Effects of diet and sodium intake on blood pressure: subgroup analysis of the DASH-sodium trial.

BACKGROUND Initial findings from the Dietary Approaches to Stop Hypertension (DASH)-Sodium Trial demonstrated that reduction of sodium intake in two different diets decreased blood pressure in participants with and without hypertension. OBJECTIVE To determine effects on blood pressure of reduced sodium intake and the DASH diet in additional subgroups. DESIGN Randomized feeding study. SETTING Four clinical centers and a coordinating center. PARTICIPANTS 412 adults with untreated systolic blood pressure of 120 to 160 mm Hg and diastolic blood pressure of 80 to 95 mm Hg. INTERVENTION Participants followed the DASH diet or a control (typical U.S.) diet for three consecutive 30-day feeding periods, during which sodium intake (50, 100, and 150 mmol/d at 2100 kcal) varied according to a randomly assigned sequence. Body weight was maintained. MEASUREMENTS Systolic and diastolic blood pressure. RESULTS In all subgroups, the DASH diet and reduced sodium intake were each associated with significant decreases in blood pressure; these two factors combined produced the greatest reductions. Among nonhypertensive participants who received the control diet, lower (vs. higher) sodium intake decreased blood pressure by 7.0/3.8 mm Hg in those older than 45 years of age (P < 0.001) and by 3.7/1.5 mm Hg in those 45 years of age or younger (P < 0.05). CONCLUSION The DASH diet plus reduced sodium intake is recommended to control blood pressure in diverse subgroups.