Is Sudoku good for your brain?

Regular puzzling is linked with sharper thinking in later life, but nobody has shown that it protects your brain. No study has found that Sudoku prevents dementia or makes you smarter at everything else. Here is what the research actually found, and what it didn’t.

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The short answer

Linked with sharper thinking. In a study of more than 19,000 adults aged 50 and over, people who did number puzzles more often scored better on tests of memory, attention and reasoning.
Linked with a lower dementia rate. In a study of more than 10,000 people aged 70 and over, those who regularly did puzzles, crosswords and similar activities were about 9 to 11% less likely to develop dementia over the following years.
Not proven to protect you.These studies watch what people do, so they can’t show that the puzzles caused the difference. People who are already sharp may simply enjoy puzzles more.
No proof it makes you smarter at everything. Practising a puzzle makes you better at that puzzle. The gains rarely spread to other kinds of thinking.

What Sudoku asks of your brain

Sudoku is a logic puzzle, not a maths one: the digits could just as well be letters or colours. Solving one leans on a few things at once:

Working memory. Holding the digits a square could still be, while you look elsewhere on the grid.
Logic. Ruling options out until only one is left, which is what every technique in our strategy guide comes down to.
Focus. One misplaced digit breaks the grid later, so it rewards slow, careful attention.

Harder puzzles stretch those further: an evil grid needs longer chains of reasoning than an easy one. That is why the research below talks about challenge, not just habit.

What the studies found

Number puzzles and thinking skills (2019)

Researchers at the University of Exeter and King’s College London studied 19,078 adults aged 50 to 93 in the online PROTECT study. Everyone said how often they did number puzzles such as Sudoku, then took a set of thinking tests. The more often people did number puzzles, the better they scored, on every one of the 14 measures, covering reasoning, attention, memory and speed of thinking. The lead researcher said that on problem-solving, regular puzzlers performed on average like people eight years younger.

The same researchers were clear about the limit: it is a snapshot, so it can’t show whether puzzles sharpen the brain or sharp brains choose puzzles.

Puzzles over a lifetime (2018)

A Scottish study followed 498 people born in 1936 for 15 years, with thinking tests along the way. People who had been more intellectually engaged through their lives, with problem solving the strongest link, started old age from a higher level. But their thinking declined at the same rateas everyone else’s. The authors described it as starting the decline from a higher point, not slowing it down.

Puzzles and dementia risk (2023)

An Australian study followed 10,318 people aged 70 and over, none with dementia at the start, for about 10 years. Those who regularly did “mental acuity” activities, such as crosswords, puzzles, cards, chess and other games, or literacy activities like writing and classes, were about 9 to 11% less likely to develop dementia. The link held regardless of education or income.

Its authors, too, said this can’t rule out that healthier people are simply drawn to these hobbies, and the lead author called puzzles no “magic pill”, to be combined with exercise, a good diet and not smoking.

What puzzles can’t do

A 2016 review of the evidence for brain-training products found that training improves the trained task itself, but there was little evidence that it carries over to everyday thinking or to unrelated tasks. Sudoku is the same: a year of daily grids will make you faster at Sudoku. It won’t, on current evidence, raise your IQ or fix a bad memory for names.

None of this is a reason not to play. A puzzle you enjoy is a good way to spend ten minutes. Just treat it as one healthy habit among several, not a treatment.

This page summarises published research for general interest. It isn’t medical advice. If you are worried about your memory, talk to a doctor.

How to get the most out of it

Keep it challenging. Once easy grids feel automatic, move up a level. Our medium, hard and expert levels each add one new technique.
Learn a new technique. Working out a new idea, like an X-Wing, is harder work than repeating one you know. The strategy guide walks through them in order.
Avoid the hint button. Checking your own logic is the part that does the work.
Mix it up. Word games, number puzzles and logic games each ask something different. Try Minesweeper or a daily Wordle alongside your Sudoku.
Make it a habit you like. The studies measured people who kept puzzling for years. Our daily Sudoku is one grid a day, gentle on Monday and hardest on Sunday, with a streak to keep.

Sudoku and the brain: questions

Does Sudoku prevent dementia?

Nobody has shown that it does. Large studies link regular puzzles with sharper thinking in later life and with a somewhat lower rate of dementia, but they observe people rather than test the puzzles, so they can't prove the puzzles are the cause. Dementia charities describe the findings as encouraging, not as proof.

Is it good to do Sudoku every day?

In the largest study of number puzzles, people who did them most often scored best on tests of memory, attention and reasoning. A daily puzzle is a fine habit as long as you enjoy it. Researchers suggest pairing mental activity with exercise, a good diet and not smoking, rather than relying on puzzles alone.

Does Sudoku increase IQ?

There is no good evidence that it does. Reviews of brain training found that people get better at the task they practise, but the gains rarely carry over to other kinds of thinking. Doing Sudoku makes you better at Sudoku.

What skills does Sudoku use?

Logic, working memory and focus. You hold possible digits in your head, rule them out one by one, and keep track of several rows, columns and boxes at once. Harder puzzles add longer chains of reasoning.

Is Sudoku better than crosswords for your brain?

The research doesn't single out a winner. The same study team found similar links for word puzzles and number puzzles. Most researchers suggest doing a mix of activities you enjoy and find challenging.

Sources

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