Effect of a chicken comb extract-containing supplement on subclinical joint pain in collegiate soccer players

Abstract

Abstract. Much of our focus of attention has been on subclinical or subtle joint pain experienced by healthy soccer players. The present study aimed to determine at which joint such subclinical pains are the most prominent, and to examine the pain-relieving effect of a chicken comb extract (CCE)-containing supplement product (test product) on these athletes. A total of 46 collegiate soccer players, consisting of 24 leading and 22 substitute players, belonging to a university soccer team were enrolled for measuring the pains at 4 different joints (ankle, knee, hip and shoulder) using 3 pain subscales of a 100-mm visual analog scale (VAS) ('pain at rest', 'pain on pressing' and 'pain on moving'), and participated in a prospective, double-blind, controlled study. A total of 23 subjects each received the test product (4,800 mg/day) (test group) and placebo (placebo group) for 12 weeks. VAS pain scores of individual joints were evaluated at baseline and following 4, 8 and 12 weeks of the intervention. VAS scores for the 'pain on moving' subscale in 46 enrolled subjects were highest at the ankle joint, and thus the values (abbreviated as 'pain scores') were used as a parameter for efficacy assessment of the test product. Compared to the baseline, the pain scores were significantly decreased for the dominant foot (but not for the non-dominant foot) in the total subpopulation (at week 4; p<0.01) and the leading player subpopulation (at week 4; p<0.01 and at week 12; p<0.05) in the test group (n=19 and 11, respectively). In comparison between the test product and placebo groups, the pain scores were significantly changed for the dominant foot (p<0.05) at week 4 in the total subpopulation and at week 12 in the leading player subpopulation in the test group. Thus, subclinical joint pain is most prominently observed at the ankle joint of the dominant foot in healthy young soccer players and may be improved by the daily intake of the CCE-containing supplement. IntroductionSoccer is one of the sports most likely to cause not only clinically recognized joint injuries but also unrecognized minute ones due to the overuse, repetitive impact and torsional loading of joints. Furthermore, these conditions may be aggravated by several factors, including excessive mechanical loads and repeated microtrauma. These factors are known to enhance articular cartilage damage in soccer players. In this context, there are supporting data demonstrating that the risk of cartilage damage is increased in soccer (and certain other sports), where the repetitive intense impact and torsional loading are subjected to the joints (1), and may be implicated in the chronic development of osteoarthritis (OA) (2-4). Indeed, several clinical studies have demonstrated that the risk of OA is higher in soccer players, as well as in certain other groups of athletes, than in control non-athlete groups (5-11).In the course of health management of collegiate soccer players, we noticed that most players, particularly leading players, suffer from subtle lower extremity...