Vegetarian diet and blood pressure in a hospital-base study

OBJECTIVE: Previous studies have reported that a vegetarian diet may lower blood pressure (BP), but the effect of diet on BP in asymptomatic participants with proteinuria is unknown. We examined the association of diet and BP in individuals with or without proteinuria. MATERIALS AND METHODS: This cross-sectional study analyzed data from participants who were more than 40 years old and received physical checkups at Taipei Tzu Chi Hospital from September 5, 2005, to December 31, 2016. Diets were assessed at baseline by a self-reported questionnaire and categorized as vegan, lacto-ovo vegetarian, or omnivore. There were 2818 (7.7%) vegans, 5616 (15.3%) lacto-ovo vegetarians, and 28,183 (77.0%) omnivores. The effect of different parameters on BP was determined using a multivariate multiple linear regression model with no intercept, with control for important characteristics and lifestyle confounders. RESULTS: The vegan group had a lower mean systolic BP (−3.87 mmHg, P < 0.001) and diastolic BP (−2.48 mmHg, P < 0.001) than the omnivore group. Participants with proteinuria had a higher systolic BP (4.26 mmHg, P < 0.001) and diastolic BP (2.15 mmHg, P < 0.001) than those without proteinuria. Interaction analysis indicated that vegan participants with proteinuria had a lower systolic BP (−2.73 mmHg, P = 0.046) and diastolic BP (−2.54 mmHg, P = 0.013) than other participants with proteinuria. However, individuals in the lacto-ovo group with proteinuria had a BP similar to other participants with proteinuria. CONCLUSIONS: A vegan diet was associated with lower BP in asymptomatic participants with proteinuria. This diet could be a nonpharmacologic method to reduce BP.