Raisins and Cavities

[Guest guest]

Compounds found in raisins fight bacteria in the mouth that cause

cavities and gum disease, according to researchers at the University

of Illinois at Chicago.

 

" Our laboratory analyses showed that phytochemicals in this popular

snack food suppressed the growth of oral bacteria associated with

caries and gum disease, " said Christine Wu, professor and associate

dean for research at the UIC College of Dentistry and lead author of

the study. Phytochemicals are compounds found in higher plants.

 

The data were presented today at the annual meeting of the American

Society for Microbiology in Atlanta.

 

Wu and her co-workers performed routine chemical analyses to identify

five phytochemicals in Thompson seedless raisins: oleanolic acid,

oleanolic aldehyde, betulin, betulinic acid and 5-(hydroxymethyl)-2-

furfural.

 

Oleanolic acid, oleanolic aldehyde, and 5-(hydroxymethyl)-2-furfural

inhibited the growth of two species of oral bacteria: Streptococcus

mutans, which causes cavities, and Porphyromonas gingivalis, which

causes periodontal disease. The compounds were effective against the

bacteria at concentrations ranging from about 200 to 1,000 micrograms

per milliliter.

 

Betulin and betulinic acid were less effective, requiring much higher

concentrations for similar antimicrobial activity.

 

At a concentration of 31 micrograms per milliliter, oleanolic acid

also blocked S. mutans adherence to surfaces. Adherence is crucial

for the bacteria to form dental plaque, the sticky biofilm that

accumulates on teeth. After a sugary meal, these bacteria release

acids that erode the tooth enamel.

 

Wu said that the findings counter a longstanding public perception

that raisins promote cavities.

 

" Raisins are perceived as sweet and sticky, and any food that

contains sugar and is sticky is assumed to cause cavities, " Wu

said. " But our study suggests the contrary. Phytochemicals in raisins

may benefit oral health by fighting bacteria that cause cavities and

gum disease. "

 

" Moreover, raisins contain mainly fructose and glucose, not sucrose,

the main culprit in oral disease. "

 

In an earlier unpublished study, Wu's collaborator Shahrbanoo Fadavi,

a pediatric dentist at UIC, found that adding raisins alone to bran

cereal did not increase the acidity of dental plaque. Raisin bran

cereal with added sugar, however, did raise acidity levels.

 

" Foods that are sticky do not necessarily cause tooth decay. It is

mainly the added sugar, the sucrose, that contributes to the

problem, " Wu said.

 

The present investigation was funded by the California Raisin

Marketing Board.

 

Wu's main collaborator in the study was A. Douglas Kinghorn, an

adjunct professor in the UIC College of Pharmacy. Other UIC faculty

involved in the work were Baoning Su, in the College of Pharmacy, and

Jose Rivero-Cruz and Min Zhu in the College of Dentistry.

 

UIC ranks among the nation's top 50 universities in federal research

funding and is Chicago's largest university with 25,000 students,

12,000 faculty and staff, 15 colleges and the state's major public

medical center. A hallmark of the campus is the Great Cities

Commitment, through which UIC faculty, students and staff engage with

community, corporate, foundation and government partners in hundreds

of programs to improve the quality of life in metropolitan areas

around the world. For more information about UIC, visit

http://www.uic.edu.

 

Contact: Sharon Butler

sbutler

312-355-2522

University of Illinois at Chicago

http://www.uic.edu