Before Anel Keys came along, they had the diet heart hypothesis right. This is Professor Tim Noakes covering some pre-Keys scientific studies that had it figured out. 

Most will not be interested in listening to this long and in depth coverage of old studies. If you are like me and have followed such research for going on three years, you might find it interesting. Professor Noakes covers this subject in depth.

https://www.youtube.com/watch?v=jyzkv5uFGt8&t=1680s