Sudoku vs Crossword: Which Is Better for Your Brain?

Pick up almost any newspaper and you’ll find them side by side: a crossword and a Sudoku. One is all words, the other all numbers. Fans of each tend to be loyal, and both are often described as “good for the brain”. So if you only have ten minutes over breakfast, which should you choose? Here is an honest comparison of the skills each puzzle uses, what the research really shows (and doesn’t), and a simple way to decide.

The short answer

Two puzzles, two kinds of thinking

Crosswords and Sudoku look like cousins, a grid of squares to fill in, but they ask your brain for quite different things.

What a crossword asks of you

A crossword is mostly a memory-retrieval puzzle. You read a clue, then search your store of words and facts for something that fits both the meaning and the number of letters. That draws on:

• Vocabulary and word knowledge: knowing that a “small, flightless New Zealand bird” is a kiwi.
• Recall: pulling a word you know out of memory, sometimes after a frustrating “tip of the tongue” pause.
• General knowledge: geography, history, films, sport, whatever the setter likes.
• Flexible reading: spotting puns, double meanings and, in cryptic crosswords, hidden wordplay.
• Using crossing letters: a few letters from other answers narrow down the options, a small piece of logic.

Because crosswords depend on what you already know, they reward a lifetime of reading. They also depend on language and culture: a crossword written in British English, full of local references, can be hard for someone who grew up elsewhere, however clever they are.

What a Sudoku asks of you

A Sudoku is a reasoning puzzle. There is nothing to know in advance except one rule: each row, column and 3×3 box contains the digits 1 to 9 once. Everything else is worked out on the page. That draws on:

• Logical deduction: “this 7 can only go in one cell of this box, so it must go there”.
• Working memory: holding “this row still needs 3 and 8” in mind while you check a column.
• Sustained attention: scanning 81 cells without losing your place.
• Pattern recognition: spotting pairs and other shapes in your pencil marks on harder puzzles.
• Checking your own work: noticing when a placement breaks the rule and backing up.

The digits are only symbols. You never add anything up, so you don’t need to be “good at maths”, and you don’t need to read any particular language. That makes Sudoku unusually open to everyone. If you’ve never played, our beginner’s guide explains the rule and your first moves.

Sudoku vs crossword at a glance

The last two rows are where most articles go wrong, so let’s look at them properly.

What the research actually says

There are three studies people usually mean when they compare word and number puzzles. They are very different kinds of study, and that matters a lot.

The PROTECT study: word and number puzzles, 19,000 adults

In 2019 researchers from the University of Exeter and King’s College London, led by Helen Brooker and Anne Corbett, published two companion papers in the International Journal of Geriatric Psychiatry. Both used the online PROTECT study: 19,078 cognitively healthy adults aged 50 to 93 said how often they did puzzles, on a six-point scale from “more than once a day” to “never”, and then took a set of standard online thinking tests.

• Word puzzles (such as crosswords): how often people did them was linked to their scores on all 14 cognitive measures, covering attention, information processing, executive function, working memory and episodic memory. People who never did word puzzles scored lowest on every measure.
• Number puzzles (such as Sudoku): the same pattern, again on all 14 measures. People who did number puzzles more than once a day did best on most core measures, though not every difference was statistically clear.

In the university’s press release, the researchers put it in years: on grammatical reasoning, regular word-puzzle users performed like people about ten years younger, and on short-term memory about eight years younger. Regular number-puzzle users did about as well as people eight years younger on problem-solving measures. These are estimates from the press release, not a measure of “brain age”.

For our comparison, the key point is simple: both kinds of puzzle showed the same kind of link. This study gives no reason to think one is better than the other. And, as Dr Corbett said, “We can’t say that playing these puzzles necessarily reduces the risk of dementia in later life.” The authors also wrote that future research should look at the type and difficulty of puzzles before judging them as an intervention.

The Bronx Aging Study: crosswords and memory decline

An older American study followed 488 people in the Bronx, New York, who had no thinking problems at the start, with check-ups every 12 to 18 months. The 2011 analysis, led by Jagan Pillai and Joe Verghese and published in the Journal of the International Neuropsychological Society, looked at the 101 people who went on to develop dementia.

Among them, those who did crosswords at the start of the study reached the point of faster memory decline about 2.5 years later than those who didn’t. Note what that does and doesn’t say: the crossword fans still developed dementia, the study observed people rather than assigning puzzles, and it didn’t include Sudoku. The authors themselves said the role of crosswords should be tested in clinical trials.

The Columbia and Duke trial: crosswords vs computer brain games

This is the one behind headlines like “crosswords beat brain games”. Researchers at Columbia University and Duke University, led by D.P. Devanand and P. Murali Doraiswamy, published it in NEJM Evidence in 2022. Unlike the studies above, it was a randomised trial: people were assigned to one activity by chance.

