Cochrane: Osteoarthritis is a disease of the joints, commonly found in knees,
hips, and hands. When the joint loses cartilage, the bone grows to try
and repair the damage but this bone growth is abnormal and makes things
worse. Osteoarthritis is one of the leading causes of disability as it
is painful and affects physical function and ability to use the joint.
Emerging
as a new treatment, chondroitin is an over-the-counter nutritional
supplement that is made primarily of chondroitin sulfate. It is said to
work by stopping the degradation of cartilage and restoring lost
cartilage. It also contains sulfur-containing amino acids which are
essential building blocks for cartilage molecules in the human body.
Previous meta-analyses have shown contradictory results on the efficacy
of chondroitin.
A team of Cochrane authors, based in United States and Canada and working with the Musculoskeletal Group,
set out to evaluate the benefit and harm of chondroitin sulfate for
people with osteoarthritis. The authors found 43 randomized controlled
trials involving 9,110 people. The majority of the studies examined knee
osteoarthritis, with few in hand or hip.Trial duration ranged from 1
month to 3 years. Several studies were funded by makers of chondroitin.
The randomized trials were mostly of low quality.
Chondroitin,
alone or in combination with glucosamine, was better than placebo in
improving pain in participants with osteoarthritis in short-term
studies. The benefit was small to moderate, with an 8 point greater
improvement in pain (range 0 to 100) and a 2 point greater improvement
in Lequesne's index (range 0 to 24), both seeming clinically meaningful.
These differences persisted in some sensitivity analyses and not
others. Chondroitin had a lower risk of serious adverse events compared
with control.
“The combination of some efficacy, low associated
risks, and the availability of chondroitin as an over-the-counter
supplement may make chondroitin popular for osteoarthritis patients,”
said Jasvinder Singh, a researcher at Birmingham VA Medical Center and
University of Alabama at Birmingham, and the lead author of the Cochrane
Review. “We need more high-quality studies to explore the role that
chondroitin plays in the treatment of osteoarthritis.”