Asked by: Paul McGuinness, Bristol
A 2002 study did find that levels of the antioxidant pronyl-lysine were eight times higher in the crust of a rye and wheat loaf than in the middle. This hints that eating crusts might protect against cancer. Yet this benefit would be largely irrelevant in previous centuries where malnutrition, war and infectious disease were the biggest killers. Your mother almost certainly just didn’t want you to waste food.
Luis trained as a zoologist, but now works as a science and technology educator. In his spare time he builds 3D-printed robots, in the hope that he will be spared when the revolution inevitably comes.