Just one more nail in the lid that’s never coming off the coffin of glucosamine and chondroitin. Despite the ubiquity of these supplements and the innumerable testimonials for their benefits in people and in pets, the research continues to accumulate that they are nothing more than a placebo when it comes to treating arthritis pain. A new meta-analysis in the British Medical Journal looking at 10 trials with over 3800 patients followed for up to 2 years found no clinically significant affect of glucosamine or chondroitin supplementation on pain scores of joint width (a measure on cartilage degradation). Not surprisingly, industry-funded trials tended to have more positive results than independently-funded trials.
Of course, people will argue that this is not directly relevant to the use of these supplements in dogs and cats, and we should not discount their potential value in these species without similar high-quality studies. There is some truth to this, but given the limitations in resources and technical difficulties of veterinary research, the absence of any plausible reason to think that these products might perform better in animals than in humans, and the uninspiring results of the non-industry funded veterinary research on glucosamine and chondroitin so far, it would seem to be placing our bets on the long shot to put much more of our limited resources into studying these therapies.
Then again, it’s hard to find a dog, cat, or horse that isn’t already on glucosamine and chondroitin, so a cynic might ask whether the evidence really matters or not anyway. Luckily, I am an inexhaustible well of optimism about human nature, so I would never be so cynical. 🙂