SynthesisThe Journal of nutrition2020
Protein Type, Protein Dose, and Age Modulate Dietary Protein Digestion and Phenylalanine Absorption Kinetics and Plasma Phenylalanine Availability in Humans.
Synthesis in The Journal of nutrition, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to 12 registered trials, which are not on this map. Cited by 65 papers, 4 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Dietary Strategies to Promote Muscle Protein Anabolism in the Elderly
The Effect of Immobilization on Myocellular Characteristics in Healthy, Young Males
Protein Ingestion Prior to Sleep as a Dietary Strategy to Improve Post-exercise, Overnight Recovery.
Overnight Protein Supply as a Dietary Strategy to Improve Muscle Mass in Elderly.
The Impact of Dietary Nitrate Ingestion on Muscle Protein Synthesis in Elderly Type II Diabetics
Impact of Carbohydrate Co-ingestion on the Post-prandial Anabolic Response of Protein in Young and Elderly Men
Post-exercise Recovery After Dietary Protein Ingestion in Healthy Young Men
The Effect of Neuromuscular Electrical Stimulation on Post-prandial Muscle Protein Accretion in Healthy Elderly Men
Impact of Fat Co-ingestion With Protein on the Post-prandial Anabolic Response in Elderly Men (Pro-Fat Study)
The Manipulation of Dietary Protein Intake on the Anabolic Response in Healthy Young Men
The Impact of Habitual Dietary Protein Intake on the Anabolic Response in Elderly Men
Cold Water Immersion as a Strategy to Promote Post-exercise Recovery in Healthy Young Men
Who cites it
65 citing papers in PubMed, 4 syntheses or guidelines pooled it, 112 citations in OpenAlex.
- Pooled it
- Association of postprandial postexercise muscle protein synthesis rates with dietary leucine: A systematic review.Physiological reports · 2023Pooled it
- Effects of Insect Consumption on Human Health: A Systematic Review of Human Studies.Nutrients · 2023Pooled it
- Effects of Milk Protein in Resistance Training-Induced Lean Mass Gains for Older Adults Aged ≥ 60 y: A Systematic Review and Meta-Analysis.Nutrients · 2021Pooled it
- Differences in amino acid digestibility between young and older adults: a randomized crossover study using the dual tracer method.The American journal of clinical nutrition · 2026Trial
- Trial
- Oral Multienzyme Supplementation Alters Postprandial Plasma Nutrient Concentrations after a Mixed Meal in Healthy Middle-Aged and Older Adults: A Randomized, Double-Blind, Placebo-Controlled, Crossover Trial.The Journal of nutrition · 2026Trial
- Effects ofNutrients · 2026Trial
- Ingestion of 20 g Whey or Canola Protein Does Not Further Increase Muscle Protein Synthesis Rates During Recovery From Resistance Exercise In Healthy, Young Females.The Journal of nutrition · 2025Trial
- Evaluation of processing of canola protein isolate on postprandial plasma amino acid profiles in healthy, young females.Amino acids · 2025Trial
- Acute Effects of Oral Microbial Protease Co-ingestion with Whey Protein on Postprandial Plasma Amino Acid Concentrations, Appetite, and Satiety in Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled, Crossover Clinical Trial.The Journal of nutrition · 2025Trial
- Protein Substitute Absorption: A Randomised Controlled Trial Comparing CGMP vs. Amino Acids vs. Micellar Casein in Healthy Volunteers.Nutrients · 2025Trial
- Effect of 3 Different Daily Protein Intakes in a 2-Meal Eating Pattern on Protein Turnover in Middle Age and Older Adults: A Randomized Controlled Trial.The Journal of nutrition · 2025Trial
- High-Moisture Extrusion of a Dietary Protein Blend Impairs In Vitro Digestion and Delays In Vivo Postprandial Plasma Amino Acid Availability in Humans.The Journal of nutrition · 2024Trial
- Ingestion of a variety of non-animal-derived dietary protein sources results in diverse postprandial plasma amino acid responses which differ between young and older adults.The British journal of nutrition · 2024Trial
- Acute Microbial Protease Supplementation Increases Net Postprandial Plasma Amino Acid Concentrations After Pea Protein Ingestion in Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled Trial.The Journal of nutrition · 2024Trial
- Short-term disuse does not affect postabsorptive or postprandial muscle protein fractional breakdown rates.Journal of cachexia, sarcopenia and muscle · 2023Trial
- Pre-sleep Protein Ingestion Increases Mitochondrial Protein Synthesis Rates During Overnight Recovery from Endurance Exercise: A Randomized Controlled Trial.Sports medicine (Auckland, N.Z.) · 2023Trial
- Vegan and Omnivorous High Protein Diets Support Comparable Daily Myofibrillar Protein Synthesis Rates and Skeletal Muscle Hypertrophy in Young Adults.The Journal of nutrition · 2023Trial
- Supplementation with Whey Protein, but Not Pea Protein, Reduces Muscle Damage Following Long-Distance Walking in Older Adults.Nutrients · 2023Trial
5 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
19 authors at 3 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundDietary protein ingestion stimulates muscle protein synthesis by providing amino acids to the muscle. The magnitude and duration of the postprandial increase in muscle protein synthesis rates are largely determined by dietary protein digestion and amino acid absorption kinetics.
objectiveWe assessed the impact of protein type, protein dose, and age on dietary protein digestion and amino acid absorption kinetics in vivo in humans.
methodsWe included data from 18 randomized controlled trials with a total of 602 participants [age: 53 ± 23 y; BMI (kg/m2): 24.8 ± 3.3] who consumed various quantities of intrinsically l-[1-13C]-phenylalanine-labeled whey (n = 137), casein (n = 393), or milk (n = 72) protein and received intravenous infusions of l-[ring-2H5]-phenylalanine, which allowed us to assess protein digestion and phenylalanine absorption kinetics and the postprandial release of dietary protein-derived phenylalanine into the circulation. The effect of aging on these processes was assessed in a subset of 82 young (aged 22 ± 3 y) and 83 older (aged 71 ± 5 y) individuals.
resultsA total of 50% ± 14% of dietary protein-derived phenylalanine appeared in the circulation over a 5-h postprandial period. Casein ingestion resulted in a smaller (45% ± 11%), whey protein ingestion in an intermediate (57% ± 10%), and milk protein ingestion in a greater (65% ± 13%) fraction of dietary protein-derived phenylalanine appearing in the circulation (P < 0.001). The postprandial availability of dietary protein-derived phenylalanine in the circulation increased with the ingestion of greater protein doses (P < 0.05). Protein digestion and phenylalanine absorption kinetics were attenuated in older when compared with young individuals, with 45% ± 10% vs. 51% ± 14% of dietary protein-derived phenylalanine appearing in the circulation, respectively (P = 0.001).
conclusionsProtein 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. These trials were registered at clinicaltrials.gov as NCT00557388, NCT00936039, NCT00991523, NCT01317511, NCT01473576, NCT01576848, NCT01578590, NCT01615276, NCT01680146, NCT01820975, NCT01986842, and NCT02596542, and at http://www.trialregister.nl as NTR3638, NTR3885, NTR4060, NTR4429, and NTR4492.
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Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.