Anti-inflammatory effects of oral supplementation with curcumin: a systematic review and meta-analysis of randomized controlled trials

Abstract

Context Chronic inflammation is a major contributor to the development of noncommunicable diseases. Curcumin, a bioactive polyphenol from turmeric, is a well-known anti-inflammatory agent in preclinical research. Clinical evidence remains inconclusive because of discrepancies regarding optimal dosage, duration, and formulation of curcumin. Objective The aim of this systematic review, conducted and reported in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and checklist, was to evaluate the efficacy of curcumin supplementation on systemic inflammatory mediators, comparing dose, duration, and bioavailability status of interventions. Data Sources The Medline, CINAHL, EMBASE, Scopus, and Cochrane literature databases were searched from 1980 to May-end 2019. Randomized controlled trials investigating effects of dietary curcumin on inflammatory mediators in humans not receiving anti-inflammatory treatment were eligible for inclusion. Two authors independently assessed titles and abstracts of identified articles for potential eligibility and respective, retrieved, full-text articles; disagreements were resolved by a third author. Evidence quality was critically appraised using the Quality Criteria Checklist for Primary Research. Data Extraction Thirty-two trials (N = 2,038 participants) were included and 28 were meta-analyzed using a random-effects model; effect sizes were expressed as Hedges’ g (95%CI). Data Analysis Pooled data (reported here as weighted mean difference [WMD]; 95%CI) showed a reduction in C-reactive protein (−1.55 mg/L; −1.81 to −1.30), interleukin-6 (−1.69 pg/mL, −2.56 to −0.82), tumor necrosis factor α (−3.13 pg/mL; −4.62 to −1.64), IL-8 (−0.54 pg/mL; −0.82 to −0.28), monocyte chemoattractant protein-1 (−2.48 pg/mL; −3.96 to −1.00), and an increase in IL-10 (0.49 pg/mL; 0.10 to 0.88), with no effect on intracellular adhesion molecule-1. Conclusion These findings provide evidence for the anti-inflammatory effects of curcumin and support further investigation to confirm dose, duration, and formulation to optimize anti-inflammatory effects in humans with chronic inflammation. Systematic Review Registration PROSPERO registration no. CRD42019148682.

Effectiveness of Curcumin on Outcomes of Hospitalized COVID-19 Patients: A Systematic Review of Clinical Trials

“…These results are in line with those of other studies which tested the effects of nanocurcumin on Th17 cell-mediated inflammation in other diseases marked by hyper-inflammation or autoimmunity responses, such as multiple sclerosis [50,51], rheumatoid arthritis [52,53], and Alzheimer's disease [54][55][56]. There is also accumulating evidence that curcumin treatment can modulate the cytokine cascade and cytokine storm caused by hyper-production of inflammatory cytokines [57,58]. This property appears to occur through inhibition of nuclear factor (NF)-κB and mitogenactivated protein kinase (MAPK) signaling, which drive cytokine production [15,59,60].…”

Oleacein Attenuates Lipopolysaccharide-Induced Inflammation in THP-1-Derived Macrophages by the Inhibition of TLR4/MyD88/NF-κB Pathway

“…Polyphenols are plant secondary metabolites, which, in the last decades, attracted the attention of the scientific community due to their health properties. Several epidemiological studies and meta-analyses strongly suggest that long-term consumption of diets rich in plant polyphenols offer protection against development of cancers, cardiovascular diseases, diabetes, osteoporosis and neurodegenerative diseases [13][14][15][16][17]. A major source of polyphenols (40-1000 mg/kg) is represented by extra virgin olive oil (EVOO), whose phenolic fraction includes simple phenols (tyrosol and hydroxytyrosol), secoiridoids (oleuropein, oleocanthal and oleacein) and lignans [18].…”

Soybean Extracts (Glycine Max) with Curcuma, Boswellia, Pinus and Urtica Are Able to Improve Quality of Life in Patients Affected by CP/CPPS: Is the Pro-Inflammatory Cytokine IL-8 Level Decreasing the Physiopathological Link?

“…Similarly, several authors reported clinical benefits of a curcumin supplementation on main functional parameters related to prostatic diseases [26,27], such as pain relief [27]. Curcumin, a bioactive polyphenol from turmeric, is a common anti-inflammatory agent in preclinical research, and a recent systematic review demonstrated its anti-inflammatory effects, suggesting further investigations to confirm dose, duration and formulation to optimize its implementation in urological practice for chronic inflammation of the lower urinary tract [28]. Finally, several authors showed the beneficial effects of soybean extracts (glycine max) on the prostate physiology [29], as well as the benefits of pinus pinaster [30].…”