It turns out the main nutritional difference between the crust and the rest is the presence of a compound called pronyl-lysine -- an antioxidant thought to fight cancer. But that antioxidant is more or less canceled out by the carcinogen acrylamide, which can occur as the crust is being formed.
Both the antioxidant and the carcinogen come from the Maillard reaction, a product of the high heat applied to the crust while baking. To be clear though, this doesn't mean bread crust is actively giving you cancer. It just means the scientific community's verdict on the matter is mixed.
"Within the bread crust, there are cancer promoters and cancer fighters," Delbridge told CNN. "It's like there's a battle going on. Who is winning the battle? I'm not sure. But anything happening or reacting is completely marginal."