Study Raises New Questions About Glucosamine

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March 14, 2000 (Atlanta) -- It's a rainy day in Omaha, and Betty Rindone's knees and hips are bothering her. "It's 100% humidity," she tells WebMD. "I can always tell."

After she had been plagued by years of minor aches and pains, Betty's knee gave out four years ago. "I just went down," she remembers. "By the time we got home, my thigh was really hurting." X-rays showed an arthritic knee and hip.

On the advice of her pharmacist son, Rindone began taking glucosamine sulfate, a dietary supplement widely touted as helping to decrease pain and joint deterioration caused by osteoarthritis. She took it along with an anti-inflammatory medication, gave it three months to work, and got little more than an uncomfortable side effect (constipation). "I didn't see any difference," says Rindone, 71. "My leg still hurt and hurt."

A recent study suggests that a certain segment of arthritic people -- those who are older and heavier and have suffered from arthritis for a long time -- may get no relief at all from the supplement. Published in the Western Journal of Medicine, the study found glucosamine to be no more effective than a placebo in reducing arthritis pain, says study author Joseph P. Rindone, PharmD. Rindone is a researcher with the VA Medical Center in Prescott, Ariz., and is Betty Rindone's son.

The study looked at a group of 98 patients, all veterans, with an average age of 65, who were being treated for osteoarthritis of the knee. For two months, the volunteers received 500 mg of glucosamine three times daily or a sugar pill. At the end of the first and second months, the volunteers' pain intensity was measured while they were walking and resting. No significant differences in pain levels were noted in either the glucosamine or the placebo group, Joseph Rindone says.

"We went into the study thinking the stuff would help," he tells WebMD. "It didn't come out that way at all. We tried to figure out why. Our patients were definitely older than previous studies, heavier (with an average weight of 200 pounds), and seemed to have had arthritis forever, 40 or 50 years. Our patients also had severe arthritis. It's somewhat suggestive that people with long-standing arthritis don't respond to glucosamine."


Many people who, like Betty Rindone, were dissatisfied with glucosamine, have had better results with the lesser known glucosamine-chondroitin combination. The two supplements are said to have a heightened effect when taken together. Brian Cole, MD, director of cartilage restoration at Rush-Presbyterian-St. Luke's Medical Center in Chicago, tells WebMD, "They seem to increase the amount of normal cartilage without toxicity or side effects." Cartilage is missing or destroyed in the joints of people with osteoarthritis.

For many elderly people, cost is an important issue in choosing between the two supplement regimens. "The chondroitin combination is fairly pricey," says Rindone.

He notes that a definitive study involving both supplements is on the way. This summer, the NIH is launching a major study of 1,000 patients to compare the effects of glucosamine, the glucosamine and chondroitin combination, and a placebo for treating osteoarthritis.

"I guess you have to say the jury's still out [on glucosamine]," says Peter Sharkey, MD, who reviewed Rindone's study for WebMD. "I've got a lot of patients who say that it works. But the problem is you have a big placebo effect. Pain scores got better even for people taking the placebo." Sharkey is associate professor of orthopaedic surgery at the Rothman Institute at Thomas Jefferson University in Philadelphia.

The way glucosamine works has not been studied, says Sharkey. "Doctors couldn't be surprised when studies show these things work or don't work, because we don't know how it benefits cartilage. It's like shooting in the dark; you just happen to hit something that works. Even results of the glucosamine-chondroitin combination don't knock your socks off. They show about 20-30% improvement."

The only thing the supplements will harm is your wallet, Sharkey tells his patients. "It's probably a reasonable thing to try. There's no downside to taking it. If you can afford it, it may work. I also tell them my wife takes it; she believes that it helps. I even take it. Just don't spend your kids' college tuition money on it."

For Betty Rindone, a glucosamine-chondroitin combination has improved her quality of life, to some extent. She still feels her arthritis some days worse than others. And she knows when she's been overdoing things. "If I use common sense, take a day off now and then, it helps. But I seem to be getting along OK. I just have to remember to slow down a bit," she tells WebMD.


Vital Information:

  • A study shows that for patients who are older and heavier and have had severe arthritis for a long time, the supplement glucosamine may not provide pain relief.
  • It is still unknown whether the combination of glucosamine and chondroitin will help these patients.
  • Many experts see nothing wrong with trying glucosamine and chondroitin to see if they work, as there are no known serious side effects.
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