I was drinking around 2-6 lattes on any given day for maybe the past 2 years. Never had a problem. About 1 month ago I started having horrible acid reflux and general stomach pains, would wake up vomiting, etc. I went to the ER, discussed my habits, did some scans - and they told me to stop drinking coffee.
First week was hard. Second week I had no cravings and was feeling great. By week 3 (last week) I had lost weight (this was my only dietary change), I was feeling sharper mentally and I was no longer still half-asleep in the morning before that first cup. In short - felt a worlds difference.
I'm not against coffee now, but cutting it out of my life, even if it's temporary, definitely was the right decision for me.
(As for alcohol, I don't drink.)