Abstract
In a previous study, we revealed that a commercially available product of dietary supplement containing a chicken comb extract (CCE), which is rich in hyaluronan, not only relieves joint pain and other symptoms, but also potentially improves the balance of type II collagen degradation/synthesis in patients with knee osteoarthritis. Since soccer is one of the sports most likely to cause knee osteoarthritis (OA), we evaluated the effect of a CCE-containing supplement on cartilage and bone metabolism in athletes. Fourteen and 15 subjects (all midfielders) were randomly assigned to receive the test product (test group) and the dummy placebo containing only vehicle (placebo group), respectively, for 12 weeks. The daily oral intake of the CCE-containing test product clearly decreased the urinary levels of both C-terminal crosslinked telopeptides of cartilage-specific type II collagen (CTX-II) as a type II collagen degradation marker and the N-terminal telopeptides of bone-specific type I collagen (NTx) as a marker of bone resorption at 12 weeks after the initiation of the intervention. By contrast, no significant reduction was detected in the placebo group at any timepoint during the intervention. These observations indicate that the test product is effective in inhibiting, not only cartilage degradation, but also bone remodeling. Thus, the CCE-containing supplement may be useful for the management of joint health in athletes.