Below is a brief (see the link) on a good study, done by a prestigious group of scientists. Before you read it I suggest you understand a bit about the processes that clog our blood vessels.
There are three things that raise cholesterol: oxidized oils (all those in clear bottles on the grocery-store shelves, sugar (a wonderful oxidizer and diuretic), and milk (especially from US dairy farms).
They define plaques as fatty substances collecting on arterial walls. One thing not mentioned in this article is that fats, unless oxidized into hardened substances, cannot stick to anything. And if they do, our body has a excellent processes to remove them. (HDL is one of them)
Milk, containing calcium that rarely goes into the bone, plus sugar, plus near-indigestible casein, is a triple threat. Pasteurizing milk just makes it worse because the enzymes (especially phosphatase) necessary to digest the proteins and fats in milk has been destroyed. Milk has all the necessary constituents to form the garbage-collecting structure (fibrin plus calcium) that allows fatty substances to build up inside the blood vessels.