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.