נק' מוניטין:
2,804
Am J Clin Nutr. 2015 Sep 9. pii: ajcn103184. [Epub ahead of print]
Differences in postprandial protein handling after beef vs. milk ingestion during postexercise recovery: a randomized controlled trial.
Burd NA1, Gorissen SH1, van Vliet S1, Snijders T1, van Loon LJ2.
Author information
Protein consumed after resistance exercise increases postexercise muscle protein synthesis rates. To date, dairy protein has been studied extensively, with little known about the capacity of other protein-dense foods to augment postexercise muscle protein synthesis rates.
OBJECTIVE:
We aimed to compare protein digestion and absorption kinetics, postprandial amino acid availability, anabolic signaling, and the subsequent myofibrillar protein synthetic response after the ingestion of milk vs. beef during recovery from resistance-type exercise.
DESIGN:
In crossover trials, 12 healthy young men performed a single bout of resistance exercise. Immediately after cessation of exercise, participants ingested 30 g protein by consuming isonitrogenous amounts of intrinsically L-[1-13C]phenylalanine-labeled beef or milk. Blood and muscle biopsy samples were collected at rest and after exercise during primed continuous infusions of L-[ring-2H5]phenylalanine and L-[ring-3,5-2H2]tyrosine to assess protein digestion and absorption kinetics, plasma amino acid availability, anabolic signaling, and subsequent myofibrillar protein synthesis rates in vivo in young men.
RESULTS:
Beef protein-derived phenylalanine appeared more rapidly in circulation compared with milk ingestion (P < 0.001). The availability of phenylalanine during the 5-h postexercise period tended to be higher after beef (64% ± 3%) compared with milk ingestion (57% ± 3%; P = 0.08). Both beef and milk ingestion were followed by an increase in the phosphorylation of mammalian target of rapamycin complex 1 and 70 kDa S6 protein kinase 1 during postexercise recovery. Milk ingestion increased myofibrillar protein synthesis rates to a greater extent than did beef ingestion during the 0- to 2-h postexercise phase (P = 0.013). However, the increase in myofibrillar protein synthesis rates did not differ between milk and beef ingestion during the entire 0- to 5-h postexercise phase (P = 0.114).
CONCLUSIONS:
Both milk and beef ingestion augment the postexercise myofibrillar protein synthetic response in young men with a stronger stimulation of myofibrillar protein synthesis during the early postprandial stage after milk ingestion. This trial was registered at www.clinicaltrials.gov as NCT01578590.
Differences in postprandial protein handling after beef vs. milk ingestion during postexercise recovery: a randomized controlled trial.
Burd NA1, Gorissen SH1, van Vliet S1, Snijders T1, van Loon LJ2.
Author information
- 1NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, Netherlands.
- 2NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, Netherlands [email protected].
Abstract
BACKGROUND:Protein consumed after resistance exercise increases postexercise muscle protein synthesis rates. To date, dairy protein has been studied extensively, with little known about the capacity of other protein-dense foods to augment postexercise muscle protein synthesis rates.
OBJECTIVE:
We aimed to compare protein digestion and absorption kinetics, postprandial amino acid availability, anabolic signaling, and the subsequent myofibrillar protein synthetic response after the ingestion of milk vs. beef during recovery from resistance-type exercise.
DESIGN:
In crossover trials, 12 healthy young men performed a single bout of resistance exercise. Immediately after cessation of exercise, participants ingested 30 g protein by consuming isonitrogenous amounts of intrinsically L-[1-13C]phenylalanine-labeled beef or milk. Blood and muscle biopsy samples were collected at rest and after exercise during primed continuous infusions of L-[ring-2H5]phenylalanine and L-[ring-3,5-2H2]tyrosine to assess protein digestion and absorption kinetics, plasma amino acid availability, anabolic signaling, and subsequent myofibrillar protein synthesis rates in vivo in young men.
RESULTS:
Beef protein-derived phenylalanine appeared more rapidly in circulation compared with milk ingestion (P < 0.001). The availability of phenylalanine during the 5-h postexercise period tended to be higher after beef (64% ± 3%) compared with milk ingestion (57% ± 3%; P = 0.08). Both beef and milk ingestion were followed by an increase in the phosphorylation of mammalian target of rapamycin complex 1 and 70 kDa S6 protein kinase 1 during postexercise recovery. Milk ingestion increased myofibrillar protein synthesis rates to a greater extent than did beef ingestion during the 0- to 2-h postexercise phase (P = 0.013). However, the increase in myofibrillar protein synthesis rates did not differ between milk and beef ingestion during the entire 0- to 5-h postexercise phase (P = 0.114).
CONCLUSIONS:
Both milk and beef ingestion augment the postexercise myofibrillar protein synthetic response in young men with a stronger stimulation of myofibrillar protein synthesis during the early postprandial stage after milk ingestion. This trial was registered at www.clinicaltrials.gov as NCT01578590.
מה שמעניין זה שהכמויות של החלבון היו זהות והחלב עדיין לקח את הבשר ב25% מבחינת סינטזת החלבון וזה למרות שהחלבון בבשר נספג מהר יותר וטוב יותר ושמדובר היה בכמות שאמורה היתה להביא לסינטזה מקסימלית בכל מקרה.
חבל שזה לא הגיע למובהקות למעט בשעתיים הראשונות כך שיצטרכו לחזור על המחקר בכל מקרה אבל זה מעיד על כך שבחלב יש משהו אחר שמעודד בניית חלבון בשרירים.
זה מגניב כי יש מצב שהתאוריה על הMicro-RNA שהפרה מפרישה לחלב כדי לעודד את העגלים לצמוח נכונה, מה שאומר ששתיה חזירית של חלב באמת עושה סוג של gene therapy וגורמת לשרירים לבטא גנים רגולטורים מבחוץ.
נערך לאחרונה ע"י מנהל:
