Many people believe that doing crossword puzzles can keep the brain sharp, and even prevent Alzheimer’s.

But it’s probably not true. Research suggests that while crosswords can form one part of a brain fitness regimen, they aren’t enough by themselves. And a recent study that pitted crossword puzzles against Posit Science brain training found that BrainHQ training improved cognitive function while crosswords seemed to have no positive effects.

Crosswords may help with a brain function called fluency, or word finding. Fluency is a type of process based in the speech and language centers of the brain. But watch out: only crosswords that challenge you can help your brain improve its function. Crossword puzzles that are too easy won’t help—you have to push yourself to the next level to change your brain. And although fluency is an important brain function, it’s just one of many.

Crosswords might not keep you sharp, but they are fun! Try our brain-trivia crossword to see how much you know about the brain. Or, to learn more about research on the effects of crosswords vs. brain training, read about this independent, peer-reviewed study in 681 participants.