I have an aunt in the early stages of dementia and she's 75 I think. They haven't called it Alzheimer's yet but she's going the same way one grandmother and several aunts did. Fortunately she realized on her own that she shouldn't be driving anymore. It's got to be one of the most evil disorders known to man.

It is all about the brain aging. The Life Extension Foundation has the answers to slow aging.

You can have your DNA tested now for $200 to find which genes can cause problems. They have used Artificial Intelligence to look at thousands of research reports to determine what nutritional supplements slow or reverse aging.

You can read about some of the findings in the April issue:

http://www.lifeextension.com/Magazine/2017/4

Went down this path with my mom and 5 years later, my dad. These events occurred ~20 years ago and the delayed stress on me was a life changer.

"The 36 Hour Day" is a book I have recommended to all who have to help others with this miserable event. It helps the care givers to understand what the patient is living with, their decent into the illness. Also what, and how you can help.

Our neighbor, mentioned in the OP, passed away late last night. Our sadness is mixed with relief in the knowledge, he is no longer in pain or torment, and there is some relief for his wife, although the devastation of her loss will still be with her.