The weird way red wine fights cavities

The claim: Need yet another reason to indulge in a glass of red wine with dinner? Vino may may help prevent cavities, finds a new study in the Journal of Agricultural and Food Chemistry.

The research: Researchers grew cultures of the types of bacteria responsible for dental diseases, and then dipped them into different liquids, including red wine, red wine without alcohol, red wine spiked with grape seed extract, and water with 12 percent ethanol. Red wine with or without alcohol and wine with grape seed extract worked best at getting rid of the bacteria. (Analyzing mouth bacteria could lead to earlier diagnosis of pancreatic cancer and treatment.)

What it means: Tooth decay starts when certain bacteria in the mouth combine to form biofilms, communities of hard-to-kill bacteria, that then form teeth-damaging plaque and produce harmful acids. Brushing and fluoride rinses have limited effect, and many antimicrobial rinses can change the color of the gums, making it less likely people will continue to use them—which is why researchers continue to search for more appealing alternatives.

"This study is about applying something to the teeth that decreases bacteria. The effectiveness of this type of product [red wine] depends on how long it stays on the tooth, known as its 'substantivity,' " says Gary L. Glasband, a dentist in private practice in Long Beach, California, who was not involved in this study. "Wine has a high substantivity, which you can see as it stains the teeth when you drink it."

This, combined with the antioxidants present in grape seeds, makes red wine effective at killing bacteria on the teeth.

The bottom line: While the antioxidant effect of red wine or grape seed extract likely works to reduce cavities, it’s a trade-off between the pros and the cons: a reduced risk of cavities vs. stained teeth and excess calories from the alcohol, says Glasband. Just as caffeine and dark chocolate offer health benefits when consumed in moderation, you should enjoy red wine the same way, he suggests.

But gargling with red wine to prevent cavities, on the other hand, isn't going to get the job done. For healthy teeth for life, follow these 5 sound strategies instead.