Why did my mum always tell me to eat my crusts?

Is there any merit to eating your crusts or was your mum just trying to prevent food from going to waste?

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.

Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun science facts.