Consumption of Milk Protein or Whey Protein Results in a Similar Increase in Muscle Protein Synthesis in Middle Aged Men

Nutrients

Cameron J. Mitchell²  Robin A. McGregor³  Randall F. D’Souza²  Eric B. Thorstensen²  James F. Markworth²  Aaron C. Fanning¹  Sally D. Poppitt³ 

[1] Fonterra Research and Development Centre, Palmerston North 4442, New Zealand;Liggins Institute, University of Auckland, Auckland 1142, New Zealand;School of Biological Sciences, University of Auckland, Auckland 1142, New Zealand;

关键词: fractional synthetic rate;    amino acids;    stable isotopes;    milk protein;    whey protein;    muscle;   

DOI  :  10.3390/nu7105420

来源: mdpi

【 摘 要 】

The differential ability of various milk protein fractions to stimulate muscle protein synthesis (MPS) has been previously described, with whey protein generally considered to be superior to other fractions. However, the relative ability of a whole milk protein to stimulate MPS has not been compared to whey. Sixteen healthy middle-aged males ingested either 20 g of milk protein (n = 8) or whey protein (n = 8) while undergoing a primed constant infusion of ring ¹³C₆ phenylalanine. Muscle biopsies were obtained 120 min prior to consumption of the protein and 90 and 210 min afterwards. Resting myofibrillar fractional synthetic rates (FSR) were 0.019% ± 0.009% and 0.021% ± 0.018% h⁻¹ in the milk and whey groups respectively. For the first 90 min after protein ingestion the FSR increased (p < 0.001) to 0.057% ± 0.018% and 0.052% ± 0.024% h⁻¹ in the milk and whey groups respectively with no difference between groups (p = 0.810). FSR returned to baseline in both groups between 90 and 210 min after protein ingestion. Despite evidence of increased rate of digestion and leucine availability following the ingestion of whey protein, there was similar activation of MPS in middle-aged men with either 20 g of milk protein or whey protein.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.