Glucosamine and Chondroitin: Effective for Arthritis?
Osteoarthritis can be a miserable condition, causing pain and stiffness that just gets worse over time. It’s no wonder many women are turning to glucosamine and chondroitin, popular arthritis supplements intended to prevent damage and reduce discomfort. But do they really work? When it comes to joint supplements, nothing flies off store shelves like glucosamine.
In 2008, Americans spent $838 million on pills, powders and drinks with glucosamine and its close cousin, chondroitin. And that’s despite that these are some of the most costly natural remedies around.
Clearly, lots of people are eager to take something that promises to relieve their osteoarthritis symptoms and fight future joint damage.
But do they actually do the job? The Medical Detective talked to several top researchers and physicians to find out. And if you’re a fan of these supplements, their answers may disappoint you.
Read on to learn more about symptoms of osteoarthritis, what glucosamine and chondroitin supplements claim to do and the treatments doctors recommend most.
Why you get osteoarthritis symptoms
Osteoarthritis refers to wear and tear on a joint that occurs as we age (or sometimes due to overuse).Under ideal circumstances, cartilage which is firm, slippery tissue cushions joints, allowing bones to glide over one another. But over time, joints lose their normal shape. Growths called bone spurs appear at the edges, and cartilage breaks away.
The result? Pain and stiffness, usually in the knees, hips, spine or hands. You may have osteoarthritis if you feel stiff when you stand up or if some of your joints are swollen.
Doctors diagnose the disease by taking a clinical history and doing a physical exam, and with X-rays or magnetic resonance imaging (MRI).
About 27 million American adults have osteoarthritis, according to a 2008 study by the Centers for Disease Control and Prevention. Before age 45, more men than women have it, possibly due to trauma to joints from sports or jobs involving heavy lifting. After 45, it’s more common in women because of diminishing estrogen, which helps prevent joint inflammation.
There may be a genetic link too, says Marc C. Levesque, M.D., Ph.D., associate professor of medicine in the division of rheumatology and clinical immunology at the University of Pittsburgh.
If you’re overweight or have a job that stresses certain joints, you’re also more likely to end up with painful osteoarthritis symptoms, doctors say.
The function of glucosamine and chondroitin
No wonder so many people turn to glucosamine and chondroitin for relief.Derived from a form of sugar known as glucose, glucosamine is naturally found in healthy human cartilage, as well as in the shock-absorbing fluid surrounding joints, according to the National Institutes of Health (NIH).
It’s also found in shellfish shells, which usually are the source of glucosamine dietary supplements. (Vegetarian versions, often made from fermented grain, are also available.)
Glucosamine sulfate is sold in tablets and liquid form that often contain other ingredients especially chondroitin, another major component of joint-cushioning cartilage.
Theoretically, the glucosamine and chondroitin are digested and circulated through the blood, where some ends up in joints to help rebuild cartilage and other connective tissue, Levesque says. But how effectively that happens is in question.
Examining the research
In the past, some trials of glucosamine and chondroitin showed benefits against symptoms of osteoarthritis, while others didn’t. But many studies that found them effective were flawed, researchers now say.
Some used too few participants for relevant results. Others lasted for varying periods of time, so they can’t be compared to each other, says Frederick Wolfe, M.D., co-director of the National Databank for Rheumatic Diseases and clinical professor of medicine at the University of Kansas School of Medicine in Wichita.
What's more, participants often have differing amounts of osteoarthritis pain when they start taking supplements. And some also take over-the-counter or prescription pain medications during the research, further muddying those results.
Also, various studies use different glucosamine preparations, according to the Cochrane Library Review, a respected British nonprofit organization that analyzes scientific research. Some may have additional ingredients, and some are given in liquid, rather than pill, form.
To say the supplements make a difference, participants have to report significant reduction in osteoarthritis pain at least 20%, according to many researchers. And that didn’t occur in a host of studies.
By accounting for all these flaws, researchers believe they can test the supplements more accurately. And the latest studies have found glucosamine and chondroitin to be mostly ineffective in easing pain and stopping cartilage deterioration.
As a result, doctors increasingly doubt these supplements are a useful way to fight arthritis. “I don’t think they work,” Levesque says. “The NIH spent a lot of money on a study [that showed they aren’t useful].”
The $12.5-million, NIH-funded “Glucosamine/Chondroitin Arthritis Intervention Trial” (GAIT) study, published in the New England Journal of Medicine in 2006, had somewhat mixed results, but was mostly negative. Overall, the researchers concluded, there were no significant differences between the supplements and a placebo.
A two-year follow-up study published in Annals of Rheumatic Diseases in June 2010 reported similar outcomes.
These studies have found some benefits from the arthritis supplements, especially in regard to knee pain but researchers assert they’re too small to be significant.
