They say that having an apple day keeps the doctor away. And in case you did not know, it also helps you to whiten your teeth naturally. Chewing the apples helps you to scrub your teeth. Apple is rich in malic acid, which is a component of many tooth pastes.
The malic acid also increases saliva, which helps to clean the teeth and remove stains. This was proven in a study conducted at the University of Grenada in Spain.