Effect of garlic intake on inflammatory mediators: a systematic review and meta-analysis of randomised controlled trials.
Postgrad Med J. 2020 Feb 12. Epub 2020 Feb 12. PMID: 32051282
BACKGROUND: Garlic is a species in the onion genus,. Data have shown that garlic has anti-inflammatory activity; however, the findings are inconclusive and inconsistent. We aimed to evaluate the impact of garlic intake on inflammatory mediators through systematic review and meta-analysis of existing data.
METHODS: Electronic databases were completely investigated using databases of ISI Web of Science, Medline, Scopus, Cochrane Library and EMBASE until October 2019. A random effects model and the generic reverse variance procedure were used for quantitative data production. Sensitivity analyses and prespecified subgroup were done to evaluate potential heterogeneity. Random effect meta-regression was conducted to investigate the effects of possible confounders on the assessed effect size.
RESULTS: Ten trials with one observational study, including 530 participants, met the eligibility criteria. The findings showed reduction in the tumour necrosis factor alpha (TNF-α) (-0.31 pg/mL, 95% CI -1.07 to 0.46) and C reactive protein (CRP) levels (-0.20 mg/L, 95% CI -1.4 to 1.05) following supplementation with garlic, although it had no marked impact on the interleukin 6 (IL-6) level (0.37 pg/mL, 95% CI -0.58 to 1.33). In the subgroup analysis, we found that garlic supplementation significantly decreased TNF-α, highly sensitive CRP and IL-6 levels in subgroups of>8,>6 and≥4 weeks of intervention duration, respectively, and dose of garlic consumption between 2 and 2.4 g/day.
CONCLUSION: These findings suggested that current evidence may support garlic as an adjunct to pharmacological management of metabolic diseases.
PROSPERO REGISTRATION NUMBER: CRD42018108816.