Unless Caveman-With-Glasses-Who-Probably-Has-A-Name knows as a fact that Caveman-With-Freakishly-Large-Teeth has Celiac disease, why would he care whether he eats gluten?
Basically, cartoonists in 2018 understand gluten about as well as cartoonists in 2012 understood global warming.
I’m imagining a lot of newspaper comics readers, whose papers, don’t carry The Phantom, thinking “I wish there were a place where they explained these things.”
I wonder whether younger comics readers can even comprehend a time when, if your local paper didn’t carry a particular comic strip, you had no opportunity to read it and might not have even heard of it. Back in the day, newspapers bought exclusive regional rights to a comic: so if you lived just outside of New York City like I did, the News had dibs on almost all the good stuff and the Post had the rest. We got… what was left. I won’t mention the names, because that would sound disrespectful to the creators, but it wasn’t pretty.
Fortunately, we did buy the News on Sunday. The big color comics section was a particular treat for kids who never saw first- (or even second-) tier comics during the week.