Many studies show that vegetarians have lowered both systolic and diastolic blood pressure. The difference in rates between vegetarians and non-vegetarians is between 5 and 10 mm Hg.
During the program “Early Detection of Hypertension and Follow-up Recommendations” found that a reduction in blood pressure of just 4 mm Hg leads to a significant reduction in mortality. In addition to this, blood pressure in general is lowered and the incidence of hypertension is reduced.
One study found that 42% of meat eaters had signs of hypertension (defined as a pressure of 140/90 mm Hg), while among vegetarians only 13%. Even semi-vegetarians have a 50% lower risk of developing hypertension than non-vegetarians.
With the transition to a vegetarian diet, blood pressure drops sharply. Lower blood pressure levels in general are not even associated with lower BMI, frequent exercise, lack of meat in the diet and lack of dairy protein, dietary fat, fiber, and differences in intake of potassium, magnesium, and calcium.
The sodium intake of vegetarians is comparable or slightly lower than that of meat eaters, but sodium also does not explain the reason for the decrease in blood pressure. It is suggested that the difference in the level of glucose-insulin responses associated with a reduced glycemic index in a vegetarian diet or the cumulative effect of nutrients contained in plant foods may be a key reason rare cases of hypertension among vegetarians.