Oral administration of (14)C labeled gelatin hydrolysate leads to an accumulation of radioactivity in cartilage of mice (C57/BL)

Oesser S, Adam M, Babel W, Seifert J · The Journal of Nutrition

The load-bearing citation for the claim that ingested collagen reaches cartilage. 95% of the dose was absorbed within 12 h, and tissue distribution matched labelled proline everywhere EXCEPT cartilage, where a pronounced long-lasting accumulation gave more than twice the radioactivity of the proline control. Peptides of 2.5-15 kDa were detected intact after intestinal passage.

Population

C57/BL mice given intragastric [14C]-labelled gelatin hydrolysate, plasma and tissue radioactivity followed for 192 h

Intervention

[14C] gelatin hydrolysate

Comparator

[14C] proline

Limitations

Mice, not humans, and never independently replicated in 26 years despite enormous commercial incentive. Radioactivity is not intact peptide — once 14C-labelled amino acids enter the general pool the label reports carbon location, so cartilage's slow matrix turnover simply trapping label is an equally parsimonious reading. Author Oesser is at the Collagen Research Institute, Kiel, the Gelita-linked research arm.