Why does wine stain your teeth? The science behind your purple smile (and tips to stop it)

Christmas is over, but the season of booze remains alive heading into New Year’s Eve. Many imbibers will reach for a glass of red wine as the clock strikes midnight — ultimately ringing in the chances of “wine teeth.”

Regular consumers are likely familiar with those streaks of pink or purple film sometimes left behind by red wine. Dentists said the phenomenon is caused by some straightforward chemistry and isn’t permanent. As such, wine teeth can be easily prevented if you plan ahead. The same goes for other dental problems that are synonymous with the gluttony of the holiday season, such as tooth decay.

A solid and regular dental routine of brushing twice daily and flossing goes a long way as a protective practice during times of indulgence. Well-cared-for teeth are less likely to suffer the ravages of tooth decay and discoloration. But even without zealous oral hygiene, there are easy tips for before, during and after parties and gatherings that can keep pearly whites from tarnishing.

“Generally during the holiday period people eat a lot,” said Dr. Uchenna Akosa, an assistant professor at the Rutgers School of Dental Medicine. “If the food or drink is colored, it can stain the teeth.”

While any colored drink can taint teeth, wine carries a triple threat when it comes to staining. Red wine contains anthocyanins — water-soluble pigments that exacerbate discoloration. There are also tannins, which are sticky organic compounds that can cause those pigments to adhere to tooth enamel.

“If you don’t brush, that [tooth] surface can also pick up the pigments from red wine or from coffee or cola,” said Dr. Leena Palomo, professor and chair at the Ashman Department of Periodontology and Implant Dentistry at NYU. “What makes red wine different is that on top of that there are tannins that further help binding that colored pigment into the [tooth] pores.”

Thirdly, wine is also acidic, which can cause tiny holes in the enamel. When that outer coating is compromised, the underlying dentin and the teeth overall can become sensitive. Because white wine is more acidic than red, it’s more likely to cause this etching. So to reduce the odds of wine teeth, try to avoid drinking white wine before red wine.

Preventive measures start before the party. Palomo recommends brushing and flossing before heading out. A good cleaning can make teeth smoother by removing plaque. This buildup roughens the tooth, increasing the adherence of colored pigments found in wine.

“It sounds counterintuitive, but brushing and flossing before you drink is useful,” Palomo said.

At the party, Akosa does not recommend ducking out of the festivities for a quick brush after every glass. In fact, too much brushing in between sips can cause teeth to be more porous — and more susceptible to staining because of wine’s acidity. It is better to wait about an hour after drinking.

But if you’re still out and notice those wine teeth in the bathroom mirror, Akosa encourages eating to help create some friction in your mouth. That will prevent the tannins in wine from binding to the tooth surface. Munching on cheese and crackers could also protect the spaces in between teeth where fluids and foods can sometimes get stuck.

“The mechanical effect of the chewing will help to reduce the staining and also stimulate saliva, which also reduces the staining,” Akosa said.

Drinking still water is strongly encouraged, not just for hangovers, but it can also go a long way in reducing stains. Drinking and swishing water inside the mouth can help neutralize the effect of the acidity. Note that sparkling water is not a good option. It’s acidic as a result of carbonation and can have an opposite effect — making teeth more porous and vulnerable to staining.

There are other dental issues that intensify during this time of year. Holiday stress often leads people to grind their teeth more. People also tend to consume more sugar, which leads to tooth decay and cavities. Palomo said drinking water can help maintain the balance of antibacterial saliva and sugar.

“Especially in the holidays where our health is sort of out of sight, out of mind, in favor of yummy things like peppermint bark and candy canes, wine and tea and coffee and hot chocolate, people need to be mindful of the pigments that are coming in contact with their teeth,” Palomo said. “Balance is important.”