So it is useless to consume ibuprofen and the like, to avoid the disease :(

From my own research (ie googling), your best bet is to build up the brain, so if the decline starts, you have a stronger starting point. This means exercise[1], B12, folate, CDP-choline[2], turmeric[3], coconut oil (medium chain triglycerides) [4]. Also, I avoid paracetamol, there are some claims about it being linked to dementia. There are some promising drug trials (aducanumab for example), but we'll have to wait and see.

[1]https://www.health.harvard.edu/blog/regular-exercise-changes...

[2]https://en.wikipedia.org/wiki/Citicoline

[3]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2781139/

[4]https://coconutketones.com

paracetamol is acetaminophen(Tylenol) for the Americans in the audience.