Walnut type affects the response to occlusion‐induced vasodilation following a high fat meal in dyslipidemic humans

Abstract

Endothelial dysfunction, resulting in impaired vasodilation, has been shown in persons with dyslipidemia. English walnuts (EW) improve such impaired vasodilation following a high fat meal, compared to other fat sources such as olive oil. Our lab has studied the effects of both EW and black walnuts (BW) on plasma lipids, but the effect of BW on endothelial function has not been studied. Thus, we compared the effects of 40 g BW versus EW with a high fat meal on vasodilation. Six dyslipidemic (LDL over 130 mg/dl) subjects were tested on two days at least one week apart. On test days, subjects ate a standardized breakfast at 7:00 am and arrived at noon for vasodilation testing. Baseline ultrasound of the brachial artery before and after 4.5 minute occlusion, was followed by high fat meal consumption. Four hours post‐meal, vasodilation testing was repeated. The high fat meal impaired the vasodilation response in both groups as expected, but the mean pre‐post meal vasodilation difference was significantly (p<0.02) greater (−8.7±2.9) with BW versus EW (−1.5±3.1). Changes in after‐occlusion blood flow rate (cm/s) following the high fat meal were not significantly different between EW and BW. Our results indicate that EW improved endothelial dysfunction compared to BW following a high fat meal in dyslipidemic subjects. Funded by University of Wisconsin‐System, WiscAMP, and NSF‐REU grants.