Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-28T21:33:15.606Z Has data issue: false hasContentIssue false
  • English
  • Français

Beetroot enriched bread consumption reduces blood pressure in normotensive males: a pilot study

Published online by Cambridge University Press:  14 October 2011

D. A. Hobbs ,
T. W. George ,
L. Methven  and
J. A. Lovegrove
D. A. Hobbs
Affiliation:
Department of Food and Nutritional Sciences, University of Reading, Whiteknights, PO Box 226, Reading, Berks, RG6 6AP, UK Institute for Cardiovascular and Metabolic Research (ICMR), University of Reading, Whiteknights, PO Box 226, Reading, Berks, RG6 6AP, UK
T. W. George
Affiliation:
Department of Food and Nutritional Sciences, University of Reading, Whiteknights, PO Box 226, Reading, Berks, RG6 6AP, UK Institute for Cardiovascular and Metabolic Research (ICMR), University of Reading, Whiteknights, PO Box 226, Reading, Berks, RG6 6AP, UK
L. Methven
Affiliation:
Department of Food and Nutritional Sciences, University of Reading, Whiteknights, PO Box 226, Reading, Berks, RG6 6AP, UK
J. A. Lovegrove
Affiliation:
Department of Food and Nutritional Sciences, University of Reading, Whiteknights, PO Box 226, Reading, Berks, RG6 6AP, UK Institute for Cardiovascular and Metabolic Research (ICMR), University of Reading, Whiteknights, PO Box 226, Reading, Berks, RG6 6AP, UK
Rights & Permissions [Opens in a new window]

Abstract

An abstract is not available for this content. As you have access to this content, full HTML content is provided on this page. A PDF of this content is also available in through the ‘Save PDF’ action button.
Type
Abstract
Information
Proceedings of the Nutrition Society , Volume 70 , Issue OCE4: Summer Meeting, 4–6 July 2011, 70th Anniversary: From plough through practice to policy , 2011 , E194
Copyright
Copyright © The Authors 2011

High blood pressure (BP) or hypertension (BP>140/90 mmHg) is an independent risk factor for CVD. Individuals with uncontrolled hypertension pose a 3-fold higher risk of developing CVD compared with normotensives(Reference Wang, Lee and Fabsitz1). Vegetables, particularly green leafy and beetroot are abundant in nitrate (NO3−), which after ingestion can be reduced to nitrite (NO2−) by oral bacteria, and further to the vasodilator nitric oxide (NO) endogenously(Reference Lundberg, Weitzberg and Gladwin2). Beetroot juice (500 ml) has been shown to lower systolic BP (SBP) by 10 mmHg in healthy individuals(Reference Webb, Patel and Loukogeorgakis3). A pilot study was designed to investigate the effects of enriching bread with two different varieties of beetroot on 24 h ambulatory BP (ABP).

Fourteen healthy male participants were recruited to a randomly controlled, single blind, cross-over, postprandial test meal study. ABP was measured at baseline, every 15 min for 4 h, followed by every 30 min for 9 h and hourly overnight after consumption of 200 g of two novel bread products enriched with either 100 g white beetroot (5.0 mM NO3−) or 100 g red beetroot (5.6 mM NO3−) and control bread containing no beetroot. White beetroot lack betalains, a group of nitrogenous pigments which are particularly abundant in red beetroot, therefore the differential effects on BP by the elimination of betalains was also demonstrated. Urine samples were collected at baseline, 2, 4 and 24 h. The participants followed a low nitrate and nitrite diet for 48 h prior to and during the study day. A low nitrate and nitrite standard meal was provided for the evening before the study day.

A significant reduction in diastolic BP (DBP) was observed approximately 2–3 h post ingestion, in the order of 19.4 (sem 6.9) and 19.4 (sem 8.5) mmHg (P<0.05) for white and red enriched beetroot bread, respectively. Incremental area under the curve (IAUC) for DBP was significantly lower from baseline to 4 h post ingestion after both beetroot enriched breads (Fig. 1A) and was significantly lower for red beetroot enriched bread for the remaining 24 h (P<0.50). Summation measures for urinary nitrates and nitrites (NOx) were significantly increased from 0 to 2 and 4 h post consumption of beetroot enriched breads (P<0.05) compared with the control bread (Fig. 1B).

Fig. 1. (A) The percentage change in IAUC for DBP from baseline to 4 h after consumption of control bread (no beetroot), white or red beetroot enriched breads (*=P<0.05 v. control) and (B) mean urinary NOx concentration at baseline, 2, 4 and 24 h after consumption of control bread (no beetroot), white or red beetroot enriched bread (*=P<0.05 v. control) (mean se).

In conclusion, this study demonstrated that bread products enriched with white or red beetroot significantly lowered BP and increased urinary NOx with no statistical differences between varieties in healthy males. This data suggests that the beneficial effects of beetroot on BP is likely to be due in part to its high NO3− content and that processing had minimal impact.

References

1.Wang, W, Lee, ET, Fabsitz, RR et al. (2006) Hypertension 47, 403–409.CrossRefGoogle ScholarPubMed
2.Lundberg, JO, Weitzberg, E & Gladwin, MT (2008) Nat Rev Drug Discov 7, 156–167.CrossRefGoogle Scholar
3.Webb, AJ, Patel, N, Loukogeorgakis, S et al. (2008) Hypertension 51, 784–790.CrossRefGoogle Scholar
Figure 0

Fig. 1. (A) The percentage change in IAUC for DBP from baseline to 4 h after consumption of control bread (no beetroot), white or red beetroot enriched breads (*=P<0.05 v. control) and (B) mean urinary NOx concentration at baseline, 2, 4 and 24 h after consumption of control bread (no beetroot), white or red beetroot enriched bread (*=P<0.05 v. control) (mean se).