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Green Tea
Inhibits Cancer of the Esophagus
July
27, 2006
A group of researchers discovered that green tea has the ability to inhibit esophageal cancer associated with Barrett’s esophagus, a disorder of the lower esophagus where it connects to the stomach marked by a benign lesion in columnar epithelium, or lining of the esophagus, caused most often by chronic irritation of the esophagus by gastric reflux, a backing up of acidic digestive juices.
Normal Healthy Tissue
Cells in the Lining of the Esophagus
In a normal and healthy esophagus, the tube that food travels through
to reach the stomach after swallowing, the lining, known as the squamous
epithelium, is pinkish-white, although some people also have red stomach
tissue, normal columnar epithelium, in the bottom part of the esophagus
where it connects to the stomach.
Abnormal Unhealthy
Tissue Cells in the Lining of the Esophagus
Barrett's esophagus is a condition in which the normal squamous epithelium
of the esophagus has been replaced by an abnormal red columnar epithelium
called specialized intestinal metaplasia. These were normal healthy
tissue cells that have been converted into abnormal cells due to chronic
stress or injury, in this case repeated exposure to the acidic digestive
juices from the stomach.
Barrett’s esophagus, is considered a precancerous condition. Some of the symptoms are heartburn and dysphagia, or difficulty in swallowing.
Drinking Green Tea
Lowers Risk of Cancers of the Digestive Tract
It has been known that drinking green tea is connected with lowering
the risk of several types of cancers of the digestive tract. The drinking
of the tea is believed to be exposing the tissues of the esophagus to
high levels of natural occurring polyphenols such as epigallocatechin
gallate (EGCG).
Study Reveals EGCG
in Green Tea Inhibits Abnormal Cell Growth
Dr. Howard Chang along with other medical researchers at Harvard Medical
School and the Veterans Administration Boston Healthcare System subjected
cultured human Barrett’s esophagus-associated adenocarcinoma cells,
cells that are cancerous, to different concentrations of the green tea
polyphenol EGCG, and then compared them to Barrett’s esophagus-associated
adenocarcinoma cells that were not given the EGCG. They discovered that
dose-dependent treatment of the cells with EGCG produced inhibited cell
growth within 72 hours.
Green Tea Polyphenol (EGCG) Causes Death of Abnormal Cells
The team of medical researchers came to the conclusion that the green
tea polyphenol, EGCG, causes apoptosis, or cell death, in as little
as 24 hours when the cancerous cells are exposed to it. They also discovered
that an elevation of two indicators of apoptosis, or cell death, were
presented in the cells treated with EGCG, but not the untreated cells.
They were the enzyme caspase 3 and cleaved poly(ADP-ribose) polymerase
(PARP) protein levels.
Physician Suggests
Green Tea is Valuable as A Preventative and A Treatment
According to Dr. Chang, “Research suggests that drinking green tea may
be both a valuable chemopreventive therapy as well as a treatment for
esophageal adenocarcinoma. Our results suggests that extracts in green
tea may help to lower the prevalence of esophageal adenocarcinoma, one
of the fastest growing cancers in Western countries.”
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