Kuroro said:
Cholesterol is required to transport the fat throughout the body, and stop the fat from blending with each other and create blocks in the arteries. Unsaturated fats require less cholesterol to be transported.
If you do heavy work like weightlifting, I'd advice that up to 50% of your calories come from fat. If you balance out the polyunsaturated, unsaturated and saturated you'll be fine. Just stay away from the trans-fat.
Its actually specialized serum lipid binding proteins in combinations with various fats, which form supramolecular assemblies that you call lipoproteins. Its LDL (low density lipoproteins), VLDL (very low), HDL (high) that along with others that transport lipids in serum.
The current thinking is that a favorable blood lipid profile will lower the risk of atherosclerosis and subsequent thrombotic events like heart attacks and strokes. Arteries are blocked not by fat, but by thrombotic events that are caused when there is a rupture of an atherosclerotic plaque and the stuff that dislodges blocks a blood vessel.
Oxidized LDL is supposed to be the principle cause for atherosclerosis (basically a chronic inflammatory condition of the endothelium, that can end with calcification)...as atherosclerosis actually means "hardening of the arteries". Our body's response to the pro-inflammatory stimulus at the endothelium is a key factor in determing the progress and outcome of any atherosclerotic plaques that form.
I think the right combination and quantities of fats are crucial, especially for people who are active. Fish oils/flax oil, and other omega 3 fat supplements are some of the most under-rated supplements around. Obviously its good to be able to get these from your food, but given the kinds of food we eat nowadays its pretty tough to do this...hence I turn to supplementation.