When researchers set out to test whether
two nutritional supplements helped relieve arthritis pain,
many were hopeful that a clear-cut answer would emerge
about the popular yet unproven alternative treatment.
Previous smaller studies suggested
the supplements — glucosamine and chondroitin sulfate
— were effective at treating aching joints. But many
of the studies were flawed or paid for by the supplement
makers.
The latest study, funded by the National
Institutes of Health and published in the latest
New England Journal of Medicine,
found the supplements overall did little to ease osteoarthritis,
the most common form of arthritis.
But patients who had more severe knee throbbing seemed
to show some improvement.
"We still have a bit of a conundrum," said Dr. Tim McAlindon,
a Tufts University rheumatologist who had no role in the
research.
Osteoarthritis afflicts more than 20 million Americans
and that number is expected to double in the next two
decades as baby boomers age. Osteoarthritis is a degenerative
joint disease that affects the knees, hips, back and the
small joints in the fingers.
Based on the findings, people with severe arthritis should
talk to their doctors about trying the supplements short-term
to see if they work, said rheumatologist Dr. Daniel Clegg
of the University of Utah, who led the study.
Worldwide sales of glucosamine and chondroitin topped
$1.7 billion last year, according to the Nutrition Business
Journal, which tracks supplements.
The supplements — made from animal cartilage and
shellfish — have had even wider appeal amid safety
concerns over certain painkillers, including the blockbuster
arthritis drug Vioxx, which
was pulled from the market in 2004.
The supplements showed no serious side effects during
the government's six-month study, considered the largest
and most rigorous test of the two supplements to date.
But the scientists didn't address the safety of longer-term
use.
The arthritis research is the third major study in a
year to find no overall benefit from some of the most
popular nutritional supplements. Recently, research showed
the herb saw palmetto didn't reduce symptoms of an enlarged
prostate, and last year a study indicated echinacea didn't
prevent or treat colds.
Unlike drugs, such supplements are loosely regulated,
and their makers don't have to prove the products are
safe or effective.
Irene Schwartzburt, a retired teacher from Plainview,
N.Y., said she plans to keep using the supplements. The
72-year-old said the remedies relieved the "sticking pain"
in her right knee when painkillers failed.
"I want to stay active," she said. "The supplements work
for me so why not continue with them?"
In the government study, 1,583 patients with arthritis
knee pain received one of five treatments: either glucosamine
or chondroitin, a combination of both, the painkiller
Celebrex or dummy pills. Neither the doctors nor patients
knew which treatment was given.
After six months, patients filled out a questionnaire
to determine how many felt a 20 percent reduction in pain.
Researchers found the supplements when taken alone or
together were no more effective than dummy pills at pain
relief.
Sixty percent who took the dummy medication had reduced
pain compared with 64 percent who took glucosamine, 65
percent who took chondroitin and 67 percent who took the
combo pills. These differences were so small that they
could have occurred by chance alone.
The drug Celebrex did reduce pain — 70 percent
reported improvement — affirming the study's validity.
However, the drug is being studied to see if it's safe
for people at risk of heart problems.
Of the 354 people with moderate to severe pain, 79 percent
who took both supplements reported relief compared with
54 percent who took the dummy pills and 69 percent who
took Celebrex.
In a journal editorial, Dr. Marc Hochberg of the University
of Maryland noted the study's limitations: a high dropout
rate (20 percent) and a whopping 60 percent who said the
dummy pills made them feel better — double the usual
placebo effect. Hochberg has received consulting fees
from Pfizer Inc., which makes Celebrex, and Merck &
Co., which made Vioxx.
Clegg and 10 other researchers in the study reported
receiving fees or grant support from Pfizer or McNeil
Consumer & Specialty Pharmaceuticals, which makes
Tylenol.
The Council for Responsible Nutrition, which represents
dietary supplement makers, said it was pleased about the
positive findings in the severe arthritis group.
