Dietary nitrate provides sustained blood pressure lowering in hypertensive patients: a randomized, phase 2, double-blind, placebo-controlled study

Single dose administration of dietary inorganic nitrate acutely reduces blood pressure in normotensive healthy volunteers, via bioconversion to the vasodilator nitric oxide. We assessed whether dietary nitrate might provide sustained blood pressure lowering in hypertensive patients.We randomly assigned 68 hypertensive patients in a double-blind, placebo-controlled clinical trial to receive daily dietary supplementation for 4-weeks with either dietary nitrate (250mL daily, as beetroot juice) or a placebo (250mL daily, as nitrate-free beetroot juice) following a 2-week run-in period and followed by a 2-week wash-out. We performed stratified randomization of drug-naïve (n=34) and treated (n=34) hypertensive patients aged 18-85 years. The primary end-point was change in clinic, ambulatory and home blood pressure compared to placebo. Daily supplementation with dietary nitrate was associated with reduction in blood pressure measured by 3 different methods. Mean (95% CI) reduction in clinic blood pressure was 7.7/2.4mmHg (3.6-11-8/0.0-4.9,p<0.001 and p=0.050). 24h ambulatory blood pressure was reduced by 7.7/5.2mmHg (4.1-11.2/2.7-7.7,p<0.001 for both). Home blood pressure was reduced by 8.1/3.8mmHg (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 0.59m/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 blood pressure 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 hypertensive patients.(Funded by The British Heart Foundation, Clinicaltrials.gov: NCT01405898).