Both sodium reduction and the DASH (Dietary Approaches to Stop Hypertension) diet, which is rich in fruits, vegetables, and low-fat dairy products, and low in saturated fat and cholesterol, lowered blood pressure. This study investigated the separate and combined effects of these two dietary strategies.
412 patients with prehypertension or stage 1 hypertension, and not using high blood pressure medication, were randomized to be on a control diet or the DASH diet. On either diet, the patients were fed three different sodium levels, 1,150 milligrams, 2,300 milligrams, and 3,450 milligrams. The DASH diet’s effect on systolic high blood pressure relative to the control diet was -4.5, -4.3, -4.7 and -10.6 mm Hg. Those who were fed the lowest sodium (1,150 milligrams a day) and were also on the DASH diet, had the greatest reduction of blood pressure: -5.3, -7.5, -9.7,and -20.8 mm Hg. The 20.8 mm Hg reduction was in the group whose starting systolic blood pressure in the study was >150 mm Hg.