Easing Arthritic Pain
How a supplement often used on animals is helping humans, too.
How might they work? Osteoarthritis results from a breakdown of cartilage,
the protective coating around the bones at the joints, Clegg says. Without this
smooth and springy substance, the bones scrape against each other, which can
cause chronic pain and limit range of motion.
Both glucosamine and chondroitin are synthesized by the body and are
naturally found in cartilage. Clegg and other researchers theorize that
glucosamine somehow helps create new cartilage, while chondroitin may slow
cartilage destruction. Taken together, some experts say, the combination offers
a one-two punch against the wear-and-tear of osteoarthritis. NSAIDs, in
contrast, primarily mask the symptoms.
Also unlike NSAIDs, glucosamine and chondroitin don't cause symptoms such as
stomach upset, nor do they carry the risk of ulcer formation. Although some
people have experienced mild gas, the side effects from the supplements are
negligible, according to the Arthritis Foundation's position statement. If
you're thinking about trying glucosamine and chondroitin, the Foundation
advises a few precautions, however. Patients who are taking the blood-thinning
medication heparin -- whose molecular structure is similar to chondroitin --
should have their blood clotting activity monitored if they add chondroitin.
Taking both at the same time could increase the risk of bleeding. Diabetic
patients wanting to try glucosamine (an amino sugar) should consider potential
effects on their blood sugar control. If you're allergic to shellfish, avoid
taking glucosamine, which is made from crab, lobster, or shrimp shells.
(Chondroitin is manufactured from cow cartilage.) And before you rush out to
buy either of them, make sure that osteoarthritis is the cause of your pain;
glucosamine and chondroitin don't seem to help other forms of the disease, such
as rheumatoid arthritis. Of course, it's always a good idea to talk to your
And be prepared: the supplements aren't cheap. A month's supply of
glucosamine alone (at 1500 milligrams a day, the amount used in most studies)
can run from $30 to $60 per month. And you should choose a brand that's been
used in a scientific study; researchers at the University of Maryland School of
Pharmacy in Baltimore recently tested several brands and found that some didn't
contain as much glucosamine and chondroitin as their labels indicated. No
matter the brand you purchase, insurance will not typically cover the cost,
because these substances are considered to be foods, not drugs.
Arbenz, who is on Medicare, admits that she finds the cost of the
supplements frustrating, but she'll continue to take her glucosamine for as
long as she needs to. "Sure, I know that they don't really know if
it works and all of that science stuff. But it's working for me. And for me
To Sign Up for the NIH Study:
To be eligible to participate in the study, you should have both knee pain
and X-ray evidence of osteoarthritis. Contact Diana Kucmeroski, study
coordinator, at the University of Utah School of Medicine, Rheumatology
Division, 50 North Medical Drive, Salt Lake City, UT 84132; or call (801)
585-6468. You will be directed to one of nine study centers (in Wichita,
Cleveland, San Diego, San Francisco, Indianapolis, Philadelphia, Omaha, Salt
Lake City, or Seattle).