Is that right? Isn't it more related to the fact that people in education/etc. actually drink more coffee for culture reasons but also use their brain more? could that be the actual reason? Because I don't see how all the coffee zombies in my workplace would last longer long term when they're already useless and aggressive today (until they had their coffee)
This was a follow-on to a study of nurses showing coffee drinkers have lower all cause mortality.
Caffeine has been shown to exert effects via adenosine receptor antagonism and influence on cAMP & AMPK pathways. These same pathways are implicated in a lot of issues with aging. Caffeine also has some anti-inflammatory properties and Coffee beans are a strong anti-oxidant though I don't really think that matters much.
The studies compared people from the same occupation, so no, that is not likely the reason
Exactly. Just another “study” finding a correlation without causation.
Yes, without a good experiment (maybe a natural one [1]) we can't know. Even if the study controls for everything observable, there may be unobserved differences that lead to the caffeination difference. For instance, even though two people might have the same job, education, etc. the one who is more ambitious, or creative, or hopeful, or simply healthy enough to feel like working more, might drink more coffee.
https://en.wikipedia.org/wiki/Natural_experiment?wprov=sfla1