By Suzanne Rostler

NEW YORK, Jan 26 (Reuters Health) - An over-the-counter dietary supplement touted as an arthritis treatment may indeed provide relief to millions of people who suffer from osteoarthritis, the type of arthritis that occurs with aging, a team of researchers concludes.

Their study found that after 3 years, glucosamine sulfate reduced cartilage damage and improved osteoarthritis symptoms up to 25% in patients taking the supplement, compared with those taking a placebo, or inactive treatment.

Osteoarthritis is caused by a gradual breakdown in cartilage and bone, and can lead to pain and limit daily functioning, especially in the elderly. Nearly 40 million Americans have the disorder. While many of these patients rely on nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin or ibuprofen to ease pain and symptoms, an increasing number are turning to 'natural' remedies such as glucosamine.

The study included 212 patients with knee osteoarthritis who took either 1,500 milligrams (mg) oral glucosamine sulphate or a placebo once a day. Patients on the placebo experienced significantly more cartilage degeneration than did patients taking glucosamine sulfate, the authors report in the January 27th issue of The Lancet.

There were no serious side effects to glucosamine, the researchers note.

"Symptoms worsened slightly in patients on placebo compared with the improvement observed after treatment with glucosamine sulfate," according to Dr. Jean Yves Reginster, from the University of Liege in Belgium, and colleagues.

In an interview with Reuters Health, Dr. Lucio C. Rovati, a co-author, noted that the supplement is a prescription drug in over 40 countries including most countries in Europe. In countries where it is available without a prescription, such as the US, doctors who recommend glucosamine should make sure they are prescribing quality products, he added.

"Better regulation will be helpful in the future to correctly direct physicians," Rovati said.

Furthermore, more studies will need to confirm whether glucosamine can prevent the need for joint surgery and lower the risk of disability over a longer period.

Still, the findings point to a new and effective therapy for a painful and debilitating disorder. Dr. Tim McAlindon, from the Arthritis Center at Boston University Medical Center in Massachusetts, calls the report "a landmark in osteoarthritis research" for highlighting the potential benefits of a nutritional supplement.

"Although inestimable resources have been poured into the development of a panoply of NSAIDs, scarce currency has been given to the notion that progression of osteoarthritis could be retarded pharmacologically, let alone by a nutritional product," McAlindon writes in a commentary.

In December, the National Institutes of Health said it would begin one of the first trials of glucosamine for arthritis and joint pain. The $14 million study will investigate whether the supplement, which is widely sold as an aid to joint pain, actually works.

US sales of the supplement, usually derived from the shells of shellfish, now top $230 million a year, according to the Nutrition Business Journal, which tracks sales of dietary supplements.

Glucosamine promotes the production of proteoglycans, the water-retaining molecules that are building blocks of cartilage, a substance that plays a major role in joint function.

From Reutershealth.com