Curcumin/turmeric supplementation could improve blood pressure and endothelial function: A grade-assessed systematic review and dose-response meta-analysis of randomized controlled trials.

BACKGROUND AND PURPOSE: A number of studies have examined the impact of curcumin/turmeric on blood pressure and the factors allegedly responsible for hypertension. In this systematic review and meta-analysis, we tried to sum up the existing literature on randomized controlled trials (RCTs) investigating this hypothesis. METHODS: Online databases (PubMed, Scopus, Web of Science Core Collection, Cochrane Library, and Google Scholar) were searched from inception up to October 2022. We used the cochrane quality assessment tool to evaluate the risk of bias. Outcomes of interest included systolic blood pressure (SBP), diastolic blood pressure (DBP), blood levels of vascular cell adhesion molecule-1 (VCAM-1) and intracellular adhesion molecule-1 (ICAM-1), flow-mediated vasodilation (FMD), and pulse-wave velocity (PWV). Weighted mean differences (WMDs) were derived and reported. In case of significant between-study heterogeneity, subgroup analyses were carried out. Significance level was considered as P-values<0.05. RESULTS: Finally, 35 RCTs out of 4182 studies were included. Our findings suggested that curcumin/turmeric supplementation significantly improved SBP (WMD: -2.02 mmHg; 95 % CI: -2.85, -1.18), DBP (WMD: -0.82 mmHg; 95 % CI: -1.46, -0.18), VCAM-1 (WMD: -39.19 ng/mL; 95 % CI: -66.15, -12.23), and FMD (WMD: 2.00 %; 95 % CI: 1.07, 2.94). However, it did not significantly change levels of ICAM-1 (WMD: -17.05 ng/ml; 95 % CI: -80.79, 46.70), or PWV (WMD: -79.53 cm/s; 95 % CI: -210.38, 51.33). CONCLUSION: It seems that curcumin/turmeric supplementation could be regarded as a complementary method to improve blood pressure and endothelial function. However, further research is needed to clarify its impact on inflammatory adhesion molecules in the circulation.

Onion supplementation and health metabolic parameters: A systematic review and meta-analysis of randomized controlled trials.

INTRODUCTION: Functional foods, such as onions, have been the center of many recent investigations. In this systematic-review and meta-analysis, we aimed to gather up the existing information with regard to the impact of onion supplementation on anthropometric measurements/indices, lipid profile, indices of glycemic control and hepatic health, systolic and diastolic blood pressures (SBP and DBP), and adiponectin and leptin. METHODS: All major online datasets (PubMed, Web of Science, Cochrane, and Scopus) were thoroughly searched from inception up to October 2022. Relevant randomized controlled trials (RCTs) were obtained using the eligibility criteria. Weighted mean differences (WMDs) were calculated and reported. Statistical significance was set as p-values <0.05. RESULTS: Among all the retrieved data, 14 RCTs were eligible to be included. The results of the crude analysis showed that onion supplementation significantly improved body fat percentage (BFP), low-density lipoprotein-cholesterol (LDL-c), total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-c), systolic blood pressure, adiponectin, and aspartate aminotransferase (AST). Subgroup analysis revealed that interventions lasting more than 12 weeks can significantly alter weight, waist circumference (WC), body mass index (BMI), BFP, LDL-c, TC, SBP, and DBP. Moreover, the intake of dosages of >300 mg/day of onion supplementation could significantly improve weight, WC, BMI, BFP, LDL-c, HDL-C, TC, AST, ALT, SBP and DBP. CONCLUSION: It seems that the intake of onion supplementation can improve health metabolic parameters. We observed that with either longer follow-up periods or higher dosages of onion supplementation, improvements in cardio-metabolic parameters could be expected.

The effects of purslane consumption on blood pressure, body weight, body mass index, and waist circumference: a systematic review and meta-analysis of randomised controlled.

