this says coffee is associated with a reduced risk of dementia which is pretty much what I've read over and over again
Those studies reported higher coffee drinkers had 31–65% decrease in the risk of AD dementia, which is quite comparable to about 65% decrease of Aβ positivity rate in higher coffee drinkers (27.14%) compared to lower coffee drinkers (17.61%). Furthermore, the relationship between higher coffee intake and lower Aβ positivity was prominent for lifetime coffee intake than for current coffee intake. This suggests that the protective effects of higher coffee intake against Aβ pathology involve the chronic effects associated with prolonged exposure rather than an acute or short-term effect.
Note: "coffee drinkers" not "caffeine"
I found no mention of MAO inhibitors, beta-carbolines or heterocyclic aromatic amines in coffee. The authors seem to be unaware of their existence, even though they could explain the results in many ways.
Big idea: a common cause may be jaw development and the resulting lack of breathing (during the day and during sleep) in large parts of the population.
Jaw development has a strong claim to be the fundamental, common cause of poor breathing and sleep because it's derived from 2 fundamental differences between humans and animals: agriculture and speech.
It's a long chain of causation, and took me awhile to learn about, but it may be what you're looking for.
Of course it could also be the case that some people are just staring at screens too much before bed and getting poor sleep. But bad sleep is an epidemic and there is evidence of this all over the world, and going back hundreds of years. The books I reference tell of orthodontists from the 1800's who noticed this problem, etc. Our diets drastically changed, which caused poor jaw development, which causes bad breathing, which causes bad sleep (I learned about this from my dentist).
There are many factors that restrict airways, including weight. Remember that the average American male is about 30 pounds heavier in 2020 than in 1960 (and similarly for females). It's hard to imagine that not having an effect of breathing and sleep (and thus dementia). But I think animals can be fat and still have plenty of air for breathing; the same isn't true for humans.
Previous comment I wrote on this including recent books (2018-2020): https://news.ycombinator.com/item?id=23435964
That article is "fitful nightly sleep linked to chronic inflammation and hardened arteries". That is another correlation, not a causation. So I would suggest that bad sleep, inflammation, hardened arteries, and dementia have a common cause in jaw and airway development. This is a lot harder to see because it took place over 10,000 years and it takes 30-50 years to kill you. You can have bad breathing your whole life but still be functional. It's very related to tooth grinding/bruxism, which is an epidemic as well.
Other threads on Hacker News: https://news.ycombinator.com/item?id=24247066
All of this means that coffee drinkers are going to self select for various other features that add confounding factors. Imagine you were doing a study on marriage patterns: I wouldn't be surprised if "Drinks their coffee in the cafe itself" was more highly associated with being single. And the headline will read "Dedicated coffee drinkers less likely to find a partner"
(1): https://hammer.purdue.edu/articles/thesis/Identification_of_... (2): https://onlinelibrary.wiley.com/doi/pdf/10.1002/ijc.20703 (3): https://www.sciencedirect.com/science/article/pii/S157002320... (4): https://academic.oup.com/toxsci/article-abstract/173/1/171/5...
1. https://www.sciencedirect.com/science/article/abs/pii/S00243...
2. https://www.sciencedirect.com/science/article/abs/pii/S03088...
Interestingly, your source’s paper on this says that coffee protects against brain disease:
> epidemiological studies have consistently shown that coffee drinkers have an apparently lower incidence of Parkinson's disease (PD), suggesting that coffee might somehow act as a purported neuroprotectant
https://pubmed.ncbi.nlm.nih.gov/16139309/
Either way, I’m not particularly interested in this subject, the point is that making wild medical claims without sources in an online forum is best avoided.
Again, the total amounts are what matters. It’s much easier to take in too much MAOIs from tobacco and coffee than by eating meat.
Something seeming to protect against one specific disorder does not mean that it protects against all diseases.
> If they drink too much coffee, they might accidentally poison themselves into dementia
Oh crap
This exact mechanism has been shown to be the cause of a very common neurological disorder called essential tremor. Patients have a genetic predisposition for building up tremor-inducing Harmala alkaloids due to reduced metabolism.
I'm really curious for a source on this, considering how much coffee I drink weekly.
If you are "addicted" to coffee sometimes you will crave it if you do just caffeine, but this goes away after a while.
Be aware also that if you want the antioxidants and other stuff in coffee beans eating just caffeine won't give you that.
The conclusions of this study seem to have it backwards. It’s not lack of sleep that causes dementia, it’s early dementia that causes insomnia.
Edit: it’s also possible that a third factor causes both of these. For example, both people low on dopamine and the sleep-deprived are likely to turn to coffee to keep them functional. If they drink too much coffee, they might accidentally poison themselves into dementia, because some of the Harmala alkaloids in coffee are neurotoxic and like to deposit themselves in brain fatty tissues for a long time.