Bread is one of humanity’s enduring staples. Cheap, filling, and portable, it’s been central to daily life and culture across civilizations. Its prominence continues today; just consider the supermarket, where bread can take up nearly an entire aisle. But here’s a key difference: while our ancestors tended to eat locally baked breads with whole grains, the scores of options in supermarkets—white bread, gluten-free tortillas, keto wraps, low-carb bagels—are usually far more processed. Only about