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Lookup NU author(s): Ellie Hayes, Shatha Alhulaefi, Dr Mario Siervo, Dr Rachel Kimble, Dr Oliver ShannonORCiD
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
Purpose: Dietary nitrate supplementation increases nitric oxide (NO) bioavailability and reduces blood pressure (BP). Inter-individual differences in these responses are suspected but have not been investigated using robust designs, e.g., replicate crossover, and appropriate statistical models. We examined the within-individual consistency of the effects of dietary nitrate supplementation on NO biomarkers and BP, and quantified inter-individual response differences. Methods: Fifteen healthy males visited the laboratory four times. On two visits, participants consumed 140ml nitrate-rich beetroot juice (~14.0mmol nitrate) and, on the other two visits, they consumed 140ml nitrate-depleted beetroot juice (~0.03mmol nitrate). Plasma nitrate and nitrite concentrations were measured 2.5 hours post-supplementation. BP was measured pre- and 2.5 hours post-supplementation. Between-replicate correlations were quantified for the placebo-adjusted post-supplementation plasma nitrate and nitrite concentrations and pre-to-post changes in BP. Within-participant linear mixed models and a meta-analytic approach estimated participant-by-condition treatment response variability. Results: Nitrate-rich beetroot juice supplementation elevated plasma nitrate and nitrite concentrations and reduced systolic (mean:-7mmHg, 95%CI: -3 to -11mmHg) and diastolic (mean:-6mmHg, 95%CI: -2 to -9mmHg) BP versus placebo. The participant-by-condition interaction response variability from the mixed model was ±7mmHg (95%CI: 3 to 9mmHg) for systolic BP and consistent with the treatment effect heterogeneity t=± 7mmHg (95%CI: 5 to 12mmHg) derived from the meta-analytic approach. The between-replicate correlations were moderate-to-large for plasma nitrate, nitrite and systolic BP (r=0.55 to 0.91). Conclusions: The effects of dietary nitrate supplementation on NO biomarkers and systolic BP varied significantly from participant to participant. The causes of this inter-individual variation deserve further investigation. Trial registration: https://clinicaltrials.gov/study/NCT05514821.
Author(s): Hayes E, Alhulaefi S, Siervo M, Whyte E, Kimble R, Matu J, Griffiths A, Sim M, Burleigh M, Easton C, Lolli L, Atkinson G, Mathers JC, Shannon OM
Publication type: Article
Publication status: Published
Journal: European Journal of Nutrition
Year: 2025
Volume: 64
Online publication date: 24/02/2025
Acceptance date: 09/02/2025
Date deposited: 10/02/2025
ISSN (print): 1436-6215
ISSN (electronic): 1436-6207
Publisher: Springer Medizin
URL: https://doi.org/10.1007/s00394-025-03616-x
DOI: 10.1007/s00394-025-03616-x
ePrints DOI: 10.57711/btzf-g896
Data Access Statement: Data described in the manuscript, code book, and analytic code will be made available upon request pending author approval.
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