The effects of purslane consumption on anthropometric measurements and blood pressure have been studied in numerous experiments. However, the research findings conflict with one another. In order to assess the impact of purslane on weight, body mass index (BMI), waist circumference (WC), systolic blood pressure (SBP), and diastolic blood pressure (DBP), this meta-analysis was carried out. Up until February 2023, PubMed, Web of Science, Scopus, Google Scholar, and the reference lists of the identified pertinent randomised controlled trials (RCTs) were all searched. The random-effects model was used to calculate the effect size and then to describe it as a weighted mean difference (WMD) and 95 % confidence interval (CI) (CRD42023427955). The systematic review was able to incorporate seven RCTs. Meta-analysis showed that purslane significantly decreased body weight (WMD): -0⋅73 kg, 95 % confidence interval (CI): -1⋅37, -0⋅09, P=0⋅025), BMI (WMD: -0⋅35 kg/m2, 95 % CI: -0⋅64, -0⋅07, P=0⋅016), and SBP (WMD: -3⋅64 mmHg, 95 % CI: -6⋅42, -0⋅87, P = 0⋅01), and for WC, there was no discernible effect (WMD: -0⋅86 cm; 95 % CI, -1⋅80 to 0⋅07; P = 0⋅06) and DBP (WMD: -0⋅36 mmHg; 95 % CI, -1⋅75 to 1⋅03; P = 0⋅61). Purslane consumption, especially in participants with a BMI of <30, might play a role in decreasing SBP, body weight, BMI, and WC. Purslane consumption significantly reduced body weight, BMI, and SBP; however, WC and DBP did not experience a reduction. More investigation is needed to verify the impact of purslane consumption on anthropometric parameters and blood pressure.

Effects of curcumin/turmeric supplementation on glycemic indices in adults: A grade-assessed systematic review and dose-response meta-analysis of randomized controlled trials.

INTRODUCTION: Glycemic control is of utmost importance both as a preventive measure in individuals at risk of diabetes and in the management of patients with disturbed glycemia. Turmeric/curcumin has been extensively studied in this field. In the present systematic review and meta-analysis, we aimed at investigating the impact of turmeric/curcumin supplementation on glycemic control. METHODS: Major online databases (PubMed, Scopus, Web of Science, Cochrane Library and Google Scholar) were systematically searched from inception up to October 2022. Relevant randomized controlled trials (RCTs) meeting our eligible criteria were included. Weighted mean differences (WMDs) with confidence intervals (CIs) were expressed using a random-effect model. Subgroup analyses were conducted to find the sources of heterogeneities. To detect risk of bias in the included studies, we used the Cochrane risk-of-bias tool. The registration number was CRD42022374874. RESULTS: Out of 4182 articles retrieved from the initial search, 59 RCTs were included. Our findings suggested that turmeric/curcumin supplementation was significantly effective in improving fasting blood sugar (WMD: 4.60 mg/dl; 95% CI: 5.55, -3.66), fasting insulin levels (WMD: 0.87 µIU/ml; 95% CI: 1.46, -0.27), hemoglobin A1c (HbA1c) (WMD: 0.32%; 95% CI: 0.45, -0.19), and homeostatic model assessment of insulin resistance (HOMA-IR) (WMD: 0.33; 95% CI: 0.43, -0.22). CONCLUSION: Our results indicate that turmeric/curcumin supplementation can be considered as a complementary method in the management of disturbed glycemia.

Effects of curcumin/turmeric supplementation on liver function in adults: A GRADE-assessed systematic review and dose-response meta-analysis of randomized controlled trials.

