The Role of the Anabolic Properties of Plant- versus Animal-Based Protein Sources in Supporting Muscle Mass Maintenance: A Critical Review.
Level 5 - mechanism / opinion, no new human data
Narrative review synthesizing mechanistic and comparative evidence without systematic review methodology
PubMed 31394788 · doi:10.3390/nu11081825
What was done
This critical narrative review evaluated literature examining the capacity of plant-based versus animal-based protein sources to maintain skeletal muscle mass, with a particular focus on healthy older adults. The authors assessed physiological mechanisms underlying differences in anabolic response and examined four nutritional strategies to enhance plant protein quality: amino acid fortification, selective plant breeding, blending multiple plant protein sources, and blending plant with animal protein sources.
What was found
The abstract reports no numerical data, pooled effect sizes, or trial counts. Qualitatively, the review notes that plant-based proteins have lower anabolic potential than animal proteins because of inferior digestibility and lower essential amino acid content (notably leucine, lysine, and sulfur amino acids), leading to greater amino acid oxidation over muscle protein synthesis. The authors report that increasing total protein intake or modifying amino acid profiles through fortification or blending improves acute postprandial muscle protein synthesis and longer-term lean mass.
Why it matters
As dietary transitions toward plant-based diets grow, identifying actionable strategies—such as combining complementary plant sources or supplementing key amino acids—is necessary to prevent muscle loss, particularly in older adults susceptible to sarcopenia.
Limits
The abstract describes a narrative critical review rather than a systematic review or meta-analysis; no search strategy, study selection criteria, sample sizes, or quantitative effect estimates are provided. Long-term comparative clinical trial data in frail or sarcopenic older populations remain limited.
Cited by
- supports Plant-based protein sources generally contain lower amounts of bioavailable leucine than animal-based sources.