Effects of supplementation with pomegranate juice on plasma C-reactive protein concentrations: A systematic review and meta-analysis of randomized controlled trials

Background: Pomegranate juice (PJ) has a high content of antioxidants and bioactive polyphenols, being widely used for its antioxidant, anti-inflammatory and chemopreventive effects.

Purpose: The objective of this meta-analysis consisted in investigating the impact of PJ on plasma C-reactive protein (CRP) concentrations.

Methods: The search included SCOPUS, Medline and two Iranian bibliographic databases namely MagIran and Scientific Information Database (from inception to December 09, 2014) to identify prospective trials for investigating the impact of pomegranate preparations on serum concentrations of CRP. Two independent reviewers extracted data on study characteristics, methods and outcomes.

Results: Among 427 participants in the selected studies, 216 were allocated to PJ groups, and 211 to control group. Meta-analysis of data from 5 eligible randomized controlled trials (RCTs) arms did not provide compelling evidence as to a significant CRP-lowering effect of supplementation with pomegranate juice (WMD: -0.22 mg/l, 95% CI: -0.45, 0.01, p = 0.061). The impact of pomegranate juice on plasma CRP levels was found to be independent of duration of supplementation (slope: 0.003; 95% CI: -0.005, 0.011; p = 0.444).

Conclusion: In conclusion, this meta-analysis of data from 5 prospective trials did not indicate a significant effect of PJ on plasma CRP levels, and this effect was independent of duration of supplementation.