Sari Harrar
Readers Digest
December 27, 2021

Researchers know more than ever about how puzzles and twisters keep your mind sharp (Hint: Start with games that are tough!)

Tonya Brigham could never resist a good sudoku—or any sudoku. A 50-year-old smoothie-store owner and mother of two, from a suburb of Washington, DC, Brigham wrestled with the puzzles while waiting in lines, and raced to solve them in record time using strategies plucked from YouTube videos. “If it’s a 30-minute puzzle, I try to figure it out in 12,” she says. “Sudoku lets me challenge myself, take a breather, and then go back into the world’s chaos.”

After several years of sudoku­mania, Brigham noticed something unexpected: Her brain seemed sharper and more focused. “I didn’t have much, if any, brain fog during menopause,” she says. At her Smoothie King shop in Bowie, Maryland, she found she could easily put together employee work schedules in her head. “A lot of stores use an electronic scheduling tool, but I have all the data in my mind,” she says. “I can very quickly see the holes and how to fill them. It’s the same with inventory. I think I have that capacity because of the game.”

We call them games, but for many people, brainteasers and challenging puzzles are serious business. Tom Brady credits his seven Super Bowl champion­ships in part to high-tech brain-training games he performs on an app called BrainHQ. Queen Elizabeth keeps a crossword puzzle stashed in her royal handbag. Half the midlife and older adults in a 2019 University of Michigan survey said they play mentally challenging games to maintain or boost memory.

The games do seem to work. In one 2020 study, researchers at the University of Edin­burgh found that 1,091 women and men who frequently played cards, bingo, or chess or did crossword puzzles had sharper thinking and memory skills—­equivalent to an IQ up to 5.6 points higher—than those who rarely did. The study doesn’t prove that the puzzles directly led to the higher IQs, but it does show that even people who increased their game-playing in their 70s seemed to get brain benefits within a few years. “In our older sample, it appears that the cognitive exercise provided by playing everyday games staved off a bit of the natural process of cognitive aging,” says lead study author Drew M. Altschul, PhD, a research psychologist at the university.

Exactly how games sharpen memory and cognitive function is still something of a mystery. But advances in neuroimaging allows researchers to study how the brain reacts to all sorts of outside stimulation, edging them closer to understanding how noggin challengers work. “We’ve known for many years that physical exercise keeps our bodies strong,” says Gary Small, MD, chair of psychiatry at Hackensack University Medical Center and former director of the Longevity Center at the Semel Institute for Neuroscience and Human Behavior at the University of California, Los Angeles (UCLA). “And now scientific evidence suggests that mental exercise keeps our brains young and limber too.”Exercise really is the key word. To get significant cognitive benefit, you need to tackle a variety of word, number and spatial-reasoning puzzles, and they need to be tough.

Does Brigham’s sudoku habit really deserve the credit for her powerful memory? Perhaps. But for the activity to be really effective, you have to up the difficulty level pretty consistently. Our brains are pretty smart. They adjust to ­problem-solving patterns quickly and easily slip into a kind of automatic pilot. That default mode—­researchers call it the low-dimensional manifold—is great for helping us take care of daily business, such as folding laundry or catching a ball, without having to figure out each time how to do the task. But low-dimensional challenges aren’t tough enough to grow your brain. “Choose challenges that make you think harder,” says University of Sydney neuroscientist James Shine, PhD. “I know that’s not easy. It’s uncomfortable and frustrating. We make mistakes. Stress hormones kick in—and that’s actually helpful for getting your brain onto new routes. Learning happens when you feel a little uncomfortable—in that zone where you get some things wrong, but it’s not so difficult that you can’t get anything right.”

That said, the challenges don’t have to be the kind of high-tech, personalized games that Tom Brady uses. For instance, a sudoku fanatic could benefit by switching things up and trying a game called Latin square, in which players shade squares in the grid rather than inserting numbers. A few years ago, 60 women and men in Australia completed Latin squares as part of a study. As the puzzles grew more difficult, with fewer clues in each grid, players slowed down and made more mistakes. That’s when Shine and his team discovered something surprising: The players’ brains had made a shift. “More regions of the brain got involved, especially in the prefrontal cortex, an area involved with problem-solving, judgment and memory,” Shine says. “The brain was moving out of the usual patterns we follow every day, exiting the major highways it normally takes when solving problems, and taking less-travelled back roads.”

