From Professor E. Ernst
SIR,—I am slightly confused by The Journal’s recent article on glucosamine (PJ, November 18, p759). Contrary to its title, the article is not a meta-analysis (which includes statistical pooling of several trials to give a new overall result) but a narrative systematic review. Moreover, a (real) meta-analysis was recently published that showed a clear positive effect of glucosamine,1 while Kayne et al’s2 conclusions seem far more negative.
Kayne and colleagues repeatedly make a potentially important point, namely that there is "no evidence that [glucosamine] is safe to take over extended periods".2 They do this on the basis of reviewing trial data. However, such data are very limited regarding safety aspects, and more meaningful information probably stems from postmarketing surveillance studies and similar long-term investigations. Finally, a recent paper (a narrative, non-systematic review) from The Pharmaceutical Journal3 concluded that "glucosamine is a safe, effective and well-tolerated alternative to NSAIDs in the treatment of degenerative joint disease". Is The Journal trying to enlighten or confuse its readers?