Dairy and Dairy Alternative Supplementation Increase Integrated Myofibrillar Protein Synthesis Rates, and Are Further Increased when Combined with Walking in Healthy Older Women.
J Nutr
; 152(1): 68-77, 2022 01 11.
Article
em En
| MEDLINE
| ID: mdl-34610129
ABSTRACT
BACKGROUND:
The stimulation of muscle protein synthesis (MPS) by dietary protein is reduced with age. We hypothesized that twice-daily milk consumption would increase daily rates of MPS in older women relative to a nondairy milk alternative and that MPS would be enhanced by increased physical activity (PA).METHODS:
Twenty-two older women were randomly assigned to 1 of 3 experimental groups whole milk (WM; n = 7, 69 ± 3 y), skim milk (SM; n = 7, 68 ± 3 y), or an almond beverage (AB; n = 8, 63 ± 3 y). From days 1 to 3, participants consumed a standardized diet (0.8 g proteinâ kg-1 â d-1) and performed their habitual PA (Phase 1, Baseline). From days 4 to 6, participants continued to perform habitual PA, but consumed an intervention diet consisting of the standardized diet plus twice-daily beverages (250 mL each) of either WM, SM, or AB (Phase 2, Diet Intervention). Finally, from days 7 to 9, the intervention diet was consumed, and PA via daily steps was increased to â¼150% of habitual daily steps (Phase 3, Intervention Diet + PA). Deuterated water was ingested throughout the study, and muscle biopsies were taken on days 1, 4, 7, and 10 to measure MPS.RESULTS:
Daily MPS rates were not differentially affected by the addition of WM, SM, or AB to a standardized diet. There was, however, a significant effect of study phase such that, when collapsed across conditions, MPS was significantly increased from Phase 1 to Phase 2 (+0.133%â d-1; 95% CI 0.035-0.231; P < 0.01) and further increased from Phase 2 to Phase 3 (+0.156%â d-1; 95% CI 0.063-0.250; P < 0.01).CONCLUSIONS:
Increasing PA through walking was sufficient to increase daily MPS rates in older women, irrespective of whether dietary protein intake is increased beyond the recommended intake of 0.8 gâ kg-1 â d-1. The trial was registered at clinicaltrials.gov as NCT04981652.Palavras-chave
Texto completo:
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Bases de dados:
MEDLINE
Assunto principal:
Proteínas Alimentares
/
Treinamento Resistido
Tipo de estudo:
Clinical_trials
Limite:
Aged
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Female
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Humans
Idioma:
En
Revista:
J Nutr
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Canadá