It came to me suddenly on lane 7 of 12 I ran a few minutes ago on the Brattleboro High School track. I think I can identify the reason for runners living longer with much lower incidence of most reasons for most deaths among humans. I had been thinking of ideas of others such as that the liver is responsible for over 200 functions we learned in veterinary school. Also one person refuses to eat liver because it filters out so much waste from our bodies. He does not want that waste in his system. It is correct that the liver is a great cleansing organ of the body among other things. Now suppose when runners exercise much more blood is circulated all through the body including the liver where waste materials are not eliminated by typical slow circulation of blood.
It seems reasonable to me that some toxic substances may build up in the liver in those who lead a sedentary life as compared to the runner who regularly flushes a huge volume of blood through that organ while running. If my thinking is correct there is another possibility and that is that for every problem that is prevented by running, then each may be due to some toxic waste from the environment and not from some strange infective agent not identified. Examples are half as much breast cancer in women runners, many fewer strokes, much less heart disease and longer life all due to toxic stuff in the environment and not due to some unknown infection. It offers researchers a direction to study to be more successful in solving many problems. How's that for another sermon?