Many people think that doing crossword and Sudoku puzzles will do the trick in keeping their brains healthy and warding off Alzheimer's. But research suggests they're probably not enough, for two reasons:
First, they affect only very specific thinking processes. For example, crosswords only train a single brain function, known as semantic memory
, out of a total of dozens. So doing Sudoku and crosswords would be like working out only your biceps or abs; these exercises don’t do all that much for the rest of your body.