I'm going to give you the benefit of the doubt, being that you are sufficiently educated to comprehend the studies you're reading - both biology and statistics - and have actually invested a non-trivial amount of time ensuring you're actively trying to seek information to disprove your hypothesis rather than the alternative. (ie. You're looking for research suggesting that cholesterol has significant predictive power as opposed to looking for research just confirming what you already believe.) [0]
And under those conditions, I agree with you! Get involved with you health and engage in discussion based dialog with your doctor, and push harder if you don't agree. The healthcare system in this country may be incredibly screwed up, but at the end of the day most doctors are incredibly intelligent and if you have information suggesting they are wrong they very much would like to hear it. (Though like the rest of humans, some of them let pride and ego get in the way of rationality.)
However, the fact of the matter is the kind of person I described makes up a fractional percent of our society. Most people are not even close to being able to do that. Even if they could comprehend the biology, statistics are hard. Most people are incredibly naive and arrogant with their regard to their comprehension of statistics (probably myself included), which is why they are so powerful in misleading people. Ex: "A and B have a strong correlation so you should do C" - when in fact the correlation's r value is 0.3 and the correlation described was more likely random noise... but there is a correlation! [1]
Thus it is important to keep in mind general population when considering the effects of changes impacting more than yourself. If our healthcare system demanded we take more control of our own health, there is a small group of people who would be greatly benefited, but there is a much larger group who would suffer.
[0]: If that came across in an attacking manner I do apologize as that isn't my intent. My thoughts are much less about your specific case rather society as a whole.
[1]: Just to clarify my thoughts, I'm not suggesting most people are not intellectually capable of acquiring the knowledge to do any of this - It's not like it takes a special kind of super genius - most people simply just have not acquired the knowledge and thus are incapable for that reason.