Amino acid absorption and subsequent muscle protein accretion following graded intakes of whey protein in elderly men.

@article{Pennings2012AminoAA,
  title={Amino acid absorption and subsequent muscle protein accretion following graded intakes of whey protein in elderly men.},
  author={Bart Pennings and Bart B. L. Groen and Anneke de Lange and Annemie P. Gijsen and Antoine H. G. Zorenc and Joan M Senden and Luc J. C. van Loon},
  journal={American journal of physiology. Endocrinology and metabolism},
  year={2012},
  volume={302 8},
  pages={
          E992-9
        }
}
Whey protein ingestion has been shown to effectively stimulate postprandial muscle protein accretion in older adults. However, the impact of the amount of whey protein ingested on protein digestion and absorption kinetics, whole body protein balance, and postprandial muscle protein accretion remains to be established. We aimed to fill this gap by including 33 healthy, older men (73 ± 2 yr) who were randomly assigned to ingest 10, 20, or 35 g of intrinsically l-[1-¹³C]phenylalanine-labeled whey… 

Figures and Tables from this paper

Ingestion of Wheat Protein Increases In Vivo Muscle Protein Synthesis Rates in Healthy Older Men in a Randomized Trial.
TLDR
Ingesting a larger amount of wheat protein substantially increases myofibrillar protein synthesis rates in healthy older men and the postprandial increase in plasma essential amino acid concentrations was greater after ingesting Whey-35 than after WPH-60.
Protein Type, Protein Dose, and Age Modulate Dietary Protein Digestion and Phenylalanine Absorption Kinetics and Plasma Phenylalanine Availability in Humans
TLDR
Protein type, protein dose, and age modulate dietary protein digestion and amino acid absorption kinetics and subsequent postprandial plasma amino acid availability in vivo in humans.
Ingestion of Casein in a Milk Matrix Modulates Dietary Protein Digestion and Absorption Kinetics but Does Not Modulate Postprandial Muscle Protein Synthesis in Older Men.
TLDR
Casein ingestion in a milk matrix delays protein digestion and absorption but does not modulate postprandial muscle protein synthesis when compared to the ingestion of micellar casein only in healthy older men.
The muscle protein synthetic response to the combined ingestion of protein and carbohydrate is not impaired in healthy older men
TLDR
It is concluded that the use of dietary protein-derived amino acids for muscle protein synthesis is not impaired in healthy older men following intake of protein plus carbohydrate.
Carbohydrate co-ingestion with protein does not further augment post-prandial muscle protein accretion in older men
TLDR
This study shows that carbohydrate ingestion may accelerate, but does not further augment post-prandial incorporation of dietary protein derived amino acids into muscle protein in healthy elderly men.
Whey Protein and Muscle Protection
  • Y. Boirie
  • Biology
    Nutrition and Skeletal Muscle
  • 2019
The use of doubly labeled milk protein to measure postprandial muscle protein synthesis rates in vivo in humans.
TLDR
The findings confirm that the postprandial MPS assessed using the primed continuous tracer infusion approach may differ if tracer steady-state conditions in the precursor pools are perturbed.
Leucine co-ingestion augments the muscle protein synthetic response to the ingestion of 15 g protein following resistance exercise in older men.
TLDR
Leucine co-ingestion further augments the post-exercise muscle protein synthetic response to the ingestion of a single 15 g bolus of protein in older men.
...
...

References

SHOWING 1-10 OF 27 REFERENCES
Whey protein stimulates postprandial muscle protein accretion more effectively than do casein and casein hydrolysate in older men.
TLDR
Whey protein stimulates postprandial muscle protein accretion more effectively than do casein and casein hydrolysate in older men, attributed to a combination of whey's faster digestion and absorption kinetics and higher leucine content.
Exercising before protein intake allows for greater use of dietary protein-derived amino acids for de novo muscle protein synthesis in both young and elderly men.
TLDR
Dietary protein digestion and absorption kinetics are not impaired after exercise or at an older age, and exercising before protein intake allows for a greater use of dietary protein-derived amino acids for de novo muscle protein synthesis in both young and elderly men.
Leucine supplementation improves muscle protein synthesis in elderly men independently of hyperaminoacidaemia
TLDR
It is concluded that leucine supplementation during feeding improves muscle protein synthesis in the elderly independently of an overall increase of other amino acids.
Influence of the protein digestion rate on protein turnover in young and elderly subjects.
TLDR
In young men, a "fast" protein may be more beneficial than a "slow" one in elderly subjects, to limit body protein loss, and the preliminary results suggest that added nonprotein energy sources to CAS and WP attenuated the differences in both the protein digestion rate and protein gain.
Ingestion of a protein hydrolysate is accompanied by an accelerated in vivo digestion and absorption rate when compared with its intact protein.
TLDR
Ingestion of a protein hydrolysate accelerates protein digestion and absorption from the gut, augments postprandial amino acid availability, and tends to increase the incorporation rate of dietary amino acids into skeletal muscle protein.
Acute postprandial changes in leucine metabolism as assessed with an intrinsically labeled milk protein.
TLDR
An intrinsically labeled protein is more appropriate than an oral free tracer to study postprandial leucine kinetics under non-steady-state conditions and protein gain after a single whey protein meal results solely from an increased protein synthesis with no modification of protein breakdown.
The Rate of Protein Digestion affects Protein Gain Differently during Aging in Humans
TLDR
During aging, protein gain was greater with WP (rapidly digested protein), and lower with CAS (slowly digesting protein), which suggests that a ‘fast’ protein might be more beneficial than a ’slow’ one to limit protein losses during aging.
The production of intrinsically labeled milk and meat protein is feasible and provides functional tools for human nutrition research.
TLDR
The production of intrinsically L-[1-(13)C]phenylalanine-labeled milk and meat protein is feasible and provides functional tools to investigate in vivo protein digestion and absorption kinetics in humans.
Co-ingestion of a protein hydrolysate and amino acid mixture with carbohydrate improves plasma glucose disposal in patients with type 2 diabetes.
TLDR
The combined ingestion of carbohydrate with a protein hydrolysate and amino acid mixture significantly increases de novo insulin production in patients with a long-term diagnosis of type 2 diabetes and stimulates plasma glucose disposal and reduces postprandial glucose concentrations.
Human Muscle Protein Synthesis is Modulated by Extracellular, Not Intramuscular Amino Acid Availability: A Dose‐Response Study
TLDR
It is concluded that the rates of synthesis of all classes of muscle proteins are acutely regulated by the blood [EAA] over their normal diurnal range, but become saturated at high concentrations.
...
...