And we need acid in the stomach for digestion, but not THAT much acid, so diet, especially before bedtime, makes a difference.

As for tilting the bed, I got it from this guy, who hypes it way too much as the Answer To Everything; but has saved me a lot of trouble; my acid reflux attacks have stopped.

http://inclinedbedtherapy.com/

“…says Fletcher in his essay "The Importance of Gravity to our Health and Wellbeing, and its Relation to Rest & Sleep". A first set of observations about sleeping in a slightly inclined position (head up, feet down, five degrees) rather than in our traditional perfectly horizontal beds, seems to confirm that the human organism requires gravitational pull to function in an optimal manner. Positive health effects were observed for those sleeping in the inclined position…”

Then they go overboard, calling it “Inclined Bed Therapy”, as if it was a new branch of medicine, and they have a 40 minute video showing how they raised the head of a bed and it took 5 hours! Me, - it took 3 minutes to jam some thick wooden blocks and the Compleat Workes of Shake-speare under the head of the bed.

As for the effects, it is NOT some sort of medical break-through; you sleep on a slope because gravity wants things to go downhill from your mouth to esophagus to intestine; and you sleep on your left side because gravity pulls left where the plumbing of the first part makes a left turn to join the plumbing of the second part. It is because water flows downhill, you see.
It is not some new “therapy”, but it is the safest way to sleep if you are drunk or have acid reflux. I found it helped me in both cases.
I rest my case, your Honour.