Randomized, double-blind, four-arm pilot study on the effects of chicken essence and type II collagen hydrolysate on joint, bone, and muscle functions

Chen CC, Chang SS, Chang CH, Hu CC, Nakao Y, Yong SM, Ow MYL, Lim CJ, Shim EK, Shih HN · Nutrition Journal

WOMAC, the endpoint the trial was sized on, was null: all four groups improved and none separated (p=0.848). One of the six pairwise pain comparisons reached significance — hydrolyzed type II collagen against placebo on the VAS at day 14, -1.3 (95% CI -2.51 to -0.13, p=0.021) — and part of that gap is the placebo group's pain rising 1.0 point from baseline to day 7. The other five comparisons return p values from 0.687 upward. Fat-free mass and grip strength did not differ among the groups at 24 weeks either; the chicken-essence advantages over glucosamine and placebo appear only after the analysis was re-run adjusted for covariates selected because an initial analysis found them significant, and the grip-strength difference is against glucosamine alone. Bone mass and SF-36 scores did not separate.

Population

Adults with Kellgren-Lawrence grade 1-3 knee osteoarthritis, joint pain >=3 months, WOMAC > 6

Intervention

2 g hydrolyzed type II collagen, or chicken essence with 2 g added hydrolyzed type II collagen, daily for 24 weeks alongside resistance training

Comparator

1.5 g glucosamine HCl and placebo (four arms)

Limitations

Five of the ten authors are employees of Suntory Beverage and Food Asia, which funded the study and makes the tested product. Described by its authors as a pilot; retrospectively registered (NCT04483024); 160 randomised and 151 analysed. All groups also did resistance training, which plausibly drove the shared improvement, and over half the participants had Kellgren-Lawrence grade 1 disease.