Probably not. you'd have to prove that people who were able bodied in their youth are less likely to have dementia than people with disabilities or bad physical health. To my knowledge there is no such link. Besides, a big part of this sample was from the US who didn't enter the war before the very end of 41 (December 7th so might as well be 1942). Occupied Europe also didn't really have it's men "away at war". Also, men at war, even during WW1, were able to go back home from time to time, so I don't think the argument holds.
> a big part of this sample was from the US who didn't enter the war before the very end of 41 (December 7th so might as well be 1942). Occupied Europe also didn't really have it's men "away at war"
The nail in the coffin for the hypothesis is the lack of significant variation between the US and European cohorts. Europeans were killed indiscriminately. Our men were selectively slaughtered. If there was a selection effect, you'd expect that to present in the American cohorts and not European ones; that is not observed.
