My point is, if you live to be 80, you won't be any less likely to get Alzheimers if you're rich. So there's not really a correlation between 90 year olds walking around NYC dementia-free and the fact that they're wealthy enough to live to 90.
I lived a couple years in a working class farm town in Spain where the old people were mostly not wealthy by but were really physically fit and mentally sharp. I think it was due to them having constant social interaction, every day walking around the plazas talking with their elderly friends. Some of these people were living alone in their mid-90s, and their diet mostly consisted of fried sardines, pork, olives, and cheap local wine. So living a good full life may be better protection against the ravages of dementia than living a wealthy one.
I lived a couple years in a working class farm town in Spain where the old people were mostly not wealthy by but were really physically fit and mentally sharp. I think it was due to them having constant social interaction, every day walking around the plazas talking with their elderly friends. Some of these people were living alone in their mid-90s, and their diet mostly consisted of fried sardines, pork, olives, and cheap local wine. So living a good full life may be better protection against the ravages of dementia than living a wealthy one.