To Your Health:

Alternative Therapy for Osteoarthritis

By Nancy DiMarco, Ph.D.

Forty million Americans have osteoarthritis.

Although arthritis is associated with old age, many people between the ages of 30 and 40 have it without showing any symptoms. But symptoms will appear, usually before age 55. And by age 70, almost everyone develops arthritis.

The disease causes the cartilage of the joints — most commonly in the knees, fingers, cervical and lumbar spine and the big toe — to become roughened and worn down. In the advanced stage, the cartilage is completely worn away and bone rubs on bone with bony spurs usually developing around the joint.

Currently, 16 million Americans with osteoarthritis require medical care that typically involves drug therapy. Treatment involves non-steroidal anti-inflammatory agents such as naproxen or cyclooxygenase inhibitors-2 (COX-2), including VIOXX, Celebrex, and Bextra. 

But recently some alternative therapies have come on the market, including glucosamine and chondroitin sulfate. These two compounds occur naturally in the body and are both involved in maintenance of normal cartilage function.

Glucosamine is an amino sugar that is thought to play a role in cartilage formation and repair. Researchers believe chrondroitin sulfate is a part of proteoglycan, a large protein, that gives cartilage its elasticity by promoting water retention and inhibiting enzymes that cause cartilage breakdown.

Both of these compounds can be found on the shelves of natural food stores, groceries and pharmacies. Glucosamine is extracted from shellfish such as lobster, crab and shrimp. Chondroitin sulfate comes from animal cartilage, such as cow hooves or shark. 

At one of my national meetings this past year, I spoke with a drug rep who was promoting his glucosamine product and he mentioned that he only advises using glucosamine for arthritis. He said that much of the chondroitin comes from the far eastern part of the world where there are lesser standards for purity and safety, and he worries about the possibility of mad cow disease contamination since bovine products are used in chondroitin's manufacture.

It's one man's anecdote, so take it with a grain of salt but be cautious, nonetheless.

Glucosamine and chondroitin sulfate have been widely marketed in the United States as nutritional supplements and suggested by anecdotal stories to be effective treatment for osteoarthritis. To date, however, very few well-controlled studies have been published.

The National Institutes of Health is currently conducting a clinical trial, called the Glucosamine Chondroitin Arthritis Intervention Trial (GAIT), to determine if glucosamine, chondroitin sulfate or a combination of the two are more effective than a placebo in the treatment of knee pain often accompanying osteoarthritis. The results will be released in 2005. 

But a handful of other studies that have been conducted have revealed some positive results, including one in a 2001 edition of Lancet.

Out of 212 people over age 50 with osteoarthritis in the knee who received 1,500 mg of glucosamine or 1,500 mg of placebo daily for three years, there was a 25 percent improvement in symptoms of those receiving the glucosamine sulfate compared to a slight worsening of symptoms for those in the placebo group. These and other studies suggest that this natural remedy may be beneficial in long-term management of osteoarthritis. 

When shopping for glucosamine or chrondroitin, be warned, the manufacture of dietary supplements is not regulated and no government agency can assure the public of the quality of these products. 

The best available standards of quality for supplements are provided by the U.S. Pharmacopeia (USP). Supplements that have USP on the label have passed quality standards for both purity and potency stated on the product's label. But it is impossible for this independent, non-profit organization to test all products on the market.

So, another good resource is www.consumerlab.com. They also have evaluated the purity and quality of a small number of the dietary supplements.

No study so far has found any serious side effects from consuming either glucosamine or chondroitin, although increased intestinal gas and stool softening are frequently mentioned.  

Dr. Nancy DiMarco is a research professor in the Department of Nutrition and Food Sciences, the nutrition coordinator for the Institute for Women's Health and coordinator of the master's program in Exercise and Sports Nutrition at Texas Woman's University. She can be reached at ndimarco@twu.edu.

Tips For Choosing Dietary Supplements Wisely

• Obtain a competent diagnosis of your condition
• Be certain of the supplement you are taking by doing your homework, which means using those resources mentioned plus Consumer Reports
• Be an educated consumer, looking out for safety and purity studies. Almost a third of the products tested by ConsumerLab did NOT pass testing
• Don't stop taking prescribed medications without talking with your physician
• Ask a pharmacist/physician about drug/supplement or supplement/supplement interactions, especially before medical testing or surgery
• Be wary of outrageous advertising
• The Office of Dietary Supplements has a database of published articles on dietary supplements called The International Bibliographic Information on Dietary Supplements (IBIDS) and can be accessed at
• In general, read supplement labels with caution. Supplement manufacturers are not required to follow strict regulations for their claims (unlike food labels).  Ask your physician or dietitian for more information on supplement claims
• Look for the USP symbol on the label.

For Further Information Contact:

Roy Kron
Director of News and Information
Tel: (940) 898-3456
e-mail: rkron@twu.edu