Previous studies have found that the major polyphenol in green tea extracts, epigallocatechin gallate (EGCG), has chemopreventive effects on cancers affecting a number of organs in the digestive tract.
The team from the Harvard Medical School reported that EGCG inhibits the growth and reproduction of cancer cells (SEG-1 and BIC-1)associated with Barrett's esophagus. Barrett's esophagus is a condition caused by stomach acid creeping back up from the stomach. The acid damage causes the cells lining the esophagus to change and raises the risk of esophageal cancer by 30 to 40 times.
The researchers concluded that exposure to EGCG induces apoptosis, or programmed cell death, and results in increased levels of the proteins caspase-3 and cleaved poly-ADP-ribose polymerase (PARP), known to play a role in DNA damage repair.
In the study (abstract 103982), the adenocarcinoma cells were treated with different concentrations of EGCG and monitored for cell growth, method of cell death and changes in apoptotic protein levels. Treatment of cells with EGCG inhibited cell growth and caused signs of early apoptosis at 24 hours.
"Research suggests that drinking green tea may be both a valuable chemopreventive therapy as well as a treatment for esophageal adenocarcinoma," said Howard Chang, an investigator of the study.
A recent study, also presented at Digestive Disease Week , has linked the increasing prevalence of cancer of the esophagus to growing consumption of sodas.