"In 2006, the New England Journal of Medicine published a $12.5 million study saying that, for most people, glucosamine and chondroitin do not soothe knee pain much better than a placebo."
"Try telling that to patients who swear that the supplements have helped their aching knees or backs — a position that the study's lead researcher, Daniel Clegg of the University of Utah School of Medicine, finds himself in often."
Glucosamine and chondroitin fare poorly in pain study, but sales are strong
By Rachel Saslow
Washington Post Staff Writer
Tuesday, March 16, 2010
In 2006, the New England Journal of Medicine published a $12.5 million study saying that, for most people, glucosamine and chondroitin do not soothe knee pain much better than a placebo.
Try telling that to patients who swear that the supplements have helped their aching knees or backs — a position that the study's lead researcher, Daniel Clegg of the University of Utah School of Medicine, finds himself in often.
"There are people who just feel like they're very effective, and it's hard to say, 'You should not take them,' " Clegg, a rheumatologist, says. "I tell patients that I don't think there's clear evidence that they're effective, but there's nothing to suggest that they're unsafe."
The supplements are promoted for anyone with joint pain, including people who suffer from the most common type of arthritis, osteoarthritis. But Clegg says both glucosamine and chondroitin are broken down during digestion and there's no evidence that they are incorporated into the deteriorating cartilage that is characteristic of the disease.
For the Glucosamine/Chondroitin Arthritis Intervention Trial, or GAIT, Clegg and his colleagues followed 1,583 osteoarthritis patients for 24 weeks. They found that overall, the supplements "were not significantly better" than the placebo in reducing pain: 64 percent of the people taking glucosamine, 65 percent of those taking chondroitin and 66 percent taking a combination of the two had at least 20 percent less pain at the end of the study, compared with 60 percent of those taking the placebo. (Side effects were minimal or, more often, nonexistent, according to the study.)
Still, the study gave some comfort to glucosamine believers. Within the subgroup of 354 patients who described their pain as moderate to severe, 79 percent of those who took the combined supplements reported 20 percent less pain, compared with 54 percent who took the placebo.
"People could have taken anything they wanted to from the result," Clegg says. The subgroup was so small that he recommended a follow-up study, he says, but to his knowledge, no one is doing one.
Sean Whelton, a Georgetown University Hospital rheumatologist, attended the American College of Rheumatology meeting where Clegg first presented the results of GAIT. He found it "impressive" that most patients found their symptoms significantly alleviated no matter what they took: glucosamine, chondroitin, both or a placebo.
Whelton says that most of his patients have taken glucosamine before they come to him. Those who continue to take it are the ones who find some benefit, which "seems to be a small proportion," he says. (However, Whelton acknowledged that people who felt better after taking glucosamine probably wouldn't make an appointment with a rheumatologist.)
"What I tell people is that it is a very safe type of product and it may or may not help them," Whelton says. "But I also review the evidence that we have from the GAIT trial that says it's not particularly effective."
According to the Nutrition Business Journal, Americans spent $838 million on glucosamine and chondroitin in 2008, up 1 percent from 2007. A 60-day supply of Osteo Bi-Flex glucosamine and chondroitin combination pills costs about $35. A 24-pack of Joint Juice, which provides a daily dose of glucosamine, sets one back $35 as well.
Glucosamine and chondroitin, both found naturally in the body, help grease your joints, so to speak. More scientifically, glucosamine is a modified sugar believed to play a role in the formation of cartilage, the connective tissue that cushions the ends of bones; chondroitin gives cartilage elasticity. The glucosamine in pills is obtained from shellfish, while chondroitin comes from shark or cow cartilage; they can also be manufactured chemically in a laboratory. Both supplements are also used for arthritic animals, especially dogs and horses.
Clegg calls the results of GAIT "unsatisfying" and "difficult," because doctors don't have many therapies to offer the 27 million adults in the United States who live with osteoarthritis. They can suggest weight loss, exercise and pain pills, but there's nothing people can do or take to build more cartilage. Whelton, who echoes Clegg's frustration about the lack of effective osteoarthritis therapies, thinks genetic research will help unlock some of the mysteries related to the disease and aging in general.
"If we had something exceptionally beneficial or effective, this debate wouldn't be happening," Clegg says.