Bread, called nan in Persian, is the staple food of Iran in all regions except around the Caspian, where rice supplants it. Nan is a Persian word first used in Achaemenid Iran (550–330 bce), from which all other languages borrowed it. In Iran, bread and salt are treated with great respect. In my childhood growing up in Iran, it was considered a sin to let bread fall to the ground or for it to be thrown away.