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

Dehzad MJ ，Ghalandari H ，Askarpour M 《Clinical Nutrition ESPEN》

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-1β)) 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-1β (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.

Dehzad MJ ，Ghalandari H ，Nouri M ，Askarpour M ... -  《-》

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

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. 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. 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). Our results indicate that turmeric/curcumin supplementation can be considered as a complementary method in the management of disturbed glycemia.

Dehzad MJ ，Ghalandari H ，Nouri M ，Askarpour M ... -  《-》

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

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). 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. 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. 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.

Dehzad MJ ，Ghalandari H ，Amini MR ，Askarpour M ... -  《-》

The effect of curcumin supplementation on endothelial function and blood pressure in patients with metabolic disorders: A meta-analysis of meta-analyses.

Several interventional studies have revealed the beneficial impact of curcumin supplementation on blood pressure and endothelial function, but the findings are conflicting. Therefore, this study was conducted to investigate the effects of curcumin supplementation on blood pressure and endothelial function. A meta-analyses of randomized clinical trials were performed by searching PubMed, Embase, Scopus, and Web of Science were searched up to March 31, 2024. Random effects models were used to calculate weighted mean differences (WMD). Pooled estimates of 10 studies revealed that curcumin decreased diastolic blood pressure (DBP) [WMD = -0.94, 95 % CI: -1.59, -0.30; p = 0.004], pulse wave velocity (PWV) [WMD = -45.60, 95 % CI: -88.16, -3.04; p = 0.03, I2 = 0.0 %, p = 0.59], and vascular cell adhesion molecule-1 (VCAM-1) [WMD = -39.19; 95 % CI: -66.15, -12.23, p =0.004; I2=73.0 %, p = 0.005] significantly, and increased flow-mediated dilation (FMD) [WMD = 1.64, 95 % CI: 1.06, 2.22; p < 0.001, I2 = 0.0 %, p = 0.61. However, curcumin did not significantly change systolic blood pressure (SBP) [WMD = -0.64, 95 % CI: -1.96, 0.67; p =0.34, I2 = 83.5 %, p <0.001], and Intercellular Adhesion Molecule 1 (ICAM1) [WMD = -17.05; 95 % CI: -80.79, 46.70, p =0.601; I2=94.1 %, p < 0.001]. These results suggest that curcumin has a beneficial effect on DBP, PWV, VCAM-1 and FMD levels and may be an effective adjunctive therapy for improving blood pressure and endothelial function.

Tang WW ，Huang FF ，Haedi AR ，Shi QY ... -  《-》