Effect of Egg-White Protein Alone or Combined With Niacin on Nutritional Status, and Phosphorus Control in Maintenance Hemodialysis Patients: A Randomized Controlled Trial.

OBJECTIVE: Niacin is reported to decrease phosphorus concentration in maintenance hemodialysis (MHD) patients. Egg white is one of the main substitutable proteins in MHD patients due to its low phosphorus content. Therefore, we aimed to evaluate the effects of combined egg white and niacin supplementation on dialysis patients' serum phosphorus and nutritional biomarkers. DESIGN AND METHODS: In this randomized controlled clinical trial, 98 patients on MHD were randomly allocated to four groups for 8 weeks: 24 g egg white (n = 25), 600 g niacin daily (n = 24), egg white combined with niacin (n = 24), and control (n = 24). Calcium, phosphorus, fibroblast growth factor-23, and other nutritional markers were assessed. RESULTS: There was a significant difference among the groups only in phosphorus at the end of the trial, which was significantly lower in the niacin group (4.38 + 0.812 mg/dL) than in both the egg white (5.07 + 0.49 mg/dL) and egg white with niacin supplementation (5.41 + 0.662 mg/dL) groups. In this regard, albumin increased in egg white and egg white with niacin supplementation, while albumin did not change significantly in the niacin group. Urea reduction ratio and Kt/V rose only in the egg-white group, while aspartate aminotransferase increased only in the niacin and control groups. CONCLUSION: Niacin decreases serum phosphorus concentration more than egg-white protein or a combined intervention. Egg white protein supplementation has beneficial effects on some nutritional statuses other than phosphorus control without the side effects of niacin.

Watermelon consumption decreases risk factors of cardiovascular diseases: A systematic review and meta-analysis of randomized controlled trials.

This meta-analysis was conducted to examine the effects of watermelon supplementation on cardiovascular diseases (CVDs) risk factors in randomized controlled trials (RCTs). The comprehensive search was done in Cochrane Library databases, ISI Web of Science, PubMed, and Scopus up to March 2022. A random-effect model was used for computing weighted mean differences (WMD). Standard methods were applied to examine publication bias, sensitivity analysis, and heterogeneity. Of the 8962 identified studies, 9 RCTs were included in the final analysis. Watermelon consumption significantly decreased systolic blood pressure (SBP), totalcholesterol (TC) and low-density lipoprotein (LDL). In addition, watermelon consumption led to a significant increase in fasting blood sugar (FBS). However, there was not any significant difference in other outcomes of interest including diastolic blood pressure (DBP), heart rate (HR), BMI, body fat, and serum levels of arginine, insulin, and CRP after watermelon supplementation. The current findings provide promising evidence of the antihypertensive effect of watermelon. However, due to the lack of evidence in human research, the result regarding the remaining outcomes needs to be used with caution. Furter RCTs with longer follow-ups and larger sample sizes should be done to confirm the current findings.

Plum supplementation and lipid profile: a systematic review and meta-analysis of randomised controlled trials.

Plums are abundant in bioactive compounds which have been associated with numerous health benefits. In the present study, we aimed at examining the impact of plum supplementation on lipid profile of individuals. Electronic bibliographical databases were searched for relevant randomised clinical trials. Articles meeting our eligibility criteria were included for data extraction and final analysis. Weighted mean difference (WMD) was estimated using a random-effect model. Of the total articles retrieved in the initial search, nine articles were found to be eligible to be included in the analysis. Our results show that plum supplementation significantly improves total cholesterols levels in the unhealthy individuals. Moreover, plum supplementation reduces the LDL-c levels in the pooled sample (WMD = -11⋅52 mg/dl; 95 % CI -21⋅93, -1⋅11, P = 0⋅03, I 2 = 98⋅7 %) and also in some of the subgroups of individuals (dried plum, unhealthy subjects, duration more than 8 weeks). Moreover, it had a significant reducing effect on TC levels just in unhealthy subjects. Although plum supplementation did not have any significant impact on serum levels of TG nor HDL-c. Our results show that supplementation with plums is potentially effective in reducing serum total cholesterol and LDL-c.

Effect of plum supplementation on blood pressure, weight indices, and C-reactive protein: A systematic review and meta-analysis of randomized controlled trials.

