Curcumin effects on glycaemic indices, lipid profile, blood pressure, inflammatory markers and anthropometric measurements of non-alcoholic fatty liver disease patients: A systematic review and meta-analysis of randomized clinical trials.

OBJECTIVES: Curcumin has antioxidant properties and has been proposed as a potential treatment for NAFLD. The aim of current systematic review and meta-analysis was to evaluate previous findings for the effect of curcumin supplementation on glycaemic indices, lipid profile, blood pressure, inflammatory markers, and anthropometric measurements of NAFLD patients. METHODS: Relevant studies published up to January 2024 were searched systematically using the following databases: PubMed, SCOPUS, WOS, Science Direct, Ovid and Cochrane. The systematic review and meta-analysis were conducted according to the 2020 PRISMA guidelines. The quality of the papers was assessed the using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist. Pooled effect sizes were calculated using a random-effects model and reported as the WMD and 95% CI. Also, subgroup analyses were done to find probable sources of heterogeneity among studies. RESULTS: Out of 21010 records initially identified, 21 eligible RCTs were selected for inclusion in a meta-analysis. Overall, 1191 participants of both genders, 600 in the intervention and 591 in the control group with NAFLD were included. There are several limitations in the studies that were included, for instance, the results are weakened substantially by potential bias or failure to account for potential adulteration (with pharmaceuticals) or contamination (with other herbs) of the curcumin supplements that were tested. However, previous studies have reported curcumin to be a safe complementary therapy for several conditions. Our study indicated that curcumin supplementation in doses of 50-3000 mg/day was associated with significant change in FBG [WMD: -2.83; 95% CI: -4.61, -1.06), I2 = 51.3%], HOMA-IR [WMD: -0.52; 95% CI: -0.84, -0.20), I2= 82.8%], TG [WMD: -10.31; 95% CI: -20.00, -0.61), I2 = 84.5%], TC [WMD: -11.81; 95% CI: -19.65, -3.96), I2 = 94.6%], LDL [WMD: -8.01; 95% CI: -15.79, -0.24), I2 = 96.1%], weight [WMD: -0.81; 95% CI: -1.28, -0.35), I2= 0.0%] and BMI [WMD: -0.35; 95% CI: -0.57, -0.13), I2= 0.0%] in adults with NAFLD. There was no significant change in HbA1C, plasma insulin, QUICKI, HDL, SBP, DBP, CRP, TNF-α and WC after curcumin therapy. Subgroup analysis suggested a significant changes in serum FBG, TG, SBP, WC in RCTs for intervention durations of ≥ 8 weeks, and SBP, TG, LDL, HDL, BMI, WC in RCTs with sample size > 55 participants. CONCLUSION: Curcumin supplementation in doses of 50-3000 mg/day over 8-12 weeks was associated with significant reductions in levels of FBG, HOMA-IR, TG, TC, LDL, weight and BMI in patients with NAFLD. Previous studies have reported curcumin as a safe complementary therapy for several diseases. We would suggest that should curcumin supplements be used clinically in specific conditions, it should be used with caution. Also, difference in grades of NAFLD may effect the evaluated outcomes, so it is suggested that future studies be conducted with an analyses on subgroups according to their NAFLD grade. Furthermore, because of the failure to conduct independent biochemical assessment of the turmeric/curcumin product used in most studies as well as potential sources of bias, results should be interpreted with caution.

The effect of ginger supplementation on metabolic profiles in patients with type 2 diabetes mellitus: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: There is some evidence regarding the positive effects of ginger supplementation on metabolic profile in patients with type 2 diabetes (T2DM). However, they are conflicting. The present systematic review and meta-analysis aimed to summarize earlier findings for the effect of ginger supplementation on metabolic profile in patients with T2DM. METHODS: Scopus, PubMed and Google Scholar databases were systematically searched up until September 2021 to collect all randomized clinical trials that evaluated the effect of ginger supplementation on FBS, HbA1c, TC, TG, LDL, HDL, SBP and DBP in patients with T2DM. We conducted our study according to the 2020 PRISMA guidelines. We included only English language publications. Pooled effect sizes were measured using a random-effects model and were reported as the weighted mean difference (WMD) and 95% CI. In addition, the Cochrane Collaboration's risk of bias tool was used to evaluate quality of the trials. RESULTS: In overall, 10 articles were included in this systematic review and meta-analysis. Our pooled meta-analysis indicated a significant reduction in FBS following ginger supplementation by polling 8 effect sizes [weighted mean difference (WMD): - 18.81; 95% CI: - 28.70, - 8.92), I2 = 77.4%] and in HbA1C through 7 effect sizes (WMD: -0.57; 95% CI: -0.93, -0.20, I2 =88.6%). Pooling 5 effect sizes, we found a significant reduction in SBP (WMD: -4.20; 95% CI: -7.64, -0.77, I2 =97%) and DBP [WMD: - 1.61; 95% CI: - 3.04, - 0.18), I2 = 93.2%] after supplementation with ginger. However, our pooled meta-analysis indicated that ginger supplementation had no significant influence on lipid profile involving TG, TC, LDL and HDL. CONCLUSIONS: We found significant reductions in FBS, HbA1C, SBP and DBP after supplementation with ginger in patients with T2DM compared to control group, with no significant changes in serum lipids. Further large RCTs are required to shed light on this issue.

Effects of curcumin supplementation on inflammatory biomarkers in patients with Rheumatoid Arthritis and Ulcerative colitis: A systematic review and meta-analysis.

BACKGROUND: Although previous studies have examined the impact of curcumin supplementation on cytokine levels in patients with autoimmune disorders, we were unable to find a systematic review of the effect of curcumin supplementation on inflammatory biomarkers such as CRP and ESR in patients with rheumatoid arthritis or ulcerative colitis; therefore we conducted this systematic review and meta-analysis. METHODS: Relevant studies published from inception to December 2020 were systematically searched through the PubMed, SCOPUS, and google scholar databases. We conducted our systematic review and meta-analysis according to the 2020 PRISMA guidelines. The quality of the papers were assessed by using the Cochrane Collaboration's risk of bias tool. Included studies were randomized clinical trials on the effects of supplementation with curcumin or its derivative on inflammatory factors in patients with rheumatoid arthritis and ulcerative colitis. Pooled effect sizes were calculated using a random-effects model and reported as the weighted mean difference (WMD) and 95 % CI. RESULTS: In all, six studies met the inclusion criteria for this study. Curcumin supplementation in doses of 250-1500 mg/day over 8-12 weeks was observed to be associated with decreases in CRP and ESR in adult patients with rheumatoid arthritis and ulcerative colitis in comparison with the control group (WMD: -0.42; 95 % CI: -0.59, -0.26, I2 = 94.3 %; WMD: -55.96; 95 % CI: -93.74, -18.17, I2 = 99.7 %, respectively). Significant findings were also observed based on subgroup analyses by the study sample size, duration, participants' age, curcumin dosage, and type of disease. CONCLUSIONS: Curcumin supplementation was associated with significant reductions in levels of CRP and ESR in patients with rheumatoid arthritis and ulcerative colitis. Earlier studies reported curcumin as a safe complementary therapy for several diseases. However, a handful of studies were found on the effect of curcumin on autoimmune diseases despite our comprehensive search. Further studies are therefore warranted in this area.