Role of whey protein in vascular function: a systematic review and meta-analysis of human intervention studies.

Abstract

Whey protein (WP) has been heavily appreciated as a rich source of bioactive peptides, with potential benefits for cardiovascular health. This study constitutes a systematic review and meta-analysis summarizing the effects of WP consumption on vascular reactivity, arterial stiffness, and circulatory biomarkers of vascular function. We searched electronic databases, including PubMed, SCOPUS, and Web of science for relevant articles from inception to July 2020. Original clinical trials published in English-language journals that investigated the effects of WP on vascular function were eligible. A total of 720 records were identified in the initial search; from these, 16 were included in our systematic review and 13 in meta-analysis. The pooled analysis of 6 studies showed a significant increase in flow-mediated dilation (FMD) after WP consumption (WMD: 1.09%, 95% CI: 0.17, 2.01, P=0.01). Meta-analysis of available data didn t show any significant reduction in arterial stiffness measures including augmentation index (effect sizes: 7, WMD: -0.29%, 95% CI: -1.58, 0.98, P=0.64) and pulse wave velocity (effect sizes: 4, WMD: -0.72 m/s, 95% CI: -1.47, 0.03, P=0.06). Moreover, the pooled analysis of 6 effect sizes showed no significant effects on plasma levels of nitric oxide following WP supplementation (WMD: 0.42 μmol/L, 95% CI: -0.52 to 1.36, P=0.38). The overall results provided evidence supporting a protective effect of WP on endothelial function measured by FMD, but not for arterial stiffness measures and circulatory biomarker of vascular function. Further research is required to substantiate the benefits of WP on vascular function.