A new study has shown that glucosamine and chondroitin can be as effective as the prescription only painkiller Celecoxib in moderate to severe knee arthritis, so is there something in this old favourite supplement?

Glucosamine and Chondroitin are widely promoted for joint health.  This stems from studies that have shown that at least in the laboratory, these compounds can stimulate the growth of cartilage. 

The argument goes:  Osteoarthritis is a disease where cartilage is lost.  These compounds make cartilage grow.  These compounds will repair knee arthritis. 

The problem is that there is really very little evidence of cartilage repair occurring in living systems.  In one important study for instance, a maximum tolerated dose of glucosamine resulted in peak concentrations in the knee 1000 times lower than the levels needed to stimulate cartilage growth. 

Despite the lack of logic however, Glucosamine remains one of the most popular alternative remedies in the world today. 

Published in Annals of Rheumatic Disease, the new study shows that in knee arthritis, Glucosamine and Condroitin combined are as good as Celecoxib.  Close to 600 patients with moderate to severe knee arthritis pain were allocated at random to receive either Celecoxib or Glucosamine/Chondroitin.  6 months after starting the study, both groups had experienced an average 50% reduction in pain and functional disability scores.  Side-effects were similar in both groups.

The researchers ensured that neither they nor the patients were aware of which medication they were taking and the selection of patients was spread over several centres in three countries.  This should be considered to be a high quality study and was conducted with rigorous attention to good scientific practice however when the researchers measured the pain score experienced over time, the scores reduced at the same rate in both groups.  Given that Celecoxib has a very rapid onset of its effect and that Glucosamine should not based on known properties, this strongly suggests that either glucosamine/chondroitin has a previously undocumented anti-inflammatory action (unlikely and lacking any evidence base) or that both worked as placebos in this case.

What is really interesting here is not that Glucosamine/Chondroitin is as effective as Celecoxib in moderate to severe knee arthritis pain, but that the prescription medication is no better.  Similarly, Glucosamine did not offer any advantage in terms of lower adverse effects.

The main reason for glucosamine remaining firmly in the alternative basket of remedies to date has been a lack of evidence for effectiveness and this study does not really add that much to what we already know.  There have been several studies comparing Celecoxib with other remedies and by and large the results have been fairly consistent - Ayurvedic medicine is also equally effective as Celecoxib for instance.  Studies comparing glucosamine with placebo (fake medication) strongly suggest that they are equally effective. 

Overall the evidence to date strongly suggests that Glucosamine and Chondroitin are NOT beneficial for osteoarthritis at any stage (UK NICE guideline).  This new study simply shows fairly conclusively, that Celecoxib does not seem to be beneficial either.

There are effective treatments for osteoarthritis and patients who would like to do their own research would be well advised to begin by reading the NICE guidelines linked above.

Credits:

Knee Replacement:  Dh@rmãßÔx