> N=1 but my grandpa loved doing the NYT crossword and still ended up with absolutely terrible Alzheimer's. Notably the article only mentions a 9 to 11 percent

> N=1 but my grandpa loved doing the NYT crossword and still ended up with absolutely terrible Alzheimer's. Notably the article only mentions a 9 to 11 percent reduction, so I wonder what the mechanism at play here is (or if there's some sort of reversed cause and effect here, i.e. people with a certain brain characteristic that reduces Alzheimer's are more likely yo play crosswords etc.). Good question - I'm also curious the effectiveness of this vs placebo. Does any regular critical thinking help stave off Alzheimer's?