Another easy way to up your brain game is to play with friends. When University of Pittsburgh researchers performed detailed brain scans of 293 older adults for a 2020 study, they found healthier grey matter in the orbito­frontal cortex, middle frontal gyrus and temporal pole—areas where cell loss contributes to age-­related ­dementia—in those who spent the most time doing brain-­stimulating activities with other people. Those who met seven times a week with friends, neighbors, and family for activities such as playing board games; going to lectures, concerts or movies; or just chatting had fewer tiny holes and spaces in these pinkish-grey clumps of cells. Brains without holes are healthier. They process information faster, are more flexible and are linked to sharper memory in older adults. Cynthia Felix, MD, MPH, a geriatrician and post­doctoral associate in the University of Pittsburgh Graduate School of Public Health’s department of epidemiology, thinks that brain-stimulating social activities may encourage the growth and maintenance of connections between the cells because the activities keep brain signals moving. That said, even a little socializing can help keep your grey cells in the pink. “To get brain health benefits, social activities can be performed with at least one other person at least once a week,” Dr. Felix says. Online virtual get-togethers may help too.

Kent Brody, a 73-year-old attorney from the Chicago area, exemplifies the game-player who incorporates his habit into a full life. By 6:30 a.m., he is hard at work on the New York Times mini crossword puzzle with a cup of coffee and Mozart playing on the smart speaker in his study. “I do three or four puzzles a day—from the New York Times, the Wall Street Journal, the Los Angeles Times and other places,” says Brody, who has competed 15 times in the American Crossword Puzzle Tournament. “I do it for fun, not for the cutthroat competition,” he says.

He also relishes the head-spinning difficulty of cryptic crossword puzzles, a type popular in the United Kingdom that features very challenging clues. “The feeling of accomplishment is wonderful when you get that aha moment and see the cleverness of the person who constructed the puzzle,” he says. Brody also enjoys Words with Friends, an app that lets you play a Scrabble-like game online with other people. He hopes his puzzle habits will help forestall age-related thin-king and memory declines that have affected others in his family. “Everyone has moments when they can’t come up with a name, but I want to avoid bigger problems,” he says.

A word about fun: While specific games seem to tickle specific parts of our brains, researchers have long touted themore general benefits that come from giving the mind an enjoyable time-out. “You have to play because it is relaxing and enjoyable, and it challenges you at the same time,” Dr Small says. “There are neurochemical changes involved in every mental experience. A positive mood is better for brain health. In contrast, depression and stress increase risk for cognitive decline. That’s why, when playing a game, you have to ask yourself, Is this fun?” In fact, Brigham recently stopped playing sudoku in favour of something she found more enjoyable: Bible study apps. This fun new activity might deserve some credit in helping her brain work better too.

If you’re willing to put down your pencil for something more high-tech—and potentially more ­effective—take a page from gamers. Two studies, published in 2015 in the Journal of Neuroscience and in 2020 in Behavioural Brain Research, found that adults young and old who played the Super Mario 3D World video game for 30 minutes a day for two to four weeks improved on tests of associative memory, which includes remembering things such as what you had for lunch or what you told your spouse a few hours earlier. “It’s a kind of memory that starts declining in our 20s and is associated with Alzheimer’s disease later in life,” says the lead author of the study, Craig Stark, PhD, professor of neurobiology and behaviour and director of the Facility for Imaging and Brain Research at the University of California, Irvine. “The change we saw in older adults in memory ability was equivalent to someone 15 years younger.” The study also found that a solitaire app did nothing to affect memory and that the older study volunteers who played the simpler game Angry Birds got only a little boost.

