Of course non of the paper associations talks about causality, but lack of caffeine is probably a worse overall health association per this paper. More people don’t drink coffee at all than have more than 6 cups a day. From the paper:
“The association between coffee consumption and dementia was non-linear (Pnon-linearity = 0.0001), with evidence for higher odds for non-coffee and decaffeinated coffee drinkers and those drinking >6 cups/day, compared to light coffee drinkers.”
Thank you. It seems rather likely to me that people that are more prone to dementia are more likely to be self-medicating with these very high caffeine intakes. Unfortunately I have only anecdata for this intuition, but if you drink these quantities and/or know anyone with experience with dementia, I think you know what I mean.
“The association between coffee consumption and dementia was non-linear (Pnon-linearity = 0.0001), with evidence for higher odds for non-coffee and decaffeinated coffee drinkers and those drinking >6 cups/day, compared to light coffee drinkers.”