Glucosamine and osteoarthritis
Studies have
produced conflicting results possibly explained by a different effect
depending on the level of pain being experienced when the glucosamine was
started. Those with mild to moderate pain at the start of treatment with
1500mg daily seemed to experience a strong painkilling effect whereas those with
severe pain did not benefit
. The same pattern occurred in a study of a combination of glucosamine and
chondroitin when treatment over 6 months benefited those with mild to moderate
OA but not those with severe OA.
Glucosamine may also have a protective effect on the cartilage. An American
study of patients with OA of the knee received either 1500mg of glucosamine or
placebo over 3 years. The treated group showed less joint space narrowing at
the end of the study
. A meta-analysis of several studies confirmed that long-term treatment with a minimum of 1500mg taken for a minimum of 3 years slowed the degenerative process in knee joint cartilage and suggested that it may have a role in prevention.
Arch Int Med 2003;163:1514-1522
Glucosamine seems safe as no serious adverse effects were noted in the
studies. No effect on blood glucose was found in type 2 diabetics.
Given its promise of painkilling effects and possible cartilage protection, a
large American study is underway (Dec 2000) to confirm or refute these
benefits. It is taking longer than expected as it is apparently difficult to
find Americans with painful OA of the knee who are not already taking
glucosamine.
The Minster Practice, Lichfield
