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 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 ... -  《-》

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 ... -  《-》

Oral turmeric/curcumin effects on inflammatory markers in chronic inflammatory diseases: A systematic review and meta-analysis of randomized controlled trials.

Turmeric extract or active component curcumin may have anti-inflammatory effects in people with chronic inflammatory diseases. The effect of turmeric or curcumin on a wide range of inflammatory markers has not been evaluated in a systematic review. We performed a systematic review of randomized controlled trials (RCTs) evaluating the effects of oral turmeric or curcumin on inflammatory markers (CRP, hsCRP, IL-1, IL-6, TNF) in patients with a wide range of chronic inflammatory diseases. Pubmed, EMBASE, Scopus, the Web of Science, and the Cochrane library were evaluated until June 2018. Random effects meta-analyses with inverse variance methods and stratified by turmeric or curcumin were performed. Effects were expressed as mean differences (MD) and their 95% confidence intervals (CI). Risk of bias of RCTs was evaluated with the Cochrane tool. Nineteen RCTs were identified; included patients had rheumatic diseases, advanced chronic kidney disease with hemodialysis, metabolic syndrome, and cardiovascular diseases. Turmeric was the intervention in 5 RCTs (n = 356) and curcumin/curcuminoids in 14 RCTs (n = 988). Follow up times ranged between 4 and 16 weeks. One RCT had high risk of bias. In comparison to controls, turmeric or curcumin did not significantly decrease levels of CRP (MD -2.71 mg/L, 95%CI -5.73 to 0.31, p = 0.08, 5 studies), hsCRP (MD -1.44 mg/L, 95%CI -2.94 to 0.06, p = 0.06, 6 studies), IL-1 beta (MD -4.25 pg/mL, 95%CI -13.32 to 4.82, p = 0.36, 2 studies), IL-6 (MD -0.71 pg/mL, 95%CI -1.68 to 0.25, p = 0.15), and TNF alpha (MD -1.23 pg/mL, 95%CI -3.01 to 0.55, p = 0.18, 7 studies). There were no differences between turmeric and curcumin interventions. High heterogeneity of effects was observed for all markers across studies, except hsCRP. Other inflammatory markers such as IL-1 alpha, TNF beta, IL-17, and IL-22 had scarce data. Turmeric or curcumin did not decrease several inflammatory markers in patients with chronic inflammatory diseases.

White CM ，Pasupuleti V ，Roman YM ，Li Y ，Hernandez AV ... -  《-》

Impact of Cinnamon Supplementation on cardiometabolic Biomarkers of Inflammation and Oxidative Stress: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

To date, cinnamon supplementation has been investigated due to its antioxidant and anti-inflammatory properties. Several studies have confirmed the effects of cinnamon supplementation on several markers of cardiometabolic health. However, the effects of cinnamon supplementation on inflammation and oxidative stress levels warrant further investigation. Hence, the current meta-analysis was conducted to elucidate the impact of cinnamon supplementation on biomarkers of inflammation and oxidative stress. To perform this systematic review and meta-analysis, we employed the Preferred Reporting Items of Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The systematic search of available clinical trials was performed using the following databases: PubMed/MEDLINE, Scopus, Cochrane Library, Web of Science, Embase, and Google Scholar, up to January 2020. After removing the duplicates, 1145 studies were eligible for analysis and 12 of them were included in the meta-analysis. The dose of cinnamon powder investigated in the included trials ranged from 1.5 to 4 g/day. Cinnamon supplementation resulted in a significant reduction of C-reactive protein (CRP) (weight mean difference (WMD): -2.22 mg/L, 95 % CI: -3.74, -0.69, P = 0.004) and malondialdehyde (MDA) (WMD: -0.79 mmol/L, 95 % CI: -1.28, -0.29, P = 0.002), and marginally statistical significant decrease in interleukin-6 (IL-6) (WMD: -1.48 pg/mL, 95 % CI: -2.96, -0.01, P = 0.049). Moreover, it was associated with an increase in the total antioxidant capacity (TAC) (WMD: 0.34 mmol/L, 95 % CI: 0.04, 0.64, P = 0.026). However, the levels of intercellular adhesion molecule-1 (ICAM-1) (WMD: 1.53 ng/mL, 95 % CI: -12.03, 15.10, P = 0.82) did not change significantly following cinnamon supplementation. Cinnamon supplementation may be an adjuvant for reducing inflammation and oxidative stress levels in humans.

Zhu C ，Yan H ，Zheng Y ，Santos HO ，Macit MS ，Zhao K ... -  《-》