Arthritis Supplements in Question
Glucosamine and Chondroitin No Better Than Placebo for Mild Pain
Another important unanswered question is whether the supplements can slow progression of knee osteoarthritis. Clegg and colleagues will attempt to answer this question by following about half of the original study participants who will continue taking the treatments for two years. Results from that trial are expected in about a year.
In the meantime, Clegg says that patients who want to take the supplements should probably take them in combination for just long enough to determine if they help relieve the pain.
Although few side effects were reported in the six-month study, National Center for Complementary and Alternative Medicine director Stephen Straus, MD, says the long-term safety of the supplements is unknown.
"We've learned from past studies that much longer exposures to certain medications are needed to reveal their true safety profile," he says.
Clegg also warned that the unregulated glucosamine and chondroitin products available commercially may be very different from the supplements used in the study.
Marc C. Hochberg, MD, MPH, who heads the division of rheumatology at the University of Maryland School of Medicine, says the findings also raise interesting questions about the placebo effect.
No fewer than half of the patients in the placebo arm of the study experienced significant reductions in pain, and responses in some placebo subgroups were as high as 62%.
Hochberg says the large placebo effect shows that the mind-body connection is very important in the treatment of arthritis pain.
He adds that physicians should consider treating these patients with minimal dosages of the safest pain medications available early on, graduating to stronger doses and drugs if pain persists.