Drinking 2-3 cups of coffee a day tied to lower dementia risk

I don't have access to the full story, but I'm curious if it answers these naive questions:

1. Why did they source men and women from separate studies?

2. How can they tell the study's results aren't equivalent to "people with dementia are bad at logging their caffeine intake reliably"?

The abstract mentions controls, but unfortunately I can't access the actual paper to see what they are. This seems really hard to isolate. Loneliness, inactivity, and depression are huge risk factors for dementia. Drinking caffeine in the morning seems like a really good proxy for whether an individual has somewhere to be that day. Definitely not 100% of course, but highly correlated.

I really don’t appreciate BigCoffee pushing their anxiety juice on me.

Ever since I stopped drinking that mini-panic-attack potion, my heart hasn’t skipped a beat, my sleep has been great and I don’t feel tired all the time.

Hopefully one day people wake up (haha) and dump it the way we’ve dumped cigarettes.

I can't get access to the full article either to see how they adjusted for confounding (which they said they did) - but I thought this tidbit was interesting:

https://www.massgeneralbrigham.org/en/about/newsroom/press-r...

“We also compared people with different genetic predispositions to developing dementia and saw the same results—meaning coffee or caffeine is likely equally beneficial for people with high and low genetic risk of developing dementia,” said lead author Yu Zhang

That seems like it indicates there is some real, independent signal here. Off to make some coffee!

The proposed mechanism is polyphenols.

Historically, you'd get your polyphenols from your garden or wild gathering. But we know that industrial crops (even organic grown) have extremely low polyphenol content compared to their wild counterparts. So coffee remains as one of the few strong sources you can buy in a grocery store.

Hypothesis: Polyphenols from other sources would be just as protective as coffee.

I might be in a higher risk group then: I can drink at most 1 coffee per morning (I love coffee but coffee doesn't love me). In addition, the only anti-allergy pill that works for me is a first generation allergy medicine (chlorpheniramine) that's strongly associated with increased chance of dementia. I could stop taking chlorpheniramine, but then my nose would keep me up at night, and poor sleep is also associated with increased chance of dementia.

So I am hoping there are confounding factors in all these studies, such that it's not coffee per se that helps with dementia but rather something along the lines of "the type of person who desires coffee is less likely to develop dementia".

Translating from normie, sounds like 30-50g of beans, assuming a "cup" is 8 floz. and the water:coffee ratio is 15:1. Assuming Arabica, that's 450-750mg of caffeine.

Who funded this research? Big Coffee?

and the other way around? dementia tied to stop drinking coffee after a full life with coffee?

very likely just the caffeine.

[dupe] Earlier: https://news.ycombinator.com/item?id=46953114

correlation does not equal causation