Raisin Compounds May Reduce Cavity-Causing Bacteria

FRESNO, Calif.—Recent data shows that raisins contain phenolics and other antioxidants that help prevent the production of acid by mouth bacteria.

Christine Wu, MD, and colleagues from the University of Illinois at Chicago College of Dentistry have shown that various compounds in raisins—oleanolic acid and its derivatives—inhibit growth of Streptococcus mutans and the periodontal pathogen Porphyromonas gingivalis that causes gum disease. These compounds also interfere with adherence of these cariogenic bacteria. Therefore, raisins may not promote dental caries like other sticky foods.

Other research has indicated polyphenolic compounds in raisins, such as catechins, epicatechins and flavonols, have anticariogenic properties. Catechins have been shown to have a direct bactericidal effect against Streptococcus mutans and Streptococcus sobrinus and prevent adherence of bacteria to teeth. They also inhibit two enzymes—glucosyl transferase and amylase—that could increase dental caries. The glucosyl transferase is involved in the biosynthesis of sticky glucan involved in plaque; amylase hydrolyzes starches into sugars, which is the first step in acid production. Catechin and other phenolic antioxidants quell reactive oxygen species that are root causes of inflammation in gingivitis.