Have some diluted vinegar after meals. It's the world's original "miracle tonic", with anecdotes dating back to antiquity, and mostly acts to facilitate digestion, which can smooth out indignities within your actual diet and therefore leave you feeling better rested and fed with lower intake. You don't need to take vinegar at full strength to see benefit, so I often have it with bubbly water.
(If you actually search around the web for the topic of vinegar you will discover the apple cider vinegar cult. This is a thing that got started in the 50s from a book author who spun his marketing as old-timey folklore. ACV is not significantly different from other vinegars, though some may prefer the taste.)
I don't drink alcoholic drinks but I really adored the ritual of mixing. Lately I've been finding that making vinegar shrubs is a lot of fun. I recommend it if you haven't tried it. Basically the same benefits, but a little bit of the mixing fun too.
In the context of the relation with gastric cancer, pickling is about fermentation, not acidity. The studies suggesting a relationship are all epidemiological and suggest a weak link at best [1].
The stomach is already very acidic; much more acidic than vinegar, which makes both gastric cancer and any potential benefits unlikely.
(If you actually search around the web for the topic of vinegar you will discover the apple cider vinegar cult. This is a thing that got started in the 50s from a book author who spun his marketing as old-timey folklore. ACV is not significantly different from other vinegars, though some may prefer the taste.)