This Thanksgiving Staple May Help Slow Dental Plaque Regrowth, New Study Finds

By helitra·November 11, 2026·4 min read

Key Points

A new study from the University of Illinois Chicago found that unsweetened 100% cranberry juice slowed the regrowth of plaque bacteria and reduced their production of acids that erode tooth enamel.
In laboratory tests, plaque bacteria collected from adults and children showed approximately 44% and 33% less regrowth, respectively, after participants rinsed with pure cranberry juice. Cranberry juice cocktail and water had no significant effect.
The study included just 22 participants, so more research is needed to confirm whether cranberry juice benefits oral health. Drinking cranberry juice is not a substitute for brushing your teeth.

Cranberries may have a starring role at Thanksgiving dinner, but according to a new study, you may want to consider adding the tart little berry’s juice to your regular rotation, as it could be doing your teeth a favor.

In October, the University of Illinois Chicago (UIC) shared the results of its new research, published in the journal Scientific Reports, which found that unsweetened 100% cranberry juice slowed the regrowth of plaque bacteria and reduced their ability to produce the acids that erode tooth enamel.

The study was led by Christine Wu, a pediatric dentistry professor at the UIC College of Dentistry, who, according to UIC, wanted to know whether the compounds that make cranberries a go-to for urinary tract infections could also work in our mouths. (Those compounds, called proanthocyanidins, or PACs, can prevent E. coli and other bacteria from adhering to cells.)

“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,” Wu said.

The team ran two small trials, one with 14 children ages 7 to 12 and another with eight adults ages 18 to 64. None of the participants had recently undergone a professional cleaning or taken antibiotics. The researchers had the participants drink Ocean Spray Unsweetened Pure 100% Cranberry Juice, Ocean Spray Cranberry Juice Cocktail, and plain water during separate visits three days apart.

Wu explained that the team tested real people and store-bought juice, noting, “It was important to us to conduct these tests with human participants and use products available on the market.” She added, “Most cranberry juice studies have been conducted using laboratory-prepared cranberry juice extract.”

The participants were also asked to skip brushing for a day and fast overnight, so they arrived with plenty of plaque to test. Researchers swabbed the left side of each mouth, then had them swish about two teaspoons of their drink for 30 seconds before swallowing, repeating this three times in a row to mimic how we sip. A half hour later, they swabbed the right side, then fed both samples sugar in the lab and tracked them for four hours.

Related: 26 Bright, Tart, and Essential Cranberry Recipes

The researchers found that the pure juice was the only one that made a real difference. Plaque exposed to it regrew by about 44% less in adults and 33% less in children over four hours, and it also produced less acid. Neither the cocktail nor the water had a significant effect, and the researchers wrote that the pure juice likely outperformed the cocktail because it contains more PACs.

“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,” Wu said.

Of course, this is a very small study with only 22 people, and no one is saying you should give up brushing in favor of gargling juice. Wu also noted that the results need to be confirmed by further research, though she isn’t against the occasional swish, with one tweak.

“But maybe by adding an appropriate sugar substitute,” she said, “to make it a bit more palatable.”

How to protect your teeth when drinking acidic juice

Cranberry juice may affect how plaque bacteria behave, but it’s still acidic. To limit your teeth’s exposure to acids in juice, the American Dental Association recommends a few simple habits:

Have it with a meal. Avoid sipping acidic drinks throughout the day, which repeatedly exposes your teeth to acid.
Skip the swishing. Although participants swished juice during the study, the ADA’s general advice is to avoid holding or swishing acidic drinks in your mouth.
Follow with water. Rinse your mouth with plain water after drinking acidic juice.