|Glucosamine and Chondroitin for
July 15, 2000
Many people inquire about the use of glucosamine for the treatment of arthritis. Glucosamine is sold as a "dietary supplement" in the U.S.A. The Dietary Supplement Health and Education Act passed by the United States Congress in 1994 permits the marketing of a product claimed to affect the structure or function of the body as a "dietary supplement" without the approval of any government agency, as long as the labeling includes a disclaimer saying that it has not been evaluated by the FDA and the product is not intended to diagnose, treat or prevent any disease.
Glucosamine and chondroitin sulfate supplements are used to slow the progression of osteoarthritis the deterioration of cartilage between joint bones and reduce associated pain. They are both naturally occurring molecules in the body. Glucosamine is thought to promote the formation and repair of cartilage. Chondroitin is believed to promote water retention and elasticity in cartilage and inhibit enzymes that break down cartilage. Glucosamine is sold in many forms, including glucosamine sulfate, glucosamine hydrochloride (HCl), and N-acetylglucosamine (NAG), and may also contain a potassium chloride or sodium chloride salt. However, there appears to be no conclusive evidence that one form is better than another. Chondroitin is typically sold as chondroitin sulfate.
In laboratory studies, glucosamine sulfate has a beneficial effect on inflammation, mechanical arthritis and other types of arthritis. The standard dose of glucosamine sulfate is 500 milligrams taken three times daily. It can take up to 4 - 8 weeks to see results from the drug.
In short-term controlled trials, glucosamine has been reported to be effective in relieving pain and increasing range of motion in patients with osteoarthritis. In all reports, the drug was generally well tolerated. Gastrointestinal discomfort and nausea have been reported, but the incidence was no higher than with placebo (a pill with no active drug component).
Glucosamine appears to be safe and might be effective for treatment of osteoarthritis, but most published trials of the drug lasted only four to eight weeks and many consultants find them unconvincing. As with other "dietary supplements" the purity of the glucosamine products sold in pharmacies, health food stores and supermarkets in the USA is unknown.
In December 1999 and January 2000 ConsumerLab.com purchased a total of 25 brands of glucosamine, chondroitin and combined glucosamine/chondroitin products. These products were then tested to determine whether they possessed the labeled amounts of the claimed glucosamine and/or chondroitin ingredients. You can see the results of these tests by visiting the Internet review at http://www.consumerlabs.com/results/gluco.html.
Standard prescription anti-arthritis medications (Motrin®, Naprosyn®, Voltaren®, etc.) carry the risk of many potential complications such as; gastrointestinal ulceration and bleeding, fluid retention, blood pressure elevation, and negative effects on the kidneys, liver and/or blood-forming systems if they are taken for prolonged periods of time. They should be carefully monitored by the prescribing physician. Additionally, these non-steroidal anti-inflammatory drugs (NSAIDs) do not keep arthritis from worsening.
Glucosamine is a reasonable alternative to NSAIDs in patients who are at high risk for complications. So far, glucosamine seems to be safe and effective and may be more effective when used in combination with chondroitin.