Extrinsic tooth stains develop due to different chromogenic polyphenols from various foods and drinks embedding themselves on the surface of your teeth in the enamel pellicle (a protein layer on the surface of your teeth that has protective properties). If many foods cause tooth staining, the question remains, are there any foods that can potentially decrease the formation of tooth stains?
Foods that can reduce tooth staining and keep your teeth whiter longer will have properties that disrupt the enamel pellicle and the stains embedded within them. This can be achieved with the following categories of food:
Of the all of the above options, you would probably get the best bang for your buck with either Ginger Root (abrasive + proteolytic properties) or Pineapple (citric acid + proteolytic properties).
Keep in mind that the enamel pellicle serves in a protective role against acids and bacteria (many polyphenols, while staining, have protective properties as well), so indiscriminate dissolution of this layer on a regular basis can make your teeth more vulnerable to decay and acid erosion.
Also, despite these foods have basic principles of stain reduction, there is currently no scientific evidence to show that any of these foods actually reduce or reverse staining. Probably the best you can ask for is to slow the rate of staining with a balanced diet that contains some of the above foods.