September 29, 2008
No Joint Benefit From Glucosamine Or Chondroitin

If glucosamine and chondroitin provide any relief from osteoarthritis 572 study participants weren't enough to prove it.

The dietary supplements glucosamine and chondroitin sulfate, together or alone, appeared to fare no better than placebo in slowing loss of cartilage in osteoarthritis of the knee, researchers from the Glucosamine/chondroitin Arthritis Intervention Trial (GAIT) team report in the October issue of Arthritis & Rheumatism.[1] Interpreting the study results is complicated, however, because participants taking placebo had a smaller loss of cartilage, or joint space width, than predicted. Loss of cartilage, the slippery material that cushions the joints, is a hallmark of osteoarthritis and its loss is typically measured as a reduction in joint space width—the distance between the ends of bones in a joint as seen on an X-ray.

Rather than slowing down the decay we really need ways to stop and reverse it. Some sort of stem cell therapy is the best bet. Gene therapy might end up helping but I expect benefits from stem cells sooner. Further out nanobots will do joint repair. I hope at least one of these becomes available before any of my joints start to ache.

Glucosamine might provide a small benefit. But if glucosamine does provide a benefit it is not so large that it shouts out.

Rheumatologist Allen D. Sawitzke, M.D., associate professor of internal medicine at the University of Utah School of Medicine, was lead investigator. "At two years, no treatment achieved what was predefined to be a clinically important reduction in joint space width loss," Sawitzke said. "While we found a trend toward improvement among those with moderate osteoarthritis of the knee in those taking glucosamine, we were not able to draw any definitive conclusions."

A whole lot of people suffer pain from osteoarthritis. How many do you know that live with constant osteoarthritic pain?

More than 21 million Americans have osteoarthritis, with many taking glucosamine and chondroitin sulfate, separately or in combination, to relieve pain.

Share |      Randall Parker, 2008 September 29 10:05 PM  Aging Diet Bone Studies

L. said at September 30, 2008 3:29 AM:

It may not change things but taking glocosamine definitely seems to reduce pain etc. : my wife has mild problems with her joints and when she takes glucosamine the problem is much less than when she doe snto take it. Might be a placebo effect, except that when she forgets to take it, she is reminded that she has forgotten by an increase in pain not by any other prompting.

Robert McLeod said at September 30, 2008 4:39 PM:

I've read the journal article. I'm not sure that I would consider three x-rays over two years the best way to assess soft tissue damage. MRI is probably a better choice.

The article you linked notes that:

* glucosamine alone group had the least average joint space width loss of 0.013 millimeters
* chondroitin alone group had an average loss of 0.107 millimeters
* glucosamine plus chondroitin group had an average loss of 0.194 millimeters
* celecoxib group had an average loss of 0.111 millimeters
* placebo group had an average loss of 0.166 millimeters.

So it seems clear that the glucosamine-only group is doing quite well since they basically lost nothing. Looking at the distributions in the groups, the chondroitin-only group had the most women (+10 %) and the least obesity (about - 8%). The others were fairly well distributed. That directly implies that the chondroitin-only group is going to have a higher risk for real osteoarthritis rather than just being obese and having a poor diet.

The study did not provide a histogram of the bone loss for each category which greatly limits the statistical value of this study given that the 95 % confidence interval didn't beat the spread. I guess the journal authors don't know how to use Excel or something.

The actual number of subjects who exceeded the 0.48 mm loss threshold was pretty small:

Therapy | No. of subjects | Progression, %of patients
Glucosamine | 77 | 18.6 %
Chondroitin sulfate | 71 | 21.4 %
Glucosamine & chondroitin sulfate | 59 | 24.4 %
Celecoxib | 80 | 20.2 %
Placebo |70 | 22.4 %

I would bet $20 that the distributions are pretty bi-modal from this threshold and the mean loss values. If 18.6 % of the glucosamine group lost greater than 0.48 mm of space between their leg bones then a bunch of them _increased_ the spacing.

Note that the suppliers for the glucosamine and chondroitin were different. From the acknowledgements:

We are indebted to McNeil Consumer and Specialty Pharmaceuticals (Fort Washington, PA) for donating acetaminophen; to Bioiberica, S.A. for donating sodium chondroitin sulfate; and to Ferro Pfanstiehl Laboratories (Waukegan, IL) for donating a portion of the glucosamine through Wilke Resources.

The particular way in which chemicals are fucntionalized often affects the ability of the human body to absorb them. Acetaminophen was the 'placebo'. Given the results maybe tylenol isn't a good placebo for arthritis.

Allan said at October 1, 2008 3:26 PM:

I have to agree with L ... I started taking G&C after I hurt my shoulder many years ago. Like L's wife, I can notice a difference whenever I run out and I'm slow to replace them. It doesn't happen overnight but I start feeling a little stiffer and sometimes even a little pain. I get back on the G&C. It takes a few days to a week but the aches go away again.

philw1776 said at October 3, 2008 11:51 AM:

Same pain experience here with G&C. Used it to relieve ankle pain from hoops injuries. I'm usually a skeptic for all such remedies but all my personal experience says this works for me. I also have a high pain tolerance level - drill cavities w/o novocain so the pre G&C pain was intense enough to really bother me. In the future our personal DNA assay will let us know which remedies are efficatious or not for us as individuals. The one pill/dosage for all era we live in will appear witch doctor primitive.

Brett Bellmore said at October 3, 2008 2:26 PM:

The problem with G and C appears to be that hardly any of it makes it to the joint. In veterinary work, it's injected directly into the joint, avoiding that problem. If you can find a cooperative doctor, you can get that done for you; My elderly mother had that done, about six months prior to her joint replacement, so that she could *temporarily* get back enough use of her joint to do some exercise the doctor recommended. The doc was willing to do it because the joint was going artificial in under a year anyway. Worked great.

There's extensive evidence that SAMe works. And does enhance cartilage metabolism enough to help it rebuild. I suspect the interest in glucosamine and chondroitin is due to their being much less expensive...

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