Background
Although the DASH (Dietary Approaches to Stop Hypertension) diet has been shown to lower blood pressure (BP) in short-term feeding studies, it has not been shown to lower BP among free-living individuals, nor has it been shown to alter cardiovascular biomarkers of risk.
Objective
To compare the DASH diet alone or combined with a weight management program with usual diet controls among participants with prehypertension or stage 1 hypertension (systolic BP, 130–159 mm Hg; or diastolic BP, 85–99 mm Hg).
Design and Setting
Randomized, controlled trial in a tertiary care medical center with assessments at baseline and 4 months. Enrollment began October 29, 2003, and ended July 28, 2008.
Participants
Overweight or obese, unmedicated outpatients with high BP (N = 144).
Interventions
Usual diet controls, DASH diet alone, and DASH diet plus weight management.
Outcome Measures
The main outcome measure is BP measured in the clinic and by ambulatory BP monitoring. Secondary outcomes included pulse wave velocity, flow-mediated dilation of the brachial artery, baroreflex sensitivity, and left ventricular mass.
Results
Clinic-measured BP was reduced by 16.1/9.9 mm Hg (DASH plus weight management); 11.2/7.5 mm (DASH alone); and 3.4/3.8 mm (usual diet controls) (P < .001). A similar pattern was observed for ambulatory BP (P < .05). Greater improvement was noted for DASH plus weight management compared with DASH alone for pulse wave velocity, baroreflex sensitivity, and left ventricular mass (all P < .05).
Conclusion
For overweight or obese persons with above-normal BP, the addition of exercise and weight loss to the DASH diet resulted in even larger BP reductions, greater improvements in vascular and autonomic function, and reduced left ventricular mass. Key words: Hypertension, Exercise, DASH diet, Blood pressure, Left ventricular mass