by Judith Horstman
Word-of-mouth has made two dietary supplements lauded as "cures" for osteoarthritis (OA) among the hottest-selling nutritional products on the market.
More than 100 versions of glucosamine or chondroitin products are available through health food stores, pharmacies, supermarkets, and they appear on nearly 300 sites on the Internet. Some stores carry more than a dozen different brands, and all are moving rapidly off the shelves.
It's no surprise that people have been rushing to buy this latest fad: Those hoping to ease the pain and stiffness of OA have tried everything from copper bracelets to snake venom.
What is surprising is the growing evidence that these substances actually relieve pain for some with OA - and that a growing number of doctors are recommending that patients try them, and are using the products themselves.
"More than half of my patients are getting symptomatic relief at least as good as they get from nonsteroidal anti-inflammatory drugs, without the side effects," says David Hungerford, MD, a professor of orthopaedic surgery and chief of the division of arthritis surgery at Johns Hopkins University School of Medicine in Baltimore.
He takes a combination of the two supplements himself for osteoarthritis of the hand and knees, and recommends a trial of the combination to most patients who aren't yet candidates for joint replacement. He reports that about 75 percent of his patients say it helps.
While this is far from the "cure" promised by some advocates, it's good news for some who want to control the pain of OA without side effects. The nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, commonly used to treat OA, have the potential for serious gastrointestinal side effects.
Dr. Hungerford is such a booster of the supplements that he appeared on NBC's "Dateline" to talk about them. All told, Dr. Hungerford - who emphasizes that he has no financial interest in any of these supplements - estimates he has about 100 patients taking the combination, and that he's putting three to five new patients on the supplements each week.
But most researchers and doctors, even those who are using these supplements themselves, are leery of the hype and commercialism surrounding glucosamine and chondroitin. A few doctors who recommend the products to patients didn't want to be quoted, and others were decidedly reluctant.
"I've been asked about it probably a hundred times, and I hardly know what to answer," says James Fries, MD, a professor of medicine and rheumatology at Stanford University in California. "I sit pretty much on the fence."
His major concern: that patients will stop the OA therapies known to be effective, such as exercise and careful nutrition, in favor of yet-to-be-proven supplements. "Alternative therapies have the problem of replacing proven therapies," he says.
Alan Philippi, DO, a Navy doctor who conducted a small study of SEALs and divers that showed positive results for supplement use among those with moderate osteoarthritis of the back and knees, agrees. "We don't want to be associated with the glamorization of these products," says Dr. Philippi, who takes a combination product himself for OA.
"The initial data look promising, but there need to be large, follow-up studies," says Dr. Philippi.
"There are misleading commercials that make extravagant claims," says Amal Das, MD, an orthopaedic surgeon in Hendersonville, N.C., who had similar successful results in a study he conducted - and who also takes the supplements.
Those follow-up studies may soon be underway, but it will be a few years before the results are in. The National Institutes of Health is calling for proposals for studies of glucosamine and chondroitin, and Dr. Hungerford is planning a four-month study this year of 350 patients with moderate osteoarthritis of the knee. Only with long-term scientifically controlled studies can anyone be sure these supplements are truly effective - and safe.
Both glucosamine and chondroitin are substances found in the body that are essential to the metabolism of cartilage. Glucosamine is a form of amino glucose that is thought to stimulate the formation and repair of cartilage. Chondroitin sulfate is thought to draw fluid into the tissue, giving the cartilage resistance and elasticity, and slow cartilage breakdown by protecting it from destructive enzymes.
The supplement products are extracted from animal tissue. Glucosamine comes from crab, lobster or shrimp shells; chondroitin sulfate most often from cattle tracheas.
The extracts have been used to treat osteoarthritis in horses and dogs for decades. In Europe, they've been used in humans since the 1980s, with no known side effects.
In more than a dozen European studies on humans, about half of those with mild to moderate osteoarthritis who took either of the supplements glucosamine or chondroitin sulfate reported some pain relief. In some studies participants continued to report relief even after the dosage was decreased.
And while more research is needed, there is even some indication the supplements may slow down cartilage loss: A Belgian study that compared chondroitin sulfate to a placebo in people with OA of the finger joints showed that those who took the supplement for three years had significantly less new joint erosion. A similar international study of people with OA of the knee showed less narrowing of the joint space in those who took chondroitin for one year.
Many U.S. doctors have been critical of the procedures used in these foreign studies, but despite that, word-of-mouth has created a lucrative market for the nutritional supplements - and problems for consumers.
"The consumer is at risk," says Natalie Eddington, PhD, a pharmacist and associate professor in the School of Pharmacy at the University of Maryland. Because these products are sold as "dietary supplements," they are not regulated by the Food and Drug Administration, so there is no quality control.
Eddington is in the process of analyzing as many glucosamine and chondroitin products as she can find. So far, she's tested about 30. While most have the levels of extracts claimed on the label, her lab tests showed a few had "significantly" less of the substances than was claimed.
Eddington suggests consumers stick with products sold by larger, well-established companies that can be held accountable. Read labels carefully, especially the fine print. It should list all the ingredients and make sense to you. If you total the ingredients and it comes to more or less than 100 percent, for example, something is wrong. If you can't figure out what the label says, ask your pharmacist to interpret it for you.
Glucosamine comes as both as "hydrochloride" (HCl) and as a "sulfate." Experts say both performed equally well in studies. But when it comes to chondroitin, Eddington says not to try the version made from shark cartilage: The quality and amount of chondroitin in this form are inconsistent.
Other experts advised buying the products locally, not through mail order, and buying from United States manufacturers. The dose recommended by most researchers will cost between $1 and $3 a day, and is not covered by most insurers.
If you decide to try the supplements, how much should you take? And how do you know if they're working?
The amount used in many studies and recommended by several doctors is 1,500 mg of glucosamine and 1,200 mg of chondroitin per day. If that relieves symptoms, the amount can be gradually decreased after a few months.
James McKoy, MD, rheumatologist at Kaiser Permanente of Hawaii in Honolulu, says he finds that 500 mg of glucosamine three times a day (a total of about 1,500 mg per day) gives about the same level of pain relief as does 1,200 mg of ibuprofen per day. He doesn't see much benefit to adding chondroitin because he says it isn't well absorbed in pill form. Many studies on chondroitin used injectable forms.
Marc C. Hochberg, MD, chief of the division of rheumatology at the University of Maryland in Baltimore, says he doesn't recommend the supplements. But if patients ask him, he also suggests glucosamine only, in the same dose as Dr. McKoy recommends.
The supplements can be taken along with NSAIDs and other medications for six to eight weeks. Then the NSAIDs can be stopped to see whether there is a change in pain or stiffness.
All of the doctors interviewed say that if you don't experience relief within a few months, you probably won't get any. Dr. McKoy says most people who are going to benefit begin to feel the effects in six to eight weeks. Some people get no response at all, while others get partial relief from these supplements, but still need to take some NSAIDs to get full pain relief. If your arthritis is advanced and you have a great deal of cartilage loss, these supplements probably won't help.
Should you decide to try these supplements consider these recommendations:
Judith Horstman frequently writes about alternative medicine for Arthritis Today.
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