Green Tea: The Miracle Tea?

There has been a great deal of hype about green tea lately. It’s on the news, all over the internet and it’s even made multiple appearances on Oprah. So are the claims true? Can it help you lose weight, lower your cholesterol or even prevent cancer? The jury is still out, but there is no denying that green tea does have the potential to improve your health.

The History of Green Tea
Archeological evidence suggests that people have been drinking tea in one form or another for 500,000 years. India and China were the first countries to purposefully cultivate tea, and green tea has been used medicinally in China for at least 4,000 years(www.umm.edu). The Chinese have used green tea to treat common aliments like headaches as well as more serious conditions like depression (Parkinson 2008). Green tea has also been used in India and China as a diuretic, astringent, and blood sugar regulator. Today, hundreds of millions of people around the world drink tea, and there is increasing research into the medicinal properties of green tea.

What makes Green Tea Special?
Green tea is made from the same plant (Camellia sinensis) as black and oolong tea, but it is steamed rather than fermented (http://www.umm.edu/). Unfermented tea leaves contain high levels of polyphenols, specifically epigallocatechin gallate or EGCG (Parkinson 2008). EGCG is an antioxidant, a chemical which degrades free radicals. Free radicals are particles which have the potential to alter DNA and cause cell death. Over time, free radicals can lead to cancer, heart disease and other health problems. Antioxidants help to neutralize free radicals, and therefore may help prevent certain diseases (www.umm.edu).

Research
In 1997, The University of Kansas found that EGCG is twice as powerful as resveratrol, the antioxidant found in red wine. The researchers hypothesized that the high consumption of green tea in Japan may explain why the rate of heart disease in men there is very low, despite that fact that seventy-five percent of Japanese men are smokers (Parkinson 2008). Animal research has also shown that the antioxidants in green tea inhibit the absorption of cholesterol and promote its excretion from the body. While these and other studies would indicate that green tea may help prevent heart disease, the FDA has concluded that there is not yet enough research to support this claim (http://www.umm.edu/).
In 1994, the Journal of the National Cancer Institute published a population study of Chinese men and women which indicated that drinking green tea reduces the risk of esophageal cancer. Along these same lines, the University of Purdue has shown that a compound in green tea actually inhibits the growth of cancer cells (Parkinson 2008).
Green tea may even aid in weight loss. It was found that men given caffeine and green tea extract burned more calories than those given caffeine and a placebo (Parkinson 2008).

The Bottom Line
The FDA has yet to back any of the claims that green tea can help prevent heart disease, cancer or any of the other many diseases researchers are considering. However, it can be said there are decidedly few negative side effects associated with drinking green tea. The only side effect reported to date is insomnia due to the caffeine in the tea. Then again, green tea has about 40-70% less caffeine than coffee (Parkinson 2008). It may take some time before researchers and the FDA reach any conclusions about the health benefits of green tea. In the meantime, I think I’ll brew myself a cup!

References
Parkinson, Rhonda. "The Miracle of Green Tea." About.com. 2008. 18 Nov 2008 .

"Green Tea." Complementary Medicine. Sept 30 2008. University of Maryland Medical Center. 18 Nov 2008 .