It's a hell of a lot more likely to find the primary causes of Alzheimers outside of the human body imo, medicines/pollution/additives/radiation etc.
The human body is a pretty amazing construction, nature doesn't make a lot of mistakes.
There is a strong correlation (noting my word choice here before the incorrectors accuse me of confusing it with causation) between general anesthesia and onset of dementia. I’m not going to dig it up, but it is easy enough to find on pubmed. There is a decent amount of noticing in the literature.
It makes a lot of mistakes. Without modern medicine we wouldn't live this long. Alzheimer's is not a modern disease.