• Who: 107 adults with mild cognitive impairment (MCI), a stage of memory or thinking problems that is more than normal ageing but not dementia. Their average age was 71.
• What: at home, on a computer, either web-based crosswords (of medium difficulty, compared to a New York Times Thursday puzzle) or a set of computerised cognitive games covering memory, matching, spatial skills and speed. Both groups trained in 30-minute sessions, four times a week for 12 weeks, then had short “booster” weeks up to week 78.
• Result: on the main memory-and-thinking scale (ADAS-Cog, where lower is better), the crossword group improved slightly, from 9.59 to 8.61, while the games group got slightly worse, from 9.53 to 9.93. That difference of about 1.4 points on a 70-point scale was statistically significant, but modest.
• Other findings: a questionnaire on everyday functioning worsened more with games, and MRI scans showed more shrinkage of the hippocampus and cortex in the games group. Most other secondary measures showed no difference.

So the trial is interesting, and it’s good news for crossword fans with mild memory problems. But it compared crosswords with one set of computer games, not with Sudoku, and it can’t be stretched into “crosswords are better for the brain than Sudoku”.

Link, cause and the chicken-or-egg problem

Most of what we know about puzzles comes from studies that observe people rather than assign them an activity. Those studies can show that two things go together, not that one causes the other. Here is why that matters:

• Sharper minds may choose puzzles. People who are good at reasoning or words probably enjoy puzzles more, so they do more of them. In that case, the sharp mind comes first and the puzzle habit follows.
• Other things travel with puzzles. Education, reading, income and general health are all linked both to puzzle habits and to test scores. Researchers adjust for what they can, but not for everything.
• Early changes can stop the habit. Someone whose thinking is starting to slip may find puzzles harder and give them up, which makes non-puzzlers look worse.

A long-running Scottish study, which we cover in Is Sudoku good for your brain?, found that intellectually engaged people started old age from a higher level but declined at the same pace. That fits the idea that engagement raises your starting point rather than protecting you from decline.

Which one should you choose?

Since the research doesn’t crown a winner, the best way to choose is by what you enjoy and what you want from your puzzle time.

Choose Sudoku if…

• You like the feeling of working something out from scratch, with no trivia required.
• You want a puzzle that is always fair: a well-made Sudoku can be solved by logic alone, without guessing.
• You’d like clear difficulty levels so you can step up gradually.
• English isn’t your first language, or you want something the whole family can share across languages.
• You enjoy a quiet, focused break, the kind we describe in Sudoku for stress relief.

Choose a crossword if…

• You love words, reading, puns and general knowledge.
• You enjoy solving with someone else, calling out clues across the kitchen table.
• You like a puzzle that rewards what you’ve learned over a lifetime.
• You enjoy the hunt for a word that’s just out of reach.

Why doing both is the best answer

If one puzzle is mostly recall and the other mostly reasoning, the obvious conclusion is that a mix covers more ground than either alone. There is no study proving that a mix is better for your brain, so we won’t claim that. But variety has some sensible, everyday advantages:

1. It uses more of your thinking. Word puzzles work your vocabulary and memory for facts; number puzzles work your logic and attention.
2. It keeps things new. Once a puzzle becomes automatic, it asks less of you. Switching keeps a bit of challenge in the routine.
3. It keeps you interested. A habit you enjoy is a habit you keep, and boredom is the main reason people stop.
4. It suits your mood. Tired? A crossword you can dip in and out of. Want to switch off from words after a day of emails? A Sudoku.

It’s also worth keeping puzzles in perspective. The World Health Organization’s guidelines on reducing the risk of cognitive decline and dementia focus on healthy behaviours and lifestyles, such as staying physically active, and on managing health conditions linked to dementia risk. A crossword or Sudoku is a pleasant part of a healthy life, not a replacement for moving your body, seeing your doctor and spending time with people you like. Our guide to Sudoku for seniors has more on combining puzzles with movement and company.

A simple weekly puzzle mix

If you’d like to try both, here is an easy pattern. It isn’t a prescription, just one way to bring variety into a short daily habit of 10 to 20 minutes.

A few tips to make it stick:

• Find your level. Aim for a puzzle you can finish, but only by thinking. When Easy feels automatic, try Medium.
• Learn one new thing at a time. A new Sudoku technique, or a new crossword convention, keeps both fresh. Our Sudoku strategies guide is a good next step.
• Use the daily puzzle as an anchor. Everyone gets the same Daily Challenge, and the calendar shows the days you’ve played.
• Don’t make it a test. Missing a day, or a crossword clue, is fine. Enjoyment is the point.

#Brain health#Research#Crosswords