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

Abstract

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 postsupplementation phase (week 4). Changes in systolic and diastolic BP were assessed during the supplementation and postsupplementation 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/m(2)). 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.

Medium-term effects of dietary nitrate supplementation on systolic and diastolic blood pressure in adults

“…Eight studies had a cross-over study design [7,16, 26]and the remaining five studies adopted a parallel study design [17][18][19]27,28]. Ten studies 129 used a double-blind placebo controlled design [7,16,18,[22][23][24][25][26][27][28].…”

“…Participant characteristics: Five studies recruited young, non-smoking, healthy 135 participants [7,21,23,25,26], three studies were conducted in older healthy subjects [17,19,27],…”

“…The 143 choice of the placebo varied between studies and included sodium chloride solutions (two 144 studies) [21,27], blackcurrant juice (two studies) [7,17], negative control (one study [19] and 145 nitrate-depleted beetroot juice (eight studies) [16,18,[22][23][24][25][26]28]. All solutions were given 146 orally.…”

“…All solutions were given 146 orally. Dietary nitrate intake was controlled in five studies [7,17,19,21,23]. Only one 147 study [25] did not measure plasma, salivary or urinary levels of nitrate and/or nitrite, which 148 was useful to provide information on the adherence to the dietary nitrate supplementation.…”

“…BP measurement: Resting BP was measured in eleven trials [7,[17][18][19][21][22][23][25][26][27][28], five 150 studies measured ambulatory 24-h BP [16][17][18][19]24] and three studies used daily home BP 151 monitoring [16][17][18]. Two studies used all three methods to assess changes in BP [17,18].…”