Beetroot supplementation and hypertension

Beetroot supplementation lowers daily systolic blood pressure in older, overweight subjects

A. Jajja a, 1, A. Sutyarjoko a, 1, J. Lara a, K. Rennie b, K. Brandt c, O. Qadir c, M. Siervo a,a Human Nutrition Research Centre, Institute of Cellular Medicine, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, UK b Centre for Lifespan and Chronic Illness Research, University of Hertfordshire, Hatfield Hertfordshire, AL10 9AB c Human Nutrition Research Centre, School of Agriculture, Food & Rural Development, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK

A B S T R A C T

Although inorganic nitrate and beetroot juice supplementation are associated with decreased systolic blood pressure (BP), these results have primarily been obtained from short-term trials that focused on healthy young adults. Therefore, we hypothesized that oral supplementation of beetroot juice concentrate would decrease systolic BP in overweight older participants but that the decline in BP would not be sustained after a 1-week interruption of the beetroot juice supplementation. For 3 weeks, 24 participants were randomized to either the beetroot juice concentrate or blackcurrant juice group, with a 1-week post supplementation phase (week 4). Changes in systolic and diastolic BP were assessed during the supplementation and post supplementation phases. Blood pressure was measured using 3 different methods:
(1) resting clinic BP, (2) 24-hour ambulatory BP monitoring, and (3) home monitoring of daily
resting BP. The first 2 methods were applied at baseline and after weeks 3 and 4. Daily measurements were conducted throughout the study, with 21 subjects completing the study (beetroot/blackcurrant = 10/11; male/female = 12/9; age = 62.0 ± 1.4 years; body mass index = 30.1 ± 1.2 kg/m2). After 3 weeks, beetroot juice supplementation was not associated with significant changes in resting clinic BP or 24-hour ABPM. Conversely, beetroot juice concentrate reduced daily systolic BP after 3 weeks (−7.3 ± 5.9 mm Hg, P = .02); however, the effect was not maintained after the interruption of the supplementation (week 4, 2.8 ± 6.1 mm Hg, P = .09). In overweight older subjects, beetroot juice concentrate supplementation was associated with beneficial effects on daily systolic BP, although the effects were not significant when measured by 24-hour ABPM or resting clinic BP.