What factors have been identified to account for the projected increase in Alzheimer's reported by the Alzheimer's Association?
In particular they note:
An estimated 5.7 million Americans of all ages are living with Alzheimer's dementia in 2018. This number includes an estimated 5.5 million people age 65 and older and approximately 200,000 individuals under age 65 who have younger-onset Alzheimer's.
I am most interested in factors outside of age or genetics which I can't do much about.
Also, I don't know how to research a question such as this outside of an internet search. Hopefully the references in any answers will give me a hint on how I can research questions such as this better myself.