INTRODUCTION: Liver conditions are major burdens upon health systems around the world. Turmeric /curcumin is believed to possess therapeutic features in ameliorating various metabolic disorders. In this systematic review and meta-analysis of the randomized controlled trials (RCTs), we examined the effect of turmeric/curcumin supplementation on some liver function tests (LFTs). METHODS: We comprehensively searched online databases (i.e. PubMed, Scopus, Web of Science, Cochrane Library, and Google Scholar) from inception up to October 2022. Final outcomes included aspartate aminotransferase (AST), alanine aminotransferase (ALT), and gamma-glutamyl transferase (GGT). Weighted mean differences (WMDs) were reported. In case of between-study heterogeneity, subgroup analysis was conducted. Non-linear dose-response analysis was carried out to detect the potential effect of dosage and duration. The registration code is CRD42022374871. RESULTS: Thirty-one RCTs were included in the meta-analysis. Turmeric/curcumin supplementation significantly reduced blood levels of ALT (WMD = -4.09 U/L; 95 % CI = -6.49, -1.70) and AST (WMD = -3.81 U/L; 95 % CI = -5.71, -1.91), but not GGT (WMD: -12.78 U/L; 95 % CI: -28.20, 2.64). These improvements, though statistically significant, do not ensure clinical effectiveness. CONCLUSION: It seems that turmeric/curcumin supplementation might be effective in improving AST and ALT levels. However, further clinical trials are needed to examine its effect on GGT. Quality of the evidence across the studies was low for AST and ALT and very low for GGT. Therefore, more studies with high quality are needed to assess this intervention on hepatic health.

Effects of curcumin/turmeric supplementation on lipid profile: A GRADE-assessed systematic review and dose-response meta-analysis of randomized controlled trials.

INTRODUCTION: Numerous approaches have been assigned to treat dyslipidemia (DLP). Turmeric/curcumin have been widely investigated with this regard. In the current study, we explored the effect of curcumin/turmeric supplementation on lipid profile. METHODS: Online databases were searched up to October 2022. The outcomes included triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), apolipoprotein B (Apo-B), and apolipoprotein A (Apo-A). We used the Cochrane quality assessment tool to evaluate the risk of bias. The effect sizes were estimated as weighted mean difference (WMD) and 95% confidence intervals (CIs). RESULTS: Out of 4182 articles retrieved from the initial search, 64 randomized clinical trials (RCTs) were included in the study. Between-study heterogeneity was significant. Meta-analysis showed that turmeric/curcumin supplementation exerts statistically significant improvements on blood levels of TC (WMD = -3.99 mg/dL; 95% CI = -5.33, -2.65), TG (WMD = -6.69 mg/dL; 95% CI = -7.93, -5.45), LDL-c (WMD = -4.89 mg/dL; 95% CI = -5.92, -3.87), and HDL-c (WMD = 1.80 mg/dL; 95% CI = 1.43, 2.17). However, turmeric/curcumin supplementation was not associated with improvements in blood levels of Apo-A or Apo-B. The studies did not thoroughly address the issues of potency, purity, or consumption with other foods. CONCLUSION: Turmeric/curcumin supplementation seems to be effective in improving blood levels of TC, TG, LDL-c, and HDL-c; but may not be capable of improving their pertinent apolipoproteins. Since the evidence was assessed to be low and very low concerning the outcomes, these findings should be dealt with caution.

Effects of curcumin/turmeric supplementation on obesity indices and adipokines in adults: A grade-assessed systematic review and dose-response meta-analysis of randomized controlled trials.

In the present study, we explored the effect of curcumin/turmeric supplementation on anthropometric indices of obesity, leptin, and adiponectin. We searched PubMed, Scopus, Web of Science, Cochrane Library, and Google Scholar up to August 2022. Randomized clinical trials (RCTs) investigating the impact of curcumin/turmeric on obesity indices and adipokines were included. We applied the Cochrane quality assessment tool to evaluate the risk of bias. The registration number is CRD42022350946. Sixty eligible RCTs, with a total sample size of 3691 individuals were included for quantitative analysis. We found that supplementation with curcumin/turmeric significantly reduced body weight (WMD: -0.82 kg, 95% CI: -1.30, -0.35; p = 0.001), body mass index (WMD: -0.30 kg/m2 , 95% CI: -0.53, -0.06, p = 0.013), waist circumference (WMD: -1.31 cm, 95% CI: -1.94, -0.69, p < 0.001), body fat percentage (WMD: -0.88%, 95% CI: -1.51, -0.25, p = 0.007), leptin (WMD = -4.46 ng/mL; 95% CI: -6.70, -2.21, p < 0.001), and increased adiponectin (WMD = 2.48 µg/mL; 95% CI: 1.34, 3.62, p < 0.001). Overall, our study shows that supplementation with curcumin/turmeric significantly improves anthropometric indices of obesity and adiposity-related adipokines (leptin and adiponectin). However, due to high between-studies heterogeneity, we should interpret the results with caution.

