Are Puzzles Good for Your Brain? What the Evidence Really Says

Pull up a chair. The lamp is on, the tea is hot, and tonight’s case is a slippery one: does solving puzzles actually do your brain any good?

You will find plenty of bold promises out there. “Ten minutes a day to a younger brain.” “The puzzle that prevents memory loss.” As a detective, I don’t trust a confession that arrives too easily, so I went to the evidence instead. Here is what the research really says, what it doesn’t, and why I think a good puzzle is worth your evening either way.

What a puzzle asks of you

Before the studies, the scene of the crime. When you sit down with a logic puzzle, you are doing a handful of very particular things:

• Holding several facts in mind at once: who was where, who held what, and which clue you have already used.
• Ruling things out: every “not the Colonel” narrows the field, until only one answer can stand.
• Testing an idea and checking it: “if this is true, then that must be true too… oh. It isn’t.”

A cryptogram works the same muscles in a different coat. You look for patterns (a lone letter is probably A or I; a three-letter word that keeps turning up may well be THE), make a careful guess, then let the rest of the message confirm it or betray it.

That’s simply a description of the work. Whether doing that work changes your brain over time is the real question, so let’s look at the evidence.

Exhibit A: training reasoning can help the skill you train

The best-known study here is the ACTIVE trial, a large randomised trial in the United States. It assigned 2,832 older adults (average age about 74) to memory training, reasoning training, speed-of-processing training, or no training. Ten years later, the reasoning and speed groups still showed improvements in the abilities they had trained. The memory group did not, although all three training groups reported less difficulty with everyday tasks than the control group (Rebok et al., 2014).

One honest caveat: ACTIVE used structured training sessions with booster sessions, not puzzle books. It tells us that reasoning can be trained, not that any particular puzzle does the job.

Exhibit B: people who puzzle often tend to score better

A UK study of 19,078 adults aged 50 to 93 found that the more often people said they did word puzzles, the better they tended to do across a range of thinking tests, including attention, reasoning and memory (Brooker et al., 2019).

Now, the detective’s eyebrow. This study took one snapshot in time, so it shows a link, not cause and effect. When the research was published, independent experts pointed out that people with sharper thinking may simply enjoy puzzles more and do them more often. One of them warned that it would be “seriously misleading” to claim the study showed puzzles “improve” cognition (Science Media Centre, 2019). Fair point, well made.

Exhibit C: crosswords beat brain-training games in one small trial

A trial published in 2022 followed 107 people with mild cognitive impairment for 78 weeks. Half trained with web-based crossword puzzles and half with computerised cognitive games. On the main memory-and-thinking measure, the crossword group did a little better than the games group (Devanand et al., 2022).

It is a small study, in one specific group of people, with no “no training” comparison group, and the authors say the results still need to be repeated in future trials. Still, I find it rather charming that the humble crossword held its own against the shiny apps.

Exhibit D: what the health authorities say

The US National Institute on Aging sums it up carefully. Structured cognitive training shows promise, and long-term observational studies link everyday mentally stimulating activities (such as reading and playing games) with better outcomes. But it also advises us to be wary of claims that particular computer or online games can improve memory, because there is not yet enough evidence for them (National Institute on Aging).

The verdict (such as it is)

Here is my honest summing-up, the way I would present it to a jury:

• No puzzle is a medicine. Nothing here proves that puzzles prevent memory loss or dementia, and anyone who promises that is selling something.
• Reasoning is a skill, and skills respond to practice. The trial evidence supports that much.
• Puzzling is part of a mentally active life, and that kind of life is linked with healthier thinking, even if the research can’t yet untangle exactly why.
• The surest benefit is the one you can feel tonight: an hour of deep focus, the quiet pleasure of a clue clicking into place, and that small, triumphant “got you.”

If you are worried about your memory, please talk to your doctor rather than a puzzle book. This article is for curiosity, not medical advice.

How I like to puzzle

• Choose “just too hard.” If you finish in two minutes, step up a level. If you are stuck for an hour, take a hint and learn the trick.
• Mix your cases. A logic puzzle one night and a cryptogram the next ask your mind for different kinds of thinking.
• Make it a ritual. The same chair, the same pencil, the same pot of tea. It is easier to keep a habit you look forward to.
• Bring a partner in crime. Solving with someone else adds talk, debate and the joy of proving them wrong.

Your next case

Ready to put the theory to work? Start with tonight’s free Daily Cryptogram, a new coded message every day. And if you would like a longer investigation, The Missing Guest List is a whole evening (or several) of pure deduction at Blackthorn Manor, and True Crime Cryptograms sets coded case files from real forensic history.

Look closer. Think deeper. Find the truth.
— Ivy

Sources

1. Rebok GW, Ball K, Guey LT, et al. Ten-Year Effects of the ACTIVE Cognitive Training Trial on Cognition and Everyday Functioning in Older Adults. Journal of the American Geriatrics Society, 2014. Read it on PubMed Central
2. Brooker H, Wesnes KA, Ballard C, et al. An online investigation of the relationship between the frequency of word puzzle use and cognitive function in a large sample of older adults. International Journal of Geriatric Psychiatry, 2019;34:921–931. doi:10.1002/gps.5033
3. Science Media Centre. Expert reaction to two studies on word and number puzzles and adult cognitive function, 2019. Read the expert reaction
4. Devanand DP, Goldberg TE, Qian M, et al. Computerized Games versus Crosswords Training in Mild Cognitive Impairment. NEJM Evidence, 2022. Read it on PubMed Central
5. National Institute on Aging. Preventing Alzheimer’s Disease: What Do We Know? nia.nih.gov