In the past decade, glucosamine and chondroitin have been among the nation's bestselling supplements as aging baby boomers seek natural remedies for their aging joints. • Sales boomed after New York Times health columnist Jane Brody wrote in a 1997 column that the combination helped her arthritic dog and relieved her own knee pain by about 30 percent. • But Brody went on to have a double knee replacement, and recent studies have found little or no benefit from glucosamine and chondroitin, either separately or in combination, for treating osteoarthritis. • And what about MSM, the supplement often found in combination with glucosamine and chondroitin?
A 2006 study of MSM (methylsulfonylmethane), found some improvement in terms of pain and physical function, but the study involved only 50 patients.
Does all this mean that people with arthritis should stop taking these supplements?
"One thing about glucosamine and chondroitin is that they're very, very safe," said Dr. John Murray of Pasadena Family Medical Associates in St. Petersburg. "So if a patient is taking them, I won't tell them to stop, or if they suggest to me that they'd like to try (taking) it, I don't object. Some patients tell me they've felt an improvement, but there might be a strong placebo component to that."
Early studies suggested that glucosamine might stimulate the production of healthy cartilage and that chondroitin might help fight the inflammation that contributes to cartilage destruction in osteoarthritis.
The two supplements also seemed to help relieve the pain of arthritis.
But the best study to date, known as the Glucosamine/Chondroitin Arthritis Intervention Trial, or GAIT, has found few such benefits.
The GAIT study investigated the two supplements on pain relief and to see if they could control the underlying cause of osteoarthritis — the deterioration of the cartilage between the bones in the joints.
One part of the study followed 1,583 patients who received glucosamine, chondroitin, both, a pain reliever, or a placebo. People taking the supplements reported no greater reduction in pain than did those receiving a placebo.
Last year new GAIT results showed that the supplements did not slow the deterioration of joint cartilage either.
Supplement makers argue that the results of the GAIT study are not conclusive.
"What they did was study people too early in the arthritic process," Luke Bucci, vice president of research at Schiff Nutrition International, a maker of glucosamine and chondroitin, told WebMD after the first GAIT results were announced. "They were starting to see some small advantages for the glucosamine group."
A closer examination of the results shows that a small subgroup of people with moderate to severe pain did gain significant pain relief, according to Arthritis Today.
Also, the GAIT study used glucosamine hydrochloride instead of glucosamine sulfate, which controlled arthritic knee pain among participants in a European study of the supplement, according to the magazine. And the dosage — once a day instead of three times a day — may have been inadequate.
Such ambiguity, combined with the apparent harmlessness of glucosamine and chondroitin, has prompted many physicians such as Murray to tolerate, if not actually recommend, the use of the supplements.
But like all nutritional supplements, their purity is not regulated, so go with a brand you know. People with diabetes note: Glucosamine may raise blood sugar. Also, since it's extracted from shellfish, ask your doctor about taking it if you have a seafood allergy.
Tom Valeo is a St. Petersburg freelance writer who specializes in medicine and food. Contact him at firstname.lastname@example.org.