INTRODUCTION: Metabolic syndrome and its components are major health concerns around the world. Among various factors, overweight/obesity, its consequent inflammation, and hypertension are of special importance. Plums are anti-oxidant-rich fruits which have long been investigated for their health benefits. In this systematic review and meta-analysis, we investigated the possible impact of plum supplementation on obesity, inflammation, and blood pressure. METHODS: All of the major databases (PubMed, Scopus, Cochrane, and Web of Science, Google Scholar and EMBASE) were searched to obtain the articles eligible for the review. Relevant data was extracted for the final analysis. Weighted mean difference (WMD) was obtained using fixed and random effect models. The main outcomes included systolic and diastolic blood pressure, body weight, body mass index (BMI), body fat percentage, waist circumference (WC) and blood C-reactive protein (CRP) levels. The effect sizes were expressed as weighted mean difference (WMD) and 95% confidence intervals (CI). RESULTS: Crude search provided 3121 articles, among which 11 were eligible to be included. After crude and subgroup analysis, we were unable to detect any significant impact of plum supplementation on body weight (weight mean difference (WMD) of 0.04 kg; 95% CI: -1.55, 1.63, p = 0.959), BMI (WMD 0.39 kg/m2; 95% CI: -0.11, 0.90, p = 0.125), body fat percentage (WMD = 0.59%; 95% CI: -0.41, 1.59, p = 0.249), waist circumference (WMD = 0.60 cm; 95% CI: -1.83, 3.04, p = 0.627), systolic blood pressure (WMD -1.24 mmHg; 95% CI: -3.08, 0.59, p = 0.185), diastolic blood pressure (WMD -4.32 mmHg (95% CI: -9.29, 0.65, p = 0.089), or inflammation indicated by C-reactive protein (CRP) levels (WMD = 0.23 mg/l; 95% CI: -0.27, 0.73, p = 0.371). CONCLUSION: Our results show that plum supplementation has no positive effect on factors of metabolic syndrome. We recommend that further research in the form of clinical trials be conducted to make a clear conclusion as of the effectiveness of plum supplementation on parameters of metabolic syndrome.

The effect of almond intake on glycemic control: A systematic review and dose-response meta-analysis of randomized controlled trials.

Number trials have evaluated the effect of almond intake on glycemic control in adults; however, the results remain equivocal. Therefore, the present meta-analysis aims to examine the effectiveness of almond intake on glycemic parameters. Online databases including PubMed, Scopus, ISI web of science, Embase, and Cochrane Library were searched up to August 2021 for trials that examined the effect of almond intake on glycemic control parameters including fasting blood sugar (FBS), insulin, HOMA-IR, and HbA1C. Treatment effects were expressed as mean difference (MD) and the standard deviation (SD) of outcomes. To estimate the overall effect of almond intake, we used the random-effects model. In total, 24 studies with 31 arms were included in our analysis. The meta-analysis revealed that almond intake did not significantly change the concentrations of FBS, HbA1c, insulin levels, and HOMA-IR. In conclusion, there is currently no convincing evidence that almonds have a clear beneficial effect on glycemic control. Future studies are needed before any confirmed conclusion could be drowned.

The role of nutritional interventions in prostate cancer: A review.

The high prevalence rate in conjunction with the long latency period made prostate cancer (PCa) an attractive and reasonable candidate for preventive measures. So far, several dietary and nutritional interventions have been implemented and studied with the aim of preventing the development or delaying the progression of PCa. Calorie restriction accompanied by weight loss has been shown to be associated with decreased likelihood of aggressive PCa. Supplements have played a major role in nutritional interventions. While genistein and lycopene seemed promising as preventive agents, minerals such as zinc and selenium were shown to be devoid of protective effects. The role of vitamins has been widely studied, with special emphasis on vitamins with antioxidant properties. Data related to Vitamin A and Vitamin C were rather controversial and positive effects were of insignificant magnitude. Vitamin E was associated with a decreased risk of PCa in high-risk groups like smokers. However, when it comes to Vitamin D, the serum levels might affect the risk of PCa. While deficiency of this vitamin was associated with increased risk, high serum levels imposed the risk of aggressive disease. Despite the seemingly promising effects of dietary measures on PCa, no firm recommendation could be made due to the limitations of the studies and evidence. However, the majority of these advices could be followed by the patients with the intent of living a healthy lifestyle.

