Well, the gluten-free thing I can see. People who can't eat gluten REALLY need to stay away from it. Maybe the cartoon could have said, "Is that bread made from whole-grain flour?"
Does it seem to anybody else as though a LOT of people are allergic to a LOT of stuff these days? I'm allergic to shellfish myself. A guy at work is allergic to chocolate - like, he gets sick to his stomach if he eats it. Just about everybody I know is allergic to something or other.
Is the human genetic code breaking down? Or have people always had these allergies and we just know more about them now? And if we have always had so much allergy trouble, how did the human race ever survive long enough to invent the epipen?
I think it's mostly what we've done to our food and the consequences to our bodies. I remember hearing about how wheat was hybridized to be more sturdy and have a better yield back in the 70's, and now we have a lot of people who are "gluten intolerant", but they've tried feeding some gluten intolerant people the older, not hybridized varieties of wheat, and they don't have near as many problems with it as they do with the modern wheat.
So in recent history we've genetically modified much of our food (especially the major in everything crops like corn and soy), we've started eating a whole lot more processed foods and carbohydrates (which studies have show raise inflammation levels in the body) and we've also found way to subject ourselves to less sleep and more chronic stress and probably have more high stress events in our lives (moving to new communities, cross cultural interactions, changing jobs, divorces, etc) than people even a couple generations ago. All of these can take a toll on our health, and my theory (based on some personal experience) is that maybe we were for the most part slightly allergic to these things all along, but we've the cumulative total of stressors on our systems make our allergy symptoms much more severe.
Personally I'm just glad that my allergies seem to be enough under control that I can open my windows without feeling like my head is going to explode.