Glucosamine - Effectiveness - Controversial?

Glucosamine Shows No Long-Term Benefit According To Canadian Study

Glucosamine popular supplement for osteoarthritis, has shown no long-term beneficial effect according to a study conducted by a researcher from the University of British Columbia working at the Arthritis Research Centre of Canada. The effectiveness of glucosamine has been questioned for years. The results of the Canadian study renew the controversy.

What is Glucosamine?
Glucosamine is derived from shellfish and is sold as a nutritional supplement. It is not a prescription drug. The ingredients in commercial products sold as glucosamine can vary widely because health agencies do not regulate nutritional supplements. It is often seen in combination with chondroitin and even MSM. The cost per month for the supplement can also vary greatly between brand names.

About the Canadian Study
Dr. Jolanda Cibere, rheumatologist and lead investigator for the study followed the progress of 137 patients. The patients were from 44-88 years old and lived in four Canadian cities. All of the study participants had been taking glucosamine for knee joint pain for an average of two years and had reported at least moderate improvement with the use of glucosamine.

The study was a six-month, double-blind, placebo-controlled study, during which time researchers documented the arthritic flare-up of the study participants. For the purpose of comparision, a flare-up was defined as increased arthritis pain and reduced activity.

Results of Glucosamine Study
No significant difference was found between the percentage of participants who flared in the placebo group versus the glucosamine group. Study results indicated that:
42% of participants in the placebo group flared
45% of participants in the glucosamine group flared

The Canadian study results conclude that even if glucosamine was initially perceived to be helpful by people taking it, there is no benefit for maintenance. Continued use of glucosamine was not effective for controlling flare-ups.

The Bottom Line
Cibere reported that despite the study results:
Some participants planned to continue taking glucosamine because they believed in it.
Other participants chose to stop taking glucosamine and noticed no difference in how they felt.

In the United States, the Glucosamine/Chondroitin Arthritis Intervention Trial (GAIT) is being sponsored by the National Center for Complementary and Alternative Medicine, a division of National Institutes of Health (NIH) and the Department of Veterans Affairs. The NIH study will determine whether glucosamine, chondroitin sulfate and/or the combination are more effective than placebo, and whether the combination is more effective than either supplement alone in the treatment of knee pain associated with osteoarthritis. The NIH trial which started April 2000 is scheduled for completion November 2005.

37 studies analyzed
The March 15, 2000 issue of the Journal of the American Medical Association included a report on a study by Timothy E. McAlindon, M.D. and colleagues from Boston University School of Medicine. After combing through more than three decades of scientific literature, the Boston researchers found 37 studies of glucosamine and chondroitin sulfate for the treatment of osteoarthritis. Of the 37 studies, 15 which were published between 1980 and 1998 were double-blind, randomized, placebo-controlled trials which lasted four weeks or more. Of the 15 trials, 6 involved glucosamine and 9 involved chondroitin.

The research team from Boston University School of Medicine analyzed and evaluated each of the clinical trials and then combined the data from the different trials. Amidst the analyzed studies, flaws in methodology and biases were discovered, some of which inflated the beneficial aspects of glucosamine and chondroitin.

Based on a calculation the researchers determined the overall effect for both glucosamine and chondroitin with 0.2 being indicative of a small effect, 0.5 corresponding to a moderate effect, and 0.8 pointing to a large effect.

The researchers determined that the effect was 0.44 for glucosamine and 0.78 for chondroitin sulfate. Reportedly, these values were lower when only the largest and highest quality trials were evaluated. During the past several years, skeptics of glucosamine and chondroitin have discouraged patients from trying the supplements, primarily because of the lack of regulation over the manufacturing and marketing of supplements in the United States and also because of insufficient scientific studies. All along patients have been urged not to stop ongoing medical treatments in order to try the supplements and have been advised to consult their doctors if contemplating a trial of glucosamine or chondroitin.

Clearly, more studies are needed which will provide evidence of the effectiveness or ineffectiveness of glucosamine and chondroitin. The National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) and the National Center for Complementary and Alternative Medicine (NCCAM), both parts of the National Institutes of Health (NIH), have launched the largest multicenter study of glucosamine and chondroitin to date. Conclusions about glucosamine and chondroitin as a treatment for osteoarthritis are yet to be drawn.