Abstract
OBJECTIVE: Previous work studying vegetarians has often found that they have lower blood pressure (BP). Reasons may include their lower BMI and higher intake levels of fruit and vegetables. Here we seek to extend this evidence in a geographically diverse population containing vegans, lacto-ovo vegetarians and omnivores. DESIGN: Data are analysed from a calibration sub-study of the Adventist Health Study-2 (AHS-2) cohort who attended clinics and provided validated FFQ. Criteria were established for vegan, lacto-ovo vegetarian, partial vegetarian and omnivorous dietary patterns. SETTING: Clinics were conducted at churches across the USA and Canada. Dietary data were gathered by mailed questionnaire. SUBJECTS: Five hundred white subjects representing the AHS-2 cohort. RESULTS: Covariate-adjusted regression analyses demonstrated that the vegan vegetarians had lower systolic and diastolic BP (mmHg) than omnivorous Adventists (β = -6.8, P < 0.05 and ẞ = -6.9, P < 0.001). Findings for lacto-ovo vegetarians (β = -9.1, P < 0.001 and ẞ = -5.8, P 139 mmHg or diastolic BP > 89 mmHg or use 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. Effects were reduced after adjustment for BMI. CONCLUSIONS: We conclude 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. This is only partly due to their lower body mass.
Generated Summary
This study, published in Public Health Nutrition, investigated the relationship between vegetarian diets and blood pressure (BP) among white subjects within the Adventist Health Study-2 (AHS-2) cohort. The research aimed to extend existing evidence suggesting that vegetarians may have lower BP compared to non-vegetarians. The study employed a calibration sub-study design, analyzing data from the AHS-2 cohort, which included participants who attended clinics and provided validated Food Frequency Questionnaires (FFQ). The study defined specific dietary patterns: vegan, lacto-ovo vegetarian, partial vegetarian, and omnivorous. Data collection involved clinics conducted at churches across the USA and Canada, with dietary information gathered through mailed questionnaires. The primary focus was to assess the impact of different vegetarian diets on systolic and diastolic BP and the use of antihypertensive medications.
Key Findings & Statistics
- The study examined the association between vegetarian diets and blood pressure among a cohort of 500 white subjects.
- Covariate-adjusted regression analyses were performed to determine the impact of vegan and lacto-ovo vegetarian diets on blood pressure.
- Vegan vegetarians showed lower systolic and diastolic BP compared to omnivorous Adventists (β = -6.8, P < 0.05 and β = -6.9, P < 0.001).
- Lacto-ovo vegetarians also exhibited lower systolic and diastolic BP compared to omnivores (β = -9.1, P < 0.001 and β = -5.8, P < 0.001).
- Vegetarians, particularly vegans, were less likely to use antihypertensive medications.
- Defining hypertension as systolic BP > 139 mmHg or diastolic BP > 89 mmHg or the use of antihypertensive medications, the odds ratio of hypertension compared with omnivores was 0.37 (95 % CI 0.19, 0.74) for vegans.
- The odds ratio of hypertension for lacto-ovo vegetarians was 0.57 (95 % CI 0.36, 0.92).
- The odds ratio of hypertension for partial vegetarians was 0.92 (95 % CI 0.50, 1.70).
- The effects on blood pressure were reduced after adjustment for BMI.
Other Important Findings
- The study found that both vegan and lacto-ovo vegetarian diets were associated with lower systolic and diastolic blood pressure compared to omnivorous diets.
- Vegetarians, especially vegans, were less likely to be taking antihypertensive medications.
- The observed effects on blood pressure were partially, but not entirely, explained by differences in BMI.
Limitations Noted in the Document
- The study acknowledges that the observed effects on blood pressure were reduced after adjusting for BMI, suggesting that body mass index is a factor. However, the study does not delve into other potential confounders.
- The study does not provide further information about the specific details on the diet or the intake of fruits and vegetables, limiting the ability to understand the role of certain nutrients or dietary components.
- The study’s reliance on self-reported dietary data through FFQs could introduce potential for recall bias or other inaccuracies in dietary assessment.
Conclusion
The study’s findings strongly support the notion that vegetarian diets are linked to lower blood pressure levels compared to omnivorous diets. Specifically, vegan and lacto-ovo vegetarian diets were associated with reduced systolic and diastolic blood pressure. The research further highlights that vegetarians were less likely to use antihypertensive medications. The study’s results have significant public health implications, suggesting that dietary choices can play a crucial role in managing blood pressure and reducing the risk of hypertension. The impact on blood pressure was partially, but not entirely, explained by differences in BMI, indicating that other factors may contribute to the observed effects. The study’s conclusion underscores the importance of adopting vegetarian diets. This study adds to the evidence that dietary interventions, particularly those emphasizing plant-based foods, are viable strategies for maintaining cardiovascular health and reducing the burden of hypertension.
IFFS Team Summary
- Vegetarians and especially vegans have the lowest BP compared to meat eaters, and partial vegetarians
- Partial vegetarians better than full meat eaters
- Largely independent of body Mass Index