Effects of grape products on inflammation and oxidative stress: A systematic review and meta-analysis of randomized controlled trials.

This systematic review and meta-analysis of randomized controlled trials (RCTs) were conducted to determine the effects of grapes and grape products on inflammation and oxidative stress among adults. PubMed, Scopus, ISI Web of Science, and Cochrane Library databases were searched up to July 2020 to identify RCTs investigating the effects of grape and grape products on inflammatory and oxidative stress markers. Weighted mean differences (WMD) were pooled using a random-effects model. Of the 8,962 identified studies, 24 RCTs (27 arms) were included in the statistical analysis. Grape products significantly reduced serum C-reactive protein (CRP) levels (WMD: -0.35 mg/L; 95% CI: -0.62, -0.09, p = .008), but they had no significant effect on serum tumor necrosis factor-alpha (TNF-α) (WMD = -1.08 pg/ml; 95% CI: -2.29, 0.11, p = .07), interleukin-6 (IL-6) (WMD = 0.13 pg/ml; 95% CI: -0.35, 0.60, p = .60), total antioxidant capacity (TAC) (WMD = 0.15; 95% CI: -0.35, 0.65, p = .54), or malondialdehyde (MDA) (WMD = 0.14; 95% CI: -0.64, 0.92, p = .72). The analysis indicated possible decreasing effects of grapes and grape products on CRP, but they might not be able to change IL-6, TNF-α, TAC, and MDA concentrations. Nonetheless, further studies are warranted before definitive conclusions may be reached.

The effect of grapes/grape products on glycemic response: A systematic review and meta-analysis of randomized controlled trials.

The aim of this study was to perform a systematic review and meta-analysis of randomized clinical trials (RCTs) to examine the effect of grapes/grape products supplementation on glycemic indices in adults. Our systematic search to find relevant RCTs was performed up to February 2020 using PubMed, Scopus, ISI Web of Science, Cochrane Library, and Google Scholar. Based on the heterogeneity between included studies, a random effects or a fixed model was applied in the meta-analysis, and results were expressed as weighted mean differences (WMD) with 95% confidence intervals (CI). Twenty-nine clinical trials (1,297 participants) fulfilled the eligibility criteria of the present meta-analysis. Overall, the grapes/grape products supplementation significantly reduced homeostatic model assessment of insulin resistance (HOMA-IR) (WMD: -0.54, 95% CI: -0.91, -0.17, p = . 004) but did not affect fasting insulin levels (WMD: -0.90 µIU/ml, 95% CI: -1.04, 2.84, p = .362) and hemoglobin A1C (Hb1Ac) percentage (WMD: 0.00%, 95% CI: -0.10, 0.11, p = . 916) in the main analyses. In addition, changes to fasting blood glucose (FBG) levels were in favor of the control group (WMD: 1.19 mg/dl, 95% CI: 0.05, 2.34, p = .041). We found that giving grapes/grape products to adults might have beneficial effects on the HOMA-IR. Further, large-scale RCTs with longer duration are required to confirm these results.

The effect of L-arginine supplementation on obesity-related indices: A systematic review and meta-analysis of randomized clinical trials.

The clinical studies regarding the effect of L-arginine in human anthropometry have not been fully consistent, therefore, we carried out a systematic review and meta-analysis of randomized clinical trials in order to precisely evaluate and quantify the efficacy of L-arginine on weight, waist circumference, and BMI. We searched online databases including PubMed, SCOPUS, and Google Scholar for relevant articles up to September 2017. Eligible articles were reviewed by two independent investigators. Mean differences of the outcomes were used for calculation of weighted mean difference (WMD) derived from the random-effects model. Statistical heterogeneity between studies was examined using Cochran's Q-test and I2 index. Funnel plot and Egger's tests were performed to assess the publication bias. In our initial search, we found 1598 publications, of which 8 RCTs (9 treatment arms) were included. The results of the meta-analysis displayed a significant reduction in WC following L-arginine supplementation (WMD: -2.97 cm; 95% CI: -4.75 to -1.18, P = 0.001). However, L-arginine intervention had not elicited a significant effect on BMI (WMD: -0.51 kg/m2; 95% CI: -1.11 to .08, P = 0.09) and body weight (WMD: -0.57 kg; 95% CI: -1.77 to 0.61, P = 0.34). Subgroup analyses displayed that longer-term interventions (≥8 weeks) had a positive effect on body weight and using < 8 g/day L-arginine with longer duration (≥8 weeks) could significantly decrease BMI. In conclusion, this meta-analysis result suggested L-arginine supplementation could reduce waist circumference without any significant effect on body weight and body mass index.