Antioxidant and anti-inflammatory effects of curcumin/turmeric supplementation in adults: A GRADE-assessed systematic review and dose-response meta-analysis of randomized controlled trials.

Turmeric and its prominent bioactive compound, curcumin, have been the subject of many investigations with regard to their impact on inflammatory and oxidative balance in the body. In this systematic review and meta-analysis, we summarized the existing literature on randomized controlled trials (RCTs) which examined this hypothesis. Major databases (PubMed, Scopus, Web of Science, Cochrane Library and Google Scholar) were searched from inception up to October 2022. Relevant studies meeting our eligibility criteria were obtained. Main outcomes included inflammatory markers (i.e. C-reactive protein(CRP), tumour necrosis factorα(TNF-α), interleukin-6(IL-6), and interleukin 1 beta(IL-1ß)) and markers of oxidative stress (i.e. total antioxidant capacity (TAC), malondialdehyde(MDA), and superoxide dismutase (SOD) activity). Weighted mean differences (WMDs) were reported. P-values < 0.05 were considered significant. Sixty-six RCTs were included in the final analysis. We observed that turmeric/curcumin supplementation significantly reduces levels of inflammatory markers, including CRP (WMD: -0.58 mg/l, 95 % CI: -0.74, -0.41), TNF-α (WMD: -3.48 pg/ml, 95 % CI: -4.38, -2.58), and IL-6 (WMD: -1.31 pg/ml, 95 % CI: -1.58, -0.67); except for IL-1ß (WMD: -0.46 pg/ml, 95 % CI: -1.18, 0.27) for which no significant change was found. Also, turmeric/curcumin supplementation significantly improved anti-oxidant activity through enhancing TAC (WMD = 0.21 mmol/l; 95 % CI: 0.08, 0.33), reducing MDA levels (WMD = -0.33 µmol /l; 95 % CI: -0.53, -0.12), and SOD activity (WMD = 20.51 u/l; 95 % CI: 7.35, 33.67). It seems that turmeric/curcumin supplementation might be used as a viable intervention for improving inflammatory/oxidative status of individuals.

The Effects of Fenugreek Seed Consumption on Blood Pressure: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

INTRODUCTION: Cardiovascular diseases (CVDs) are growing health issues worldwide. Hypertension (HTN) is one of the most common among CVDs in all populations. Fenugreek has recently been the center of multiple investigations. AIM: In this systematic review and meta-analysis, we aimed at gathering and summing up the existing literature regarding the impact of fenugreek seed on systolic blood pressure (SBP) and diastolic blood pressure (DBP). METHODS: All major databases (MEDLINE, Cochrane library, EMBASE, and Web of Science) were searched from inception up to 28 June 2022. Relevant randomized controlled trials (RCTs) meeting the inclusion criteria were included and the required data was extracted. The pooled effects were reported as weighted mean differences (WMDs). I-squared test was used to detect between-study heterogeneities. Subgroup analyses were conducted to find sources of heterogeneities. P-values < 0.05 were considered as statistically significant. RESULTS: Six RCTs including a total of 373 participants were included in the final meta-analysis. Fenugreek seed supplementation significantly reduced SBP (WMD: 3.46 mmHg, 95% CI - 6.33, - 0.59, P=0.018), but not DBP (WMD: 3.19 mmHg; 95% CI, - 5.82 to 12.21, P=0.488). Subgroup analyses showed that fenugreek seed administered in dosages ≥ 15 g/day and durations ≤ 12 weeks significantly reduced SBP and DBP. CONCLUSION: Supplementation with fenugreek seed, especially in dosages ≥ 15 g/day and durations ≤ 12 weeks, might play a role in reducing SBP, but not DBP. However, further investigations are warranted to ensure the clinical relevance of these 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.

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.

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.

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.

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.

Effect of flaxseed supplementation on lipid profile: An updated systematic review and dose-response meta-analysis of sixty-two randomized controlled trials.

