Re: Alternate and Traditional Medicine
Problem with citing a single study is there is usually an equal and opposite study, looking just at Glucosamine sulfate the full text of the study referenced is available here as a pdf here http://www.oarsijournal.com/article/S1063-4584%2805%2980007-X/pdf a brief look suggests it is a reasonably well run study however of you head over to http://www.arthritisresearchuk.org/arthritis-information/complementary-and-alternative-medicines/cam-report/complementary-medicines-for-osteoarthritis.aspx an analysis of multiple studies shows that its effects are uncertain.
Also as its a dietary supplement there are issues with over use (people taking more than the recommended safe levels) which could potentially increase the risks of diabetes (ref http://www.ncbi.nlm.nih.gov/pubmed/20923823 full text available free of charge).
Also commercially available glucosomine products are not what you would call natural being ground up shellfish shells that are then subject to various chemical processes.
This isn't to say the products of 'big pharama' are any better as there is a tendency to hide or not publish research that is negative or indicates problems.