Scientists Were Shocked to Discover Yet Another Surprising Benefit of Cranberry Juice

3 min readNew research suggests 100% cranberry juice may help slow plaque growth on teeth.It may even interrupt a chain of events that can lead to cavities.More research is needed, but it’s worth considering the next time you reach for a glass of cranberry juice or a cranberry juice cocktail. Cranberry juice is known in certain circles as a helpful way to prevent the risk of future UTIs, but there's more to this beverage than that. Now, new research suggests the drink could also help your teeth...or at least help reduce plaque associated with tooth decay.The study, which was published in the journal Scientific Reports, found that 100 percent cranberry juice could slow the growth of dental plaque and reduce the production of certain acids that could lead to cavities.It's important to stress that the findings are preliminary at this point. But dentists say the idea of using cranberry juice to lower the odds of tooth decay isn't as out there as it seems. Here's the deal.Meet the experts: Mark S. Wolff, DDS, PhD, dean at the University of Pennsylvania School of Dental Medicine; Christine D. Wu, PhD, lead study author and professor in the Department of Pediatric Dentistry at the University of Illinois Chicago; Julie Meyerson, DMD, a dentist in New York City; and Matthew J. Messina, DDS, clinical associate professor at The Ohio State University College of DentistryWhat did the study find?For the study, researchers recruited 22 people (eight adults and 14 kids) and randomly assigned them one of three drinks: unsweetened 100 percent cranberry juice, cranberry juice cocktail (made up of 27 percent juice and added sugar), or water.The participants didn't brush their teeth the morning of the experiment. To start, researchers collected dental plaque samples that had accumulated overnight with cotton swabs. The participants then rinsed their mouths with water, before having three small amounts of their assigned drink, swishing each around their mouths several times before swallowing.After 30 minutes, the researchers took plaque samples again. (This time, they took samples from teeth that hadn't been swabbed earlier.) The researchers discovered that people who swished with and drank pure cranberry juice had slower plaque regrowth than those who didn't use the drink.The pure cranberry juice was also linked with less acid production in dental plaque. (The acids made by oral bacteria can break down tooth enamel and increase the risk of cavities.)Why might cranberry juice fight tooth decay?Again, the study was small, so much more research is needed. And though the decision to study cranberry juice for oral health seems random, there's some precedent, according to Christine D. Wu, PhD, lead study author and professor in the Department of Pediatric Dentistry at the University of Illinois Chicago. "[Cranberry juice] has a polyphenol chemical compound called proanthocyanidin," she says. During research on the compound, Wu says her team discovered that proanthocyanidin can impact dental plaque."These compounds may interfere with processes involved in plaque formation," says Julie Meyerson, DMD, a dentist in New York City. For example, bacteria like Streptococcus mutans produce enzymes that convert dietary sugars into sticky substances called glucans, which help bacteria attach to teeth and form plaque biofilms, she says. "Cranberry polyphenols may interfere with these processes, making it more difficult for bacteria to adhere and form mature biofilms on teeth," Meyerson says. (That biofilm is also known as plaque.)Cranberry compounds may also influence the metabolism of bacteria and reduce acid production as a result, she says. "This is important because acids produced by plaque bacteria lower the oral pH, contributing to enamel demineralization and tooth decay," Meyerson says.Matthew J. Messina, DDS, clinical associate professor at The Ohio State University College of Dentistry, agrees that the proanthocyanidins are likely fueling this link. "These are the same compounds associated with cranberry’s reputation for urinary tract health," he says. "Proanthocyanidins don’t so much kill bacteria as interfere with them."What we don't know right now is how this will actually impact dental health. "It could very well suppress plaque, but will it affect disease?" says Mark S. Wolff, DDS, PhD, dean at the University of Pennsylvania School of Dental Medicine. "The findings are very preliminary."What's the takeaway here?Wu says that cranberry juice "may be a functional food" for dental health, but more research is needed.Messina agrees. If you like cranberry juice, he recommends having unsweetened 100 percent juice over a cranberry juice cocktail. But at the same time, "don’t trade your toothbrush for a juice glass," he says. " Brushing twice a day with fluoride toothpaste, cleaning between teeth, limiting sugar, and seeing your dentist regularly are still what prevent cavities."Carina Hsieh, MPH, is the deputy features editor of Women’s Health. She has more than a decade’s worth of experience working in media and has covered everything from beauty, fashion, travel, lifestyle, pets, to health. She began her career as an intern in the fashion closet at Cosmopolitan where she worked her way up to Senior Sex & Relationships Editor. While covering women’s health there, she discovered her passion for health service journalism and took a break to get her Masters in Public Health. Post-grad school, she worked as a freelance writer and as The Daily Beast’s first Beauty, Health, and Wellness Reporter. Carina is an alum of the Fashion Institute of Technology and the Yale School of Public Health. She and her French Bulldog, Bao Bao, split their time between Brooklyn and Connecticut. She enjoys reformer Pilates, (slow) running, and smelling the fancy toiletries in boutique fitness class locker rooms.