Don't count on glucosamine/chondroitin to treat knee osteoarthritis
- High value
- Evidence A
- Saves money
- Disputed
- Free
- Takes minutes
- No willpower
In plain words
People with knee osteoarthritis who took a fake pill for 24 weeks also had about 60% say it hurt less. People taking glucosamine or chondroitin did only 4 to 5 percentage points better than that, a gap so small it may be chance. For 700 to 1800 CNY a year, you get an effect basically the same as taking a fake pill.
- Cost
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About 2 to 5 CNY a day, 700 to 1800 CNY a year.
- What you get
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The GAIT trial enrolled 1,583 people with knee osteoarthritis and ran for 24 weeks. Even among those given a placebo (fake pill), 60.1% said their pain eased. Glucosamine beat that by only 3.9 percentage points (P=0.30). Chondroitin by 5.3 points (P=0.17). The two together by 6.5 points (P=0.09). All these gaps are too small to rule out chance. In the same trial, celecoxib, a real drug used as a comparison, beat it by 10.0 points (P=0.008). It looks like a good deal because “building blocks for cartilage” sounds like it fits the problem exactly, and a fake pill alone gets about 60% of people saying it works
- Notes
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Dispute: in the same trial, among those who had severe pain at the start, the response rate with the two taken together was 79.2% versus 54.3% in the comparison group (P=0.002). But the authors say this was dug out of the data after the fact, so it can only be a lead, not a conclusion. What actually has evidence for knee arthritis is losing weight and building muscle; see §6.33 (arthroscopic cleanup)
- Evidence grade
- A : Specific numbers from meta-analyses, large cohorts or randomized trials; for law and policy, the statute or official text.
- Sources
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- Clegg DO et al. (2006). Glucosamine, chondroitin sulfate, and the two in combination for painful knee osteoarthritis. NEJM. https://doi.org/10.1056/NEJMoa052771
Mentioned in
Translated from the Chinese original. Original book, section 6, tip 5. Content may be out of date and rules differ by place. When you actually deal with an agency, a doctor or a court, follow what local officials, doctors and lawyers tell you. Disclaimer