Update on arthritis.

Recent years have brought a spate of research reports on glucosamine sulfate, the nutraceutical used to soften the sting of arthritis. Osteoarthritis is the irreversible result of a slow deterioration of cartilage and bone, which leads to pain and limits mobility. Patients usually resort to non-steroidal anti-inflammatory medications like ibuprofen or the newer COX-2 drugs. But NSAIDs can cause stomach problems and do nothing to slow the progress of the disease.

Glucosamine sulfate, usually derived from the shells of shellfish, is thought to promote the production of proteoglycans, spongy water-holding molecules associated with cartilage formation. In a new long-term, double blind study, 212 patients with knee osteoarthritis took either 1,500 mg of glucosamine sulfate or a placebo daily over three years. Measurements of joint space in the knee and symptoms were monitored. Among the patients taking the placebo there was a progressive, significant worsening both of symptoms and joint space. Among the patients taking glucosamine there was no significant joint space loss and patients reported that their symptoms had improved. There were no reports of serious side effects either.

For runners interested in glucosamine to slow the progress of osteoarthritis there are still a few caveats. This research, although interesting, does not definitively show that "joint space" deterioration was slowed. It is possible that it was simply an artifact created by better mobility. More research is needed to confirm or refute the claims (which should be available since this report coincides with the beginning of a $14 million study at the National Institutes of Health to determine the safety and efficacy of glucosamine sulfate).

Purity of dietary supplements is also a big issue since there is little regulation and oversight of the industry. Contamination with lead or other potentially dangerous substances is always a possibility. In a report by Reuters, potentially harmful levels of manganese were found in a random sampling of supplements including products sold as glucosamine sulfate. The Institute of Medicine (this is the organization that sets dietary requirements) has announced that manganese intake should not exceed 11 mg per day. Manganese is a necessary dietary substance and is involved in bone and joint formation, but amounts that are too high can cause neurological and liver problems. All of the samples in the Reuters report exceeded the 11 mg upper limit. According to the consumer hotline for one of the most popular manufacturers of glucosamine, manganese is not measured because it is naturally occurring in the product, leaving consumers in the dark.

Where does this leave you? Most of the studies reporting benefits of glucosamine sulfate have been funded by the supplement industry (including the one reported here) but that is not an automatic indictment of the research. Many of the studies while not perfect, have produced significant data and most medical professionals agree that glucosamine may help patients with osteoarthritis pain. Look for upcoming reports from the NIH study, which should shed unbiased light on these products. Meanwhile, be sure to let your doctor know if you'd like to give it a try and expect it to take six to eight weeks before you notice results. For more information visit The Arthritis Foundation at www.arthritis.org or the NIH's Office of Dietary Supplements and its Center for Complementary and Alternative Medicine which can be found at www.nih.gov.

(The Lancet, 2001, Vol. 357, No. 9252, pp. 251-256)