Single dose administration of dietary inorganic
nitrate acutely reduces blood pressure (BP) in normotensive healthy volunteers, via bioconversion to the
vasodilator nitric oxide. We assessed whether dietary
nitrate might provide sustained BP lowering in patients with
hypertension. We randomly assigned 68 patients with
hypertension in a double-blind, placebo-controlled clinical trial to receive daily dietary supplementation for 4 weeks with either dietary
nitrate (250 mL daily, as beetroot juice) or a placebo (250 mL daily, as
nitrate-free beetroot juice) after a 2-week run-in period and followed by a 2-week washout. We performed stratified randomization of
drug-naive (n=34) and treated (n=34) patients with
hypertension aged 18 to 85 years. The primary end point was change in clinic, ambulatory, and home BP compared with placebo. Daily supplementation with dietary
nitrate was associated with reduction in BP measured by 3 different methods. Mean (95% confidence interval) reduction in clinic BP was 7.7/2.4 mm Hg (3.6-11.8/0.0-4.9, P<0.001 and P=0.050). Twenty-four-hour ambulatory BP was reduced by 7.7/5.2 mm Hg (4.1-11.2/2.7-7.7, P<0.001 for both). Home BP was reduced by 8.1/3.8 mm Hg (3.8-12.4/0.7-6.9, P<0.001 and P<0.01) with no evidence of tachyphylaxis over the 4-week intervention period. Endothelial function improved by ≈20% (P<0.001), and arterial stiffness was reduced by 0.59 m/s (0.24-0.93; P<0.01) after dietary
nitrate consumption with no change after placebo. The intervention was well tolerated. This is the first evidence of durable BP reduction with dietary
nitrate supplementation in a relevant patient group. These findings suggest a role for dietary
nitrate as an affordable, readily-available, adjunctive treatment in the management of patients with
hypertension (funded by The British Heart Foundation).
CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT01405898.