Blood Pressure Graphic print version (3)JAMA meta-analysis shows link between diet, hypertension

Study Highlights:

  • A meta-analysis of 21,604 people from 32 observational studies and 311 people from seven clinical trials shows a strong association between vegetarian diets and low blood pressure.
  • In observational studies, vegetarian diets are associated with blood pressure readings that are, on average, 7 mm Hg and 5 mm Hg lower for systolic and diastolic blood pressure, respectively.
  • The blood pressure reduction is independent of salt intake, overweight, and exercise levels.
  • A reduction of 5 mm Hg in systolic blood pressure leads to a 7 percent reduced risk of all-cause mortality, a 9 percent reduced risk of heart disease, and a 14 percent reduced risk of stroke.
  • Study participants who follow a vegetarian diet typically have higher fiber and potassium intakes, lower fat intakes, lower blood viscosity, and a lower BMI, compared to study participants who follow an omnivorous diet.

Vegetarian diets reduce the risk of hypertension, according to new research published today in JAMA Internal Medicine by Physicians Committee president Neal Barnard, M.D., and researcher Yoko Yokoyama, Ph.D., M.P.H. The meta-analysis compares blood pressure from more than 21,000 people around the world and finds study participants who follow a vegetarian diet have a systolic blood pressure about 7 mm Hg lower and diastolic blood pressure 5 mm Hg lower than study participants who consume an omnivorous diet.

“Instead of readjusting the definition for hypertension, as was done in the recent guideline revision, let’s write prescriptions for plant-based foods,” says Dr. Barnard. “Compared to antihypertensive drugs, a diet change brings only desirable “side effects,” including healthy weight loss and improved cholesterol, along with the lower blood pressure.”

The meta-analysis report also points out that:

  • Obesity, sodium, and alcohol consumption increase blood pressure and risk for hypertension.
  • Potassium intake and physical activity correlate directly with lower blood pressure.
  • Unsaturated fat, protein, magnesium, and dietary fiber may reduce risk for hypertension.
  • Hypertensive study participants who combine antihypertensive medications with a plant-based diet lower blood pressure by an average of 5/2 mm Hg in just six weeks.

The meta-analysis shows a foundation of fruits, vegetables, whole grains, and legumes helps study participants keep blood pressure in a healthful range of less than 120/80 mm Hg. For individuals between 40 and 70 years, a 20 mm Hg increase in systolic BP, starting at just 125/75 mm Hg, doubles the risk for heart disease. For comparison, smoking has a similar effect. The Centers for Disease Control and Prevention reports more than 67 million Americans, or one in three  adults, have high blood pressure, a risk factor for heart attack, stroke, and kidney disease. The American Heart Association reports high blood pressure is up 27 percent in children and accounts for 350,000 preventable deaths each year.