Phew, that was a short blog. Time for a cuppa and a biccie I think…
Alas, if only it was that simple…
… I get asked a lot about Glucosamine and Chondroitin (G&C) supplements in my clinic. They are, in theory, the building blocks to cartilage and have been widely recommended to reduce the progression of arthritis and cartilage problems. They are also part of a multimillion pound industry and one that funds much of its own research.
In 2010 the British Medical Journal (one of the most reputable of all scientific publications) published this article by Wandel et al. which reached fairly damning conclusions about the use of G&C. They performed a 'Network Meta-Analysis' of the available evidence (up to June 2009) and reviewed the data from the 10 trials that met their inclusion criteria (i.e. that they found were of suitable quality). These trials included a total of 3803 patients with arthritis of the knee or hip.
Their review examined the effect of G&C supplements (including Glucoasmine, Chondroitin and a combination of the two) on pain and joint space narrowing versus placebo. Pain was measured on a 10 point Visual Analog Scale (VAS – this means they were asked to rate their pain from 0 no pain to 10 worst possible pain and note it on a 10cm scale). Joint space narrowing can be seen on X-ray and occurs as a consequence of arthritic change.
They found that the overal difference in pain intensity compared with placebo (on the 10cm VAS) was -0.4 for Glucosamine, -0.3 for Chondroitin and -0.5 for the combination of both. All except 3 trials were funded by the manufacturers of the supplements. For those that were independent the treatment effect was 'minute to zero and by no means clinically relevant.' The changes in minimal joint space width were also all described as minute leading them to conclude,
“Compared with placebo, glucosamine, chondroitin, and their combination do not reduce joint pain or have an impact on narrowing of joint space. Health authorities and health insurers should not cover the costs of these preparations, and new prescriptions to patients who have not received treatment should be discouraged.”
So is it fair to conclude that it's not worth taking G&C supplements?
Well, sort of.
That's the definitive answer you were after! With any aspect of health care the decision is always that of the individual. I won't say, “take this” or, “don't take that”, instead I present the evidence to people to let them make an informed decision. I have seen patients describe dramatic reductions in pain after taking G&C. If the supplement helps your symptoms it may be worth continuing it, especially if stopping taking it causes an increase in pain. I've also seen many report no change and complain about the ongoing cost. 1 or 2 have reported occasional side effects, although these supplements are generally considered fairly safe to take.
Other studies have shown more promising results, with Bruyere et al. (2008) concluding G&C may reduce the need for total joint replacement. It's worth noting however, that in terms of quality of evidence, a systematic review of multiple research papers is usually considered better evidence than an isolated study. A recent meta-analysis of over 1500 cases by Lee et al 2010 did show that G&C may slow progression of osteoarthritis (as measured by X-ray change) although it required taking it daily over 2-3 years.
Sawitzke et al. 2010 found “no clinically important difference in pain or function” when compared to placebo. The Cochrane Review (2009) – Glucosamine Therapy for Treating Osteoarthritis had somewhat mixed results but concluded it may reduce pain and improve function.
The National Institute of Clinical Excellence (NICE) guidelines are seen by many as a reliable opinion on medical matters. Their guidelines on the management of osteoarthritis stated that,
“The use of glucosamine products is not recommended for the treatment of osteoarthritis.”
Prices of G&C vary a great deal, currently Boots Pharmacy has a 2 month supply at £30, meaning a 2-3 year course would be £360-540. If you chose to use just Glucosamine (without chondroitin) a 6 month supply is £30 meaning £120-180. So the question you need to ask yourself is, am I willing to spend that much on a treatment that might help or may make no difference to my pain or the progression of arthritis?
Words of caution: If you are planning to take supplements to treat arthritis or other conditions discuss this with your GP or Pharmacist.