Go Green (Tea)!

Article by Amy Bragagnini, MS, RD, CSO
Posted on February 09, 2010

Historians hypothesize that tea leaves steeped in boiling water had been consumed for 500,000 + years. There are three main types of tea: green, black, and oolong (the difference between the three is in the processing). Green tea generally contains the highest amount of antioxidants called catechin polyphenols (specifically epigallocatechin gallate or EGCG). In traditional Chinese medicine, green tea was used as a diuretic, as an astringent, to help regulate temperature and blood sugar, and to help reduce flatulence. Current research suggests that it can help inhibit the growth of cancer cells without harming healthy tissue. It has also been suggested that it can assist by inhibiting the abnormal formation of blood clots, reduce bad (LDL) cholesterol levels, improve blood sugar levels for people with diabetes, and may even help prevent tooth decay.

A recent study released looks at green teas potential role in reducing lung cancer. Results of this study were presented at the AACR-IASLC Joint Conference on Molecular Origins of Lung Cancer. Population for this study included 170 people with lung cancer and 340 healthy people. A questionnaire was distrubuted which included smoking history, fruit and vegetable intake, cooking practices, etc. All participants also underwent genotyping on insulin-like growth factors (IGF1, IGF2, IGFBP3). Results indicated that among all participants, those who did not drink green tea had a 5.16-fold increased risk of lung cancer compared with those who drank at least one cup of green tea per day. In addition, those that smoked had a 12.7 increased risk for the development of lung cancer. Researchers suspect that genetics plays a factor in these findings. “Heavy smokers carrying susceptible IGF1, IGF2 and IGFBP3 genotypes also had a higher risk of lung cancer compared with nonsmokers carrying non-susceptible IGF1, IGF2 and IGFBP3 genotypes”

Green tea is safe for most adults in moderate amounts. Healthcare professionals urge caution when it comes to taking green tea in a supplemental pill form, as the supplements are not regulated by the Food and Drug Administration. It is suggested that you keep your healthcare team informed of the usage of green tea. Keep in mind that there is generally caffeine in green tea, which may cause insomnia, gastric irritation, nausea, or diarrhea.