A Single Dose of Dietary Nitrate Increases Maximal Knee Extensor Angular Velocity and Power in Healthy Older Men and Women
Year: 2019
Type: article
Study designs: Randomized Controlled Trial, Clinical Trial
Abstract: BACKGROUND: Aging results in reductions in maximal muscular strength, speed, and power, which often lead to functional limitations highly predictive of disability, institutionalization, and mortality in elderly adults. This may be partially due to reduced nitric oxide (NO) bioavailability. We, therefore, hypothesized that dietary nitrate (NO3-), a source of NO via the NO3- → nitrite (NO2-) → NO enterosalivary pathway, could increase muscle contractile function in older subjects. METHODS: Twelve healthy older (age 71 ± 5 years) men and women were studied using a randomized, double-blind, placebo-controlled, crossover design. After fasting overnight, subjects were tested 2 hours after ingesting beetroot juice containing or devoid of 13.4 ± 1.6 mmol NO3-. Plasma NO3- and NO2- and breath NO were measured periodically, and muscle function was determined using isokinetic dynamometry. RESULTS: N O 3 - ingestion increased (p < .001) plasma NO3-, plasma NO2-, and breath NO by 1,051% ± 433%, 138% ± 149%, and 111% ± 115%, respectively. Maximal velocity of knee extension increased (p < .01) by 10.9% ± 12.1%. Maximal knee extensor power increased (p < .05) by 4.4% ± 7.8%. CONCLUSIONS: Acute dietary NO3- intake improves maximal knee extensor angular velocity and power in older individuals. These findings may have important implications for this population, in whom diminished muscle function can lead to functional limitations, dependence, and even premature death.
Language: English
Subfield: Cell Biology
Domain: Life Sciences
Open Access status: bronze
Funders: Ministry of Education, India, National Institutes of Health, National Institute on Aging, National Heart, Lung, and Blood Institute, National Institute of Diabetes and Digestive and Kidney Diseases, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Center for Advancing Translational Sciences
Awards: Longitudinal Assessment of Skeletal Muscle Physiology in Dialysis Patients, G6250015116, G6428621359, Indiana Clinical and Translational Sciences Institute, G9000246291, G9000280919, G9000307091, G9000308271, Washington University Nutrition Obesity Research Center, Washington University Institute of Clinical and Translational Sciences, Indiana Core Center for Clinical Research in Musculoskeletal Health
OpenAlex ID: W2956052777