Mediterranean diet increases endothelial function in adults: A systematic review and meta-analysis of randomized controlled trials:Mediterranean diet and endothelial function

Background: The endothelium plays a key role in the maintenance of vascular health, and represents a potential physiological target for dietary and other lifestyle interventions designed to reduce risk for cardiovascular diseases (CVD) including stroke or coronary heart disease. Objective: To conduct a systematic review and meta-analysis of randomized controlled trials investigating effects of the Mediterranean dietary pattern (MedDiet) on endothelial function. Methods: Medline, Embase and Scopus databases were searched from inception until January 2019 for studies that met the following criteria: 1) RCTs including adult participants, 2) interventions promoting a Mediterranean dietary pattern, 3) inclusion of a control group and 4) measurements of endothelial function. A random-effects meta-analysis was conducted. Meta-regression and sub-group analyses were performed to identify whether effects were modified by health status (i.e., healthy participants vs participants with existing comorbidities), type of intervention (i.e., MedDiet alone or with a co-intervention), study duration, study design (i.e., parallel or crossover), body mass index (BMI), and age of participants. Results: Fourteen articles reporting data for 1930 participants were included in the meta-analysis. Study duration ranged from 4 weeks to 2.3 years. We observed a beneficial effect of the MedDiet on endothelial function (standardised mean difference (SMD): 0.35 95% CI: 0.17, 0.53, P 0.05). Conclusions: MedDiet interventions improve endothelial function in adults, which suggest that the protective effects of the MedDiet are evident at early stages of the atherosclerotic process with important implications for the early prevention of CVD.