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Double-blind, placebo-controlled pilot trial of L-Leucine-enriched amino-acid mixtures on body composition and physical performance in men and women aged 65–75 years

Ispoglou, T.; White, H.; Preston, T.; McElhone, S.; McKenna, J.; Hind, K.

Double-blind, placebo-controlled pilot trial of L-Leucine-enriched amino-acid mixtures on body composition and physical performance in men and women aged 65–75 years Thumbnail


Authors

T. Ispoglou

H. White

T. Preston

S. McElhone

J. McKenna

K. Hind



Abstract

Background/Objectives: Adequate protein intake is essential to retaining muscle and maintaining physical function, especially in the elderly, and L-Leucine has received attention as an essential amino acid (EAA) that enhances protein retention. The study’s aim was to compare the efficacy of EAA mixtures on lean tissue mass (LTM) and functional performance (FP) in a healthy elderly population. Subjects/Methods: Thirty-six subjects (65–75 years) volunteered to receive capsules with EAAs (Groups A and B containing 20% and 40% L-Leucine, respectively) or placebo (lactose containing 0% L-Leucine, Group C) for 12 weeks. The daily amount ranged from 11 to 21 g (0.21 g/ kg/day) and was taken in two equal dosages alongside food, morning and evening. Main outcomes measured before and after intervention were LTM and FP (30-s arm-curl test; 30-s chair-stand test (30-CST); 6-min walk test (6-WT); and handgrip strength). Secondary outcomes included dietary intakes and physical activity. Results: Twenty-five subjects (11 male and 14 female) completed the study (Group A, n=8; Group B, n=8; Group C, n=9). Gains associated with medium effect sizes were noted in LTM (Group B, 1.1 ±1.1%, P=0.003) and FP (Group A in 30-CST (11.0±11.5%, P=0.02) and 6-WT (8.8±10.0%, P=0.02); Group B in 6-WT (5.8±6.6%, P=0.03) and a trend in 30-CST (13.2±16.0, P=0.06)). Significant differences between groups were not observed in secondary outcomes. Conclusions: Twice-daily supplementation of EAAs containing 20% or 40% L-Leucine improved aspects of functional status and at the higher level improved LTM. Further work to establish change in a larger sample and palatable supplemental format is now required.

Citation

Ispoglou, T., White, H., Preston, T., McElhone, S., McKenna, J., & Hind, K. (2016). Double-blind, placebo-controlled pilot trial of L-Leucine-enriched amino-acid mixtures on body composition and physical performance in men and women aged 65–75 years. European Journal of Clinical Nutrition, 70(2), 182-188. https://doi.org/10.1038/ejcn.2015.91

Journal Article Type Article
Acceptance Date Apr 17, 2015
Online Publication Date Jun 17, 2015
Publication Date Feb 1, 2016
Deposit Date Sep 5, 2018
Publicly Available Date Sep 13, 2018
Journal European Journal of Clinical Nutrition
Print ISSN 0954-3007
Electronic ISSN 1476-5640
Publisher Springer Nature
Peer Reviewed Peer Reviewed
Volume 70
Issue 2
Pages 182-188
DOI https://doi.org/10.1038/ejcn.2015.91
Public URL https://durham-repository.worktribe.com/output/1315629
Related Public URLs http://eprints.leedsbeckett.ac.uk/1487/

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This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/





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