I've found that a good way to get a crowd's attention is to say "everyone in this room is going to die." Then, over the stunned silence, I say, "but not today, and probably not soon." Then I move on to the message. At that point, everyone is facing front.
Whenever something -- smoking, firearms, cholesterol, pollution, driving like an idiot -- is cited as a cause of "preventable death," I get annoyed. There are no preventable deaths. Just postponable. Ad te omnis caro veniet.
In all these years here I have not come across many of your posts but you are hitting the nail on the head on this thread.
I like that attention getter you use wonder if that would work for our biology teacher friends at the high school at least once anyway.