Unsweetened cranberry juice reduced dental plaque regrowth in small US study
Researchers at the University of Illinois Chicago found that pure cranberry juice slowed plaque regrowth and cut bacterial acid levels among 22 participants. The authors stress the findings are preliminary and larger, longer studies are needed.
American scientists have examined how store-bought cranberry juice affects oral bacteria in children and adults. Researchers at the University of Illinois Chicago concluded that unsweetened juice can slow the return of dental plaque and reduce the amount of acid produced by bacteria, according to the Ukrainian news site Unian.net. The results come from a small, short-term experiment, so the conclusions are tentative.
Why cranberries were studied
Cranberries are usually recommended for people who often get urinary tract infections, and they have also been linked to heart and digestive health. Researchers believe the effect rests on proantocyanidins, natural compounds with anti-inflammatory properties. These compounds hinder bacteria such as E. coli from attaching to the walls of the urinary tract. A similar mechanism has been observed with Helicobacter pylori, a bacterium associated with stomach disease. Kristin Wu, a professor of pediatric dentistry, set out to test whether the same might work against microorganisms on teeth.
How the experiment worked
The study involved 14 children and eight adults. Samples of plaque that had built up overnight were taken first, and participants were then split into three groups. One used 100% cranberry juice, another a sweetened cranberry drink containing only 27% juice, and the third plain water. Each person rinsed their mouth several times with the assigned liquid and swallowed it. New plaque samples were collected 30 minutes later.
People who used pure juice saw plaque return considerably more slowly. In both children and adults, the amount of bacterial acids fell significantly; these acids damage tooth enamel and promote tooth decay. Wu noted that her team's earlier studies found no similar effect from other common juices, such as orange or apple.
A note of caution
The sample was small and the effect was assessed only over a short period. It is unknown what would happen with regular rinsing or long-term juice consumption. Cranberry juice is acidic, so using it regularly is not automatically safe for enamel. The study does not prove that the drink prevents cavities or replaces normal oral hygiene.
