The effect of casein, hydrolyzed casein, and whey proteins on urinary and postprandial plasma metabolites in overweight and moderately obese human subjects

TY - JOUR

T1 - The effect of casein, hydrolyzed casein, and whey proteins on urinary and postprandial plasma metabolites in overweight and moderately obese human subjects

AU - Schmedes, Mette S

AU - Bendtsen, Line Quist

AU - Gomes, Sisse

AU - Liaset, Bjørn

AU - Holst, Jens Juul

AU - Ritz, Christian

AU - Reitelseder, Søren

AU - Sjödin, Anders Mikael

AU - Astrup, Arne

AU - Young, Jette F

AU - Sundekilde, Ulrik K

AU - Bertram, Hanne C

N1 - CURIS 2018 NEXS 210

PY - 2018/12

Y1 - 2018/12

N2 - BACKGROUND: Casein and whey proteins differ in amino acid composition and absorption rate; however, the absorption rate of casein can be increased to mimic that of whey proteins by exogenous hydrolysis. In view of these compositional differences, we studied the metabolic responses to intake of casein, hydrolyzed casein, and whey proteins in overweight and moderately obese men and women by investigating select urinary and blood plasma metabolites. RESULTS: A total of 21 urinary and 23 plasma metabolites were identified by nuclear magnetic resonance spectroscopy. The postprandial plasma metabolites revealed a significant diet–time interaction for isoleucine (P = 0.001) and tyrosine (P = 0.001). The level of isoleucine and tyrosine peaked 90 min postprandially with a 1.4-fold difference following intake of whey proteins compared with either casein or hydrolyzed casein. A 1.2-fold higher urinary level of lactate was observed after intake of whey proteins compared with intake of intact casein (P < 0.01). CONCLUSION: The plasma metabolites revealed different amino acid profiles reflecting the amino acid composition of casein and whey proteins. Furthermore, the results support that casein hydrolysates neither affect the postprandial amino acid absorption rate nor the amino acid level compared with that of intact casein. The urinary lactate increases following whey protein intake might indicate a higher metabolism of glucogenic amino acids.

AB - BACKGROUND: Casein and whey proteins differ in amino acid composition and absorption rate; however, the absorption rate of casein can be increased to mimic that of whey proteins by exogenous hydrolysis. In view of these compositional differences, we studied the metabolic responses to intake of casein, hydrolyzed casein, and whey proteins in overweight and moderately obese men and women by investigating select urinary and blood plasma metabolites. RESULTS: A total of 21 urinary and 23 plasma metabolites were identified by nuclear magnetic resonance spectroscopy. The postprandial plasma metabolites revealed a significant diet–time interaction for isoleucine (P = 0.001) and tyrosine (P = 0.001). The level of isoleucine and tyrosine peaked 90 min postprandially with a 1.4-fold difference following intake of whey proteins compared with either casein or hydrolyzed casein. A 1.2-fold higher urinary level of lactate was observed after intake of whey proteins compared with intake of intact casein (P < 0.01). CONCLUSION: The plasma metabolites revealed different amino acid profiles reflecting the amino acid composition of casein and whey proteins. Furthermore, the results support that casein hydrolysates neither affect the postprandial amino acid absorption rate nor the amino acid level compared with that of intact casein. The urinary lactate increases following whey protein intake might indicate a higher metabolism of glucogenic amino acids.

KW - Faculty of Science

KW - Dairy proteins

KW - Absorption kinetics

KW - Metabolomics

KW - Postprandial metabolism

U2 - 10.1002/jsfa.9103

DO - 10.1002/jsfa.9103

M3 - Journal article

C2 - 29696654

SN - 0022-5142

VL - 98

SP - 5598

EP - 5605

JO - Journal of the Science of Food and Agriculture

JF - Journal of the Science of Food and Agriculture

IS - 15

ER -