The vegetarian diet and vascular function

Lennon, Shannon L.The health benefits of vegetarian diets are well documented. As compared with their omnivorous counterparts, vegetarians have lower body weight, blood pressure (BP) and cardiovascular disease risk, however, the exact mechanisms of these benefits remain unclear. It is hypothesized that the vegetarian diet may protect the endothelium, which is significant in that vascular endothelial dysfunction is an underlying factor in the pathogenesis of atherosclerosis and high blood pressure (BP). Therefore, the purpose of this study was to determine if individuals who have followed a vegetarian diet for at least five years have improved vascular function when compared to a non-vegetarian diet containing red meat in apparently healthy individuals. Vegetarianism (V) was defined as the absence of meat, poultry, and fish from the diet. Omnivorism (O) was defined as habitual red meat consumption of at least two times per week. Subjects, both men and women, between the ages of 18-45 years were recruited. Assessment of vascular function included brachial artery flow-mediated dilation (FMD), passive leg movement (PLM), pulse wave analysis (PWA), and carotid-to-femoral pulse wave velocity (PWV). A total of 18 subjects, 8 lacto-ovo-vegetarians (age 25.9±2.8 yr; BMI 21.8±0.8 kg/m2) and 10 habitual red meat eaters (age 23.3±1.2 yr; BMI 23.4±0.5 kg/m2), completed the study. Omnivores consumed on average three servings of red meat per week. Significant differences in macronutrient consumption existed between groups with vegetarians consuming more carbohydrate, less fat and protein than omnivores even when normalized for energy intake. Endothelial function as assessed by FMD (O, 8.91±3.67%; V, 7.65±3.85%) was not statistically different nor was PLM as assessed by peak leg blood flow (O, 681.1 ± 153.7; V, 543.0 ± 110.2) between groups. Brachial systolic BP (O, 118 ± 4; V, 106 ± 4; p<0.05) and central systolic BP (V, 99±3 mmHg; O, 108±3 mmHg; p