Chondroitin No Help for Arthritis Pain
Popular Supplement No Better Than Sugar Pill, Large Studies Show
WebMD News Archive
April 16, 2007 -- Chondroitin, a dietary supplement, works no better than a
sugar pill, analysis of clinical data suggests.
In the U.S., chondroitin is almost always combined with glucosamine, another
supplement. Annual U.S. sales of the chondroitin/glucosamine combination were
$810 million in 2005, according to figures cited by the Council for Responsible
Nutrition (CRN), a supplement industry trade group.
And sales "continue to grow at a phenomenal pace," Andrew Shao, PhD,
the CRN's vice president for scientific and regulatory affairs, tells WebMD.
Shao says only omega-3 supplements sell faster than chondroitin-based
"Sales continue to grow. This is presumably because consumers are
finding a benefit," Shao says.
That benefit appears to be an illusion, suggests Peter Juni, MD, head of
clinical epidemiology and biostatistics at the University of Bern in
David T. Felson, MD, MPH, professor of medicine and epidemiology at Boston
University, uses stronger language.
"What WebMD readers should take home about the possible efficacy of
chondroitin is that it doesn't work," Felson tells WebMD. "The
confusion is there was some early evidence suggesting it does work. The better
evidence suggests it does not."
Juni's study, and Felson's accompanying editorial, appear in the April 17
issue of Annals of Internal Medicine.
Chondroitin Zero Benefit
Chondroitin usually comes from animal cartilage. People with osteoarthritis
lose cartilage in their joints. Researchers disagree over whether chondroitin
taken by mouth ever finds its way to the joint. They also disagree over whether
it offers any benefit to people with arthritis.
Juni and colleagues analyzed every clinical study of chondroitin as a
treatment for arthritis. The studies focused on chondroitin alone and not in
combination with glucosamine.
Early clinical trials showed a fabulous benefit for chondroitin -- in one
case finding the supplement was more effective than knee replacement surgery. A
close look showed many kinds of problems with these early trials. Three more
recent trials avoided these problems.
"Early, methodologically insufficient trials showed overoptimistic
benefits for chondroitin," Juni tells WebMD. "The longer people
evaluated the drug, the better they evaluated it, the worse the drug looked. In
the last few years, large trials showed effects that were nearly or entirely
null. It is likely these trials show a reliable estimate of the benefit of this
drug, which is zero."
"There is pretty strong evidence it doesn't work any better when
combined with glucosamine," Felson says. "There is a huge National
Institutes of Health trial and two others showing no effect for chondroitin.
And all of the publicly funded studies of glucosamine suggest it doesn't work,
Shao disagrees. He says that Juni and Felson are basing their conclusions on
just three trials -- and ignoring data from 19 other studies.
"When you can leave out what you want and put in what you want, you get
the conclusion that you want," Shao says. "As far as [the Juni study]
goes, it is just three of 22 trials. ... Does that mean that they can make a
judgment on whether chondroitin works in general for everybody? No."