The diabetes/metabolic theory was one pitched theory, and it isn’t even a terribly mainstream one. There is no consensus that Alzheimer’s is a “metabolic disease”. Even thought ApoE is implicated, that association could be explained by numerous mechanism, even viral.

Thanks for clarifying. I'm no expert just passing on things I've read.

Regardless, it's unrelated to prions.

No expert, but the latest studies have been about the correlation with the herpes virus and how the plaque build-ups that are part of Alzheimer's may be the immune system's attempt to protect the brain.