Monday, October 14, 2013

The Science Behind Glucosamine & Chondroitin

When I was in high school & spending a good chunk of my time riding horses, running track / cross-country, & doing gymnastics, I suffered from fairly frequent knee pain. I look a lot of Ibuprofen, iced them whenever I could, & garnered quite the collection of braces and ace bandages. As far as I could tell none of this ever helped very much, which is pretty disconcerting when you're sixteen.

When I was in the tenth grade, my doctor sent me to an orthopedic surgeon for a consult, & after a few x-rays & other tests, he proclaimed my knees perfectly healthy, except for, y'know, hurting all the time.

"Keep icing & taking Ibuprofen," he told me at the end of my visit. "It certainly won't hurt. You can also try glucosamine & chondroitin. That works for some people."

He explained to me that both glucosamine (an amino sugar that may help renew cartilage) & chondroitin sulfate (a complex carbohydrate thought to help cartilage retain water) were natural compounds found in cartilage, and had been shown to improve joint function somewhat in horses, and some of his arthritic patients swore by it. I took it religiously for a couple of years, saw no difference whatsoever, & gave it up.

So this article about the two supplements on NPR today caught my attention. As a mathematician and social scientist, I'm always interested in the actual research and scientific data behind claims like this. P-values are my hustle.

You can click through to read the details for yourself, but here's the highlights:

  • In a nation-wide double-blind study called GAIT, arthritis patients were assigned to take chondroitin, glucosamine, a combination of the two, an anit-inflammatory drug, or a placebo (ie, sugar pill, ie, nothing). (Double blind means that neither the patients nor the researchers knew which group they were in until after the study was over.)
  • At the end of the study, 66% of the patients taking supplements reported a 20% improvement in pain, but so did 60% of the placebo patients. Statistically, this means that there was no real difference between taking glucosamine, chondroitin, both, or nothing at all. (Because of the number of participants, the 6% difference between the two group is most likely random chance, not an indication that 6% of the supplement patients actually did better.)
  • Taking the supplements did not improve the structure of the joint, physical performance, or delay the progress of the disease.
  • However, a small subset of patients with particularly severe arthritis saw a statistically significant improvement in pain. In that group, 79% had a 20% or greater reduction in pain, compared to 54% for placebo.

What does this mean?

  • Objectively, neither glucosamine nor chondroitin likely has any objective effect on joint pain, structure, or function in the vast majority of humans.
  • For ~60% of people, believing it does something is enough to trick your mind into perceiving less pain. (Ie if you think your pain is better, then it is. See placebo effect.)
  • There may be some real benefit for people with particularly severe pain.

Two more larger-scale studies are attempting to confirm the results found in the GAIT study.

So what, according to the research, gives the best results for improving joint pain & function?

Easy. According to Drs. Patience White & David Felson, three things:

  • Increased physical activity
  • Increased flexibility
  • Weight-loss

"It's quite striking. If you lose only five pounds, you're talking about the equivalent of 20 pounds [less stress] across those knees, so you can imagine it would make quite a difference." -Dr. White

"There have been a variety of different exercise studies which have tried everything from water aerobics to walking to muscle strengthening, and they all seem to work." -Dr. Felson

* * *

So little running happened this week that it's barely worth recounting.


Karate/strength only.


a.m. strength / p.m. 3 easy.

On days when I do, like, *actual* strength training (vs what I call "light strength," ie, a few sets of push-ups & crunches or planks or something), I usually go to the actual gym so I can do deadlifts & backsquats & other fanciness like that in the group exercise room, which is free early in the morning. Free, that is, except for 3-4 other girls whose workout seems mostly to consist of lying on a mat for a few minutes, doing like 7 leg lifts, lying on the mat for another few minutes, fiddling with the music player for a few minutes, doing another 5-6 leg lifts, wash/rinse/repeat. I do more in the first five minutes than they do the whole time they're in there, and it's not like I'm some sort of gym god. I don't get it.

