Jane: My understanding (from one of my vets) is that there have been several controlled studies done...initially, there were positive effects on (1) dogs who already suffered joint issues, and later (2) on puppies at risk but who had not presented symptoms yet.
One of my vets (an Irishman) told me that in Ireland human patients must undergo a year of therapy on G/C before they are eligible for certain joint surgeries. One can never be sure if this requirement is because of demonstrated effectiveness of the nutraceutical or a need for the health care system to manage the flow of patients to the operating theatre. Now to make this all the more confusing, more recently, I read (maybe in the Mayo or Harvard Health Newsletter - can't remember exactly) that there is some very preliminary clinical evidence that use of G/C can raise blood cholesterol levels in SOME fraction of human patients. As a person who is trained in research design and statistics, there are many variables in assessing the validity and quality of research studies. For example, typically, in human studies one cannot performed controlled experiments in certain treatment circumstances because of ethical reasons (e.g., withholding a cure for AIDS from the control group to evaluate the effectiveness of the cure in the treatment group). In many cases, we as researchers cannot do the ideal or perfect study because we cannot collect the data that we want or we cannot randomly assign subjects to treatments. While I do not think that a test of the effectivenss of G/C is in that category, I do know that a lot of what passes as "research" and "definitive studies" (including on the effectiveness of various medical therapies) is fundamentally flawed from a design point of view and does not permit the conclusions that some authors would like to assert. Having said that, what we as laypersons try to do is make the best decisions that we can with the information that we have obtained through our reading and consulting with veterinary or human health care professionals in whom we have developed confidence in their knowledge and trust in their abilities to use that knowledge wisely. Nancy Melone Mars, PA