What is the Impact of Cinnamon Supplementation on Blood Pressure? A Systematic Review and Meta-Analysis.

AIM: This study was designed to make a systematic review and meta-analysis on randomized controlled trials (RCTs) assessing the effect of cinnamon on blood pressure (BP). METHODS: A systematic computerized literature search of PubMed, Scopus, Web of Science, Cochrane Library and Google Scholar databases was conducted up to August 2019. All RCTs using cinnamon supplements in adults were included in this systematic review and meta-analysis. RESULTS: Out of 927 records, 8 trials that enrolled 582 participants were included. The pooled effect size showed that SBP did not change following cinnamon supplementation. (WMD: -0.61mmHg; 95% CI: -1.36, 0.14, P= 0.111). Also cinnamon supplementation in long-duration (≥ 8weeks) had a significant effect on SBP (WMD: -1.25 mmHg; 95% CI: -2.22, -0.28, P= 0.012). Pooled analysis showed that cinnamon had a significant effect on DBP (WMD: -0.93mmHg, 95% CI: -1.55 to -0.32, P= 0.003). In addition, results from both duration subsets and high dose (>1500 mg/day) of cinnamon supplementation were significant. CONCLUSION: Our findings revealed that cinnamon supplementation has favorable effects on DBP although results of SBP were not the same. Nonetheless, further studies are required.

The Effects of Magnesium Supplementation on Blood Pressure and Obesity Measure Among Type 2 Diabetes Patient: a Systematic Review and Meta-analysis of Randomized Controlled Trials.

In this study, we aimed to systematically review the literature to evaluate the effects of magnesium (Mg) supplementation on blood pressure (BP) and obesity measure among patients with type 2 diabetes mellitus (T2DM). Major electronic databases of Web of Science, the Cochrane library, PubMed, and Scopus were searched completely from the inception until 15 October 2019 to identify randomized clinical trials (RCTs) pertaining to the topic of interest. All outcomes were pooled using a random-effects model and expressed as weighted mean differences (WMD) with 95% confidential intervals (CI). Heterogeneity, sensitivity analysis, and publication bias were also assessed using standard methods. The pooled analysis of five RCTs showed that Mg supplementation did not affect body weight (WMD: - 0.01 kg, 95% CI: - 0.36 to 0.33), BMI (WMD: - 0.07, 95% CI: - 0.18 to 0.04), and waist circumference (WMD: 0.12, 95% CI: - 1.24 to 1.48) in T2DM patients compared to the control groups of the patients who received placebo. However, pooling seven RCTs together showed significant reduction of systolic blood pressure (WMD: - 5.78 mmHg, 95% CI: - 11.37 to - 0.19) and diastolic blood pressure (WMD: - 2.50 mmHg, 95% CI: - 4.58 to - 0.41) in T2DM patients. Furthermore, subgroup analysis by dose of intervention, intervention duration, and type of intervention suggested that Mg supplementation for > 12 weeks, in doses higher than 300 mg/day or inorganic forms, could significantly decrease both systolic and diastolic BP in T2DM patients. Based on the findings, Mg supplementation has beneficial effects on BP in type 2 diabetes patients independent of body weight status. However, further investigations are needed to provide more reliable evidences.

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.

Effect of vitamin D supplementation on CREB-TrkB-BDNF pathway in the hippocampus of diabetic rats.

