans: A systematic review and meta‐analysis of clinical trials

The effects of pycnogenol on plasma lipids are controversial. A systematic review and meta‐analysis of clinical trials were conducted to obtain a conclusive result in humans. PubMed, Scopus, and Google Scholar were systematically searched until March 2018, to explore the clinical trials that examined the effect of pycnogenol supplementation on lipid parameters among adult human. Methodological quality of the eligible studies was evaluated using the Cochrane Collaboration's tool. To estimate the effect size, changes in blood lipids were implemented. Results were pooled using a random effects model. Potential sources of heterogeneity were explored by subgroup analysis. A systematic review and meta‐analysis of 14 clinical trials with 1,065 participants suggested a significant increase in plasma concentration of high density lipoprotein cholesterol (HDL‐C; 3.27 mg/dL; 95% CI [0.19, 6.36]; p = 0.038). In contrast, plasma levels of total cholesterol (TC; ?4.45 mg/dL, 95% CI [?11.24, 2.34]; p = 0.199), triacylglycerol (TAG; ?3.64 mg/dL; 95% CI [?17.89, 10.61]; p = 0.616), and low density lipoprotein cholesterol (LDL‐C; ?3.61 mg/dl; 95% CI [?8.76, 1.55]; p = 0.171) were not altered. Adjustment for confounding variables was poor in included studies. Also, these studies did not assess dietary lipid intake. The results indicate that pycnogenol supplementation improves levels of HDL‐C; however, the changes in TC, TAG, and LDL‐C were not clinically relevant. Since there are few phytochemicals that have a significant increasing effect on HDL‐C levels, pycnogenol may have important role in prevention of cardiovascular diseases.     

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.     

Effect of Nigella sativa (black seed) supplementation on glycemic control: A systematic review and meta‐analysis of clinical trials

This study was aimed to quantify the antihyperglycemic effect of Nigella sativa (N. sativa). An in‐depth search to identify clinical trials investigating the impact of N. sativa on glycemic indices via MEDLINE, EMBASE, Scopus, Web of Science, Cochrane Library, and Google scholar databases were performed up to November 2018. We used a random effects model to estimate pooled effect size of fasting plasma glucose (FPG), postprandial blood glucose (PPBG), and hemoglobin A1c (HbA1c). A total of 17 randomized controlled trials investigating the effects of N. sativa on FPG, PPBG, and HbA1c were included. Meta‐analysis suggested a significant association between N. sativa supplementation and reduction in FPG (weighted mean difference [WMD]: ?9.93 mg/dl, 95% CI [?13.44, ?6.41]), PPBG (WMD: ?14.79 mg/dl, 95% CI [?24.19, ?5.39]), and HbA1c (WMD: ?0.57%, 95% CI [?0.77, ?0.37]). Subgroup analysis revealed that N. sativa oil was more effective than N. sativa powder in reduction of FPG. To sum up, N. sativa consumption has a significant lowering effect on glycemic status. Further studies with prolonged durations and powerful design are needed to specify the exact mechanism, optimal dosage, and duration of N. sativa supplementation to obtain a beneficial effect on glycemic status.     

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.     

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.     

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 supplementation on body mass index,body weight,and waist circumference in patients with nonalcoholic fatty liver disease: A systematic review and dose–response meta‐analysis of randomized controlled trials

Nonalcoholic fatty liver disease (NAFLD) is a major cause of liver‐related morbidity; its prevalence is elevating due to the rising epidemic of obesity. Several clinical trials have examined the effects of curcumin supplementation on anthropometric variables in NAFLD patients with inconclusive results. This dose–response meta‐analysis aimed to evaluate the impact of curcumin supplementation on body mass index (BMI), body weight, and waist circumference (WC) in patients with NAFLD. A systematic review of the literature was conducted using PubMed/Medline, ISI Web of Science, Scopus, Cochrane Library, EMBASE, Google Scholar, Sid.ir, and Magiran.com to identify eligible studies up to March 2019. A meta‐analysis of eligible studies was performed using the random‐effects model to estimate the pooled effect size. Eight randomized controlled trials with 520 participants (curcumin group = 265 and placebo group = 255) were included. Supplementation dose and duration ranged from 70 to 3,000 mg/day and 8 to 12 weeks, respectively. Curcumin supplementation significantly reduced BMI (weighted mean difference [WMD] = ?0.34 kg/m², 95% CI [?0.64, ?0.04], p < .05) and WC (WMD = ?2.12 cm, 95% CI [?3.26, ?0.98], p < .001). However, no significant effects of curcumin supplementation on body weight were found. These results suggest that curcumin supplementation might have a positive effect on visceral fat and abdominal obesity that have been associated with NAFLD.     

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.     

Impact of flaxseed supplementation on plasma lipoprotein(a) concentrations: A systematic review and meta‐analysis of randomized controlled trials

The aim of the study was to investigate the impact of supplementation with flaxseed on plasma lipoprotein(a) [Lp(a)] levels through a systematic review and meta‐analysis of eligible randomized placebo‐controlled trials. PubMed, Scopus, Cochrane Library, and ISI Web of Science were searched for randomized controlled trials (RCTs) which have been published up to November 2019. RCTs that investigated the effect of flaxseed supplementation on plasma Lp(a) levels in adults were included for final analysis. The random effects model was used for calculating the overall effects. Meta‐analysis of 7 selected RCTs with 629 individuals showed significant lowering effect of flaxseed supplementation on Lp(a) (MD ?2.06 mg/dl; 95% CI: ?3.846, ?0.274, p = .024), without considerable heterogeneity between studies (p = .986, I² = 0%). Subgroup analysis also revealed that longer duration only showed significant lowering effect of flaxseed supplementation on Lp(a). This meta‐analysis has shown that flaxseed supplementation might significantly decrease plasma Lp(a) levels. Future well‐designed and long‐term clinical trials are required to confirm these results.     

Effects of garlic supplementation on liver enzymes: A systematic review and meta‐analysis of randomized controlled trials

Current evidence on the beneficial effects of garlic on liver enzymes is contradictory. Therefore, the aim of this systematic review and meta‐analysis is to evaluate the effect of garlic supplementation on human liver enzymes, such as Alanine Transaminase (ALT/SGPT) and Aspartate Transaminase (AST/SGOT). To collect the required data, PubMed, Scopus, ISI Web of Science, and Google scholar databases were systematically searched from inception to June 2019. A meta‐analysis was conducted using the random‐effects model to evaluate the effects of garlic supplementation on ALT and AST levels. The Cochran's Q‐test and inconsistency index were also used to evaluate heterogeneity among the studies. Among a total of 15,514 identified articles, six studies (containing 301 participants) met the inclusion criteria. Results of the meta‐analysis showed that garlic supplementation significantly decreased AST level (Hedges' g = ?0.36, 95% confidence interval [CI]: ?0.72, ?0.004, p = .047); whereas, it had no significant effect on ALT level (Hedges' g = ?0.22, 95% CI: ?0.64, 0.20, p = .310). Results showed that garlic supplementation reduced AST levels significantly; however, had no significant effect on ALT levels. Further studies are still needed to confirm the results.