I am not a scientist, but I believe that almost nothing you eat will prevent heart disease. The best one can do is minimize the chances of developing it, and of making it worse if you have it. Besides, some people are predisposed to high cholesterol and other problems (like my husband) and some are not (like me); remember that the body manufactures cholesterol and nothing can prevent that.
I believe that the key is moderation. Almost all cooking fats have their place -- at least those that impart a distinct flavor or have useful cooking properties do -- but none should be used to excess. So I choose my cooking fat based on what I want it to do or what flavor I want it to give the dish, and try to use the minimum amount necessary.
I firmly believe that the more real flavor our food has, the LESS likely we are to overeat. So anything we can do to bring out the inherent flavor of our food, the better. Of course, this requires starting with flavorful vegetables, meats, fish, etc. and treating them with respect. That is the hard part, but worth the effort!
So I will saute in olive oil, or clarified butter, or duck fat (Yup, that is actually one of the healthier animal fats, as well as one of the tastiest! :lips: ), or canola, depending on the heat I'm using and the flavor I want. I have even been known to use rendered beef and lamb fats, and lard, if I want that flavor :eek:. BUT then I defat the finished dish (especially stews and braises) before serving it.
And even though my husband shrieks when he sees the container in the fridge, I may even add a smidge of cream to a dish if it will bump up the flavor. You know, he stops complaining when he tastes the (moderate size) portion I give him. :D
BTW: I just saw a demo and picked up some literature on avocado oil, and it shows promise: a pleasant, mild flavor; lots of good fats, and the highest smoke point of all oils (more than 500 degrees F). Might be worth following up.