March 11, 2014
News Review From Harvard Medical School -- Study: Glucosamine No Help for Knee Pain
A new study finds that glucosamine does not slow damage to knee joints in people with long-term (chronic) pain. Glucosamine is a dietary supplement. It is not regulated by the Food and Drug Administration. Many people take it as a treatment for osteoarthritis, but its benefit is uncertain. Prior studies have had conflicting results. The new study included 201 adults with chronic knee pain. They were randomly divided into 2 groups. One group received a daily drink (diet lemonade) that contained glucosamine. The other group received a placebo drink that did not contain the supplement. The study lasted 24 weeks. MRI images were taken of people's knees before and after the study. The images showed no difference between groups in the degree of cartilage loss during the study. Breakdown of cartilage is a major source of osteoarthritis pain. There were also no differences between groups in their self-reported pain levels after 12 and 24 weeks of treatment. The journal Arthritis & Rheumatology published the study. HealthDay News wrote about it March 11.
By Lori Wiviott Tishler, M.D.
Harvard Medical School
What Is the Doctor's Reaction?
I am always happy to see a well-done study about nutritional supplements or alternative treatments. In my experience, patients often feel that supplements must be "better" than other options because they are all natural. But without data, we don't really know if they are helpful or harmful.
This study looked at the role of glucosamine on the health of knee joints.
Osteoarthritis is the most common form of arthritis. Many of us develop it as we age. It causes a breakdown in the cartilage that lines our knees and other joints. Osteoarthritis is the primary cause of disability in the elderly.
We lack good treatments to stop it from getting worse and good treatments to reduce symptoms. It's no surprise, then, that people who suffer with severe arthritis look toward alternative therapies.
Glucosamine is commonly used for treatment of osteoarthritis. According to the article, in 2007 more than over 10% of adult Americans used it for this purpose. It's a big business: more than $2 billion a year. Glucosamine is supposed to slow the wearing away of cartilage in our joints. The loss of cartilage allows bones to rub against each other, causing arthritis pain.
Studies have shown conflicting results about glucosamine. Studies sponsored by industry have been more likely to show a benefit than studies with independent funding. This study was sponsored in part by the Coca-Cola Company.
The current study enrolled 201 people in Pennsylvania. Everyone had long-lasting knee pain. But it was not necessarily caused by knee osteoarthritis. Half of them drank glucosamine in a bottle of diet lemonade. Half had a placebo drink.
The study was designed to see whether glucosamine slowed the process of cartilage damage in knees. Researchers measured this mainly using MRI. They also looked at tests that showed biochemical changes.
The results showed no benefit on MRI or other tests for people who took glucosamine. The study did not detect any benefit in pain scores at 12 or 24 weeks, either.
The authors note that the study had limitations. It was relatively short. People did not have to have proven knee osteoarthritis. Strengths included the fact that researchers looked at structural effects on the knee, not just pain reduction. All of their measures also showed consistent results, which strengthens the conclusions.
What Changes Can I Make Now?
Knee arthritis can be very painful. If you have arthritis in your knees, a few simple things can help to decrease the pain and increase your ability to move.
- Maintain a healthy weight. Every pound you lose feels like 3 pounds off your knees.
- Exercise! You can't fix the knee joint itself. But strengthening the muscles around the knees can make a huge difference in how well you function.
- Physical therapy can be helpful for learning which exercises are best for you.
- Pain relievers will not change the course of your arthritis, but they may make you feel more comfortable.
If you have more severe arthritis and get no relief from these treatments, you may be a candidate for joint replacement surgery. Surgery is always a big decision. However, the benefits can be great for people who are suffering from severe osteoarthritis.
What Can I Expect Looking to the Future?
I hope that we can expect to see more studies about whether natural supplements and treatments help a variety of chronic conditions. I also hope that we continue to learn more about osteoarthritis and how to prevent the destruction of cartilage in our bodies.