Researchers at the University of Illinois at Chicago College of Dentistry found that unsweetened pure cranberry juice can slow dental plaque growth and reduce acid production in humans, challenging long-held assumptions about sticky sugars and oral health.
Christine Wu and the UIC College of Dentistry Study
Cranberries are a holiday staple in sauces, salads, and festive decor, but researchers at the University of Illinois at Chicago College of Dentistry found another reason to add these tart treats to your grocery cart: oral health. Medicinally speaking, cranberry juice is often used to ward off urinary tract infections. This occurs because the red-hued fruit possesses proanthocyanidins, which are anti-inflammatory substances that detach microbes such as E. coli from human cells.
UIC College of Dentistry researcher Christine Wu wanted to see how those same proanthocyanidins affect dental plaque bacteria, which use sugars to produce acids that cause enamel decay. Since people do not typically snack on chemical compounds, she presented them as a more palatable refreshment: pure cranberry juice.
Just like sugar damage is linked to diet, I’m interested in how the food and beverages we consume can help combat the harmful bacteria and benefit our oral health.
Christine Wu, UIC College of Dentistry researcher
Testing Pure Juice and Cocktails on Human Participants
A total of eight adults and 14 children took part in the small human trial published in Scientific Reports, where they were randomly allocated to consume water, an unsweetened 100% pure cranberry juice, or a sweetened cranberry beverage containing 27% juice.
It was important to us to conduct these tests with human participants and use products available on the market. Most cranberry juice studies have been conducted using laboratory-prepared cranberry juice extract. Moreover, limited studies have been performed in children.
Christine Wu, professor of pediatric dentistry
On the morning of the study, participants arrived with a night’s worth of plaque buildup. Researchers collected plaque samples from one side of their mouths using cotton swabs. Subjects first rinsed their mouths with water, after which they took three small sips of their designated drink, swished it around a few times, and finally swallowed it. Thirty minutes later, researchers collected plaque samples from the unswabbed teeth to assess the beverages’ effects.
Cranberry Juice Slows Plaque Regrowth and Acid Production
The plaque exposed to pure cranberry juice appeared to be growing more slowly than the unexposed samples. Both adults and children who swished with 100% pure cranberry juice demonstrated lower acid production, which is vital for maintaining strong enamel.
Most people think of cranberry juice as very sour, very acidic and sugary, and therefore may not contribute positively to oral health. This study found the opposite: that cranberry juice affected dental plaque regrowth and acid production which may counteract some of the damage done by sugar.
Christine Wu, professor of pediatric dentistry
Wu is excited for the potential of cranberry juice to be considered a function beverage
that benefits oral health, especially because other popular juices, such as orange and apple, did not fit the bill.
Next Steps for Cranberry Juice Research
Further investigations are required to confirm these findings, given the limited participant pool and the brief duration of the study. In the meantime, Wu is open to the occasional pure cranberry juice mouth cleanser, with a caveat.
But maybe by adding an appropriate sugar substitute, to make it a bit more palatable.
Christine Wu, professor of pediatric dentistry