Despite identifying five compounds known as phytochemicals in raisins that can be beneficial for teeth and gums, researchers haven't proven that people who actually eat raisins have heathlier mouths.
"Raisins are perceived as sweet and sticky and any food that contains sugar and is sticky is assumed to cause cavities," Christine Wu of the University of Illinois at Chicago College of Dentistry said in a statement.
"But our study suggests the contrary. Phytochemicals in raisins may benefit oral health by fighting bacteria that cause cavities and gum disease," said Wu, whose work was funded by the California Raisin Marketing Board.
"Foods that are sticky do not necessarily cause tooth decay; it is mainly the added sugar (sucrose) that contributes to the problem."
Wu's team found five compounds in Thompson seedless raisins that might help make teeth and gums healthier - oleanolic acid, oleanolic aldehyde, betulin, betulinic acid and 5-(hydroxymethyl)-2-furfural.
Wu told a meeting of the American Society for Microbiology in Atlanta that all of the compounds are phytochemicals - antioxidants found in plants.
In their research, oleanolic acid slowed growth of a bacteria that causes cavities and another that causes periodontal disease. The acid also stopped bacteria from sticking to surfaces, which prevents them from forming plaque.
