It’s official: crosswords are a waste of time.

A waste of time, that is, if you’ve ever justified your hobby by insisting that it’s insurance against dementia.

The notion of crosswords as a cerebral prophylactic has been around for years, despite the little problem of there being no research to back it up. Until recently, the only study that I’d seen was from the Journal of Experimental Psychology, and it found no evidence ...

... to suggest that amount of crossword puzzle experience reduces age-related decreases in fluid cognition or enhances age-related increases in crystallized cognition.

In plainer language, puzzles don’t help us (a) to remember the words we need to fill in the blank squares, or (b) to reason our way through cryptic clues’ wordplay.

Last week, newspapers reported a new study, with headlines variously stating and denying an effect of crossword-solving on Alzheimer’s disease (trudge through the coverage yourself, if you can bear it). As is often the way, the title of the original paper – Effect of Intellectual Enrichment on AD Biomarker Trajectories Longitudinal Imaging Study – does not, in fact, mention crosswords.

And, well, nor does the paper itself. Crosswords seem to have appeared somewhere between publication and press release. But if we take “crosswords” as journalistic shorthand for “using your noddle”, there is something of interest hiding in the coverage.

What is termed “high midlife cognitive activity” – which is how I’m going to refer to the Guardian quiptic from now on – doesn’t do anything to prevent dementia for most people. But it is “associated with lower amyloid in APOE4 carriers”, for which read: if you have a gene variant (that’s the APOE4 bit) which increases your risk of developing Alzheimer’s disease, get yourself doing some cognitive activity and get rid of those sticky protein fragments (that’s the amyloid bit).

But ... what if you don’t know whether you’re an APOE4 carrier or not? Perhaps a more cheering way of looking at negative results is to conclude that there is no evidence that doing crosswords causes any mental disorders, or indeed any kind of suffering beyond frustration, which is pretty much what a solver signs up for anyway. Just because you don’t have a specious justification for something doesn’t mean you can’t do it.

I’m not a doctor. But my advice is: carry on solving, and find yourself another excuse.