A pilot study of 10 patients found that patients who initially had a low glycosaminoglycan (GAG) content of the knee cartilage showed a 19% GAG increase in 6 months while taking Cosamin DS (glucosamine hydrochloride/low molecular weight chondroitin sulfate/manganese ascorbate; Nutramax Laboratories), a joint supplement. GAG is the substance responsible for the cushioning effect and resiliency of cartilage.
The purpose of the study, reported on recently in the American Journal of Roentgenology, was to evaluate using a magnetic resonance imaging (MRI) contrast agent as a method for measuring changes in cartilage in the patients administered Cosamin DS. The uptake of the MRI contrast agent was inversely related to the GAG content of joint cartilage. The researchers concluded that patients with low GAG levels in their cartilage might benefit most from taking the supplement.