February 22, 2006
Supplements fail to help mild knee arthritis: study
By Gene Emery
BOSTON (Reuters) - Two food nutritional supplements widely
taken by consumers including U.S. President George W. Bush for
joint problems are no better than a placebo for treating
arthritic pain in the knee, a study said.
But the study of glucosamine and chondroitin also suggested
that combining them, rather than consuming one or the other,
might help ease moderate to severe knee pain.
"The bottom line is, over all there wasn't any benefit over
placebo," said Daniel Clegg of the University of Utah School of
Medicine and the chief author of the study, which will appear
in Thursday's edition of The New England Journal of Medicine.
He said the findings from tests at 16 medical centers also
show that the supplements, either alone or in combination, are
unlikely to stop the pain from developing in the first place.
Consumers spend about $730 million a year on the
supplements, usually hoping to find relief from a condition
that afflicts at least 20 million people in the United States.
Past tests of the supplements, taken by millions of
arthritis sufferers worldwide, have shown some benefit. But the
rigor of some of those studies has been questioned.
The Council for Responsible Nutrition, a trade association
that represents the dietary supplement industry, said Clegg's
study revealed that the combination "provide significant pain
relief for moderate to severe sufferers of osteoarthritis."
Clegg told Reuters that the council is focusing on the
"interesting finding" in a subset of the study that only looked
at volunteers whose pain was rated as moderate to severe.
Those people "did have a pretty rigorous response" to the
supplements, he said.
NO BETTER THAN PLACEBO
But the number of people who fell into that group -- just
354 of the 1,583 volunteers -- was "not big enough to make
definitive comments," so a further test would be needed to see
if the benefits were real, Clegg said.
"We need to look more."
For now, "there is no evidence that these agents prevent
osteoarthritis in healthy persons or in persons with knee pain"
whose knees have a normal-looking X-ray, said Marc Hochberg of
the University of Maryland School of Medicine, in a journal
Hochberg said it was clear that the two substances alone
were no more effective than a placebo.
In the study, in which all volunteers had evidence of
osteoarthritis and had been dealing with some degree of knee
pain for a least six months, 60.1 percent of the people taking
the placebo had a 20 percent decline in knee pain after 24
That compared to 64 percent taking 1,500 milligrams of
glucosamine each day, 65.4 percent getting 1,200 milligrams of
chondroitin, and 66.6 percent taking both.
None of those improvement rates were statistically
In contrast, the response rate was 70.1 percent for those
taking the Pfizer Inc. pain reliever Celebrex, known
generically as celecoxib.