Do Crossword Puzzles Prevent Dementia? What the Bronx Aging Study Showed

Do crossword puzzles prevent dementia? No study has shown that they do. In the best-known study, 488 older adults in the Bronx were followed for years. Among the 101 who developed dementia, the 17 who did crosswords had their memory decline speed up 2.54 years later. They still got dementia, and their decline then ran faster. A 2022 trial gives a first randomized look, in people who already had memory problems.

Below: what the Bronx Aging Study found, and why 17 people cannot show cause. Then what a 2022 trial and a larger one under way add, and what else is linked to later decline. This is not medical advice.

Do crossword puzzles prevent dementia?

No trial has shown that crosswords prevent dementia. So, do crosswords prevent dementia? Not on this evidence. The evidence is of two kinds. One observational study links crosswords to a later slide in memory. One randomized trial tested crosswords in people who already have mild cognitive impairment (MCI), a stage of noticeable memory or thinking problems that is not yet dementia.

The authors of the main study said as much. They wrote that their result needs to be tested in clinical intervention trials. Brain training to prevent dementia is a wider field, and our guide to whether brain training apps work covers it.

A randomized trial gives each person an activity by chance. That removes the problem that people who do crosswords may differ from people who do not. It is the test the main study's authors asked for, and it is why an observational result alone cannot settle the question.

What did the Bronx Aging Study find about crosswords and memory decline?

It found that older adults who did crosswords had their memory decline begin later. Pillai and colleagues published the study in the Journal of the International Neuropsychological Society in 2011.

The study followed 488 community residents who had no memory problems at the start. They were checked every 12 to 18 months. By the end, 101 had developed dementia. For those 101, the team tracked scores on the Buschke Selective Reminding Test, a word-recall test. They looked for the point where memory began to fall faster.

• Crossword players: the fast fall began about 2.88 years before diagnosis
• Non-players: the fast fall began about 5.42 years before diagnosis
• The difference from crosswords: 2.54 years, from the authors' change-point model

After that point, the crossword players fell faster, by 3.31 points a year more on the memory test. At diagnosis the two groups scored about the same: 23.67 for the players and 24.05 for the rest. So the delay did not leave the players with a better score at the end.

On crosswords and memory decline, the pattern fits the idea of cognitive reserve. A brain with more reserve copes with disease for longer, then declines faster once the reserve runs out. It is an idea the study fits, not one it proved. The authors name two other possibilities: crosswords might act on the disease directly, or they may simply mark other healthy habits. Our article on cognitive reserve and brain wiring explains it in more detail.

Why can't the study show that crosswords cause the delay?

Because only 17 of the 101 people did crosswords, every one of them went on to develop dementia, and the two groups differed in other ways. Five limits matter most.

• A small group: 17 players and 84 non-players. Nine of the 17 did crosswords less than once a week, and five did them every day
• No one escaped dementia. The analysis asks when memory decline sped up, not whether dementia happened
• The players had a higher estimated verbal IQ at the start. Matching 14 players to 14 non-players on verbal IQ gave a similar pattern, but the difference was not statistically significant
• Crosswords were recorded once, by self-report, at the first visit
• It is observational. People who do crosswords may differ in other ways, or may drop the habit as memory slips

The last point is a known problem. A 2003 paper from the same research group says so plainly. It is unclear, the authors wrote, whether more leisure activity lowers dementia risk or whether people do less in the early phase of dementia.

Has anyone tested crosswords in a trial?

Yes. One randomized trial has, in people who already had MCI, and a larger one is under way. Devanand and colleagues published the first in NEJM Evidence in 2022.

They gave 107 adults with MCI either web-based crossword puzzles (56 people) or web-based cognitive games (51 people). Training was intensive for 12 weeks, with six booster sessions, and outcomes were measured at 78 weeks. On the ADAS-Cog, a 70-point scale where higher means more impairment, the games group worsened from 9.53 to 9.93. The crossword group improved from 9.59 to 8.61. The adjusted difference was 1.44 points (P = 0.04).

There are three cautions. The comparison group played computer games, not nothing, so the trial shows crosswords did better than games. The people already had memory problems. And the confidence interval, from 0.06 to 2.83 points, comes close to zero. Our article on whether Sudoku increases IQ covers the trial in more detail.

A follow-up trial, COGIT-2, plans 240 people with MCI. It compares four crossword puzzles a week with one a week and with a health-education group, over 78 weeks. A 2025 paper describes its design. We found no results from it.

Are crosswords good for your brain, and what else is linked to later decline?

Crosswords are one of several mentally active hobbies linked to a slower slide in studies, and none has been shown to cause it. The same Bronx group reported the wider picture in the New England Journal of Medicine in 2003.

• 469 people over 75 with no dementia at the start, followed for a median of 5.1 years. 124 developed dementia
• Reading, board games, musical instruments and dancing were linked to a lower risk of dementia
• Each extra point on a cognitive-activity score went with a hazard ratio of 0.93 (95% interval 0.90 to 0.97)
• A physical-activity score showed no link (hazard ratio 1.00)

Crosswords are not among the activities named in that abstract. They were one of six cognitive activities asked about in the Bronx interview, and the 2011 study pulled them out. The authors again called for controlled trials.

So are crosswords good for your brain? They are a harmless, mentally active hobby, and one small trial favours them over computer games in MCI. Do crossword puzzles prevent dementia in a healthy brain? Nobody has shown that. If you or a relative notice memory problems, a doctor is the right next step. A screening score such as the MoCA can start that talk. Our guide on whether an IQ test can detect dementia explains why an IQ test is not the tool.

Try our logic puzzle game and the other Brain Games. To see where your reasoning sits among adults, use our IQ tools or take the IQ Metrics test.

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