Glucosamine supplements fail to improve knee osteoarthritis
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A previous meta-analysis of clinical trials had suggested that the benefits of glucosamine supplements were exaggerated, and noted that most of the studies had been carried out by manufacturers of the supplements.1
Now, a recent study called “Joints on Glucosamine,” presented at the annual meeting of the American College of Rheumatology has concluded that glucosamine has no beneficial effects on osteoarthritis of the knee. The 201 participants, given either glucosamine or placebo, were subject to MRI at baseline and after 6 months to structurally assess arthritic conditions. The odds of worsening of the cartilage were the same in the control and treatment groups, indicating that glucosamine did not slow the damage to the cartilage.2
In a news story covering this study, Eric Matteson, MD, chair of rheumatology and professor of medicine at the Mayo Clinic, commented:
"We do know that glucosamine therapy does not appear to be harmful, but there is no evidence it is helpful."3
In October, in a review of the literature on glucosamine and chondroitin supplements, the Center for Science in the Public Interest reported that the evidence for each of these supplements (and combined glucosamine and chondroitin) were inconclusive.4 They also note that for arthritis symptoms, the placebo effect is particularly strong – the author of the article, David Schardt states:
“Studies show that a sugar pill relieves arthritis pain in up to 60% of patients.”
This fact highlights the importance of the results of this new study – the scientists quantified cartilage damage via MRI, rather than relying on the subjects’ reports of knee pain.
Like so many other diseases, the best way to prevent and treat osteoarthritis is to remove the cause. A recent meta-analysis of 85 studies on the risk factors for osteoarthritis found that being overweight posed the greatest risk.5 For most of us, reaching and then maintaining a healthy weight with nutritional excellence is the best protection against osteoarthritis.
References:
1. McAlindon TE et al. Glucosamine and chondroitin for treatment of osteoarthritis: a systematic quality assessment and meta-analysis. JAMA. 2000 Mar 15;283(11):1469-75.
2. http://acr.confex.com/acr/2009/webprogram/Paper15123.html
3. http://www.medpagetoday.com/MeetingCoverage/ACR/16561
4. Schardt, David. “Do arthritis supplements work? Don’t bet your joints on it.” Center for Science in the Public Interest: Nutrition Action Healthletter, October 2009
5. Blagojevic M et al. Risk factors for onset of osteoarthritis of the knee in older adults: a systematic review and meta-analysis. Osteoarthritis Cartilage. 2009 Sep 2. [Epub ahead of print]
