Long-Term Intake of Animal Flesh, Fruits and Vegetables and the Incidence of Hypertension in Three Prospective Cohort Studies

Abstract

Vegetarian and vegan diets are associated with a lower prevalence of hypertension when compared with animal-based diets. Small, short-term interventional studies showed that replacing an omnivorous diet with a vegetarian diet lowered blood pressure. The potential mechanisms by which plant-based food intake is linked to a reduced risk of hypertension are not well understood. However, proposed effects include systemic inflammation, endothelial dysfunction, and the activation of the renin-angiotensin system (RAS) among those eating animal-based foods. We propose the VEGIE-BP (VEGetarian Initiative on the Endpoint of Blood Pressure) study, a prospective longitudinal study examining the incidence of hypertension in three large-scale, ongoing prospective cohorts with decades of follow-up: the Nurses’ Health Study 1 (NHS1), the Nurses’ Health Study 2 (NHS2), and the Health Professionals Follow-up Study (HPFS). These cohorts have validated information about health outcomes, as well as longitudinal and repeated measures of diet using detailed food-frequency questionnaires. Biomarkers of inflammation and endothelial function have also been measured on many of these participants, and at several time points in some participants. These cohorts therefore represent a unique resource to analyze the longitudinal associations of vegetarian/vegan diets and specific foods with the incidence of hypertension as well as associations with inflammation and endothelial dysfunction. In addition, we will explore the possible mechanisms of vegetarian diets, using not only these pre-existing inflammatory and endothelial biomarkers from the three cohorts, but also by examining the associations of diet with gold-standard measurements of endothelial function and RAS activation in 225 individuals enrolled the Modifiable Effectors of Renin System Activation Treatment Evaluation (MODERATE) trial. VEGIE-BP is the first prospective, longitudinal study examining the relation of vegetarian/vegan diets and specific foods on the incidence of hypertension and its potential mechanisms. From a public health perspective, this study will advance the understanding of how vegetarian diets are related to blood pressure and will help patients to avoid hypertension, chronic kidney disease and cardiovascular disease.