Green tea may strengthen teeth, gums
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J of Periodontology – A study recently published in the Journal of Periodontology, the official publication of the American Academy of Periodontology (AAP), uncovered another benefit of green tea consumption. Researchers found that routine intake of green tea may also help promote healthy teeth and gums.
With origins dating back over 4,000 years, green tea has long been a popular beverage in Asian culture, and is increasingly gaining popularity in the United States. And while ancient Chinese and Japanese medicine believed green tea consumption could cure disease and heal wounds, recent scientific studies are beginning to establish the potential health benefits of drinking green tea, especially in weight loss, heart health, and cancer prevention.
The study analyzed the periodontal health of 940 men, and found that those who regularly drank green tea had superior periodontal health than subjects that consumed less green tea.
“It has been long speculated that green tea possesses a host of health benefits,” said study author Dr. Yoshihiro Shimazaki of Kyushu University in Fukuoka, Japan. “And since many of us enjoy green tea on a regular basis, my colleagues and I were eager to investigate the impact of green tea consumption on periodontal health, especially considering the escalating emphasis on the connection between periodontal health and overall health.”
Male participants aged 49 through 59 were examined on three indicators of periodontal disease: periodontal pocket depth (PD), clinical attachment loss (CAL) of gum tissue, and bleeding on probing (BOP) of the gum tissue. Researchers observed that for every one cup of green tea consumed per day, there was a decrease in all three indicators, therefore signifying a lower instance of periodontal disease in those subjects who regularly drank green tea.
Green tea’s ability to help reduce symptoms of periodontal disease may be due to the presence of the antioxidant catechin.
What is catechin? Catechin is a tannin peculiar to green tea because the black tea fermentation process reduces catechins in black tea. Catechin is a powerful, water soluable polyphenol and antioxidant that is easily oxidized.
Several thousand types are available in the plant world. As many as two thousand are known to have a flavon structure and are called flavonoids. Catechin is one of them.
Research aimed at finding the active compounds in green tea revealed that its protective effects are due chiefly to catechins. Tea contains four main catechin substances: EC, ECg, EGC and EGCg, all of which are inclusively called catechin. Epigallocatechin gallate (EGCG) is the most powerful of these catechins. EGCG as an antioxidant is about 25-100 times more potent than vitamins C and E.
One cup of green tea provides 10-40 mg of polyphenols and has antioxidant effects greater than a serving of broccoli, spinach, carrots, or strawberries. The high antioxidant activity of green tea makes it beneficial for protecting the body from oxidative damage due to free radicals.
Research shows that green tea may help the arterial wall by reducing lipids. Green tea can protect against experimentally induced DNA damage, and slow or halt the initiation and progression of undesirable cell colonies. Studies show evidence that green tea provides immunoprotective qualities, particularly in the case of patients undergoing radiation or chemotherapy. White blood cell count appear to be maintained more effectively in patients consuming green tea compared to non-supplemented patients.
Green tea is manufactured from fresh, unfermented tea leaves; the oxidation of catechins is minimal, and hence they are able to serve as antioxidants. Researchers believe that catechin is effective because it easily sticks to proteins, blocking bacteria from adhering to cell walls and disrupting their ability to destroy them. Viruses have ‘hooks’ on their surfaces and can attach to cell walls. The catechin in green tea prevents viruses from adhering and causing harm. Catechin reacts with toxins created by harmful bacteria (many of which belong to the protein family) and harmful metals such as lead, mercury, chrome, and cadmium.
Tannin in green tea is mostly catechin and is a key component in its taste providing the astringency. The amount of catechin tends to increase as the season progresses. Spring tea (first crop) contains 12-13% catechin (13-17% as tannin) while summer tea (third crop) contains 13-14% (17-21% as tannin). If leaf order is compared, younger leaves include more catechin than mature ones. First leaves contain 14%, second 13%, third 12%, and fourth 12%. This explains why second and third crop summer teas are more astringent while Bancha is less so. Gyokuro green tea, whose leaves are covered during growth, contains less catechin and astringency (10% as tannin) because it gets less sunshine then Sencha.
Previous research has demonstrated antioxidants’ ability to reduce inflammation in the body, and the indicators of periodontal disease measured in this study, PD, CAL and BOP, suggest the existence of an inflammatory response to periodontal bacteria in the mouth. By interfering with the body’s inflammatory response to periodontal bacteria, green tea may actually help promote periodontal health, and ward off further disease. Periodontal disease is a chronic inflammatory disease that affects the gums and bone supporting the teeth, and has been associated with the progression of other diseases such as cardiovascular disease and diabetes.
“Periodontists believe that maintaining healthy gums is absolutely critical to maintaining a healthy body,” says Dr. David Cochran, DDS, PhD, President of the AAP and Chair of the Department of Periodontics at the University of Texas Health Science Center at San Antonio. “That is why it is so important to find simple ways to boost periodontal health, such as regularly drinking green tea – something already known to possess certain health-related benefits.”
[Journal of Periodontology 2009, Vol. 80, No. 3, Pages 372-377]
