The Claim

The solubility of casein protein powders (5% for micellar casein, 53% for calcium caseinate, 99% for cross-linked sodium caseinate) is strongly correlated with their post-prandial amino acid absorption kinetics, indicating that solubility is a key determinant of digestion rate.

Source: Casein Protein Processing Strongly Modulates Post-Prandial Plasma Amino Acid Responses In Vivo in Humans

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
80score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Correlation
1 study reviewed
In plain English

Different types of casein protein powders dissolve in water to different degrees, and the amount that dissolves directly affects how quickly amino acids enter the bloodstream after consumption.

See the scientific wording

The solubility of casein protein powders (5% for micellar casein, 53% for calcium caseinate, 99% for cross-linked sodium caseinate) strongly correlates with their post-prandial amino acid absorption kinetics, suggesting solubility is a key determinant of digestion rate.

Why this might work

When protein powder dissolves easily in water, it stays mixed in the stomach instead of forming a thick clot, so it moves faster into the small intestine where enzymes break it down into amino acids that enter the blood. When protein powder doesn't dissolve well, it forms a dense clot in the stomach that takes longer to break down and empty, slowing down amino acid absorption.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: Casein Protein Processing Strongly Modulates Post-Prandial Plasma Amino Acid Responses In Vivo in Humans

    The study found that when people drank protein powders that dissolve better in water, their bodies absorbed the amino acids faster and more completely. The most soluble powder (cross-linked sodium caseinate) worked best, supporting the idea that how well the protein dissolves affects how quickly your body uses it.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.