Funded in part by G's Fresh Ltd
Pharmacokinetic Profile of Incremental Oral Doses of Dietary Nitrate in Young and Older Adults: A Crossover Randomized Clinical Trial
Capper TE, Siervo M, Clifford T, Taylor G, Iqbal W, West D, Stevenson EJ
The Journal of nutrition · 19 citations
Review labels
Neutral facts our review recorded about how this study was done. They describe method, never whether we like the result.
How it was studied
- Design
- Randomized controlled trial (indexed by PubMed)
- Studied in
- People
- Main outcome
- Mechanisms only
- Intake measured by
- Food provided by researchers
Who paid for it
- Funding
- Industry funded
- Company
- G's Fresh Ltd
Based on 1 listed funder(s).
Publication
- Published
- 2021-09-30 · J Nutr · vol. 152 · issue 1 · pp. 130–139
- Publisher
- Elsevier BV
- Cited
- 22 citations · more than 82% of similar papers · 1.5× the field average
- References
- 35 works
- Access
- Open access (hybrid journal) · CC-BY
- Research areas
- Salivary Gland Disorders and Functions · Nitric Oxide and Endothelin Effects · Olfactory and Sensory Function Studies
- Keywords
- Nitrite, Nitrate, Saliva, Crossover study, Ingestion, Urine, Animal science, Potassium nitrate, Internal medicine, Repeated measures design, Chemistry, Medicine, Potassium, Biology, Placebo
- MeSH
- humans, beta vulgaris, vegetables, nitrates, nitrites, cross-over studies, aging, blood pressure, aged
7 authors
From GB
- Tess E. CapperQueen's University Belfast; Newcastle University
- Mario SiervoUniversity of Nottingham; Newcastle University
- Tom CliffordLoughborough University; Newcastle University
- Guy TaylorNewcastle University
- Wasim A IqbalNewcastle University
- Daniel J. WestNewcastle University
Abstract
Background
Dietary nitrate consumption can increase concentrations of nitrate and nitrite in blood, saliva, and urine. Whether the change in concentrations is influenced by age is currently unknown.
Objectives
We aimed to measure changes in nitrate and nitrite concentrations in plasma, urine, and saliva and exhaled NO concentrations after single incremental doses of dietary nitrate in young and older healthy adults.
Methods
Twelve young (18-35 y old) and 12 older (60-75 y old) healthy, nonsmoking participants consumed single doses of 100 g, 200 g, 300 g whole beetroot (BR) and 1000 mg potassium nitrate (positive control) ≥7 d apart in a crossover, randomized clinical trial. Plasma nitrate and nitrite concentrations and exhaled NO concentrations were measured over a 5-h period. Salivary nitrate and nitrite concentrations were measured over a 12-h period and urinary nitrate over a 24-h period. Time, intervention, age, and interaction effects were measured with repeated-measures ANOVAs.
Results
Dose-dependent increases were seen in plasma, salivary, and urinary nitrate after BR ingestion (all P ≤ 0.002) but there were no differences between age groups at baseline (all P ≥ 0.56) or postintervention (all P ≥ 0.12). Plasma nitrite concentrations were higher in young than older participants at baseline (P = 0.04) and after consumption of 200 g (P = 0.04; +25.7 nmol/L; 95% CI: 0.97, 50.3 nmol/L) and 300 g BR (P = 0.02; +50.3 nmol/L; 95% CI: 8.57, 92.1 nmol/L). Baseline fractional exhaled NO (FeNO) concentrations were higher in the younger group [P = 0.03; +8.60 parts per billion (ppb); 95% CI: 0.80, 16.3 ppb], and rose significantly over the 5-h period, peaking 5 h after KNO3 consumption (39.4 ± 4.5 ppb; P < 0.001); however, changes in FeNO were not influenced by age (P = 0.276).
Conclusions
BR is a source of bioavailable dietary nitrate in both young and older adults and can effectively raise nitrite and nitrate concentrations. Lower plasma nitrite and FeNO concentrations were found in older subjects, confirming the impact of ageing on NO bioavailability across different systems.This trial was registered at www.isrctn.com as ISRCTN86706442.
Abstract via Europe PMC. Copyright remains with the authors or publisher (CC BY).
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