Your conspiracy theory approach to science backed by Youtube videos is obnoxious. The cause of Alzheimer's is still unknown, but most likely related to amyloid plaques. Diet may contribute. Or it may not. In a 38 year old, it's genetics. Period.
Breaking the site guidelines with throwaway accounts eventually gets your main account banned as well, so please don't.
For example in the video "Oxidized Cholesterol as a Cause of Alzheimer’s Disease", the sources cited are summarized here in this article - https://nutritionfacts.org/video/oxidized-cholesterol-as-a-c...
If you scroll down and click on the tab "Sources", the linked studies are there.
38 years is a long time, I don't see why the age makes you immediately conclude that it can only be genetic and not influenced by diet.
Getting obese is also genetic, some people can still be slim with the standard western diet, while others start gaining weight at a certain age.
Yey, if you eat right you will likely never get obese, even though you have an obesity-prone genetics.
If some people can get heart attacks at 38, why is it so surprising that they can also get Alzheimer's if they have been eating foods very high in fat and cholesterol multiple times a day non-stop since birth?
If Alzheimer's is triggered or strongly linked to dietary choices, at least we should be informed of that while the studies continue.
You may want to post peer-reviewed research papers backing those videos instead. It’s a lot easier to review.
https://nutritionfacts.org/video/oxidized-cholesterol-as-a-c...
You can see the sources by scrolling down and hitting the "Sources Cited" tab. Do you have reasons to believe that the information has been misinterpreted?