I don't have access to the full New Scientist article but the headline and first 2 graphs appear to be a bit overblown. It's clear that as of the moment I am typing this reply, scientists do not know exactly what causes Alzheimer's disease nor how to fully ward it off or cure it. It's likely more than one cause, more than one path. Lots more to investigate. I wrote about SOME aspects of this recently, here: https://medium.com/wise-well/our-brains-are-mysteriously-shrinking-and-deteriorating-prematurely-66ce651aa912