Glucosamine and chondroitin supplements have been suggested for years as a way to reduce pain and help rebuild cartilage in arthritic joints, but the jury is still out on their effectiveness.
There are several types of arthritis, but these supplements are usually suggested for osteoarthritis. The Arthritis Foundation estimates that 27 million Americans suffer from osteoarthritis, making it the most common type by far. It causes pain and stiffness in the affected joints, namely the knees, hips, hands and spine.
Dr. Christopher Wise, a rheumatologist and professor of internal medicine at Virginia Commonwealth University, says osteoarthritis has no official known cause: "It is likely the result of mechanical stresses on the cartilage that may be caused by activities, injuries, malaligned joints, and inherited metabolic problems in the cartilage."
Glucosamine is an amino sugar, which is a precursor to glycosaminoglycans, a component of the cartilage and thick synovial fluid in joints. Similarly, chondroitin is a sulfated glycosaminoglycan. "The theory behind taking supplements is that these will be absorbed and make their way to the diseased cartilage and help restore the deficiency," Wise says.
However, he says that there is conflicting evidence on their effectiveness in rebuilding joints, since the disease takes a long time to develop and progress and behaves differently in different patients. "In addition, we have no standard way to assess whether a drug truly alters the course of osteoarthritis," Wise says. "Looking at X-rays has been used in some studies, but looking for tiny [millimeter-sized] differences in hundreds of patients can be difficult."
Some studies have shown improvement, but others have not. A study published in the New England Journal of Medicine in 2006 showed that glucosamine and chondroitin were more effective than placebo in patients suffering from moderate to severe knee pain, but those with mild pain experienced minimal symptom relief.
Wise doesn't suggest supplements as a main part of treatment for osteoarthritis patients but tells those who want to try them to do so for a few months. If they get symptom relief, he says they need to weigh the cost-benefit ratio. At South River Compounding Pharmacy, a one-month supply of a pill combining both glucosamine and chondroitin runs from $35 to $40.
"I put a lot more emphasis on regular exercise, muscle-strengthening exercises and weight loss for patients with osteoarthritis," he says, adding that low doses of pain relievers such as acetaminophen are part of the treatment plan as well. Another option for pain relief is nonsteroidal anti-inflammatory drugs (NSAIDS).
Annie Magnant, the president of the Virginia chapter of the Arthritis Foundation, encourages patients to discuss all treatments, including supplements, with their doctors, but says that "there is evidence that glucosamine does help some people."
Rhonda Matthias, a nutritionist at the South River Compounding Pharmacy, says that she doesn't necessarily recommend glucosamine and chondroitin supplements, but she tries to make sure people who want them are getting a quality product, something all patients should investigate.
"The way we choose what people can purchase over the counter is by researching the company that makes it, to make sure we are getting pharmacy-grade supplements that actually have in them what they say they do," she says.
Glucosamine and chondroitin are classified as dietary supplements in the United States, which means they are regulated differently by the Food and Drug Administration than conventional prescription medications. According to the FDA's Web site, the manufacturer of a dietary supplement is responsible for ensuring the safety of their product before it is put on the market, and they generally don't have to register their products with the FDA, nor do they have to get FDA approval. After a supplement reaches the market, the FDA takes action if there is a safety concern or concerns that the product doesn't contain what the label says it does.
Matthias says South River Compounding Pharmacy sells supplements only from companies that use third-party testing to verify their wares. The Arthritis Foundation's 2004 statement on glucosamine also supports this type of research for patients considering taking supplements.
While their effectiveness hasn't been fully proven, these supplements do generally seem to be safe. They also appear to have fewer side effects than NSAIDS, some of which, such as Vioxx and Rextra, have been taken off the market because of increased risk of heart attack and stroke. "As far as we know, glucosamine and chondroitin have no side effects," Wise says.