where does the saying “if you eat your crusts your hair will go curly” come from?

The origin of the myth that eating crusts can curl hair is unknown, it is thought to have emerged at least 300 years ago in Europe. At that time, survival was more precarious and starvation was much more of a real possibility for everyone.

Could you have misheard? I think it’s carrots that they say makes your hair curly. Vitamin A and beta carotene (what makes carrots orange) are good for your hair, but I doubt they make it curly!