I had a problem with this thread because other members wanted a serious response. Should I ignore them, try (as always) to help, or add to the humour ? On a forum with 500 or so active members it's impossible to keep everyone happy ! Maybe the answer is to put me on your "ignore" list.
However, for those who do look for advice, the role of genes and Alzheimer's is NOT understood, nor is its cause. Until we do understand the cause(s), "good all round living" (as you put it) is the best way to reduce your chances of getting it . Read more on the links provided