Strattie,
I was concerned with he same issue (especially because Dad died a few years ago with a severe dementia) and thus, watched a few documentaries made with neurologists experts on this matter.
What I recall is when they talked about the hyppocampus ipart of the brain that must be stimulated to make new routes and connections to avoid the ''scarves'' efect in that area when people are aging.
So I still used 3 things they mentionned:
1) each night when I get into bed try to view my home form above and see the floor plan of each room. (very good exervice)
2) I try to stay away from the GPS to trace my itinerary...I look on a 2d google map (sometiems print it) and then use the old good method and still use my brain to find where i am located in a city and to know the directions.
3) I learn new languages (english and spanish) This is one of the best thing since learning a new language uses part of the brain that will prevent alzheimer and dementias to developp.
And I will stick to it as long as I can, like coming on ESMB to perfect my english.
Although, one thing that will allow dementias to developp, are the routines; Doing the same things, same places, same people, and avoiding challenges, new things, new places, new people. So we must remain intellectually and socially curious and willing for new adventures.