Glucosamine and Osteoarthritis
Is glucosamine all it’s cracked up to be?
When studies with funding independent of industry are reviewed, the difference in effect between glucosamine and placebo vanishes, Dr Tam reports
Glucosamine is certainly popular and recommended enthusiastically by many doctors. However, is it effective in osteoarthritis?
In a paper published in Australia’s Medical Observer (late 2012), Dr Michael Tam, Sydney GP and lecturer in the School of Public Health and Community Medicine at the University of NSW, explains why glucosamine is not the osteoarthritic panacea some people believe it to be.
He cites recent research literature to support his view, including a 2009 meta-review by The Cochrane Library that is commonly cited as evidence for the efficacy of glucosamine.
Tam points out that a benefit is only found, in fact, when low quality studies are included in the Cochrane analysis. When the analysis is restricted to high quality studies, glucosamine does not appear different to placebo.
Tam also reviewed a meta-analysis by Wandel et al (2010) that investigates the effect of glucosamine sulphate, glucosamine hydrochloride and chondroitin sulphate on osteoarthritic pain, compared to a placebo. The study excluded doses of less than 1500mg a day of glucosamine and less than 800mg a day of chondroitin. Notably, each study arm involved at least 100 patients, thus excluding many smaller trials.
Tam found that both the Cochrane and Wandel meta-studies came up with similar results.While both glucosamine and glucosamine sulphate result in slightly less pain than placebo, the difference is not even close to being clinically significant, says the GP and UNSW academic.
And, curiously, when the analysis is restricted to trials with independent funding, the difference in effect between glucosamine and placebo vanishes. Rather, glucosamine as compared to placebo results in a non-statistically significant and miniscule difference.
Tam’s conclusion? Glucosamine won’t help knee pain, though it does appear to be very safe. So, for those who suffer osteoarthritis, best rather to keep up the exercise regimen and to use paracetamol regularly.