We don’t currently have any data that shows any clear way to halt or slow Alzheimer’s.
As someone with family affected by this disease, it’s a very personal choice whether you want to know or not, but I wish people understood that there are many things you can do with it, particularly for those who will be there for you if/when it hits.
Taking care of a loved one with this disease is extremely hard, and it’s even harder when they haven’t had any chance to prepare for this eventuality. Stuff like written records of your history (health, life, etc.), clear powers of attorney, and so on.
It also makes things much easier for healthcare professionals.