[Filligree]

Sleep hygiene is important, and it's critically important not to drink coffee late in... well, in the second half of the day really.

A lack of sleep is also a serious risk factor for dementia.

How much of this is just chronic sleep deprivation, I wonder?

[Plough_Jogger]

There is also the possibility that the causation happens in reverse: those with early symptoms of dementia could be self-medicating with excess caffeine.

[maxerickson]

Or the coffee could be preventing other health problems so that more drinkers make it to dementia.

[wutbrodo]

I doubt the study would fail to control for this; it's literally the most basic thing you can control for.

[leephillips]

I drink coffee after dinner and sleep like a baby (an expression invented by those who have not had babies, but you know what I mean). But it was not always thus. The secret is drug tolerance!