Alzheimer's disease may be inherited more often than previously known (opens in new tab)

Does everybody with two copies get Alzheimer’s? If not, then there must be at least one additional ingredient / cause.

I read a book called "Brain trust" last year about prion diseases being the cause of massive increases in Alzheimers cases. The idea was intriguing but one fact the author mentioned was about how the US does not test meat in decent intervals for CJD or other prion diseases, while Japan does. The book was written in the early 2000's so alot of the stuff that was posited can be checked today and that was one thing that I did check, comparing Japans rate of Alzheimers to the US and both countries are seeing the same huge uptick in cases. So it seems like its a global issue and not really one that is based in the US due to "potentially" infected meat.

On a side note I know alot of people(not related to me) that are being affected with severe memory issues in their 60's and 70's. A friends Dad is in a memory care facility and he is in his mid 60's and was extremely fit(he was also a avid hunter - unsure if this was a cause). My Wife's aunt's Mom (not related by blood to her) has severe dementia and is in her 70's and needs $7k a month constant memory care. A friends mom has sundowners and every day her memory "erases", my Friend was looking into memory care for her and was quoted $13k a month for this. All these cases seem quite strange as the individuals led normal lives and then just started suffering these extreme memory/brain issues. I do not know what is causing it but I think its alot more widespread than people know.