Description: 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