GLUCOSAMINE - does it really stop knee pain ?

Andy commented on a post I did a few months back 

http://bodyrestored.blogspot.com/2008/11/running-arthritis-knee-pain-glucosamine.html

Andy is right in saying that glucosamine naturally occurs in our bodies and that taking a glucosamine supplement is just increasing the body availability of glucosamine. The US government is reasonably positive about glucosamine - see this reference.

Of course there is always another point of view: see this post from Dr John Crippen.

I've wondered why some people get great results with glucosamine but it never worked for me. 

One of my clients has arthritis, takes glucosamine, has done for years and finds it works somewhat. She knows, because if she goes through a spell of missing taking the supplement, then she starts to feel the difference. 

Another client told me recently that her husband had had knee pain for years and mentioned the pain frequently. He started taking glucosamine about 4 months ago. After the first couple of months he stopped mentioning knee pain and she can see from the way he walks that the knees have stopped being an issue.

Scientists call this anecdotal evidence - meaning that it doesn't get rated too highly. 

The research I mentioned in the November 2008 post 

http://www3.interscience.wiley.com/journal/121425887/abstract?CRETRY=1&SRETRY=0

was pretty dismissive on glucosamine. So what's happening ? Is it all just the placebo effect ?

My guess is that it comes down to genetics. Some people have the genes to make good use of glucosamine in their food and are able to take this nutrient input and repair damaged cartilage. If you don't have the right gene mix then the good affects just do not happen.

Going back to that research study, it was big, and because of that a whole bunch of people with lots of genetic variants were swept into the study. Just through talking to people who workout with me, my guess is that 20% of people with knee issues benefit from glucosamine but the majority do not. 

My personal bottom line: if you have knee issues then by all means try glucosamine for 3 months. If you are going to get any benefit from glucosamine then you start to feel a difference in about 6 to 8 weeks and then even more improvement for the next 6 to 8 weeks. However if by 3  months no improvement can be felt then it's not going to happen for you. Time to try something else.