A popular food supplement used to treat osteoarthritis pain in knee joints has been shown to have no long-term beneficial effect, according to a national study conducted by a University of British Columbia post-doctoral fellow working at the Arthritis Research Centre of Canada (ARC), part of Vancouver Coastal Health Research Institute (VCHRI).
Rheumatologist Dr. Jolanda Cibere, the study’s principal investigator, followed the progress of 137 patients aged 44-88, living in four Canadian centres: Vancouver, Winnipeg, London and Saint John. All research participants had been using glucosamine for knee joint pain for two years on average and had reported at least moderate improvement with use.
During the six-month double-blind study, participants received either a placebo or glucosamine, and researchers documented subjects’ experience of arthritic flare-up (pain and reduced activity).
Cibere found minimal difference between the percentage of subjects who flared in the placebo and glucosamine groups. Results showed 42 per cent flared in the placebo group and 45 per cent flared in the glucosamine group. In addition, subjects using glucosamine flared as quickly and as severely as those using a placebo.
“Glucosamine has been used for many years and its effectiveness has been controversial all along,” says Cibere, a post-doctoral fellow in UBC’s Dept. of Medicine. “Our study shows that even if the supplement was initially perceived by study participants to be helpful, it has no benefit for maintenance and continued use is not effective to control flare-ups.”
Arthritis is a leading cause of pain, physical disability and health care utilization in Canada. By the year 2026, it is estimated that more than six million Canadians 15 years of age and older will have arthritis, according to the Public Health Agency of Canada.
In North America, glucosamine – a highly purified derivative of shellfish – is a health food supplement, not a prescription drug. Costs of taking the supplement can range from $15 to $50 per month.
Although researchers used a medicinal grade of the supplement, ingredients in commercial products may vary widely because food supplements are not regulated by health authorities.
ARC is a multidisciplinary research team of medical doctors and scientists working for the benefit of all people with arthritis. It works closely with The Arthritis Society and is part of VCHRI.
VCHRI is a joint venture between UBC and Vancouver Coastal Health that promotes development of new researchers and research activity.