Vascular Function in Healthy Adults Consuming Vegetarian and Omnivore Diets

Abstract

Consumption of a vegetarian diet has been associated with a lower blood pressure (BP), lower incidence of overweight/obesity and decreased cardiovascular disease risk as compared to consumption of a diet containing red meat. The exact underlying mechanisms remain unclear however, it is hypothesized that a vegetarian diet may protect the vascular endothelium, whose optimal function is necessary to prevent pathogenesis of atherosclerosis.PURPOSETo determine if individuals who have been following a vegetarian diet have greater endothelial function compared to individuals consuming a non‐vegetarian diet containing red meat.METHODSHealthy, normotensive males and females between the ages of 18–50 years were recruited. Vegetarianism (V) was defined as following a plant‐based diet for at least 5 years that could include eggs and dairy and omnivores (O) were defined as consuming at least two servings of red meat a week. Diet history was assessed via a food frequency questionnaire. Vascular function was assessed using passive leg movement (PLM) to evaluate leg blood flow (LBF), an indicator of nitric oxide‐mediated endothelial function. Arterial stiffness was assessed by carotid‐to‐femoral pulse wave velocity (PWV), and aortic augmentation index (AI), an index of wave reflection. Females were tested in the early follicular phase of the menstrual cycle.RESULTSForty‐eight subjects (V: 6M/20F, 28 ± 2 yr; BMI 22 ± 0.6 kg/m2; O: 9M/13F, 24 ± 1 yr; BMI 23 ± 0.6 kg/m2) completed the study. While total energy consumption did not differ between groups, there were significant differences in macronutrient consumption with V consuming more carbohydrate and fiber, less cholesterol, saturated fat, and protein than O, even when normalized to energy intake (P<0.05). Systolic BP tended to be lower in V (V: 113 ± 2, O: 117 ± 2 mmHg; P=0.06) while diastolic BP was not different between groups (V: 70 ± 1; O: 70 ± 2 mmHg; P>0.05). Pulse pressure was lower in V than O (V: 42 ± 1; O: 47 ± 2 mmHg; P<0.05). Vascular function as assessed by PLM showed differences in baseline LBF (V: 147 ± 14 mL/min, O: 199 ± 18 mL/min; P<0.05) and % change in LBF (V: 265 ± 43 mL/min, O: 169 ± 31 mL/min; P=0.05) while area under the curve (V: 125 ± 19, O: 95 ± 24) remained unchanged between the two groups (P>0.05). Arterial stiffness as assessed by PWV (V: 5.6 ± 0.2 m/s, O: 5.4 ± 0.2 m/s) and AI (V: 10 ± 3 %, O: 11 ± 2 %) were not different between groups (P>0.05).CONCLUSIONThese preliminary data suggest following a vegetarian diet may improve overall resting hemodynamics and peripheral vascular function compared to consumption of a diet containing red meat in apparently, healthy adults.Support or Funding InformationNIH NIGMS P20GM113125This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.