Background: Although the DASH (Dietary Approaches to Stop Hypertension) diet has been shown to lower blood pressure (BP) in short-term feeding studies, it had not been shown to lower BP among free-living individuals, nor had 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 [measure of vascular function], baroreflex sensitivity [measure of autonomic function], and left ventricular mass [increases with elevated BP; measure of heart failure].
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.
Clinical Trial Registration: clinicaltrials.gov Identifier: NCT00571844
Source: Archives of Internal Medicine, Jan 25, 2010;170(2):pp126-35. PMID: 20101007, by Blumenthal JA, Babyak MA, Hinderliter A, Watkins LL, Craighead L, Lin PH, Caccia C, Johnson J, Waugh R, Sherwood A. Departments of Psychiatry & Behavioral Sciences and Medicine, Duke University Medical Center, Durham, North Carolina; Department of Medicine, University of North Carolina at Chapel Hill; Department of Psychology, Emory University, Atlanta, Georgia, USA. [E-mail: Blume003@mc.duke.edu]