The effects of whole foods and dietary patterns on flow mediated dilation: a systematic review and meta-analysis of randomized controlled trials.

Diet is a key modifiable risk factor for cardiovascular diseases (CVD), which remain the leading cause of death worldwide. Impaired endothelial function is an early predictor of CVD and important risk marker to determine the impact of dietary interventions. A systematic review with meta-analyses was conducted to determine the effects of whole foods and dietary patterns on endothelial function in adults. Eligible studies were randomized controlled trials investigating the effects of whole foods or dietary patterns for ≥28 days on endothelial function in adults, measured as fasting brachial artery flow mediated dilation (FMD). Meta-analyses and meta-regression analyses were performed in order to explore the effects of whole foods and dietary interventions on FMD. Risk of bias, GRADE and publication bias were performed. PROSPERO registration number: CRD42023453352. There were 133 studies included; 102 whole food interventions comparing 14 food groups, and 31 dietary interventions comparing 11 diet patterns. The following interventions consistently showed improvement in FMD (i.e., improved endothelial function) across the studies: fruits (MD: 0.85% (95%CI: 0.16, 1.55)), vegetables (1.37 (0.34, 2.40)), soy (1.58 (0.32, 2.83)), nuts and seeds (1.39 (0.17, 2.60)), cocoa (1.68 (0.08, 3.29)), tea (3.22 (2.01, 4.42)), and the Mediterranean diet (2.32 (1.86, 2.78)), with tea showing the greatest improvement in FMD. Weight loss interventions showed no change in FMD with weight loss <10% body weight. The GRADE certainty of evidence ranged from moderate to low. The systematic review provides evidence that fruits, vegetables, soy, nuts and seeds, cocoa and tea, as well as following a Mediterranean diet are the most effective dietary strategies for improving endothelial function as measured by FMD. However, findings should be interpreted with caution due to moderate to low certainty of evidence and some concerns or high risk of bias in many cases.