New Explanation for DASH Diet Success

If your systolic (heart contraction) blood pressure is above 120 mm/hg before you go to bed at night, you have high blood pressure and are at increased risk for heart attacks, strokes and premature death. You can protect yourself from premature death caused by high blood pressure with the DASH diet, exercising, avoiding overweight, and getting adequate amounts of vitamin D.

The DASH diet is based on fruits, vegetables, whole grains, fish, poultry, nuts and legumes, and low-fat dairy. Several studies have shown that the DASH diet lowers high blood pressure as effectively as most blood pressure drugs, prolongs life, and prevents heart attacks and strokes. The most common explanation for this success has been the high potassium, magnesium and fiber content of vegetables. However, a study from Medical University of South Carolina in Charleston (Journal of Human Hypertension, August 2009) shows that the DASH diet lowers blood pressure better than a diet supplemented with extra potassium, magnesium and fiber, so there must be other factors.

Now a study of 4706 men and women aged 40-59 in the United States, the United Kingdom, China, and Japan suggests that glutamic acid, an amino acid that relaxes blood vessels, may explain why a high-vegetable diet treats high blood pressure. (Circulation, August 2009.) A vegetable-based diet has five percent more glutamic acid than a diet rich in meat and prepared foods.

Calories do count; the DASH diet may not lower high blood pressure if you eat too much food. More on the DASH diet