Dear Doctors column April 30, 2007
Studies Show Popular Supplements Do Little To Combat Arthritis Pain
Question:
I take glucosamine and chondroitin to help with my arthritis pain. A friend told me research shows the supplements don’t work and that I’m wasting my money. I think they help. Is there any reason I should stop taking them?
Answer:
You’re not alone — glucosamine and chondroitin, most often sold in combination — are among the most popular supplements in the United States, with annual sales in 2005 of more than $800 million. Many people say the supplements ease osteoarthritis pain and some scientific research backs up anecdotal reports. A few studies also have suggested the supplements can slow or stop the ongoing loss of cartilage (the substance in the body that cushions joints) that is the hallmark of osteoarthritis. Most studies, however, were small, poorly designed, or had other scientific flaws that raised concerns about accuracy among experts.
Conflicting or suspect scientific evidence, along with the huge popularity of glucosamine-chondroitin combinations, prompted the National Institutes of Health to carry out a large, rigorously conducted clinical trial designed to provide definitive answers as to the supplements’ effectiveness. During the trial, called GAIT (Glucosamine/Chondroitin Arthritis Intervention Trial), investigators randomly assigned patients with osteoarthritis of the knee to treatment with the combined supplements, a placebo (sugar pill), or the prescription anti-inflammatory drug Celebrex. Overall, results showed the supplements didn’t reduce painful arthritic symptoms anymore than a placebo. Celebrex, however, did produce statistically meaningful pain relief.
A more recent European paper, which looked at results from a number of trials of chondroitin alone, found similar results, and study investigators concluded the supplement provides little or no relief for arthritis pain.
Adding to scientific skepticism surrounding the issue is uncertainty as to how taking the supplements by mouth could work to ease pain or stop cartilage loss. Although glucosamine and chondroitin naturally occur in the body and promote cartilage growth, repair, and elasticity, the process is complex and requires interactions with other natural substances. Scientists know that the body quickly breaks down oral formulations of glucosamine and chondroitin, which are made from animal tissue and cartilage, and that very little of these substances actually reach the joints.
Glucosamine and chondroitin do appear to be safe. The same studies that found the supplements weren’t effective for pain relief also found that people had few side effects, and those that did occur — upset stomach and diarrhea — were mild. Many physicians tell their patients that if they feel the supplements help, there’s no medical reason to stop taking them.
Some people, however, may want to consider the cost and quality of the products they’re buying: The glucosamine-chondroitin combination is relatively expensive, with monthly costs between $30 and $50, and the substances fall into the category of dietary or nutritional supplements (also called nutraceuticals), which are not regulated by the government. Analyses of various products on the market show pills contain anywhere from 0% to 115% of the amount of glucosamine and chondroitin claimed on the label.
The Arthritis Foundation recommends that people considering the supplements:
Ø Consult their doctor before taking them.
Ø Make sure that osteoarthritis is the cause of pain.
Ø Not stop or reduce current prescribed medications without talking with a doctor.
Ø Choose products sold by large, well-established companies that can be held accountable.
Ø Read the product labels carefully to make sure the ingredient lists make sense. If the information is hard to interpret, ask a pharmacist for help.
Visit the Arthritis Foundation for advice on coping with and improving the painful symptoms of arthritis.