Could improving your oral health be as simple as drinking more tea? A new study from researchers at the Oral Ecology Research Group has examined how components of black tea might fight cavity-causing bacteria and gingival inflammation. The active ingredient the team focused on investigating is a particular subset of polyphenols called theaflavins. Polyphenols were the fad nutrient of the late 90s and early 2000s for their supposed anticancer properties, but in recent years have faded from the limelight.
While the miracle anticancer serum never emerged from the study of polyphenols, further research has been quietly conducted on the properties of these theaflavin molecules in other contexts. Preliminary studies indicated they had a modulating effect on certain proinflammatory signals in the oral mucosa, and so the researchers decided to investigate the topic with greater specificity as to the chemical signaling produced.
The researchers administered an extract of black tea containing 40.23% theaflavin, to cell cultures of oral epithelial cells, the cariogenic bacteria P. gingivalis, F. nucleatum, and P. intermedia, as well as gingival fibroblast cells that had been aggravated by P. gingivalis. Upon addition of the tea extract, the bacterial cultures were then incubated and assessed for growth, and the gingival fibroblast cells were assayed for interleukin-8 and hBD secretion.
P. gingivalis and P. intermedia were particularly affected by the tea extract, growing almost as poorly as the control culture which was inoculated with tetracycline. F. nucleatum was also affected, but to a lesser extent. The aggravated fibroblast cells treated with the tea extract displayed lower levels of interleukin-8 than the control culture, and increased hBD, which is an antibacterial peptide.
All together, the results show that the tea extract inhibited bacterial growth, reduced inflammation in the gingival cells, and increased their ability to combat oral bacteria. Theaflavins show promise in maintaining oral health, and further research may reveal novel anticariogenic therapies based on their method of action. For now, enjoy that cup of tea knowing you're promoting a healthy mouth, so long as you don't put too much cream and sugar in!
Lombardo Bedran, T. B., Morin, M.-P., Palomari Spolidorio, D., & Grenier, D. (2015). Black tea extract and its Theaflavin derivatives inhibit the growth of Periodontopathogens and modulate Interleukin-8 and β-defensin secretion in oral Epithelial cells. PLOS ONE, 10(11), e0143158. doi:10.1371/journal.pone.0143158