Dietary Protein Digestion and Absorption Rates and the Subsequent Postprandial Muscle Protein Synthetic Response Do Not Differ between Young and Elderly Men
Rene Koopman, Stephane Walrand, Milou Beelen, Annemie P Gijsen, Arie K Kies, Yves Boirie, Wim HM Saris, Luc JC van Loon
Journal of Nutrition | OXFORD UNIV PRESS | Published : 2009
Impaired digestion and/or absorption of dietary protein lowers postprandial plasma amino acid availability and, as such, could reduce the postprandial muscle protein synthetic response in the elderly. We aimed to compare in vivo dietary protein digestion and absorption and the subsequent postprandial muscle protein synthetic response between young and elderly men. Ten elderly (64 +/- 1 y) and 10 young (23 +/- 1 y) healthy males consumed a single bolus of 35 g specifically produced, intrinsically l-[1-(13)C]phenylalanine-labeled micellar casein (CAS) protein. Furthermore, primed continuous infusions with l-[ring-(2)H(5)]phenylalanine, l-[1-(13)C]leucine, and l-[ring-(2)H(2)]tyrosine were appl..View full abstract
Supported by a grant from DSM Food Specialties (Delft, The Netherlands).