Coffee and Tea Intake, Dementia Risk, and Cognitive Function

Per [0] risk factors for dementia are "lower levels of education, high blood pressure, hearing impairment, smoking, obesity, depression, physical inactivity, diabetes, and low social contact."

A recreational stimulant often taking in social settings seems to hit a lot of those.

The interesting one is blood pressure. Caffeine would spike it, but I have long wondered if "exercising" the vasculature with transients is a good idea and long-term elevation is the real killer. Like school fire drills.

[0]: https://en.wikipedia.org/wiki/Dementia

Skimming the study leaves some weird results.

- There's a sharp decrease in incidence between 2.5 drinks/day and 4.5 (3rd/4th quartile)

- Technically decaffeinated coffee actually had more dementia cases in the NHS cohort

- The highest decaf group is 1 drinks/day

- They didn't track the kinds of tea people were drinking (black, green, herbal)

- Drinking one cup of tea seems nearly as effective as 2.5 cups of coffee.

while it seems they were controlling for caffeine intake the tea vs coffee groups would have had wildly different intake with similar results.

also I couldn't tell if they tracked if the people drinking 40oz of coffee a day simply dropped dead before they could go crazy

Man anything can cause dementia huh.

The only thing that feels better than a caffeine buzz is having my biases confirmed. Thanks, JAMA! Can I have mine with cream, sugar, and an hour of CME credit?

https://en.wikipedia.org/wiki/Gustav_III_of_Sweden%27s_coffe...

Needs an obligatory mention

> higher caffeinated coffee intake was significantly associated with lower dementia risk (141 vs 330 cases per 100 000 person-years comparing the fourth [highest] quartile of consumption with the first [lowest] quartile; hazard ratio, 0.82 [95% CI, 0.76 to 0.89])

That's a very big difference.

The public communication around research like this is terrible.

> "2 to 3 Cups of Coffee a Day May Reduce Dementia Risk. But Not if It’s Decaf." - NYT

> "Daily cups of caffeinated coffee or mugs of tea may lower dementia risk." - Science News

"Reduce," "Lower" - this is all causal language for a study that is purely observational. The authors do a good job keeping causal language out of the paper, so why can't media do the same?

This leads to an environment where everyone knows that "correlation != causation," but almost nobody understands why.

> The most pronounced associated differences were observed with intake of approximately 2 to 3 cups per day of caffeinated coffee or 1 to 2 cups per day of tea.

Weird, tea is supposed to have half the caffeine of coffee.

I'm still spitballing here, but I speculate it's because caffeine increases calorie consumption*, reducing diabetes risk. Diabetes is a major risk factor for dementia.

*calorie expenditure