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

Cytokine. 2023 Apr:164:156144. doi: 10.1016/j.cyto.2023.156144. Epub 2023 Feb 15.

Abstract

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.

Keywords: Antioxidant status; Curcumin; Inflammation markers; Meta-analysis; Turmeric.

Publication types

  • Systematic Review
  • Meta-Analysis
  • Review

MeSH terms

  • Adult
  • Anti-Inflammatory Agents* / analysis
  • Anti-Inflammatory Agents* / pharmacology
  • Anti-Inflammatory Agents* / therapeutic use
  • Antioxidants* / analysis
  • Antioxidants* / pharmacology
  • Antioxidants* / therapeutic use
  • Biomarkers / analysis
  • C-Reactive Protein / analysis
  • Curcuma*
  • Curcumin* / pharmacology
  • Curcumin* / therapeutic use
  • Dietary Supplements* / analysis
  • Humans
  • Inflammation / drug therapy
  • Interleukin-6
  • Oxidative Stress / drug effects
  • Randomized Controlled Trials as Topic
  • Superoxide Dismutase
  • Tumor Necrosis Factor-alpha

Substances

  • Anti-Inflammatory Agents
  • Antioxidants
  • Biomarkers
  • C-Reactive Protein
  • Curcumin
  • Interleukin-6
  • Superoxide Dismutase
  • Tumor Necrosis Factor-alpha