Red Wine and Science to the Rescue

Every once in a while, a new medical study comes out that seems like a gift from above. It indicates that something we already want to do is good for us and will help us meet one or more health goals. We know the saying, “if it seems too good to be true, it probably is,” but it’s hard to resist the siren song of hearing exactly what you want to hear. But, if it seems too good to be true, you should probably spend some extra time evaluating the evidence to be sure it’s worthy of your time and trust.

This brings us to a compelling study published in 2018  telling us that red wine might be magical health juice. Or, phrased more specifically, there are some compounds in red wine that may interfere with some common cavity-causing bacteria’s ability to form a dangerous biofilm. On its face, this study is interesting, but it’s worth a close read to see what’s behind the quick headline.

The study’s authors took simulated gum tissue to try and replicate the conditions of the human mouth. They introduced dental bacteria that are associated with plaque and cavity formation, then introduced red wine, both with and without alcohol, and some additional polyphenol containing compounds (like grape seed extract). They then measured whether the compounds killed the bacteria and if they made it harder to for surviving bacteria to stick together and form a biofilm, plaque. They concluded that polyphenols can indeed make it harder for bacteria to become dental plaque.

As with everything in research, sometimes the conclusions must be taken with a grain of salt. Studies are never all black or all white and are influenced by many factors including the study design and the study population. Despite the noted scholar George Clooney’s claim, the science is NEVER settled; that’s the nature of science and research. That’s particularly true in studies like this one, that employ analogs (not actually happening in the body) and situations that are not realistic for daily habits and life (47 hours of continuous exposure to the polyphenols–longer than one generally holds a sip of wine).

We have long established that polyphenols have an antibacterial effect. The specific polyphenols this study looked at are also found in many other foods: dark chocolate, most types of berries, some vegetables, and, most notably, coffee and tea. The anti-cavity properties of tea polyphenols have been extensively studied in China. Cranberries are another really great source of polyphenols. It’s not a surprise that fruits and vegetables don’t get top billing in these studies since most people are not going to get excited about a study claiming that red onions and spinach will save your teeth from cavities. These foods do not have the same glamour as red wine and chocolate, foods that frequently headline medical study news.

Further, it should be noted that polyphenols, even if they can help control bacterial behavior, come with a downside as well. All of these high-polyphenol foods and drink are highly chromogenic; they cause tooth staining. Wine mouth is a common condition that haunts red wine drinkers, leaving teeth vaguely purple after an evening of drinking. This dark staining can be made worse because wine is acidic, etching teeth and giving stains more spots to cling to, and it sticks to plaque (biofilm) already on the teeth.

This would be a good time to remember the concept “all things in moderation.” Red wine may indeed help prevent oral diseases, and some studies have shown that in moderation it can contribute to overall health and longevity. But, don’t think of it as a health drink. If you are so inclined, enjoy one glass of red wine for your health, and recognize the additional glasses are for witty comebacks and flawless dance moves.