Breaking
News!
The results
of the study on the effectiveness of
glucosamine-chondroitin in relieving knee pain (Glucosamine/chondroitin
Arthritis Intervention Trial) have just been published
in The New England Journal of Medicine
(February 23, 2006).
The article
below, previously published in Arthritis Today, details
the search for evidence that the two popular supplements
effectively relieve knee pain.
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Arthritis Today Special Report
Good News for Knees
Arthritis Today,
JANUARY-FEBRUARY 2006
by Sara Altshul
Glucosamine and chondroitin have been on the
radar screen of arthritis researchers for a decade. For most of that time, these
natural substances have been viewed with a skeptical eye. Early but inconclusive
evidence suggested glucosamine helped repair cartilage damage.
Early studies showing positive results were
sponsored by glucosamine manufacturers, notes Beth Anne Biggee, MD, a researcher
at Tufts-New England Medical Center in Boston. Non-industry funded studies were
small and produced negative findings, such as the 12-week study Dr. Biggee and
her team did in 2004. Her study of 205 people concluded that glucosamine was no
more effective than placebo.
“This disparity invited skepticism. We needed
the results of the two-year Glucosamine-chrondroitin Arthritis Intervention
Trial (GAIT) to know whether glucosamine was effective,” says Dr. Biggee.
And now, the results are in. GAIT measured the
effects of taking glucosamine alone, chondroitin alone, a
glucosamine-chondroitin combination, and celecoxib alone against placebo in
1,583 people with either mild or moderate-to-severe pain from knee OA.
Results show that the combination of
glucosamine and chondroitin is better than placebo, but the benefits appear to
depend on pain severity.
Mild pain. The glucosamine and chondroitin
combination did not show effectiveness for people with mild pain. Sixty-three
percent of those with mild pain responded to the glucosamine and chondroitin
combo, and 62 percent responded to the placebo.
Moderate-to-severe pain. Of the people with
moderate-to-severe knee OA pain, 79 percent who took the glucosamine-chondroitin
combo experienced pain relief, compared with 66 percent who took glucosamine
alone, 61 percent who took chondroitin alone, and 54 percent who took placebo.
“The people with moderate-to-severe pain who took glucosamine and chondroitin
sulfate together showed significant improvement in their knee pain,” says lead
author Daniel O. Clegg, MD, professor of medicine and chief of the division of
rheumatology at the University of Utah School of Medicine in Salt Lake City, one
of 16 rheumatology centers involved in the NIH-sponsored GAIT.
The results of a second smaller trial, called
the GUIDE trial, were also announced recently. Conducted in Spain and Portugal,
the six-month-long study measured the effects of a 1,500-mg daily dose of
glucosamine against a 3,000-mg daily dose of acetaminophen (Tylenol) or placebo
in 318 people with knee OA. The researchers concluded that glucosamine relieved
pain significantly better than the acetaminophen or placebo.
“Glucosamine is a safe compound, and its use
should be considered in the early stages of OA,” says Gabriel Herrero-Beaumont,
MD, a researcher at Fundacion Jimenez Diaz, a hospital in Madrid, Spain, and
lead author of the GUIDE trial.
Researchers still don’t know exactly how
glucosamine or chondroitin work, says Dr. Clegg. Studies on glucosamine and
chondroitin are moving in the opposite direction of pharmaceutical studies.
Pharmaceutical companies usually find and patent a chemical that produces a
certain known effect, then test it in animals before people. Glucosamine and
chondroitin were used by people first, so scientists already knew it was safe;
now they’ve studied effectiveness, and next they will study exactly how it
works. “Scientists and funding agencies have been awaiting the GAIT results
before contributing resources to evaluate biologic actions of these agents,”
says Dr. Clegg.
How You Can Use this News
Interested in trying glucosamine and
chondroitin? First discuss all treatment options with your doctor, says Daniel
O. Clegg, MD, professor of medicine, and chief of the division of rheumatology
at the University of Utah School of Medicine in Salt Lake City.
“Glucosamine and chondroitin may be another
effective therapeutic option for managing pain in select OA patients but recent
positive study results do not change the cornerstones of OA management:
education, exercise, physical therapy, weight reduction (if appropriate) and
simple analgesics,” he says.
If you get the green light, look for
supplements containing a combination of 500-mg glucosamine and 400-mg chondroitin – and take three times a day. Be aware you may not notice an
effect until several days or weeks after starting glucosamine.
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