Subject: Endothelial function
Background Results of previous clinical trials evaluating the effect of pistachio supplementation on endothelial reactivity (ER) are controversial. Aims We aimed to assess the impact of pistachio on ER through systematic review of literature and meta-analysis of available randomized, controlled-feeding clinical studies (RCTs). Methods The literature search included SCOPUS, PubMed-Medline, ISI Web of Science and Google Scholar databases up to 1st August 2017 to identify RCTs investigating the impact of pistachio on ER. Two independent reviewers extracted data on study characteristics, methods and outcomes. Overall, the impact of pistachio on ER was reported in 4 trials. Results The meta-analysis did not suggest a significant change in brachial artery flow-mediated dilatation (FMD) (WMD: +0.28%; 95%CI: -0.58, 1.13; p = 0.525) while brachial artery diameter (BAD) improved (WMD: +0.04%; 95%CI: 0.03, 0.06; p<0.001) following pistachios consumption. Conclusion The present meta-analysis suggests a significant effect of pistachios on ER, affecting BAD but not FMD.