Tuesday's running plan became more and more anemic as the day went on. On my schedule was

  • 1.5 warm-up
  • 5x(1200m @ 5K pace / 3:00 jog)
  • 1.5 warm-up

which, for the sake of my hip, I was planning to modify to something more like

  • 1 warm-up
  • 3x(1200m @ 5K pace / 3:00 jog)
  • 1 warm-up

Lately, though, I have been shying away from the track because 1) doing more than just a little fast running at a time has been painful, 2) it's fall sportsball season & 50% of the time the track is closed anyway, and 3) parking in my neighborhood lately has been SHIT-TAY. I used to be able to park right away basically in front of the house when I got home from work around 4:45-5, but lately it's taking me 5-10 minutes to find a spot 2-3 blocks away. Normally getting home from the track around 7 means it could take me maybe 5-10 minutes to park a block or so away, which I can totally deal with once a week. The last two times, though, it took nearly half an hour, AND I had to walk 3 blocks. LAME.

So given all this, and that my hip was already a bit tweaky, I thought I would maybe attempt the tempo workout I never did last week (1 easy, 2x[2 @ HM pace / 2:00 jog], 1 easy), but as soon as I started running I knew that it would not be smart to run very far at all today. About a mile in the hip started to loosen up a bit & I thought maybe I could do some faster running, but as soon as I tried the pain immediately got worse. I ended up turning around at 1.5 miles for 3 in all. The middle mile was in the HM range, but honestly, I don't think one mile really means much in terms of tempo / threshold work. Hey, I tried. :P


a.m. 2.5 speed + light strength / p.m. karate + moar light strength. Although at first I was not sure my hip would be up for it, I was secretly glad that Coach Robert assigned us pure uphill speed work Wednesday morning as the three easy miles the evening before had left me feeling a bit unfulfilled.

The hill in question is definitely noticeable but nothing obscene, and more or less ~200m long. The idea was to sprint (more or less) up the hill, then jog back down, basically every three minutes, for eight reps. (This amounted to ~35 seconds sprinting, ~1:00 jogging back, & ~1:30 of rest.) With the easy half-mile warm up, it ended up being a nice, peppy little mini-speed workout that never overwhelmed my hip, and together with the three miles from the day before, made me feel as if I'd gotten an actual full workout in.

I dialed it back even further at karate, & it seems to have helped. I've also been incredibly diligent about rolling out everything, including my lower back, which is what my PT originally thought might have been the source of all the trouble with my right leg to begin with. (If you are having trouble motivating yourself to take care of your tissues by strength training, stretching, & rolling, I suggest checking out the picture in that post of what he was doing to my back on a weekly basis.)


Rest. Although my hip did feel better Thursday evening, I knew that it wasn't really better & trying to run on it again would only make it worse again. So back to aggressive rest it was. It felt better and better every day, but never fantastic. I've just gotten so sick of "Yay! It feels better," then running, then "Boo! Now it hurts again!," then resting a day, "Yay! Better!" wash/rinse/repeat. I do wonder if I've pushed it just a little too hard too soon this past month and it really just need just a little more complete rest before I can start building mileage.

No matter; just more unused awesome to save up for later, I say.

I got an appointment to see my PT on Tuesday, so I'll be very curious to run all this by him & hear what he thinks. We'll see!


  1. Interesting to read the glucosamine study results. I started taking it maybe 2 months ago, and I did seem to notice that my knees hurt less since I started taking it. Though it might just be timing, since I havent't been running as much the last 2 months either - and I've been concentrating on trying to run with a true midfoot strike too. But as far as I know there are no negative side affects from taking it, so likely I'll continue taking it. Down the road I may stop taking it to test how I feel without taking it - to see the affects. Though I need to get into a regular training routine in order to perform the control tests down the road though so that the conditions are the same.

  2. This is interesting. My other takes this for rheumatoid arthritis. Sorry about your hip. Hope your PT can help.

  3. This is interesting. And this seems to suggest that the reduction of pain felt by those patients is all in their mind. If they believe that the glucosamine and chondroitin will reduce the pain they feel, then they will really feel a decrease in pain.

  4. wow.this is very interesting..u give very valuable information for visitor... so thanks for sharing.....

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