Specific Collagen Peptides Improve Bone Mineral Density and Bone Markers in Postmenopausal Women-A Randomized Controlled Study

König D, Oesser S, Scharla S, Zdzieblik D, Gollhofer A · Nutrients

A structural outcome in bone, not cartilage, and both co-primary endpoints separated: spine T-score rose +0.1 on collagen against -0.03 on control (p=0.030) and femoral neck +0.09 against -0.01 (p=0.003), by ANCOVA, surviving a Bonferroni-Holm correction, with effect sizes of 0.47 and 0.50. Twelve months, DXA-measured, 131 women. The bone markers carry less: P1NP rose within the collagen group (p=0.007) and CTX-1 within the control group (p=0.011), but each was tested only against its own baseline by paired t-test, never between groups — and the control group's P1NP was the higher of the two both at entry and at twelve months.

Population

Postmenopausal women with primary age-related reduction in bone mineral density (spine T-score -2.4, femoral neck -1.4)

Intervention

5 g specific collagen peptides daily for 12 months

Comparator

5 g maltodextrin

Limitations

The conflict declaration states all five authors have none, while the acknowledgements state that part of the study was financed by GELITA AG and co-author Oesser is at the GELITA-linked Collagen Research Institute in Kiel. Randomisation left the collagen arm with significantly worse spine density at baseline (-2.5 against -2.3, p=0.005) and a higher BMI (p=0.016), which is why the analysis is ANCOVA rather than a plain comparison. 102 of 131 completed and the missing twelve-month values were filled in by linear-trend imputation before the intention-to-treat analysis. Both groups were encouraged to take calcium and vitamin D, and that intake was neither prescribed nor recorded. Bone density is not cartilage, and the result should not be transferred to a joint claim.