The base-line characteristics of the participants are
shown in Table 1. A total of 95 percent of the participants
assigned to the DASH-diet group (198 of 208)
and 94 percent of those assigned to the control-diet
group (192 of 204) completed the study and provided
blood-pressure measurements during each intervention
period. Mean urinary sodium levels averaged
142 mmol per day during the high-sodium period,
107 mmol per day during the intermediate-sodium
period, and 65 mmol per day during the low-sodium
period (Table 2). The levels of urinary potassium,
phosphorus, and urea nitrogen (reflective of the intake
of fruit and vegetables, dairy products, and protein,
respectively) were higher in the DASH-diet group than
in the control-diet group, and were nearly identical
for all three sodium levels. Weight remained stable, as
intended.
The reduction of sodium intake significantly lowered
systolic and diastolic blood pressure in a stepwise
fashion, with both the control diet and the DASH diet
(Fig. 1). The level of dietary sodium had approximately
twice as great an effect on blood pressure with the
control diet as it did with the DASH diet (P