Study finds cranberry juice may slow dental plaque bacteria growth

A study led by Christine Wu, professor of pediatric dentistry at the University of Illinois at Chicago, has found that natural cranberry juice with no added sugar may reduce the activity of dental plaque bacteria. The findings were published in the journal Scientific Reports.

Researchers examined proanthocyanidin compounds in cranberries, which prevent bacteria from adhering to cells. The study involved 14 children and 8 adults, who consumed small amounts of three beverages: pure cranberry juice, a sweetened drink containing 27% juice, and water.

In the morning, researchers collected samples of overnight dental plaque from one side of each participant’s teeth. Volunteers then rinsed with water and drank three small servings of one of the beverages, distributing it around the mouth beforehand. After 30 minutes, plaque samples were taken from the other side and the characteristics before and after drinking were compared.

Results showed that plaque bacteria multiplied more slowly and produced less enamel-damaging acid after pure cranberry juice consumption, in both children and adults. Wu noted that these properties make unsweetened cranberry juice a potential functional beverage for oral health, as its compounds may reduce the activity of bacteria involved in tooth decay.

However, Wu emphasized that these conclusions are preliminary due to the limited scope of the trial, and it is still unknown whether the juice actually reduces the risk of cavities. She also cautioned that the acidic drink may not be safe for enamel if consumed in large quantities.