An examination of post mortem records of Finnish hospitals before and after the 2nd World War shows that deaths from heart disease declined significantly during the war years. Some researchers have concluded that the decrease was because of reduced consumption of fats (meat, eggs, dairy and butter) as a result of shortages during the war years. Apparently deaths from atherosclerosis (hardening of the arteries) did not decline as much in the United States and this is attributed to more severe food shortages in Europe than in America. This trend was also observed in the Scandinavian countries. See this link -http://www.epi.umn.edu/cvdepi/slider_morta.swf . A full blown analysis is available at http://healthylongevity.blogspot.com/2012/08/forks-over-knives-and-healthy-longevity.html.
Correlation does not mean cause. Subscribers to the Paleolithic diet, also referred to as the hunter-gatherer diet, take an opposite tack and believer that a large intake of meat and fish is good for you. Their meat and fish is not purchased in a supermarket but taken directly from nature. A hunter acquaintance said he will only eat meat he has personally killed/”harvested” since only then does he know what he is eating. He also avoids most fish.
Now to complicate matters a new study released in March 2013 suggests there was atherosclerosis in mummies from 5,000 years ago. This has produced a slew of differing interpretations. A friend, who is not against junk food, argues that these findings show that junk food is not the cause of artery hardening since junk foods were not around 5,000 years ago. Another argument is that hardening of the arteries is a natural aging process influenced perhaps, but not significantly, by nutrition. To further confuse matters the mummies which were analyzed came from different parts of the world where some were hunter-gatherers who ate a lot of fatty meats, and others were from agricultural societies where they ate grains as well as domesticated animals.
This stuff is complex (as opposed to complicated, which means you can eventually figure it out) and, as with the debate on global warming, the experts are not definitive. The best they can offer is the palliative that exercise, avoiding tobacco, and eating healthy will all help to reduce heart disease.