Most arthritis supplements contain glucosamine, a compound made by our bodies that helps form cartilage. Yet 25 randomized controlled trials over the last 33 years haven’t produced a consensus about whether glucosamine pills are more effective than a placebo.
“Glucosamine doesn’t work, period,” says David Felson of the Boston University School of Medicine. Not so certain is Roland Moskowitz of the University Hospitals Case Medical Center in Cleveland.
“There are reasons to think that it may help, and some studies that suggest it does,” he counters. Yet Moskowitz helped run the National Institutes of Health’s GAIT trial, which found that glucosamine doesn’t work.
One reason for the uncertainty: there are two forms of glucosamine. Glucosamine hydrochloride–the kind in most supplements and the one used in the GAIT trial—was no better than a placebo in three studies.
Glucosamine sulfate, on the other hand, seems to relieve pain and improve function, according to the Cochrane Collaboration, a network of scientists who review the evidence for medical therapies.
But all nine trials that found a benefit were funded and run by the supplement industry, usually by the Italian manufacturer of one glucosamine sulfate formulation. In the three trials that were conducted by independent investigators, glucosamine sulfate was no better than a placebo.
Despite the lack of evidence, Felson doesn’t talk his patients out of trying glucosamine. “If they think something is working and it’s not dangerous, I don’t discourage its use.”
Sources: New Engl. J. Med. 354: 795, 2006; Cochrane Database Syst. Rev. 2009. CD002946; Arthritis Rheum. 56: 2267, 2007.
Other relevant links:
- Eat fatty fish to get a good dose of DHA. See: DHA and Arthritis
- What is the impact of consuming milk on arthritis progression? See: How to Diet: Is Drinking Milk Good for Your Knees?
- Maintaining a healthy weight helps prevent arthritis, and control its symptoms. See: Diet and Weight Loss: Osteoarthritis and Weight