I was pointed at a couple of fascinating health-related articles (which I
should have posted about Tuesday, but procrastinated):
First, Drinking Coffee Daily May Stave Off Early Death, Study Suggests.
Which I was already assuming from prior reading, but this is good
confirmation. What was new to me was that a teaspoon of sugar actually
enhances the effect -- I don't use it, but generally eat something
fruit-like with it, which presumably counts. Good to know, given my
liter/day habit.
(Supported by this research article: Association of
Sugar-Sweetened, Artificially Sweetened, and Unsweetened Coffee
Consumption With All-Cause and Cause-Specific Mortality: A Large
Prospective Cohort Study: Annals of Internal Medicine.)
Second, On Your Back? Side? Face-Down? Mice Show How We Sleep May Trigger Or
Protect Our Brain From Diseases Like ALS | IFLScience tl;dr: side.
Lately I've found that I can't get to sleep lying on my back (I used to;
darned if I know what changed), so it's good to know that side-sleeping is
healthier as well.
(Supported by The
Effect of Body Posture on Brain Glymphatic Transport - PubMed The
Glymphatic System – A Beginner's Guide - PMC.) The glymphatic
system was apparently discovered in 2013; this set of articles was the
first I'd heard of it.
Sleeping on one's left side, in particular, is better for other reasons,
including reducing heartburn. (See "Side Sleeping: Benefits and Which Side to Sleep On | Sleep
Foundation" and "6 Hidden Health Benefits of Sleeping On Your Left Side That You've NEVER
Heard About" -- although I'd already heard about several of those.)
The benefits for sleep apnea and back pain appear to be less
side-dependent, and there seem to be arguments in favor of both
directions, e.g. Right vs. Left Side Sleeping: What's the Best for Your Health? - Sleep
Junkie.
Edited to correct paste error in the coffee study link text.