[Skip to Content]
Access to paid content on this site is currently suspended due to excessive activity being detected from your IP address 34.238.248.103. Please contact the publisher to request reinstatement.
[Skip to Content Landing]
Original Investigation
April 2014

Vegetarian Diets and Blood Pressure: A Meta-analysis

Author Affiliations
  • 1Department of Preventive Medicine and Epidemiologic Informatics, National Cerebral and Cardiovascular Center, Osaka, Japan
  • 2Japan Society for the Promotion of Science, Tokyo, Japan
  • 3Physicians Committee for Responsible Medicine, Washington, DC
  • 4Division of Evidence-Based Medicine and Risk Analysis, Preventive Medicine and Epidemiology, National Cerebral and Cardiovascular Center, Osaka, Japan
  • 5Department of Nephrology, School of Medicine, Fujita Health University, Aichi, Japan
  • 6Department of Medicine, George Washington University School of Medicine and Health Sciences, Washington, DC
  • 7Department of Healthcare Epidemiology, Kyoto University School of Medicine and Public Health, Kyoto, Japan
  • 8Department of Preventive Cardiology, National Cerebral and Cardiovascular Center, Osaka, Japan
  • 9Department of Epidemiology, University of Pittsburgh, Pittsburgh, Pennsylvania
  • 10Department of Preventive Medicine and Public Health, School of Medicine, Keio University, Tokyo, Japan
JAMA Intern Med. 2014;174(4):577-587. doi:10.1001/jamainternmed.2013.14547
Abstract

Importance  Previous studies have suggested an association between vegetarian diets and lower blood pressure (BP), but the relationship is not well established.

Objective  To conduct a systematic review and meta-analysis of controlled clinical trials and observational studies that have examined the association between vegetarian diets and BP.

Data Sources  MEDLINE and Web of Science were searched for articles published in English from 1946 to October 2013 and from 1900 to November 2013, respectively.

Study Selection  All studies met the inclusion criteria of the use of (1) participants older than 20 years, (2) vegetarian diets as an exposure or intervention, (3) mean difference in BP as an outcome, and (4) a controlled trial or observational study design. In addition, none met the exclusion criteria of (1) use of twin participants, (2) use of multiple interventions, (3) reporting only categorical BP data, or (4) reliance on case series or case reports.

Data Extraction and Synthesis  Data collected included study design, baseline characteristics of the study population, dietary data, and outcomes. The data were pooled using a random-effects model.

Main Outcomes and Measures  Net differences in systolic and diastolic BP associated with the consumption of vegetarian diets were assessed.

Results  Of the 258 studies identified, 7 clinical trials and 32 observational studies met the inclusion criteria. In the 7 controlled trials (a total of 311 participants; mean age, 44.5 years), consumption of vegetarian diets was associated with a reduction in mean systolic BP (−4.8 mm Hg; 95% CI, −6.6 to −3.1; P < .001; I2 = 0; P = .45 for heterogeneity) and diastolic BP (−2.2 mm Hg; 95% CI, −3.5 to −1.0; P < .001; I2 = 0; P = .43 for heterogeneity) compared with the consumption of omnivorous diets. In the 32 observational studies (a total of 21 604 participants; mean age, 46.6 years), consumption of vegetarian diets was associated with lower mean systolic BP (−6.9 mm Hg; 95% CI, −9.1 to −4.7; P < .001; I2 = 91.4; P < .001 for heterogeneity) and diastolic BP (−4.7 mm Hg; 95% CI, −6.3 to −3.1; P < .001; I2 = 92.6; P < .001 for heterogeneity) compared with the consumption of omnivorous diets.

Conclusions and Relevance  Consumption of vegetarian diets is associated with lower BP. Such diets could be a useful nonpharmacologic means for reducing BP.

×