Raised plasma lipids are one the most important risk factors for cardiovascular disease. Flaxseed contains considerable amounts of α-linolenic acid, phenolic compounds, and lignans, which each have the capacity to reduce circulating lipid concentrations. This study aimed to systematically review current evidence to identify the potential effects of flaxseed supplementation on blood lipid profiles using a meta-analysis of randomized controlled trials (RCTs). PubMed, Scopus, Web of Science, and Google Scholar databases were searched for publications between January 1900 and May 2019. Weighted mean differences (WMDs) were analyzed using a random-effects model. The Cochrane Collaboration tool was also used to assess the risk of bias of the studies included. Sixty-two RCTs with a total of 3772 participants met the eligibility criteria. Our analysis showed that flaxseed supplementation significantly reduced total cholesterol (TC) (WMD = -5.389 mg/dL; 95% CI: -9.483, -1.295, p = 0.010), triglyceride (TG) (WMD = -9.422 mg/dL; 95% CI: -15.514, -3.330, p = 0.002), and low-density lipoprotein cholesterol (LDL-C) (WMD = -4.206 mg/dl; 95% CI: -7.260, -1.151, p = 0.007) concentrations. However, it had no effects on high-density lipoprotein cholesterol (WMD = 0.047 mg/dl; 95% CI: -0.777, 0.872, p = 0.910). This meta-analysis suggested that flaxseed supplementation improves serum TC, TG, and LDL-C, which could delay the progression of heart disease. Further studies with large-scale and better design are now needed to confirm these results.

Phytosterol Supplementation Could Improve Atherogenic and Anti-Atherogenic Apolipoproteins: A Systematic Review and Dose-Response Meta-Analysis of Randomized Controlled Trials.

Phytosterol and phytostanol (PS) supplementation is reported to improve atherogenic and anti-atherogenic apolipoproteins (Apo). The purpose of the present study is to critically investigate the effectiveness of PS supplementation on Apo in adults.A comprehensive search was conducted of all randomized controlled trials (RCTs) conducted up to September 2018 in the following databases: PubMed, Web of Science, Cochrane Library, and Scopus. Mean difference with 95% confidence intervals (CIs) were pooled using a random-effects model (DerSimonian-Laird method).Fifty-one arms from 37 RCTs were included in the present meta-analysis. Findings showed that PS supplementation and fortification increased Apo-AI (weighted mean difference [WMD]: 0.014 mg/dl, 95% CI: 0.001, 0.028, p = 0.042) and Apo-CII (WMD: 0.303 mg/dl, 95% CI: 0.084, 0.523, p = 0.007) and lowered Apo-B (WMD: -0.063 mg/dl, 95% CI: -0.075, -0.051, p < 0.001), Apo-B/Apo-A-I ratio (WMD: -0.044 mg/dl, 95% CI: -0.062, -0.025, p < 0.001), and Apo-E (WMD: -0.255 mg/dl, 95% CI: -0.474, -0.036, p = 0.023). However, PS supplementation did not have significant effects on Apo-AII and Apo-CIII. PS supplementation or fortification significantly changes Apo-E (r = -0.137, p nonlinearity = 0.006) and Apo-CIII (r = 1.26, p nonlinearity = 0.028) based on PS dosage (mg/d) and Apo-CIII (r = 3.34, p nonlinearity = 0.013) and Apo-CII (r = 1.09, p nonlinearity = 0.017) based on trial duration (weeks) in a nonlinear fashion.Based on our findings, supplements or fortified foods containing PS might have a considerable favorite effect in achieving Apo profile target; however, due to high heterogeneity among included studies, results must be interpreted with caution.KEY TEACHING POINTSCardiovascular diseases (CVDs) recognized as main public health concern worldwide with considerable mortality of all global deaths.Apo-lipoproteins are amphipathic molecules involved in the lipoprotein metabolism which introduced as biomarkers in the evaluation of CVD risk.Phytosterols bioactive components of plants have important biological functions in cholesterol metabolism in humans.Here we showed that phytosterols and phytostanols improve apo-lipoproteins profile of humans; finding from meta-analysis of randomized controlled trials.Phytosterols supplementation lowered atherogenic apo-lipoproteins (Apo-B and Apo-E) and increased anti-atherogenic apo-lipoproteins (Apo-AI, Apo-CII).

