Marathons Cause Heart Disease?

I found this link trying to find a connection between the repetitive stress marathon runners endure, and heart disease. It is kind of a tough read, but it's only three pages long. Food for thought anyway. Marathons have always been something I haven't been interested in running myself, I've always believed being a 5K'er is plenty enough exercise, and that marathons may be overdoing it.

Link: http://www.psychologytoday.com/blog/p-nu/201103/cardio-may-cause-heart-disease-part-i