This past summer Medical News Today, Huffington Post and other media outlets covered a story about how red wine may prevent cavities based on a laboratory study published in the Journal of Agricultural and Food Chemistry. The researchers reported that red wine and red wine without alcohol inhibit the growth of certain bacteria found in oral biofilm.
The researchers reported that red wine and dealcoholized red wine were effective in limiting growth of certain types of bacteria, but not in any practical way. You'd have to swish it in your mouth for two minutes every seven hours for seven days for it to be effective, but doing so would likely stain your teeth and harm your enamel (wine is acidic).
Alternatives to Red Wine for Preventing Cavities
You don't have to swish red wine to prevent cavities. First start by reducing the amount of sugary food you eat, then make sure you're brushing and flossing regularly, and then make sure you're getting the daily nutrition you need to keep your body healthy. If you still want to swish, consider oil pulling with coconut oil.