One day, we may have the legendary puzzle creator Will Shortz to thank for defending our brains against the ravages of aging. Spending extended time with a crossword or number-based puzzle, scientists show, has incredible potential to keep memory sharp, even when time begins to take its toll on the brain.
Over the course of two years, Anne Corbett, Ph.D., a senior lecturer in dementia research at the University of Exeter, has worked on two studies that point to the anti-aging power of word-based puzzles like crosswords and number-based puzzles like Sudoku.
In both studies, she leveraged data from the UK-wide PROTECT study, a massive survey of data on aging brains. Corbett and her team used data from 19,078 participants between 50 and 93 years old and found that people who did word- or number-based puzzles had far better scores on tests measuring 14 different types of cognition. She and her team reported their findings on word puzzles in November 2018 and number puzzles in February 2019 the International Journal of Geriatric Psychiatry.
These studies show that older adults who frequently pick up a puzzle tended to have the short-term memory capacity of someone eight years their junior and the grammatical reasoning of someone 10 years younger.
“We hope this will encourage people to consider how they challenge their brain on a regular basis, and perhaps consider taking up puzzles or evidence-based brain training games as part of a lifestyle approach to keep their brains healthy,” Corbett tells Inverse.
The Benefits of Word and Number Puzzles
Corbett’s study is one of a few showing that frequent engagement with puzzles has lasting effects on memory and cognitive decline, the slow loss of memory and other problem-solving skills that accompany aging (and is also a feature of brain diseases like Alzheimer’s). Other studies include the Bronx Aging study, which showed that dementia patients who did crossword puzzles started to lose their memory about 2.54 years later than those who didn’t do crosswords.
"No other study has this size cohort completing such sensitive brain function tests."
We can’t exactly draw clinical conclusions from Corbett’s study just yet — all of her participants were healthy individuals who didn’t have brain diseases — but for anyone who just wants to maintain their mental edge later in life, her results are powerful. “PROTECT is the largest online cohort of older adults,” she says. “No other study has this size cohort completing such sensitive brain function tests.”
Comparing people who did word puzzles with those who didn’t, Corbett saw the starkest differences in grammatical reasoning tests, pattern recognition tests, and attentional intensity indexes. Those who never did puzzles were “significantly inferior” to people who did any level of puzzles, even only a few times per week.
Meanwhile, people who frequently engaged in number puzzles had better episodic memory — the long-term memories that incorporate emotions and context, in addition to facts. They also performed well in tests of spatial working memory, which involves remembering cues about a physical environment, and they showed improvements in attention, processing speed, and executive function.
Why These Puzzles Protect the Brain
These results double down on the idea of “use it or lose it,” says Corbett, a phrase that encapsulates the cognitive reserve hypothesis. This idea posits that there are things we can do during our lives to help protect against declining memory or even dementia in later years.
Education is often listed as one of those things (though there’s some evidence that complicates that idea). Leisure activities, like exercise, may also help fortify the brain. Now, based on Corbett’s results, we can add crossword puzzles and Sudoku to the list.
“Doing word and number puzzles stimulates parts of our brain that handle problem-solving and memory, as well as other functions like concentration and attention. This is probably why these aspects of brain function showed the most impact in our research,” she explains.
Corbett herself isn’t a daily crossword doer. “I try!” she says, noting that she does pick up a puzzle every now and then. Her results, however, suggest it’s worth building in some time with a puzzle book or an app into your daily schedule. Even if it doesn’t pay off now, the results may manifest when they really count.
Objective: Establishing affordable lifestyle interventions that might preserve cognitive function in the aging population and subsequent generations is a growing area of research focus. Data from the PROTECT study has been utilised to examine whether number‐puzzle use is related to cognitive function in older adults.
Methods: Data from 19 078 healthy volunteers aged 50 to 93 years old enrolled on the online PROTECT study were evaluated for self‐reported frequency of performing number puzzles. Two cognitive‐test batteries were employed to assess core aspects of cognitive function including reasoning, focussed and sustained attention, informa- tion processing, executive function, working memory, and episodic memory. Analysis of covariance was used to establish the differences between the six frequency groups.
Results: Highly statistically significant main effects of the frequency of performing number puzzles were seen on all 14 cognitive measures, with P values of less than 0.0004. Interestingly, participants who reported engaging in number puzzles more than once a day had superior cognitive performance on 10 core measures compared with all other frequency groups, although not all were statistically significant. Conclusions: This study has identified a close relationship between frequency of number‐puzzle use and the quality of cognitive function in adults aged 50 to 93 years old. In order to determine the value of these findings as a potential intervention, further research should explore the type and difficulty of the number puzzles. These findings further contribute to the growing evidence that engaging in mentally stimulating activities could benefit the brain function of the ageing population.