Dose-dependent changes in the levels of free and peptide forms of hydroxyproline in human plasma after collagen hydrolysate ingestion.
Level 4 - case-series / case-control
Uncontrolled small human pharmacokinetic dose-escalation study (n=4).
PubMed 24767063 · doi:10.1016/j.foodchem.2014.02.091
What was done
Four healthy volunteers ingested three different doses of collagen hydrolysate (30.8, 153.8, and 384.6 mg per kg body weight) to examine dose-dependent changes in plasma concentrations of free and peptide-bound hydroxyproline (Hyp).
What was found
Average plasma concentrations of Hyp-containing peptides increased dose-dependently, reaching maximum levels of 6.43, 20.17, and 32.84 nmol/ml after the 30.8, 153.8, and 384.6 mg/kg doses, respectively. Ingestion of 153.8 mg/kg or more significantly increased the average concentrations of both free and peptide forms of Hyp. The Hyp absorption limit was not reached at the highest tested dose of 384.6 mg/kg.
Why it matters
This study provides human pharmacokinetic data on the bioavailability and dose-dependent absorption of circulating hydroxyproline peptides following oral collagen hydrolysate ingestion.
Limits
The sample size is extremely small (n=4), and participant demographics or testing intervals are not detailed in the abstract. The study measured only acute blood concentrations without evaluating functional or clinical health outcomes.
Cited by
- supports Circulating hydroxyproline levels increase after ingesting collagen, but ingested hydroxyproline is not directly incorporated as a precursor into newly synthesized endogenous collagen.