The effects of pomegranate supplementation on biomarkers of inflammation and endothelial dysfunction: A meta-analysis and systematic review

Objects: Cardiovascular disease (CVD) is one of the leading causes of death worldwide. CVD is associated with increased levels of reactive oxygen species which are pro-inflammatory and can damage the endothelium. The pomegranate fruit is a rich source of phytochemicals with a high antioxidant and anti-inflammatory activity, possessing thus health benefits. This systematic review and meta-analysis aims to evaluate the effect of pomegranate juice on the biomarkers of inflammation and vascular dysfunction.

Methods: Studies were identified using the PubMed/Medline and SCOPUS databases. Screening of relevant articles and references was carried out from inception until May 2019. This systematic review and meta-analysis was performed using the Preferred Items for Reporting of Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

Results: Overall, 16 randomized controlled trials (RCTs) involving 572 subjects were included in this study. Combining effect sizes from 16 studies, we recorded that pomegranate supplementation significantly reduced hs-CRP, IL-6 and TNF-α (Weighted Mean Diff ;erences (WMD): -6.57 mg/L, 95 % CI: -10.04 to -3.10, P = 0.000; WMD: -1.68 pg/mL, 95 % CI: -3.52, 0.157, P = 0.000; WMD: -2.37 pg/mL, 95 % CI: -3.67, -1.07, P = 0.00, respectively) levels, when compared to placebo. No significant reduction was found in CRP (WMD: 2.19 mg/dL, 95 % CI: -3.28, 7.67, P = 0.61), E-selectin (WMD: 8.42 ng/mL, 95 % CI: -22.9, 39.8, P = 0.599), ICAM (WMD= -17.38 ng/mL, 95 % CI: -53.43, 18.66, P = 0.107), VCAM (WMD: -69.32 ng/mL, 95 % CI: -229.26, 90.61, P = 0.396) or MDA (WMD: 0.031 μmol/L, 95 % CI: -1.56, 0.218, P = 0.746) comparing pomegranate supplementation to placebo.

Conclusion: We found a significant effect of pomegranate supplementation on hs-CRP, IL-6 and TNF-α in adults. However, the effects of pomegranate supplementation on CRP, E-selectin, ICAM, VCAM or MDA were not significant in this meta-analysis.