"The secret to this inexpensive home whitening method is malic acid, which acts as an astringent to remove surface discoloration. Combined with baking soda, strawberries become a natural tooth-cleanser, buffing away stains from coffee, red wine, and dark sodas. While it’s no replacement for a bleaching treatment at your dentist’s office, “this is a fast, cheap way to brighten your smile,” says Adina Carrel, DMD, a dentist in private practice at Manhattan Dental Arts in New York. “Be careful not to use this too often, though, as the acid could damage the enamel on your teeth.”
1 ripe strawberry
1/2 teaspoon baking soda
Directions: Crush the strawberry to a pulp, then mix with the baking soda until blended. Use a soft toothbrush to spread the mixture onto your teeth. Leave on for 5 minutes, then brush thoroughly with toothpaste to remove the berry–baking soda mix. Rinse. (A little floss will help get rid of any strawberry seeds.) Carrel says you can apply once a week."