Would a Cheeto kill a Pilgrim? What a question. Let’s see: Pilgrims didn’t eat a lot of processed foods, so their old-timey guts would have probably squawked at the sorts of 21st-century junk we routinely ingest. But would a Cheeto, with its unholy mélange of chemicals, orange dye and “cheese seasoning,” actually kill somebody accustomed to a steady diet of shellfish, veggies and whole grains?¹ Who knows? The better question might be: Who wants to know?

Turns out, lots of folks on the internet, who have made an intellectual game of puzzling out which modern foods might kill a child of the Victorian era, say, or at least put one in a coma. It’s easy to understand the popularity of such discussions. Unlike many similar online quibbles that require a certain base of specialized ...