Dietary inorganic nitrate lowers central blood pressure

Background: Dietary inorganic nitrate is reduced to (nitric oxide) NO in the body. Beetroot is a rich source of dietary inorganic nitrate and has been shown to lower brachial blood pressure (BP) by this mechanism. The effect on aortic (central) BP, which may be a better predictor of cardiovascular disease, has not been studied. Objectives: To measure the effect of dietary nitrate in beetroot juice on central BP at both 30 minutes and over a 6 hour period post-beetroot juice consumption. Method: A double-blind, randomised, placebo-controlled crossover trial was performed in nine healthy, normotensive men and women aged between 22 and 45 years. Participants were randomised to receive beetroot juice (6.5-7.3 mmol nitrate) or placebo juice (0.04-0.06 mmol nitrate). Brachial and central BP were measured at baseline, 30 and 60 minutes post-ingestion, and at least hourly for the following 24 hours. Following a washout period, the procedure was repeated within seven days with crossover to the opposite arm of the trial. There were no dietary restrictions during the study. Results: Compared with placebo, beetroot juice lowered central systolic BP at 30 minutes (change in beetroot juice: -2.6±3.4 mmHg vs. change in placebo: 1.8±5.9 mmHg, P=0.045). Beetroot juice also lowered central systolic BP averaged over 6 hours post-ingestion (beetroot: 106±8 mmHg vs. placebo: 111±11 mmHg, P=0.029). Conclusion: Consumption of beetroot juice lowered central BP. Beetroot juice could have a role in CV risk management in the general population, but further research is required to establish its long-term benefits, safety and tolerability.