The One Brain Exercise That Works (Hint: It Isn't Crosswords)

I can't tell you how many people have told me, proudly, that they do the crossword every morning to keep their brain sharp. Their mother did it, a doctor mentioned it once, and it just feels right. For years I nodded along, and it turns out we were all wrong.

A big new study just landed, and it's the kind that actually changes the advice. Researchers followed more than 2,800 healthy older adults for twenty years. That's two decades, not two months. The results came out this year in the journal Alzheimer's and Dementia, and the National Institutes of Health paid for it. So this isn't a supplement company trying to sell you a subscription.

What the study actually did

Here's what they did. They took healthy folks over 65 and split them into groups. One did memory training. One did reasoning training, the logic-puzzle kind. And one did something called speed training. Then they waited, and waited, and checked who ended up with dementia twenty years down the road.

The crossword-and-puzzle crowd showed no benefit at all. The memory training and the reasoning training, the stuff that looks like the brain games everybody buys, did not lower anybody's risk of dementia. I know, I didn't want to believe it either.

The one that worked was the speed training. Those folks had about a 25 percent lower risk of being diagnosed with dementia twenty years later, a quarter lower, from a handful of sessions.

So what is speed training?

It's not trivia or Sudoku, it's quick visual stuff, where things flash on a screen and you have to spot them and react fast. Researchers call it processing speed. In plain English, it's training your brain to take in what's around you and respond in a split second. It's the same skill you use when a kid darts out in front of your car and you hit the brake before you've even finished the thought.

That's the part that stuck with me. The brain skill that seems to protect you isn't recalling a fact, it's reacting fast to the world right in front of you.

A few honest things before you start

First, this was a specific kind of training, not just playing fast video games. The exercises go by names like processing speed or useful field of view. So if you want to chase this, look for that, not a generic brain-game app making big promises.

Second, the people who got the biggest benefit didn't do it once and quit. They came back for a few booster sessions over the next couple of years. Like everything else that's good for you, a little kept up over time beats a big burst and done.

Third, don't throw out the crossword. If you love it, keep doing it, it's a fine way to spend a morning. Just don't tell yourself it's holding dementia at bay, because this study says it isn't doing that job.

I'm not telling you this to scare you, it's the opposite, really. For once the research points at something simple, cheap, and in your control, not a pill and not a procedure. Just training the quick, alert part of your brain, and keeping at it.

So the next time somebody tells you they do the puzzle every day to stay sharp, you'll know the friendlier truth. It's a lovely habit, but if you really want to protect that mind of yours, work on your reflexes.