My dad would disagree--he's 84, was on statins for years and they did terrible things to his body. I'm sure the drugs kept him alive, but the side effects, as he describes them, particularly to his legs and kidneys, were pretty severe. He only got better when he stopped taking them.
And that doesn't address the role that fiber plays in managing it (and the virtues of fiber for health in general that are coming to light at a rapid clip)
I believe statins reduce risk by about 30%, so there's a roughly 30% chance the statins have done good things for your dad.
(I think that's what the stats mean, right? I'm open to correction on this. I do believe the statin studies, I'm not a science denier. I think what I've said matches the science, as far as I understand.)