An extensive study was undertaken by the University of Oxford, comprising a study of over 11,000 British men and women with an age group of 20-78 years.
The study concludes that non-meat eaters (especially vegans) have a lower prevalence of hypertension and lower systolic & diastolic blood pressures than meat eaters. Age adjusted prevalence of hypertension was 15% for male meat eaters (5.8% for male vegans) and 12.1% for female meat eaters (7.7% in female vegans). Blood pressure was found to be 4.2 mmHg (systolic) and 2.8mmHg (diastolic) lower for male vegans, compared to male meat eaters.
Hypertension and blood pressure among meat eaters, fish eaters, vegetarians and vegans in EPIC – Oxford-