The GAIT study followed 1,538 osteoarthritis patients at 16 rheumatology research centers to see if taking glucosamine and chondroitin sulfate for 24 weeks reduced knee pain.
So did they?
Overall, the supplements weren’t “significantly better” than the placebo: 64% of those taking glucosamine, 65% of those taking chondroitin and 66% taking a combination of the two reported having at least 20% less pain. But so did 60% of those who took fake versions of the supplements. That suggests the benefits were psychological rather than physical.
Among those with moderate to severe pain, however, 79% who took the combined arthritis supplements reported 20% less pain, compared with just 54% who took the placebo. Still, that slight benefit wasn’t convincing to researchers. “The net outcome is that they didn’t work,” Levesque adds. “I think they put the issue to rest with this study.”
The Food and Drug Administration and Cochrane Library Review came to the same conclusions.
So why are these supplements still so popular? Years of contradictory study results have muddied the message to the public, researchers say. “They’re taken more as a matter of belief than for their actual effect,” Wolfe says.Still, if you want to take glucosamine and chondroitin, your doctor probably won’t stop you.
“I don’t think glucosamine and chondroitin are effective at reducing pain or preventing worsening disease,” says rheumatologist Krishna Chaganti, M.D., assistant clinical professor of medicine at the University of California-San Francisco and a member of the university’s Rosalind Russell Medical Research Center for Arthritis. “But if a patient feels that glucosamine and chondroitin are working and it’s not doing them obvious harm I don’t force anyone to go off them.”
Effective treatments for symptoms of osteoarthritis
If arthritis supplements aren’t helpful in fighting pain, what is?
Here’s what doctors recommend:
Exercise. Move those aching joints.
“Exercise makes OA better even though many patients think it makes it worse,” says rheumatologist Eric P. Gall, M.D., professor of clinical medicine at the University of Arizona in Tucson and interim director of the Arizona Arthritis Center.
Lower-impact activities such as swimming, yoga, walking, weight training and golf to name a few help reduce joint pain and stiffness and build strong muscles, according to the Arthritis Foundation. Regular exercise also increases your daily energy level and helps you sleep better. “Exercise and medications go hand in hand” to fight arthritis, Levesque says.
Weight loss. If you’re carrying extra pounds, drop them. Losing weight is a major factor in any OA treatment regimen. The more you weigh, the tougher it is on joints that support your body.
For example, to determine how much stress is put on your knees during everyday activity, multiply your body weight by 8, says Gall. A 140-pound woman, for example, places 1,120 pounds of pressure on her knees. “For overweight people, losing as little as 10 pounds can reduce knee pain,” says Levesque.
Medications. If exercise and weight loss don’t take care of the pain, you’ll probably need an over-the-counter or prescription pain reliever.
Acetaminophen (Tylenol, for example) is the drug of first choice among most doctors, especially if you’re over 55, says Chaganti. That’s because it has less impact on the gastrointestinal tract and kidneys, Chaganti says. But be sure to take less than 4,000 mg per day to avoid possible liver damage.
If acetaminophen doesn’t relieve pain effectively, non-steroidal anti-inflammatory drugs (NSAIDs), such as Advil, often are recommended. Take no more than 3,200 mg per day.
Take these only when you’re in pain, not as a preventive measure, Gall says. Overuse can damage your gastrointestinal system.When over-the-counter medications don’t relieve enough pain, Tramadol, a prescription pain reliever and synthetic opioid, often helps. It may be used with acetaminophen. Tramadol can be addictive to some people, although less so than narcotic-based medications.
Patients experiencing severe pain may take mild prescription narcotic painkillers such as codeine or hydrocodone. They’re used only on a short-term basis to prevent addiction.
Injections. Corticosteroids are anti-inflammatory hormones injected into the affected joints. They can relieve up to 75% of osteoarthritis pain, but should be limited to 2-3 times a year, says Gall.
“More than that, and cartilage can break down,” he warns.
Surgery. This is a last resort for those whose osteoarthritis symptoms are preventing them from enjoying an acceptable quality of life, Chaganti says.
Consider it only if you’ve “tried all of the other therapies and those measures aren’t working,” she says. “Sometimes only surgery can put Humpty Dumpty together again,” Gall adds.
Options include total joint replacement removal of the damaged joint and replacement with an artificial one and arthrodesis, or joint fusion, a surgical fusing together of joints that makes them unable to move.
“Surgery can be very good, particularly for knees and hips,” Gall says, “but it’s less effective for overweight people or those out of shape.”Surgical options have improved in recent years, Gall adds. “We get better results from that now than we used to,” he says. “We can get 15-20 years out of artificial joints.”
By Diane Wedner,