What’s so super about Mario? Stark believes that complex, three-­dimensional video games have the same effect as when our brains are forced to navigate new, immersive environments. A study of Stark’s, published in 2020 in Frontiers in Aging Neuroscience, found that people who went on scavenger hunts—­following clues for signs, benches, towers and gates in several California parks—scored significantly higher for memory skills. Both experiences seem to stimulate the seahorse-shaped hippocampus, which plays a starring role in learning and memory. Ageing and chronic health conditions such as high blood pressure and diabetes diminish its powers, contributing to age-related lapses and even dementia. Stark thinks that exercising the hippocampus could counteract these things. He’s seen something similar in studies on mice and other animals that play with new toys and then experience a boost of chemicals that carry signals from one brain cell to another.

There’s good news and bad news related to these findings. The good news: “Even just carefully looking around you at everything in a room, at where objects are placed in relationship to one another, can help. So can getting outdoors and going to new places,” says Stark. The bad news: “The New York Times Thursday crossword puzzle won’t do for you what putting yourself in a new environment can,” he says. “Humans didn’t develop a whole hippocampus and memory system to sit on a porch playing crossword puzzles.”

Perhaps, but that doesn’t mean your preferred puzzle isn’t helping you. Truth be told, there is considerable debate in the world of neuro­biology about what does and doesn’t work to grow our brains. “People don’t respond to physical exercise programs or diets in the same way. We have evidence they don’t respond to brain challenges in the same way either. One type of game or training may work well for some people but not for others,” says Aaron Seitz, PhD, director of the Brain Game Center for Mental Fitness and Well-Being at the University of California, Riverside. Seitz is in the process of recruiting 30,000 volunteers for what may be the world’s biggest brain-game study. Funded by the National Institute of Mental Health, it will look at the effects of a variety of games and trainings on working memory in people of various ages, personality types, and levels of game experience and with different conditions such as diabetes and heart disease that can affect brain health. “The challenges won’t all be games,” Seitz says. “We think some people respond better to plain training programs without the extra distractions of a game.” Subjects will play a free 20-to-30-­minute game or take a training program twice a day for a total of 11 days on a smartphone or tablet. They will fill out a questionnaire beforehand and take an assessment months later. (Learn more at bgc.ucr.edu/trainmymemory/.) “The results could help brain scientists build better brain-­fitness programs and aid consumers in choosing brain challenges best suited for them,” Seitz says. That data is sorely needed.

“Finding out how games and brain trainings work and exactly how much they help is complicated,” Dr. Small notes. For one thing, a game may train you only to play that game better, not to remember the grocery list or your new neighbour’s name. And studies of brain benefits for long-term game players may not fully factor out their other habits. “People who play games regularly also tend to have more education and be more likely to exercise, eat a healthy diet and not smoke,” Dr. Small says. “All those factors also influence brain health.”

One fact all researchers embrace: Your brain loves pampering. If your goal is to slash the risk for dementia, ongoing research suggests that your little grey cells will work better if you eat well, exercise and pay attention to artery health in addition to playing brain games. Following a ­Mediterranean-style diet packed with produce and good fats, getting regular exercise and maintaining healthy blood pressure and body weight along with brain-­training games slashed risk for the thinking and memory declines that lead to dementia by 25 per cent compared to a control group in a 2015 Finnish study. Participants in the study, called FINGER (Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability), also boosted memory by 40 per cent and increased mental processing speed by 150 per cent. An American version of the study, called U.S. POINTER, is underway at several universities. Cosponsored by the Alzheimer’s Association, the two-year study will involve 2,000 older adults who don’t have thinking and memory lapses but are at risk for declines. Dr Small agrees that an all-around brain-health strategy can be powerful. In research at UCLA, he found that just two weeks of eating and sleeping better made volunteers’ brains function more efficiently. “There was less activity in certain areas,” he says. “The brain didn’t have to work as hard.”

In fact, Dr Small suggests that if you find yourself debating whether to spend the next 20 minutes taking a walk or playing a brain game, you should choose the walk. Physical activity can help keep the arteries that deliver oxygen and fuel to your brain cells healthy and can even promote the growth of new brain cells and connections between them. “If you do one thing to help your brain, I’d say it’s exercise,” he says. “Reducing stress and getting good sleep and a healthy diet are also important. Brain games work best as part of a whole package of brain-healthy strategies.” And remember: A little fun never hurts.