Abstract 5058: Dietary Intake of Fruits and Vegetables Improves Vascular Function in a Dose Dependent Manner - A Randomised Controlled Trial
Observational evidence has consistently linked increased fruit and vegetable consumption with reduced cardiovascular morbidity. However, there is little direct trial evidence to support the concept that fruit and vegetable consumption improves vascular function. This study has assessed the dose-dependent effects of a fruit and vegetable intervention on arterial health in subjects with hypertension. Following a common 4 week run-in period during which fruit and vegetable intake was limited to 1 portion/day, participants consumed either 1, 3 or 6 portions daily for the next 8 weeks. Endothelium-dependent and independent arterial vasodilator responses were assessed using venous occlusion plethysmography in the brachial circulation pre- and post-intervention. Compliance was monitored using serial contemporaneous 4-day food records and by measuring concentrations of circulating dietary biomarkers. A total of 118 volunteers completed the 12 week study. Participants in the 1, 3 and 6 portions/day groups reported consuming on average 1.1, 3.2 and 5.6 portions of fruit and vegetables respectively, while serum concentrations of ascorbic acid, lutein and β-cryptoxanthin increased across the groups in a dose-dependent manner. For each 1 portion increase in reported fruit and vegetable consumption, there was a 6.2% improvement in forearm blood flow responses to intra-arterial administration of the endothelium-dependent vasodilator acetylcholine (p=0.03). There was no association between increased fruit and vegetable consumption and vasodilator responses to sodium nitroprusside, an endothelium-independent vasodilator. This study illustrates that among hypertensive volunteers, increased fruit and vegetable consumption produces significant improvements in an established marker of endothelial function and cardiovascular prognosis.