Apples have a mildly acidic nature and a fiber rich flesh which makes for an ideal candidate to cleanse and brighten teeth. Apples are a crunchy food, like carrots and celery, which act like toothbrushes when you chew them. These foods can actually scrub away stubborn stains over time. Even if you're a coffee drinker, the effects of chewing on the fruit are noticeable, even if only slightly. If you start eating an apple a day as a snack in between meals, it is still a good idea to brush afterward. If you don't have the chance to brush after an apple, drink a glass of water. This will wash away any sugar, acid, and plaque it has removed from your enamel. So your mother was almost right...an apple a day, keeps the cosmetic dentist away!