Siervo, M., Oggioni, C., Jakovljevic, D.G. et al. (9 more authors) (2016) Dietary nitrate does not affect physical activity outcomes in health older adults in a randomized, crossover trial. Nutrition Research, 36 (12). pp. 1361-1369. ISSN 0271-5317
Abstract
Although dietary nitrate (NO3−) ingestion appears to enhance exercise capacity and performance in young individuals, inconclusive findings have been reported in older people. Therefore, we conducted a double-blind, crossover randomized clinical trial using beetroot juice in older healthy participants, who were classified as normal weight and overweight. We tested whether consumption of beetroot juice (a rich source of NO3−) for 1 week would increase nitric oxide bioavailability via the nonenzymatic pathway and enhance (1) exercise capacity during an incremental exercise test, (2) physical capability, and (3) free-living physical activity. Twenty nonsmoking, healthy participants between 60 and 75 years of age and with a body mass index of 20.0 to 29.9 kg/m2 were included. Presupplementation and postsupplementation resting, submaximal, maximal, and recovery gas exchanges were measured. Physical capability was measured by hand-grip strength, time-up-and-go, repeated chair rising test, and 10-m walking speed. Free-living physical activity was assessed by triaxal accelerometry. Changes in urinary and plasma NO3− concentrations were measured by gas chromatography–mass spectrometry. Nineteen participants (male-to-female ratio, 9:10) completed the study. Beetroot juice increased significantly both plasma and urinary NO3− concentrations (P < .001) when compared with placebo. Beetroot juice did not influence resting or submaximal and maximal oxygen consumption during the incremental exercise test. In addition, measures of physical capability and physical activity levels measured in free-living conditions were not modified by beetroot juice ingestion. The positive effects of beetroot juice ingestion on exercise performance seen in young individuals were not replicated in healthy, older adults. Whether aging represents a modifier of the effects of dietary NO3− on muscular performance is not known, and mechanistic studies and larger trials are needed to test this hypothesis.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2016 Elsevier Inc. This is an author produced version of a paper subsequently published in Nutrition Research. Uploaded in accordance with the publisher's self-archiving policy. Article available under the terms of the CC-BY-NC-ND licence (https://creativecommons.org/licenses/by-nc-nd/4.0/) |
Keywords: | Inorganic nitrate; Nitric oxide; Exercise; Oxygen consumption; Aging |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Medicine, Dentistry and Health (Sheffield) > The Medical School (Sheffield) > Division of Genomic Medicine (Sheffield) > Department of Oncology and Metabolism (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 17 Jan 2017 11:33 |
Last Modified: | 14 Nov 2017 01:38 |
Published Version: | https://doi.org/10.1016/j.nutres.2016.11.004 |
Status: | Published |
Publisher: | Elsevier |
Refereed: | Yes |
Identification Number: | 10.1016/j.nutres.2016.11.004 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:109829 |