What glucosamine and chondroitin are: Glucosamine and chondroitin sulfate are produced in the human body and are involved in the production and maintenance of the cartilage that cushions joints. The supplement glucosamine is made from shellfish shells; chondroitin, usually from cow bone.
Claims, purported benefits: Cure or alleviate arthritis pain; improve joint function; help build cartilage and cushion the joints; prevent deterioration of cartilage.
Glucosamine and chondroitin: the latest research
In 2006, the government-sponsored Glucosamine/chondroitin Arthritis Intervention Trial (GAIT) reported that neither glucosamine hydrochloride nor chondroitin sulfate, alone or together, reduced pain and other symptoms significantly better than a placebo. (The prescription pain reliever Celebrex, also tested, fared only slightly better.)
But what about the main claim made for these supplements—that they slow or prevent the deterioration of joint-cushioning cartilage (the hallmark of arthritis)? In 2008, results of the other part of the study answered this question. The first GAIT study lasted six months and included 1,600 people with osteoarthritis of the knee. In the follow-up study, 357 of these subjects continued treatment (glucosamine hydrochloride, chondroitin, both supplements together, Celebrex or placebo) for an additional 18 months and then had X-ray exams to measure cartilage loss. The exams found only insignificant differences in cartilage loss between the groups. Interestingly, glucosamine and chondroitin did worse when taken together than each alone, but nothing worked much better than the placebo.
Also in 2008, a Dutch study of 222 people with arthritis of the hip found that another form of glucosamine (sulfate) did not reduce pain or stiffness better than a placebo, and X-rays revealed no differences.
In 2010, a well-designed Norwegian study involving people with low-back pain and osteoarthritis of the lower spine also found that glucosamine sulfate works no better than a placebo. Moreover, longer-term findings from the GAIT study confirmed that glucosamine and chondroitin, taken singly or together for two years, are no better than a placebo at reducing pain from arthritis of the knee.
Later in 2010 a European meta-analysis in the journal BMJ, which included data from 10 clinical trials and 3,800 patients, also found that glucosamine and chondroitin, individually or in combination, work no better than a placebo in reducing joint pain or narrowing joint space. “Health authorities and health insurers should not cover the costs for these preparations, and new prescriptions to patients who have not received treatment should be discouraged,” it concluded.
In light of this research, the American College of Rheumatology, in its 2012 guidelines, recommended that people with osteoarthritis not use glucosamine or chondroitin sulfate.
Meanwhile in 2013, another meta-analysis, this one published in the International Journal of Clinical Practice, looked at 19 trials and concluded that both glucosamine sulfate and glucosaminehydrochloride are ineffective for pain reduction in osteoporosis of the knee, though the sulfate form may help improve function.
Side effects: No serious side effects were reported in the GAIT studies or in the recent meta-analysis. Early on, some researchers had questions about these supplements’ effects on blood sugar. A small study reported in JAMA Ophthalmology in 2013 linked glucosamine supplements with increased intraocular pressure in people with glaucoma and suggested that this “deserves further exploration.”
Bottom line: Americans spend billions of dollars every year on unproven arthritis remedies. There is no cure, but everything seems to work at least for some people for a while.The placebo in the GAIT study helped relieve symptoms in a whopping 60 percent of subjects, about the same as the supplements.
Pain relievers help many arthritis sufferers but don’t affect the underlying loss of cartilage. Discuss the options with your doctor. We suggest you forget about glucosamine and chondroitin—unless you are willing to pay $20 or more a month for what is probably a placebo effect. If you already take these supplements and find they help, continue with them, but consider stopping for a while to see if there’s a difference.