Endothelial dysfunction, which is an early event in the development of vascular disease, is commonly associated with atherosclerosis and its risk factors. Various recent studies show that coronary endothelial dysfunction predicts CAD events in the near future. Vascular reactivity can be improved by dietary factors such as marine n-3 fatty acids, and antioxidants. To test the hypothesis that walnut intake would improve endothelial function, the scinetists performed a randomized, crossover feeding trial by substituting a walnut-enriched diet for a healthy Mediterranean-type diet for effects on brachial artery vasomotor function and circulating markers of endothelial activation.
Before the study, the general recommendations of a Mediterranean-type, cholesterol-lowering diet were reinforced in all eligible subjects, and baseline data were collected after 1 month. The self-reported nutrient contents of the baseline diet showed good adherence to dietary advice.
Of all participants randomly assigned to dietary intervention, 98% completed both study phases. The rest of them withdrew for personal reasons. According to participants’ reports and recounts of empty packages, compliance with walnut ingestion was 100%. Walnut consumption every day was tolerated by all subjects. The walnut meal in a background walnut diet was associated with significant improvement in brachial artery EDV. The walnut diet also attenuated endothelial activation, as suggested by the reduction in VCAM-1 levels.