Glucosamine Trials Show Little Benefit Against Arthritis

Results vary widely between trials, suggesting industry bias, experts say.

By E.J. Mundell
HealthDay Reporter
Saturday, June 30, 2007; 12:00 AM

Copyright © 2007 ScoutNews, LLC. All rights reserved.

FRIDAY, June 29 (HealthDay News) -- Although millions of arthritis sufferers buy glucosamine supplements to ease their joint pain, there's still no convincing proof the product works, according to a major new analysis.

In fact, the results of 15 trials of over-the-counter glucosamine vary so widely that industry bias may be a factor influencing the more positive outcomes, concludes a team writing in the July issue of Arthritis & Rheumatism.

"There's a big difference between trials, much more than you would expect by chance," explained lead investigator Dr. Steven Vlad, a fellow in rheumatology at Boston University Medical Center.

But an editorialist in the journal refutes those claims.

Dr. Jean-Yves Reginster, of the World Health Organization's Collaborating Center for Public Health Aspects of Rheumatic Disease, in Liege, Belgium, counters that industry trials are typically more stringent than independent academic research. He also believes that Vlad's group included trials in their analysis that were very unalike in terms of timeframes and methodology, confusing the results.

So, the years-long scientific debate on glucosamine continues. The popular supplement did take a major hit earlier this year, when a major U.S. study published in the New England Journal of Medicine found glucosamine hydrochloride to be of little help for knee osteoarthritis.

But Vlad also knew that other studies had found a real benefit to regular glucosamine use. Why the differences between trials?

To find out, he and his team combed through the available literature and selected 15 double-blind, placebo-controlled, randomized clinical trials that looked at the use of glucosamine for more than four weeks to help fight hip or knee osteoarthritis pain.

Trials involved either of the two major glucosamine preparations: glucosamine hydrochloride or glucosamine sulfate. Each delivers glucosamine bound to a different chemical salt.

First of all, the team determined one of the preparations to be useless.

"I think we have shown pretty conclusively that glucosamine hydrochloride doesn't work," Vlad said. "The data there is all consistent, it goes together -- there's just no evidence that it works."