Tea, Coffee and Cocoa - All Good for Your Teeth

It may not come as a big surprise to you that green tea is good for dental health. After all, green tea is the miracle cure for pretty much anything, right? If you're not a huge fan of green tea, worry not: there are other beverages out there that can do the same. In fact, if you're a long time follower of this blog, then you already know that not only green tea but also black tea helps prevent dental caries. Both are also good for the gums.

The good news doesn't stop there, however. A recent review found that in addition to tea, cocoa and coffee showed anti-cariogenic potential as well (link). The reason behind this effect is the polyphenol content in all three. Though each three has different polyphenols that work in different ways, they all appear to get the job done and improve oral health.

Cocoa and dental caries

According to the authors of the review, studies have shown that additing cocoa powder or chocolate to hamster diets reduces their caries incidence. Unsurprisingly, cocoa powder or dark chocolate works better than chocolate with high sugar and low cocoa levels. Water-soluble extracts of cocoa powder also inhibited caries formation in rats.

The two main strains of bacteria that cause caries are Streptococcus sanguinis and Streptococcus mutans. Although the case is not entirely clear, cocoa polyphenols seem to inhibit the growth of the former but not the latter.

Cocoa also reduces plaque formation by inhibiting the enzyme dextransucrase, which forms plaque extracellular polysaccharides from sucrose. In one study, a mouth-rinse made from the ground husk of cocoa beans was effective in reducing plaque scores in children.

Coffee and dental caries

Roasted coffee beans were shown in two studies to be antibacterial against S. mutans. Coffee also appears to interfere with the adsorption of S. mutans to teeth. In another study, coffee did not inhibit the growth of the bacteria, but did reduce the adherence of bacterial cells to dental surface. In other words, while coffee might not kill the bacteria, drinking coffee could prevent it from sticking to your teeth.

The compounds in coffee that are most active in terms of dental health are trigonelline, caffeine and chlorogenic acid. It is possible that the anti-adhesive effect is due to the synergistic action of these (and other) chemicals in coffee.

Tea and dental caries

Since I've already covered the topic of tea and dental health in an earlier post, I'll just go over the review findings briefly here.

Tea polyphenols appear to protect from dental caries primarily through their anti-microbial action. While cocoa and coffee are mostly effective against the adhesion of bacteria on the surface of teeth, tea in addition actually inhibits the growth of several strains of Streptococcus. The polyphenols in tea also reduce the formation of plaque, the production of acidic compounds and the synthesis of glucan from sucrose. Importantly, commercial teas have been shown to inhibit salivary amylase activity, which may significantly reduce caries formation from foods with starch.

Green tea, black tea and oolong tea (which is somewhere between the two in terms of fermentation time) have all been shown to be beneficial for oral health. Even though white tea has not been studied, it very likely has much of the same benefits as green tea. Due to its light color, it may also stain teeth less than green or black tea.

Conclusion Tea, coffee and cocoa are all beneficial for dental health. Tea appears to be the best choice, since the polyphenols in tea are not only able to inhibit the adherence of bacteria to teeth, but also prevent the growth of cariogenic bacteria.

Tea is also effective against S. sanguinis and S. mutans, the two main strains responsible for caries, while coffee and cocoa seem to only work against the latter. While the effects of coffee have only been tested in vitro, cocoa has been shown to prevent caries formation in animals and reduce plaque in humans.