I have two bottles of glucosamine and chondroitin on top of my refrigerator for my dog, who has terrible arthritis in her hind legs. I was surprised when my vet recommended it, but had heard enough of the hype for humans that I figured what the heck, maybe it would help the dog.

I don't really know if it's done much for my dog, a mutt, but a review of 10 studies of glucosamine and chondroitin in humans suggests the supplements don't have any benefit on arthritic knees and hips.

European researchers compared studies looking at glucosamine and chondroitin alone and in combination with placebo pills and found that there was no discernable difference or changes in the joints.

"Compared with placebo, glucosamine, chondroitin and their combination do not reduce joint pain or have an impact on narrowing of joint space," the researchers concluded in their article published online Friday in the journal BMJ.com

"We are confident that neither of the preparations is dangerous," the researchers added. "Therefore, we see no harm in having patients continue these preparations as long as they perceive a benefit and cover the costs of treatments themselves."

But why would any patient want to spend good money if the supplements don't work? And what about dogs? I have two nearly full bottles of the stuff on my frig, and it seem  a waste to just throw it away.

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