A brain-training game that takes less than 2 hours a week can reduce your risk of developing dementia by 25%, study finds

• An online speed training game can lower your risk of developing dementia by 25%, a new study suggests.
• People who played memory and reasoning games didn't get the same long-term benefits.
• Researchers aren't sure why speed training is so good for your brain, but it might boost connectivity.

A groundbreaking new study suggests you may be able to train your brain to stay healthier as you age — but you have to pick the right game.

The study results stunned neurologist Marilyn Albert, one of the researchers who analyzed the data.

"It's an astonishing result," Albert, who directs the division of cognitive neuroscience at Johns Hopkins School of Medicine, told Business Insider. "It's absolutely made me think that I have to get online and do the training."

The ACTIV study, funded by the US National Institutes of Health, is the largest cognitive training study in the world. It was conducted over 20 years with a diverse group of 2,000 people aged 65 and up across the US.

Though the study was independent and academic, the winning brain-training is available online through a company that Albert is not affiliated with, called Posit Science. The company's Brain HQ website and app offers more than two dozen cognitive games, but only one of them was included in this study, and it was the only game in the study that had a measurable effect on a person's long-term dementia risk.

Speed training seems to help the brain stay connected as we age

During the study, participants were randomly divided into four groups: one control group with no training, and three active groups that each tried one particular game that researchers thought might help improve cognition as people age, based on earlier research.

The games included:

• A memory game, which is not commercially available
• A problem-solving and reasoning game, also not commercially available, and
• The winning speed training game, which is called "Double Decision"

Only the speed training participants showed significant, long-term improvements to their brain health: they had a 25% lower risk of developing dementia, compared to the others. The researchers used Medicare claims data to track dementia diagnoses over time.

The study didn't require participants to do that much training, either. People in the study did roughly one or two 60- to 75-minute training sessions each week, for an initial period of 6 weeks. Then, they were given "booster" sessions, up to four 75-minute training sessions, roughly one year later, and again up to four more sessions three years later.

What's it really like to play this game? Hard.

For years, the general advice for how to lower your risk of developing dementia has been pretty vague: eat a healthy diet, get some exercise, and control high blood pressure.

"To me, this changes the conversation," Albert said. "It's enormously convincing."

Retired teacher Joyce Grego, 71, has been playing Double Decision for years. She wasn't in the study, but started doing BrainHQ exercises around 2019, as she was learning more about brain plasticity and regeneration.

"People used to think that your brain was static, it didn't grow," she said. Now she does a few brain games every day.

Grego said she feels different from her peers now, sharper. She's better than others at word recall, she said, and she notices little things her peers don't, especially when she's out driving around town, picking up little things in her peripheral vision like the plastic covers over plant beds on the side of the road during a recent cold snap.

"I just am very aware of my surroundings, and I feel like I take so much in, and I just attribute it to this, especially Double Decision," she said. "I know that my awareness has developed."

The game doesn't only require dual tasking, it also adjusts to your ability, speeding up as you improve, slowing down if you're having trouble playing. That adaptive nature of the game may be a key part of its success: it's always working at your limits, providing you with the right level of challenge, pushing your abilities just a little bit. That adaptability is similar to another successful online video game called EndeavorOTC, which was recently approved by the US Food and Drug Administration to treat adult ADHD. Neither of the other brain games people played in this study were adaptive like that.

"It goes really fast," Grego said. "And sometimes when you're doing it, you feel like, I have no idea where this is, what circle I'm supposed to hit. But you do know. Your brain encompasses and sees the whole image."

Grego is a true believer in BrainHQ and has tried to recruit family members and friends to do the exercises, even paying for some subscriptions for them, which run from $8 to $14 per month. Some have tried it, but many quit, complaining it's too hard or too time-consuming.

"Hard is good," Grego said, alluding to the idea of hormesis, the concept that a little bit of stress and challenge is good for our longevity. "You feel like you're improving cognitively because you're making progress and you're able to pick these things up that are put to you in literally milliseconds."

Why does it work?

For now, scientists like Albert can only venture guesses as to what's going on when people are playing this game, why it seems to have a measurable impact on brain health and dementia risk over the course of decades.

"My guess is that this cognitive training task does something with brain connectivity," Albert said. There might be something about the speed training that helps maintain connections between different areas of the brain, which diminish as we age. "That's my guess — but we don't have any data at all."

Could other tasks we do off-screen that require a lot of speed and dual decision-making do the same thing? There are elite brain gyms that offer dual-tasking exercises, and sports like tennis or judo that challenge players to react to multiple stimuli at the same time. Could those kinds of activities give you the same benefits?

"I wish I could say yes, because I don't want to have to say that you have to do this task," Albert said. "The task is pretty tedious."

Unfortunately, scientists just don't know for sure how or why this works. "We obviously need to understand the mechanisms better," she said.