Q. Will glucosamine and chondroitin supplements relieve my arthritis pain?

A. The jury is still out on whether folks with one type of arthritis, called osteoarthritis, may benefit from the supplements glucosamine and chondroitin.

These substances, which occur naturally in our bodies, help produce and maintain cartilage, our built-in joint cushions. Osteoarthritis occurs when cartilage is worn down and not replaced.

Studies of the effectiveness of these supplements in preventing cartilage deterioration and reducing pain show mixed results. Some small studies show positive effects from glucosamine.

Results from the first phase of a large study sponsored by the National Institutes of Health add to the confusion. For six months, 1,583 patients with osteoarthritis of the knee were given one of five treatments: glucosamine, chondroitin, a combination of the two, Celebrex (a prescription medication used for arthritis pain), or a placebo, or fake pill.

Overall, neither glucosamine nor chondroitin, alone or in combination, worked better than the placebo pill. In fact, 60 percent of those given the fake pill felt less pain after taking it!

A small subgroup of participants who had moderate to severe pain showed positive results. This group felt more relief from the combination supplement than those who took the placebo.

The type of glucosamine used may have influenced the results. This study used glucosamine hydrochloride. Many previous studies that showed positive results used a different form — glucosamine sulfate.

Phase 2 of this study is now under way. When this phase ends, participants' knees will be X-rayed to see if the supplements slow loss of cartilage over the long term. Medications such as Tylenol, aspirin, ibuprofen and naproxen help relieve arthritis pain but don't affect the underlying loss of cartilage. They may also cause stomach bleeding or ulcers.

If glucosamine and chondroitin delay cartilage loss without the side effects of other treatments, they may be worthwhile.

If you have moderate to severe knee pain from osteoarthrithis, check with your doctor about trying these supplements. They make take up to two months to start working.

Glucosamine supplements are derived from the shells of shrimps, crabs or lobsters, so those with seafood allergies should avoid them. Glucosamine also may raise blood sugar in some diabetics.

You can also relieve pain and increase mobility by doing exercises such as tai chi, water-exercise or walking. If you are overweight, losing weight takes pressure off your joints.

Amy Tousman is a registered dietitian with the Health Education Center of Straub Clinic & Hospital. Hawai'i experts in traditional medicine, naturopathic medicine and diet take turns writing the Prescriptions column. Send your questions to: Prescriptions, Island Life, The Advertiser, P.O. Box 3110, Ho-nolulu, HI 96802; fax 535-8170; or islandlife@honoluluadvertiser.com. This column is not intended to provide medical advice.