Posted on: Wednesday, April 6, 2005

SHAPE UP
Joint-pain compound worth try

By Charles Stuart Platkin

Glucosamine, often recommended for joint pain, is one of the most popular supplements on the market. And considering the health concerns recently associated with nonsteroidal anti-inflammatory medications, I thought it would be worth looking into whether glucosamine lives up to the hype.

Background

Glucosamine and chondroitin often are combined together and are used to treat osteoarthritis, which occurs when cartilage covering the end of the bone near the joint breaks down. Osteoarthritis affects the knees, backs, hips, hands and feet of more than 21 million people older than 45. And, according to Dr. Roland W. Moskowitz, professor of medicine at Case Western Reserve University's Arthritis Translational Research Program, about 90 percent of the population will suffer from osteoarthritis by age 75.

What is it?

Glucosamine and chondroitin sulfate are found naturally in the body. Glucosamine is a form of amino monosaccharide (sugar) believed to play a role in cartilage formation and repair. Chondroitin sulfate is part of a large protein molecule that provides cartilage elasticity. The glucosamine and chondroitin in supplements are extracted from animal tissue: glucosamine from crab, lobster or shrimp shells, and chondroitin sulfate from animals such as sharks.

How it works

Glucosamine is believed to stimulate and repair joint cartilage, ease pain and slow deterioration. Chondroitin fights harmful enzymes that destroy cartilage and helps surviving cartilage retain water and elasticity. Most research, however, is focused on glucosamine. Although many experts say the specifics of how it works aren't known, Dr. Jean-Yves Reginster, director, World Health Organization Collaborating Center for Public Health Aspects of Rheumatic Diseases, University of Liege, Belgium, claims, "Glucosamine has been shown to reverse several of the negative effects of interleukin-1 on the joints. IL-1 promotes both joint inflammation and joint destruction."

Does it work?

According to Reginster, the original crystalline glucosamine sulfate 1,500-milligram once-a-day formulation, approved as a prescription drug in Europe and available as a supplement in the United States, "has been shown to be effective (in treating osteoarthritis of the knee) in two separate long-term clinical trials of three years duration. Besides symptom control, these two trials showed that the compound was able to delay the joint structural changes. This would allow glucosamine sulfate to be possibly classified as the first disease-modifying agent in osteoarthritis."

In a key review completed by the Arthritis Center, Boston University School of Medicine and reported in the "Journal of the American Medical Association," the authors analyzed all available glucosamine studies, concluding, "Trials of glucosamine and chondroitin preparations for osteoarthritis symptoms demonstrate moderate to large effects, but quality issues and likely publication bias suggest that these effects are exaggerated. Nevertheless, some degree of efficacy appears probable."

However, Dr. David Felson, professor of medicine at Boston University School of Medicine and one of the authors, has since modified his opinion: "There's a good chance we've been hoodwinked. Most of the successful trials were funded by industry, and all three of the public, nonindustry studies have shown no impact from using glucosamine."

Others take a more pragmatic approach. Moskowitz, for example, says, "There's enough evidence that you can't simply dismiss glucosamine." And according to Dr. C. Thomas Vangsness Jr., a surgeon and professor at the University of Southern California Keck School of Medicine, about 25 percent of glucosamine users are probably experiencing a placebo effect, meaning they feel better but it's not caused by the glucosamine. "And that's OK, too," he adds.

Even the Arthritis Foundation believes there is emerging evidence that for people with osteoarthritis of the knee, glucosamine provides a number of benefits, such as symptom relief, improved function and a slowdown in cartilage damage.

One of the most important clinical trials of glucosamine for osteoarthritis of the knee is the Glucosamine/Chondroitin Arthritis Intervention Trial, currently being conducted by the National Institutes of Health. Although the results will not be reported until the end of 2005, glucosamine advocates are anticipating potential negative findings, claiming that GAIT is not testing the original glucosamine sulfate 1,500-milligram once-a-day formulation used in the other trials, but a previously untested capsule of 500 milligrams of glucosamine hydrochloride taken three times daily.

Is it safe?

One thing no one disputes is that glucosamine is generally safe. A recent review in the journal "Food and Chemical Toxicology" found, "Glucosamine is safe and does not affect glucose metabolism."

"Glucosamine seems to be a very safe agent, and I certainly do not discourage people from taking it," says Dr. Anisur Rahman, a senior lecturer in rheumatology at University College London. There are, however, a few populations for whom it's not recommended, including pregnant or breast-feeding women and people with liver disease or shellfish allergies.

Bottom line: If you have osteoarthritis, especially osteoarthritis of the knee — why not try it?

Charles Stuart Platkin is a nutrition and public-health advocate. Write to info@thedietdetective.com.