I think the 90+ study at UC Davis knew years ago that some people had evidence of plaques and tangles but didn't have dementia, the question then was why (and IMO still is).
What is the most interesting is that doc's have long thought it was the build-up of plaques and tangles that caused dementia. Now there are people with plaques and tangles that do not experience symptoms of dementia. Is it back to the drawing board?
According to Dr. Joel Wallach. ND. (youngevity) Alzheimer's is a doctor created disease, caused by the use of Statin drugs. Take them off statin's and put them on a good Vitamin & Mineral supplement and within a week or two you will see a remarkable difference.