OBJECTIVES: Cyclic AMP (adenosine monophosphate) response element-binding protein (CREB) and Brain-derived neurotrophic factor (BDNF) are reported to broadly involve in learning capacity and memory. BDNF exerts its functions via tropomyosin receptor kinase B (TrkB). BDNF transcription is regulated by stimulating CREB phosphorylation. The CREB-TrkB-BDNF pathway is reported to be affected by diabetes, which may contribute to its cognitive deficits. This study was conducted to investigate the effect of vitamin D supplementation on the hippocampal fraction of this pathway in an animal model of type-1 diabetes mellitus (T1DM). MATERIALS AND METHODS: Thirty-six adult male Sprague-Dawley rats were randomly divided into 4 groups as follows: Group 1: normal healthy rats (n=8); group 2: normal healthy rats receiving sesame oil supplementation as placebo (n=8); Group 3: diabetic rats receiving sesame oil (n=10); and Group 4: diabetic rats treated with 4300 IU/kg/week vitamin D dissolved in sesame oil (n=10). Diabetes was induced by intraperitoneal (IP) injection of streptozotocin. Blood and hippocampal samples were acquired at the end of the experiment. RNA was extracted from the hippocampus, and real-time PCR (polymerase chain reaction) was performed for BDNF and TrkB gene expression. RESULTS: Administration of vitamin D (4300 IU/kg/week) in a T1DM animal model increased CREB phosphorylation in the hippocampus, but the serum and hippocampal BDNF levels and TrkB and BDNF gene expression did not change significantly. CONCLUSION: Vitamin D increased hippocampal CREB phosphorylation in a T1DM animal model. Our findings showed that vitamin D might be protective against central nervous system complications in diabetes. However, future studies are warranted.

The effect of almond intake on blood pressure: A systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: The present systematic review and meta-analysis aimed determine the efficacy of almond intake on blood pressure (BP). METHODS: PubMed, Scopus, ISI Web of Science, Cochrane library and Google Scholar were comprehensively searched to infinity until December 2019. Randomized clinical trials (RCTs) reporting effects of almond intake on aortic and brachial BP were included. Weighted mean differences (WMDs) were pooled using a random-effects model. Standard methods were used for assessment of heterogeneity, sensitivity analysis, and publication bias. RESULTS: A total of 16 RCTs (1128 participants) were included in the meta-analysis. Pooled analysis suggested that almond intake can reduced diastolic BP (DBP) (WMD = -1.30 mmHg; 95 % CI: -2.31,-0.30, p = 0.01, I2 = 0.0 %). However, there was not any impact of almond intake on systolic BP (SBP) (WMD = -0.83 mmHg; 95 % CI: -2.55, 0.89, p = 0.34, I2 = 58.9 %). Subgroup analysis revealed a significant reduction in SBP levels in subjects with lower SBP and lower dose of almonds. CONCLUSION: We found that almonds might have a considerable favorite effect in BP and especially in DBP, and it could be encouraged as part of a healthy diet; however due to the high calorie content, the intake should be part of healthy diet.

Effects of synbiotic consumption on lipid profile: a systematic review and meta-analysis of randomized controlled clinical trials.

BACKGROUND AND AIMS: Existing evidence on the possible effects of synbiotics on lipid profile is inconclusive. The aim of the present systematic review was to clarify the effects of synbiotics consumption on lipid profile. METHODS: A systematic literature search of online databases PubMed, Scopus, ISI Web of science, Cochrane's library and Google Scholar was conducted up to January 2019. Randomized controlled trials (RCTs) investigating the effects of synbiotics on lipid profile in adults were included. The overall effect was presented as weighted mean difference (WMD) and 95% confidence interval (CI) in a random-effects meta-analysis model. RESULTS: A total of 23 RCTs with 1338 participants were included. Synbiotic consumption resulted in a significant decrease in plasma concentrations of total cholesterol (WMD = - 10.17 mg/dL; 95% CI - 15.74 to - 4.60; p < 0.001), triglyceride (WMD = - 14.30 mg/dL; 95% CI - 25.32 to - 3.28; p = 0.01), low-density lipoprotein cholesterol (WMD = - 8.32 mg/dL; 95% CI - 13.21 to - 3.43; p < 0.001), and an increase in plasma high-density lipoprotein cholesterol (WMD = 1.3 mg/dL; 95% CI 0.03 to 2.56; p = 0.04) levels compared to control (placebo supplements/control foods/conventional products). The effects are more pronounced when synbiotics supplements are consumed for > 8 weeks. CONCLUSION: Synbiotic supplements may be beneficial to improve lipid profile, especially when they are consumed for > 8 weeks.

