Green tea may boost oral health, reduce tooth loss

Drinking one cup of green tea may improve dental health and reduce the risk of loosing teeth by about 20 per cent, according to a new study from Japan.

And drinking more cups appears to confer additional risk reductions, with five or more cups a day associated with a 23 per cent reduction in risk, according to findings from the Ohsaki Cohort 2006 Study published in Preventive Medicine.

Being an observational study, the findings do not prove causality, but the link does appear to be biologically plausible, state the authors, led by Yasushi Koyama from Tohoku University Graduate School of Medicine. Previous studies have reported that green tea catechins may inhibit the action of oral bacteria linked to development of periodontal disease, they said.

“A number of experimental studies have shown that green tea catechins inhibit oral bacteria, while some experiments have indicated that the concentration of tea catechin conferring the above effect should be more than 100 mg/100 ml,” wrote the authors. “A typical preparation of green tea contains a catechin concentration of 50–150 mg/100 ml.

“Therefore, this amount of catechin contained in one cup of green tea might be sufficient to aid tooth retention,” they added.

Green tea

The majority of science on tea has looked at green tea, with benefits reported for reducing the risk of Alzheimer’s and certain cancers, improving cardiovascular and oral health, as well as aiding in weight management.

Green tea contains between 30 and 40 per cent of water-extractable polyphenols, while black tea (green tea that has been oxidized by fermentation) contains between 3 and 10 per cent. Oolong tea is semi-fermented tea and is somewhere between green and black tea. The four primary polyphenols found in fresh tealeaves are epigallocatechin gallate (EGCG), epigallocatechin, epicatechin gallate, and epicatechin.

source: Preventive Medicine
Published online ahead of print, doi: 10.1016/j.ypmed.2010.01.010
“Association between green tea consumption and tooth loss: Cross-sectional results from the Ohsaki Cohort 2006 Study”
Authors: Y. Koyama, S. Kuriyama, J. Aida, T. Sone, N. Nakaya, K. Ohmori-Matsuda, A. Hozawa, I. Tsuji