The benefit of vegetarian diets for reducing blood pressure in Taiwan: a historically prospective cohort study

OBJECTIVE: Past vegetarians research has often found that they have lower blood pressure (BP). Effects may include their lower BMI and higher intake levels of fruit and vegetables. Besides, the study pursues to extend this evidence in a diverse population containing vegans, lacto-ovo vegetarians and omnivores. DESIGN: The study analyzed data on five hundred vigorous individuals aged 20 years or older from a standard medical screening program and provided validated questionnaire. Criteria were established for vegan, lacto-ovo vegetarian, partial vegetarian and omnivorous dietary patterns. SETTING: Health screening programs were conducted at a standard medical screening program in Taiwan between 2006 and 2017. Dietary data were gathered by self-administered questionnaire. SUBJECTS: Five hundred Taiwanese subjects representing the cohort. RESULTS: Multiple regression analyses confirmed that the vegan vegetarians had lower systolic and diastolic BP (mmHg) than omnivorous Taiwanese (β = − 6.8, p < 0.05 and β = − 6.9, p < 0.001). Findings for lacto-ovo vegetarians (β = − 9.1, p < 0.001 and β = − 5.8, p < 0.001) were similar. The vegetarians were also less likely to be using antihypertensive medications. Defining hypertension as systolic BP > 139 mmHg or diastolic BP > 89 mmHg or routine of antihypertensive medications, the odds ratio of hypertension compared with omnivores was 0.37 (95% CI = 0.19–0.74), 0.57 (95% CI = 0.36–0.92) and 0.92 (95% CI = 0.50–1.70), respectively, for vegans, lacto-ovo vegetarians and partial vegetarians. Results were reduced after adjustment for BMI. CONCLUSIONS: The study concludes from this relatively large study that vegetarians, especially vegans, with otherwise diverse characteristics but stable diets, do have lower systolic and diastolic BP and less hypertension than omnivores.