Vegetarian Diets and Blood Pressure: A Meta-Analysis

Study Questions:

Does a vegetarian diet improve blood pressure (BP) control?

Methods:

This meta-analysis used articles identified through MEDLINE and Web of Science. Manuscripts were published in English from 1946 to October 2013 (for MEDLINE), and from 1900 to November 2013 (for Web of Science). Studies were included if the subjects were 20 years or older, were consuming a vegetarian diet (for the intervention), used BP as an outcome, and had a study design of a controlled trial or observational study. Studies were also excluded if they used twin participants, used multiple interventions, reported only categorical BP data, or relied on case series or case reports. Data from the studies were pooled using a random-effects model. The primary outcome of interest was net difference in systolic and diastolic BP.

Results:

Of the 258 studies identified, seven clinical trials and 32 observational studies met the inclusion criteria. In the seven controlled trials, 311 subjects were included; the mean age was 44.5 years. A vegetarian diet was associated with a significant reduction in mean systolic BP (−4.8 mm Hg; 95% CI, −6.6 to −3.1; p < .001; I2 = 0; p = 0.45 for heterogeneity), and mean diastolic BP (−2.2 mm Hg; 95% CI, −3.5 to −1.0; p < 0.001; I2 = 0; p = 0.43 for heterogeneity) as compared with a usual diet. A similar pattern was observed with the observational studies, which included 21,604 participants (mean age, 46.6 years). A vegetarian diet was associated with a lower mean systolic BP (−6.9 mm Hg; 95% CI, −9.1 to −4.7; p < 0.001; I2 = 91.4; p < 0.001 for heterogeneity) and diastolic BP (−4.7 mm Hg; 95% CI, −6.3 to −3.1; p < 0.001; I2 = 92.6; p < 0.001 for heterogeneity).

Conclusions:

The investigators concluded that consumption of vegetarian diets is associated with lower BP.

Perspective:

These data suggest that a vegetarian diet my assist in the control of BP; however, one should note that the mean ages were young in this study. Still, this study complements others including DASH, which support a healthy lifestyle including one high in fruits and vegetables, which will help promote a healthy BP.

Clinical Topics: Diabetes and Cardiometabolic Disease, Prevention, Diet

Keywords: Fruit, Life Style, Diet, Vegetarian, Vegetables, Blood Pressure Determination, MEDLINE


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