Effect of L-Carnitine Supplementation on Liver Enzymes: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

BACKGROUND AND AIM: Possible Hepato-protective effects of L-carnitine have been reported in previous studies. Present study was conducted to systematically review the efficacy of L-carnitine supplementation on liver enzymes. METHODS: The following databases were searched up to December 2018: PubMed, Scopus, ISI Web of Science, and the Cochrane library. Only randomized controlled trials (RCTs) evaluating the effects of L-carnitine supplementation on liver enzymes including alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transferase (GGT) were included. Pooled effect size measured using random effect model (Dersimonian-Liard). RESULTS: A total of 16 studies (including 1025 participants) were included in the present meta-analysis. Pooled analysis indicated that L-carnitine supplementation significantly decreased ALT (weighted mean difference (WMD): -10.729 IU/L, 95% CI: -13.787, -7.672, p <0.001; I2 = 95.9%), AST (WMD: -7.149 IU/L, 95% CI: -9.202, -5.096, p <0.001; I2 = 93.5%) and GGT (WMD: -7.395: IU/L, 95% CI: -9.171, -5.619, p <0.001; I2 = 80.1%). Subgroup analysis revealed that effect of L-carnitine supplementation on liver enzymes was not significant in normal weight and healthy subjects. Baseline BMI and health status were the potential source of heterogeneity. CONCLUSION: L-carnitine supplementation showed beneficial hepato-protective effects on circulating liver enzymes.

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.

Effect of fenugreek supplementation on blood lipids and body weight: A systematic review and meta-analysis of randomized controlled trials.

ETHNOPHARMACOLOGICAL RELEVANCE: Fenugreek is a traditional herbal medicine that has been used for centuries to treat hyperglycemia, muscle spasms, gastritis, constipation, edema, and other metabolic disorders. Recently, lipid-lowering effects of fenugreek have been identified. AIM OF THE STUDY: The aim of this systematic review and meta-analysis was to determine and clarify the impact of fenugreek supplementation on anthropometric indices and serum lipid levels. MATERIALS AND METHODS: We searched PubMed, Scopus, ISI Web of Science, Cochrane Library, and Google Scholar from inception to June 2019 using relevant keywords. All randomized controlled trials (RCTs) investigating the effects of fenugreek on anthropometric indices and plasma lipids in adults were included. A random-effects model was used for quantitative data synthesis. A sensitivity analysis was conducted using the leave-one-out method. RESULTS: A meta-analysis of 12 RCTs (14 arms) with 560 participants suggested a significant decrease in plasma concentrations of total cholesterol (WMD = -9.371 mg/dL; 95% CI: -15.419, -3.323, p = 0.002), triglycerides (WMD = -13.776 mg/dL; 95% CI: -26.636, -0.916, p = 0.036), and low density lipoprotein cholesterol (WMD = -6.590 mg/Dl; 95% CI: -13.042, -0.137, p = 0.045), as well as an increase in plasma high density lipoprotein cholesterol (WMD = 3.501 mg/dL; 95% CI: 1.309, 5.692, p = 0.002), while body weight (WMD = 0.223 kg; 95% CI: -0.509, 0.955, p = 0.551) and body mass index (WMD = 0.091 kg/m2; 95% CI: -0.244, 0.426, p = 0.596) were not altered. CONCLUSION: Fenugreek supplementation improved lipid parameters in adults. However, to confirm these results, more studies, particularly among hyperlipidemic patients, are needed.

The effect of flaxseed supplementation on circulating adiponectin and leptin concentration in adults: A systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: Our objective was to perform a systematic review and meta-analysis on randomized controlled trials (RCTs) assessing the effect of flaxseed supplementation on serum adiponectin and leptin concentration. METHODS: Electronic searches were performed in PubMed, Scopus, Web of Science, and Google Scholar up to May 2019 without any restriction. All RCTs that reported the effect of flaxseed supplementation on circulating adiponectin and leptin concentration were included. A random-effects model was used to pool calculated effect sizes. RESULTS: Nine RCTs (11 arms) were eligible to be included. Our analysis showed that flaxseed supplementation did not significantly affect adiponectin (weighted mean difference [WMD]: 0.15 µg/ml; 95% CI [-0.16, 0.47], p = .34) and leptin (WMD: 0.47 ng/ml; 95% CI [-3.10, 4.06], p = .79) concentration in comparison with control. Furthermore, subgroup analysis revealed that effects remained nonsignificant in all subgroups of trial duration, flaxseed type, and health status of participants. The pooled effect size was also robust and remained nonsignificant in the sensitivity analysis. CONCLUSION: Flaxseed supplementation had no significant effect on adiponectin and leptin levels in adults. However, future well-designed trials are still needed to confirm these results.