Glucosamine: Does It Work?
Test results vary widely, prompting suggestions of bias

(HealthDay News) -- Millions of arthritis suffers shell out cash for glucosamine supplements in hopes of easing their joint pain -- either unaware or unconcerned that no proof exists that they work.

In fact, an analysis of 15 studies of over-the-counter glucosamine found that the results vary so widely that industry bias might be influencing the more positive outcomes.

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

But Dr. Jean-Yves Reginster, a professor of epidemiology, public health and health economics at the University of Liege in Belgium , said that industry trials are tougher than independent academic research. He also said that Vlad's group included studies in its analysis that were very different from one another, which muddled the results.

According to the National Institutes of Health, glucosamine is a natural compound that is found in healthy cartilage. Glucosamine sulfate is a normal constituent of glycoaminoglycans in cartilage matrix and synovial fluid.

Synovial fluid is like joint oil.

Glucosamine is usually taken with chondroitin, which is derived from cartilage.

Vlad said he knew that studies had found a benefit to regular glucosamine use, but he wondered why the trials produced such different results. To find out, he and his team selected 15 double-blind, placebo-controlled, randomized clinical trials that looked at the use of glucosamine for more than four weeks to help fight the pain of hip or knee osteoarthritis. The trials involved either of the two major glucosamine preparations: glucosamine hydrochloride or glucosamine sulfate.

One result was clear, Vlad said: "We have shown pretty conclusively that glucosamine hydrochloride doesn't work."

That wasn't the case with glucosamine sulfate, but the results varied among the trials.

A factor that appeared to play a role in the variance in the glucosamine sulfate trial results was industry involvement, he said.

"It's really hard to know just how big a factor that is -- whether it's manufacturing the whole effect or just exaggerating an effect that's there," Vlad said.

"If there is a bias from industry, I doubt very much that it is intentional," he added. "People want to sell their product, but I think that they rarely go into a study with the intention of twisting the results."

Whether people do or do not take glucosamine supplements, other methods exist to help take control of their pain, according to the Arthritis Foundation. The mind plays an important role in how a person feels pain, which often leads to feelings of helplessness and depression, the foundation says. With such feelings can come decreased activity, low self-esteem and even more pain.

To counter those feelings and regain a sense of control over your life, the foundation suggests:

• Keeping a positive attitude. Pain doesn't have to control your life. One way to reduce pain is to build your life around wellness.
• Keeping (or rediscovering) your sense of humor.
• Eating a balanced diet.
• Exercising regularly.
• Surrounding yourself with positive people.

On the Web

To learn more about dealing with the pain of arthritis, visit the Arthritis Foundation.

SOURCES: HealthDay News ; Steven Vlad, M.D., fellow in rheumatology, Boston University Medical Center , Boston ; July 2007, Arthritis & Rheumatism ; U.S. National Library of Medicine (www.nlm.nih.gov)
Author: Anne Thompson
Publication Date: July 31, 2008
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