1.
Meta-analysis of randomized controlled trials of 4 weeks or longer suggest that curcumin may afford some protection against oxidative stress.
Qin, S, Huang, L, Gong, J, Shen, S, Huang, J, Tang, Y, Ren, H, Hu, H
Nutrition research (New York, N.Y.). 2018;:1-12
Abstract
Oxidative stress (OS) is associated with aging and multiple diseases, yet the effects of curcumin in humans are not definite. We undertook a meta-analysis of the effects of curcumin on OS biomarkers. In January 2018, we searched PubMed, Books@Ovid, Journals@Ovid, EMBASE, MEDLINE(R), and Web of Science to identify randomized controlled trials conducted ≥4 weeks and investigating the effects of curcumin on OS biomarkers, including glutathione peroxidase (GPX) activity in red blood cells (RBC), serum malondialdehyde (MDA) concentrations, and superoxide dismutase (SOD) activity. The standardized mean difference (SMD) with a 95% confidence interval (CI) was used to present the results. The meta-analysis included eight clinical studies (626 patients). There was a significant reduction in circulating MDA concentrations (SMD = -0.769, 95% CI: -1.059 to -0.478) and a significant increase in SOD activity (SMD = 1.084, 95% CI: 0.487 to 1.680) following curcumin supplementation. There was no change in the GPX activity in RBC. There was no significant association between the MDA-lowering effect of curcumin with underlying diseases or treatment duration. However, curcumin showed the MDA-lowering effect at curcuminoids doses ≥600 mg/d (P < .0001). This effect was greater when combined with piperine than curcuminoids alone (SMD = -1.085, 95% CI: -1.357 to -0.813; SMD = -0.850, 95% CI: -1.158 to -0.542). Curcumin may play an anti-oxidative role by reducing circulating MDA concentrations and increasing SOD activity. Further research of curcumin in different populations with multiple biomarkers of redox status is required.
2.
Efficacy and safety of turmeric and curcumin in lowering blood lipid levels in patients with cardiovascular risk factors: a meta-analysis of randomized controlled trials.
Qin, S, Huang, L, Gong, J, Shen, S, Huang, J, Ren, H, Hu, H
Nutrition journal. 2017;(1):68
Abstract
BACKGROUND Dyslipidemia is an important and common cardiovascular risk factor in the general population. The lipid-lowering effects of turmeric and curcumin are unconfirmed. We performed a meta-analysis to assess the efficacy and safety of turmeric and curcumin in lowering blood lipids in patients at risk of cardiovascular disease (CVD). METHODS A comprehensive literature search was conducted on PubMed, Embase, Ovid, Medline and Cochrane Library databases to identify randomized controlled trials (published as of November 2016) that assessed the effect of turmeric and curcumin on blood lipid levels including total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG). Pooled standardized mean difference (SMD) with 95% confidence interval (CI) was used to assess the effect. RESULTS The analysis included 7 eligible studies (649 patients). Turmeric and curcumin significantly reduced serum LDL-C (SMD = -0.340, 95% confidence interval [CI]: -0.530 to -0.150, P < 0.0001) and TG (SMD = -0.214, 95% CI: -0.369 to -0.059, P = 0.007) levels as compared to those in the control group. These may be effective in lowering serum TC levels in patients with metabolic syndrome (MetS, SMD = -0.934, 95% CI: -1.289 to -0.579, P < 0.0001), and turmeric extract could possibly have a greater effect on reducing serum TC levels (SMD = -0.584, 95% CI: -0.980 to -0.188, P = 0.004); however, the efficacy is yet to be confirmed. Serum HDL-C levels were not obviously improved. Turmeric and curcumin appeared safe, and no serious adverse events were reported in any of the included studies. CONCLUSIONS Turmeric and curcumin may protect patients at risk of CVD through improving serum lipid levels. Curcumin may be used as a well-tolerated dietary adjunct to conventional drugs. Further research is required to resolve uncertainties related to dosage form, dose and medication frequency of curcumin.