The impact of nut consumption on vascular endothelial function: a GRADE-assessed systematic review and meta-analysis of data from randomised controlled trials

This meta-analysis aimed to evaluate the effect of nut consumption on vascular endothelial function through the conduction of a comprehensive review of randomised controlled trials. We explored the major electronic databases for published RCTs examining the repercussions of nuts consumption on vascular endothelial function indicators in adults (&gt;18 years). We used random-effects models to compute pooled estimates of weighted mean differences and confidence intervals. The protocol of the present study was registered in the international database of systematic review protocols (CRD42023472892). Nineteen articles, comprising 21 arms, were deemed eligible. According to the pooled estimations, eating nuts significantly improved flow-mediated dilation (FMD) (weighted mean difference (WMD): 1.12%, 95% CI 0.28 to 1.97, <i>p</i> &lt; 0.05), and reactive hyperaemia index (RHI) (WMD: −0.04, 95% CI −0.07 to −0.00, <i>p</i> = 0.04). However, findings revealed that consuming nuts had no significant impact on pulse wave velocity (PWV), the index of augmentation (AIx), or heart rate. The endothelial function was considerably enhanced by nut consumption through the improvement of FMD, while the certainty of such evidence was assessed as very low.