Glucosamine sulphate is a sulphur-containing amino sugar that occurs naturally in connective tissue and cartilage. It stimulates the cells that are involved in the production of new bone and cartilage and therefore has a role in maintaining the mobility, strength and integrity of joint structures.

The effects of oral glucosamine supplementation on knee pain were recently examined in a trial at the University of Western Australia. The study involved randomly supplementing 46 subjects with either glucosamine or placebo over a 12 week period. During this time changes in knee pain and function were assessed 4 times using both clinical and functional tests and participant subjective evaluations.

The tests carried out in the study involved joint line palpation, a "duck walk" over a distance of 3 metres, a repeated stair climb (walking pace) and the completion of two questionnaires - the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Knee Pain Scale (KPS).

The results of the clinical and functional tests showed improvement over the 12-week period but without any significant difference between the two groups. The results of the questionnaires also showed improvement with time, but the glucosamine group was found to have significantly better KOOS quality of life scores at the third (after 8 weeks) and final (after 12 weeks) testing sessions, and lower KPS scores at week eight, when compared to the placebo group.

The results of the participant subjective evaluations suggested a significant difference between the two groups with favourable results for glucosamine supplementation. 21 of the 24 subjects (88%) in the glucosamine group reported improvement in their knee pain compared with only 3 out of 22 subjects (17%) in the placebo group.

In conclusion the authors suggest that taking a glucosamine supplement may reduce pain and improve function in persons who experience regular knee pain, possibly caused by previous cartilage damage or osteoarthritis.

Br J Sports Med 2003 Feb; 37(1):45-9; discussion 49