WEDNESDAY, Feb. 22, 2006 (HealthDay News) -- The dietary supplements glucosamine and chondroitin, taken by millions of people with aching knees, don't do much to help those with arthritis, a carefully controlled study finds.
However, there's some evidence that these non-prescription medications might yet be helpful in easing more severe cases, two experts said.
Additionally, one of the physicians questions whether the study used the correct supplement combination to determine their effectiveness in fighting pain.
These assessments come from the doctor who led the study and one who wrote an editorial accompanying the report in the Feb. 23 issue of the New England Journal of Medicine.
The study enrolled 1,583 people, averaging 59 years of age, with knee pain caused by osteoarthritis, the wear-and-tear condition that often occurs in older people. Participants were divided into five groups: one group received 1,500 milligrams daily of glucosamine; another got 1,200 milligrams of chondroitin; a third group got both glucosamine and chondroitin; a fourth group received 200 milligrams of the prescription painkiller Celebrex; and the last group got a placebo.
The goal was to reduce knee pain by at least 20 percent.
Overall, the two supplements were not significantly better than placebo in reaching that 20 percent goal. But the researchers added there were indications some people with more severe pain might have benefited from the supplements.
Many more people with moderate to severe pain reported benefit from the combination of both supplements (79.2 percent) than with placebo (54.3 percent). And it is that response that interested study author Dr. Daniel O. Clegg, chief of rheumatology at the University of Utah School of Medicine.
"That group needs to be studied better, and that is what I will pursue as a scientist," Clegg said.
His advice as a practicing physician to pain sufferers who might be considering the supplements is cautious, and addressed specifically to those with osteoarthritis.
"I would lose weight, exercise, take nonprescription pain medicine, and then an NSAID [nonsteroidal anti-inflammatory drug] if necessary," Clegg said. "Then if I still had more severe pain, I would discuss with my physician the potential for supplements."
If the decision is to take supplements, "I would probably use the combination" of glucosamine and chondroitin, Clegg said. "Glucosamine, if it works, seems to work best in [this] combination."
A different view was offered by Dr. Marc C. Hochberg, a professor of medicine and head of the division of rheumatology and clinical immunology at the University of Maryland School of Medicine, who wrote an accompanying editorial.
He believes the study was flawed because it used glucosamine hydrochloride rather than a different version, glucosamine sulfate. Other studies have shown that the sulfate form of glucosamine can be helpful against pain caused by osteoarthritis, he said.
The sulfate form of glucosamine was not used in the study because it was not possible to find a version that met federal pharmaceutical requirements, Clegg said.
Hochberg said he would recommend use of glucosamine sulfate, "if people want to take glucosamine on their own or on the recommendation of a health-care provider for pain of osteoarthritis of the knee, not just pain in general or pain at another site."
Glucosamine sulfate "can be taken as a single dose of 1,500 milligrams a day and people can try it for up to 12 weeks," Hochberg said. "If you didn't notice any clinically important effect by three months, I would stop. Otherwise, I would continue it indefinitely. It is safe, and not associated with any risk of side effects."
Hochberg differed somewhat with Clegg on the wisdom of using the two supplements in combination. "There is little data to support combination therapy," he said. "But most products on the shelf are combination products, and there is no data to suggest an increase in risk with the combination, and no data suggesting that the combination reduces the efficacy of the individual components."
In general, he added, the use of such supplements for pain relief "is a difficult subject for consumers and difficult for health-care providers."
More information
For more on arthritis pain, head to the U.S. National Institute of Arthritis and Musculoskeletal and Skin Diseases.
