According to the American Academy of Orthopaedic Surgeons, there are three types of arthritis: osteoarthritis, rheumatoid and injury-induced arthritis -- which leads to osteoarthritis. The most common cause of knee pain is osteoarthritis, a gradual degeneration of the cartilage. Knee pain can also develop from rheumatoid arthritis characterized by inflammation that gradually damages cartilage. Since the marketing of glucosamine as a supplement around 1997, people have wondered if it really works to reduce knee pain.
About Glucosamine
Glucosamine is a substance produced naturally in the body and used for building and maintaining cartilage. Supplements, however, consist of glucosamine derived from animals. The AAOS states that it may help people with OA in the early development of the condition. Glucosamine is often combined with another natural substance called chondroitin, both of which can react with other medications and cause side effects such as nausea, vomiting, headaches and rash. Additionally, the AAOS reports that treatment may help reduce pain and swelling while improving range of motion and use of the knee but warns that use of this product is ongoing and it must be used consistently over a period of time, at least two months, to see results.
The GAIT Study
As published in the October 2008 issue of "Arthritis and Rheumatism," one study evaluated the effects of glucosamine and chondroitin on the the knees. Both glucosamine and chondroitin were tested together and alone. In this two-year, double-blind study there were 572 participants with OA assigned into five different groups randomly. One group received 500 mg of glucosamine three times daily, another group 400 mg of chondroitin three times a day, the third group a combination of glucosamine and chondroitin, the forth group 200 mg of celecoxib, a non-steroidal anti-inflammatory used for the treatment of arthritis, and the fifth group a placebo. Researchers measured the space within the participants knee joint before and after and found no difference between any groups receiving treatment and the placebo group.
Counter Opinions
"Arthritis Today" magazine cited a flaw in the GAIT study. The participants claimed varying levels of pain, the majority of which admitted to only mild pain. A small group of participants claiming more severe pain received "significant pain relief." Due to their minority, their results were overlooked. Critics fault the study for including participants with negligible pain who may not experience enough to notice any change with little "room to improve." Another critic claimed that glucosamine sulfate would have been a better treatment option than glucosamine hydrochloride, citing a similar study using glucosamine sulfate showed it to be effective for pain control.
Considerations
Glucosamine and chondroitin, reports the AAOS, are used regularly in Europe with few side effects. They state that there is a lack of evidence that either substance works alone or together, and more research is needed. Additionally, the AAOS warns to use only those supplements from trusted sources, a recent study evaluated glucosamine and chondroitin supplements and found the listed amounts did not match the content. Other medications, exercise and treatments are proven effective, the AAOS states. Consult your doctor before adding any supplements to your routine.
References
- American Academy of Orthopaedic Surgeons: Arthritis of the Knee; October 2007
- "Arthritis and Rheumatism"; The Effect of Glucosamine and/or Chondroitin Sulfate on the Progression of Knee Osteoarthritis: A Report from the Glucosamine/Chondroitin Arthritis Intervention Trial; A. D. Sawitzke, et al; October 2008
- "Arthritis Today"; Study Says Glucosamine Supplements Fail to Stop Arthritis Pain
- American Academy of Orthopaedic Surgeons: Glucosamine and Chondroitin Sulfate; 2009
