Glucosamines: A remedy for arthritis?

Glucosamines occur naturally in our bodies as a kind of sugar; they’re a component of soft connective tissues that join bones and joints and tie skin and organs together. They’re also a key element in the production of cartilage, the tough, springy material covering bone ends in joints-the same stuff eroded by arthritis.

It’s been suggested that a disfunction in glucosamine regulation may play a role in the development of OA. That’s what’s behind the idea that ingesting glucosamine will help normalize cartilage metabolism by inhibiting inappropriate cartilage degradation; it’s even thought that glucosamine supplementation can stimulate the synthesis of new tissue, so cartilage is partially restored. If that’s true, glucosamine may address causes of OA in ways NSAIDs and non-prescription painkillers don’t.

There’s also mounting evidence that NSAIDs, while they reduce symptoms, may accelerate the disease process; they’re also associated with a slate of side effects, especially among older people, whereas glucosamine’s only known side effect is mild gastric upset.

All of this has doctors joining patients in the glucosamine parade. Dr. David Hungerford, a pressor of orthopedic surgery and chief of the Division of Arthritis Surgery at Johns Hopkins University in Baltimore, MD, takes glucosamine and chondroitin sulfate for his own OA. He’s done a full media tour, including NBC-TV’s Dateline, to sing the praises of the supplements, and claims that more than half his patients enjoy symptomatic relief as good as or better than that from NSAIDs-without the side effects.

There are also doctors who use the supplements without being totally sold. The American journal Arthritis Today reported on a U.S. Navy doctor who conducted a small study of glucosamine among navy divers. Dr. Alan Philippi refused to be associated with what he called "the glamorization of these products. The initial data look promising, but there need to be large follow-up studies."

That view’s echoed by others, including Dr. James Fries, coauthor of several books on arthritis and director of the mammoth ARAMIS arthritis database at California’s Stanford University. Fries won’t speculate on glucosamine’s efficacy until it’s been proven in validated clinical trials. Denis Morrice, president and CEO of The (Canadian) Arthritis Society (TAS), has long pushed for such trials, though he admits funding will be hard to find. In the meantime, TAS has bankrolled an evaluation of existing research through Queen’s University in Kingston, Ont., which may help clarify the picture.

Or not. It may only corroborate the view held by a majority of western scientists-that most of the positive glucosamine studies (from Europe, South America and Pacific Rim countries) cited by proponents were poorly designed and conducted or inadequately described. In one trial pharmacist Stephanie Edwards examined for a 1996 issue of Pharmacy Practice, it wasn’t even clear the patients actually had OA, and "none of the controlled studies showed long-term symptom relief or slowing of the underlying degenerative disease process."

With that in mind, Toronto rheumatologist Dr. Joseph Houpt launched his own eight-week trial with about 100 OA patients last year, using a glucosamine hydrochloride formulation. Funding was difficult to secure, but he eventually received a grant from the nutriceutical company Wampole, "without any strings attached," he says (although the company now markets several glucosamine products, including a hydrochloride formulation called "Arthroid").

Houpt is bullish on the results: "I can tell you that glucosamine seems to work in some people," he says. However, using a mix of techniques to measure efficacy, Houpt admits they "could not prove to our epidemiologist’s satisfaction that there was a statistically significant difference in WOMAC scores-that’s a measurement instrument looking at pain, function and stiffness."

Houpt’s positive spin is based on patient diaries, which record such things as how much pain they had on a given day as compared to the day before. "Over an eight-week period," Houpt says, "it appeared as if the glucosamine patients were doing better [than] the placebo group. Similarly, when we examined their knees, it appeared as if those patients on glucosamine had some improvement in function."

Houpt isn’t disheartened by the mixed results. "It tells me that we have a difficult job to determine changes in patients with [OA]," he says, "because what are you measuring? There isn’t a number you can apply. You’re dealing with a disease that has exacerbations and remissions, that’s affected by time-of-day examination, by humidity, by barometric pressure-and at the end of the day, you’re really dependent on a patient’s answer: How do you feel today? You’re dealing with answers that often are very soft, so you’re dealing with very soft data."

That’s typical with dietary supplements. There are contradictions in The Arthritis Cure, too, which cites many of the studies other scientists criticize or reject. Theodosakis’s title is especially questionable, since the book doesn’t offer "an arthritis cure," Houpt notes. "He says, if you do these exercises, if you live right, and if you take glucosamine and chondroitin, then you’re going to feel better. But it’s really not a cure, and I think he did a disservice to the arthritis population by calling it a cure. He realizes that now, and he’s said so in public."

Then there’s the issue of chondroitin sulfate. It works "synergistically" with glucosamine, he writes, "to stimulate the synthesis of new cartilage while simultaneously keeping the cartilage-busting enzymes under control… in essence treating the disease at the cellular level."

Again, not everyone agrees. Michael T. Murray, N.D., is a naturopathic doctor and author (of 20-odd books, including Encyclopedia of Natural Medicine) who teaches botanical medicine at Bastyr University in Seattle, WA. On the basis of chemical composition, absorption rates and even molecular size, he asserts that "there is no additional benefit provided by a combination of glucosamine sulfate and chondroitin sulfate over glucosamine sulfate alone."

So, here’s the bottom line: International studies are suspect; more recent studies are debatable; there’s clear disagreement about chondroitin sulfate; and among those who use glucosamine, there’s little consistency about its effects.

On the up side, there’s no debate about its safety profile: side effects are few and usually mild when they do occur.

So, should you try it? If you can afford to, why not? You may be one of the lucky folk for whom it makes a difference. Keep your doctor informed, though, and don’t abandon a medical regimen that may be controlling your arthritis.

And keep in mind that glucosamine isn’t classified as a drug, so it isn’t subject to the rigorous testing approved medications undergo, nor is it as pure or consistent as the glucosamine used in research-nor are there any guarantees that what you’re buying is safe, effective or even consistent from manufacturer to manufacturer, or even batch to batch.

Your best bet: Look for products with a drug identification number (DIN), which means they’ve been manufactured according to Health Protection Branch standards.

Or wait: There are several initiatives underway, including a call for research proposals by the U.S. National Institutes of Health. Eventually there will be results you can count on.<!–

Dr. Ken Walker practises medicine in Toronto and also writes under the pen name of Gifford-Jones.—>