Is Oolong Tea Good For Teeth Or Oral Health?

Oolong tea comes from Camellia sinensis, the same species of plant that green, black and white teas comes from. The only difference among these varieties is how they are processed. Oolong, which means "black dragon tea" in Chinese, is rolled and dried in the sun until the leaves whither and turn greenish-blue. Aside from being a beverage, tea has held a place in traditional Asian systems of medicine for thousands of years. More recently, research shows that tea may enhance oral health.

Background

Camellia sinensis is a flowering shrub native to southeast China now widely cultivated in India, Japan, Pakistan, Turkey and Argentina. According to legend, tea was "discovered" around 4,000 years ago in China when leaves from the tree were carried by wind into a vat of boiling water. Although tisanes, or infusions, are made from many other plants today, these are herbal teas and do not contain any true tea.

Chemical Composition

The more tea leaves are allowed to ferment, the more oxidation takes place. Similarly, the greater the oxidation, the more enzymes present in the tea leaves degrade into less active compounds. Green tea, which undergoes the least amount of oxidation, has the highest levels of antioxidant catechins intact. According to the "Physicians' Desk Reference for Herbal Medicines," green tea has six times more antioxidant value than black or oolong teas. However, all teas are composed of essentially the same catechin compounds. In oolong tea, oxidation results in the conversion of these compounds into theaflavine, theaflavin acid and thearubigene, chemicals with stimulatory effects similar to caffeine. The flavonoids quercetin, kaempferol and myrecetin are also present. In addition, oolong tea contains up to 160 mg of fluoride per kg of weight, although this appears to be due to systemic pollution from the environment rather than biological design.

Effects on Teeth

Collectively, the active compounds in oolong tea are referred to as polyphenols. In addition to having potent antioxidant properties, tea polyphenols are anti-inflammatory and antimicrobial. These agents suppress oral bacterial enzymes that contribute to the formation of dental plaque and cavities. Specifically, tea polyphenols block the activity of Streptococcus salivarius, Streptococcus mutans and Escherichia coli.

Periodontal Disease Prevention

Tea compounds inhibit the growth of Porphyromonas gingivalis, an oral bacteria responsible for causing gingivitis. In a study published in the "Journal of Periodontology" in March 2009, Dr. Yoshihiro Shimazaki from the Kyushu University Faculty of Dental Science reports a modest inverse association between tea drinking and periodontal disease. For each cup of tea consumed by the 940 men who participated in the study, there was a measurable decrease in gum loss, pocket depth between teeth and bleeding on examination. Like many studies in the medical literature, this one focused on green tea consumption. However, you could expect similar results with oolong tea, but perhaps to a lesser extent.