aging and erectile function

My urologist said about 10% of men never experience problems with erections, even through their 70s and 80s. He said they say, "my erections are as hard as ever". Is anyone aware of data collected on these 10% of men who don't seem to have issues in their older years? Why do they succeed when...

ABSTRACT The authors review and discuss numerous factors that influence erectile function and their interactions, based on the published literature. Of critical importance are vascular nitric oxide; nutrition; exercise; weight control and maintaining insulin sensitivity; early treatment of...