Effect of flaxseed supplementation on markers of inflammation and endothelial function: A systematic review and meta-analysis.

OBJECTIVES: The rationale for the current study was to evaluate the efficacy of flaxseed supplementation on important adhesion molecules and inflammatory cytokines in adults. METHODS: We conducted searches of published literature in PubMed, Scopus, Web of Science, and Google Scholar databases from inception until May 2019. All randomized controlled trials (RCTs) which investigated the effects of flaxseed supplementation on the circulating concentrations of C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), vascular cell adhesion protein 1 (VCAM-1), E-selectin, and intercellular adhesion molecule 1 (ICAM-1) were included in our analysis. Results were summarized using weighted mean differences (WMDs) by random-effects model. RESULTS: Forty eligible RCTs, including 2520 participants were identified. The results of the meta-analysis revealed flaxseed supplementation reduced the concentrations of CRP (WMD = -0.387 mg/L; 95% CI: -0.653, -0.121, p = 0.004), IL-6 (WMD = -0.154 pg/Ml; 95% CI: -0.299, -0.010, p = 0.036), and VCAM-1 (WMD = -22.809 ng/ml; 95% CI: -41.498, -4.120, p = 0.017) but had no significant effect on TNF-α (WMD = -0.077 pg/mL; 95% CI: -0.317, 0.163, p = 0.530), ICAM-1 (WMD = -8.610 ng/ml; 95% CI: -21.936, 4.716, p = 0.205), and E-selectin (WMD = -1.427 ng/ml; 95% CI: -4.074, 1.22, p = 0.291). CONCLUSIONS: These findings showed that flaxseed supplementation may improve some circulating concentrations of specific adhesion molecules and inflammatory cytokines. However, well-designed trials are needed to confirm the range of non-significant and/or equivocal findings.

Beneficial effects of l-carnitine supplementation for weight management in overweight and obese adults: An updated systematic review and dose-response meta-analysis of randomized controlled trials.

Despite preclinical studies demonstrating the efficacy of l-carnitine supplementation for weight management, findings in clinical setting are contradictory. Electronic bibliographical databases were systematically searched up to February 2019 with no limitation in language, including Scopus, PubMed, ISI Web of Science and Cochrane Library. Clinical trials registry platform were also searched. All randomized controlled trials (RCTs) which reported an effect of l-carnitine supplementation on obesity-related indices were included. Weighted mean difference (WMD) was estimated using a random-effect model (DerSimonian-Laird method). Eventually 43 eligible RCTs were included for quantitative analysis. Meta-analysis results revealed that l-carnitine supplementation significantly decreased weight (WMD: -1.129 kg, 95 % CI: -1.590, -0.669; I2: 63.4), body mass index (BMI) (WMD: -0.359 kg/m2, 95 % CI: -0.552, -0.167; I2: 85.2) and fat mass (WMD: -1.158 kg, 95 % CI: -1.763, -0.554, I2: 15.5). However, l-carnitine supplementation did not change body fat percentage (WMD: -0.874 %, 95 % CI: -1.890, 0.142, I2: 98.2) or waist circumference (WMD: -0.883 mg/dl, 95 % CI: -1.770, 0.004, I2: 74.8). l-Carnitine supplementation changed weight (r = -0.98) and BMI (r = -0.67) in a non-linear fashion based on carnitine dosage and BMI according to trial duration (r = -0.04). Interestingly subgroup analysis revealed that l-carnitine showed anti-obesity effects only in overweight and obese subjects; l-carnitine decreased weight, and BMI alone when combined with other lifestyle modifications. Anthropometric indexes were not changed following l-carnitine supplementation among patients' undergoing hemodialysis. Our study revealed that l-carnitine supplementation might have a positive effects in achieving an improved body weight and BMI especially in overweight and obese subjects.