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Postprandial kinetics of dietary amino acids are the main determinant of their metabolism after soy or milk protein ingestion in humans
- Source :
- Scopus-Elsevier
-
Abstract
- Soy proteins have been shown to result in lower postprandial nitrogen retention than milk proteins, but the mechanisms underlying these differences have not been elucidated. To investigate this question, we measured the postprandial kinetics of the appearance of individual (15)N-amino acids in the serum of healthy adults after the ingestion of either (15)N-soy (n = 8) or (15)N-milk proteins (n = 8) in a mixed single meal (46 kJ/kg). The kinetics of total and dietary amino acids (AA) in the peripheral circulation were characterized by an earlier and higher peak after soy protein ingestion. Dietary AA levels peaked at 2.5 h in the soy group vs. 3.9 h in the milk group (P < 0.02). This time interval difference between groups was associated with a faster transfer of dietary N into urea in the soy group (peak at 3 vs. 4.75 h in the milk group, P < 0.005) and a higher level of incorporation into the serum protein pool from 3 to 8 h after the soy meal. The dietary AA pattern in the peripheral blood closely reflected the dietary protein AA pattern. Postprandial glucose, insulin, and glucagon levels and profiles did not differ between groups. Soy AA were digested more rapidly and were directed toward both deamination pathways and liver protein synthesis more than milk AA. We conclude that differences in the metabolic postprandial fates of soy and milk proteins are due mainly to differences in digestion kinetics; however, the AA composition of dietary proteins may also play a role.
- Subjects :
- Adult
Male
Food Handling
medicine.medical_treatment
Medicine (miscellaneous)
Body Mass Index
medicine
Humans
Ingestion
Food science
Amino Acids
Soy protein
chemistry.chemical_classification
Meal
Nutrition and Dietetics
Chemistry
Insulin
Body Weight
Metabolism
Milk Proteins
Postprandial Period
Body Height
Diet
Amino acid
Postprandial
Soybean Proteins
Female
Digestion
Food Analysis
Subjects
Details
- Database :
- OpenAIRE
- Journal :
- Scopus-Elsevier
- Accession number :
- edsair.doi.dedup.....36a4fbd03b2ebb4a573c3ee39f00419a