In an attempt to decrease the pain of knee osteoarthritis, many people turn to a combination of two supplements that can be bought at any pharmacy—chondroitin sulfate and glucosamine sulfate. Some people swear they get great relief. Today we look at what the best research says about these supplements.
A group of university researchers in Spain just published a study in Arthritis and Rheumatology to objectively see if the suupplements really work. They recruited 164 men and women with moderate-to-severe knee arthritis, and randomly divided them into two groups.
Supplements vs. placebo
One group received 1200 mg of chondroitin sulfate and 1500 mg of glucosamine sulfate daily. The other group also took two pills a day, which looked just like the supplement pills, but they were filled with an inactive placebo. At 6 months— the end of the study—each person was asked if the pills helped their pain, and by how much.
The results were unexpected. For the people who received the real supplements, on average they noted a 19% reduction in their pain. But the people who took the inactive placebo noted an average 33% reduction in their pain. The people who took the placebo did better than the people who took the two supplements!
Previous research investigating these supplements have shown mixed results. The largest and best run study, called the Glucosamine/Chondroitin Arthritis Intervention Trial (GAIT) published in 2010, found that taking the two supplements were no better than taking a placebo for pain reduction.
However, some people with knee arthritis are sure that these supplements help them. While the research shows the supplements don’t relieve pain, when studied in a big group, some individuals may be more sensitive to a positive effect than others. For this reason, the American College of Rheumatology recommends that if people have been taking these supplements, and they think they help, they should continue taking them. But they don’t recommend starting them if they haven’t used them before, based on the best research.
The rheumatology group also recommends that if you do decide to take the supplements, that you buy high quality ones. Some evidence suggests that low quality versions don’t help, but the higher quality supplements may help some people. Ask your doctor or pharmacist to recommend good brands to you.
We note that the recent Spanish study (showing the supplements don’t work) used high quality medications from reliable sources. The good news is that at least these supplements seem to be safe for long-term use. Still, the overall best medical evidence shows that, at least for most people, they are not worth the cost.
What does work for knee arthritis
The things that have been proven to work include: weight loss (to decrease stress on the knees if you are overweight), muscle strengthening exercises (to let the muscles take the stress rather than your joints), and analgesics and non-steroidal anti-inflammatory medications. In more severe cases, injections into the joint of corticosteroid and hyaluronic acid have been shown effective, but for that you need to see a specialist (rheumatologist or orthopedic surgeon).
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