How does eating FAT help your arteries/heat?
Eating FAT per se doesn’t necessarily help, but minimizing the carbs, which lessens insulin, minimizes irritation/inflammation, and inflammation causes plaqueing in coronary arteries, obstructing them.
You, and I, and everyone else on the face of the planet are descended from THOUSANDS of generations of people who ate saturated fat every chance they could get.
First, here's a book you might want to check out, in reference to your question:
Also, you might want to go to youtube, and just enter her name (Nina Teicholz) in your search (or just click here >>===> https://www.youtube.com/results?search_query=nina+teicholz), and take the time to watch some of her videos related to eating fat and health.