Green Tea Targets Cancer
Speaking at an international conference on diet and cancer, researchers funded by the American Institute for Cancer Research (AICR) presented evidence that a major component in green tea may short-circuit the cancer process in a striking new way that scientists had not foreseen.
AICR experts also released the results of surveys showing that only 15 percent of Americans say they drink green tea on a typical day, and less than one percent of Americans are currently drinking enough green tea to match the average per capita consumption in Asian countries.
The AICR experts highlighted the low levels of green tea consumption in the United States in relation to what they called "intriguing evidence" from studies conducted among Asian populations that suggest a protective effect for green tea. They also pointed to the rapidly increasing number of laboratory studies exploring green tea's effects on a cellular level.
New Evidence That Green Tea Short-Circuits the Cancer Process
"We have determined that a unique quirk of biochemistry allows green tea's protective effects to extend to many different kinds of cells," said Dr. Thomas A. Gasiewicz, a Professor of Environmental Medicine at the University of Rochester Medical Center. "In fact, the active green tea substance, called EGCG, seems to target one protein that is particularly common throughout our bodies, and it does so with a degree of precision that cancer drugs still aren't able to match."
The protein in question is called HSP90, which is present at higher levels in many cancer cells. Scientists believe that in some circumstances, HSP90 helps to trigger the cascade of events that eventually leads to cancer.
When EGCG binds to this protein, however, it helps prevent these events from happening. This is important, because HSP90 is found throughout our bodies, in many different cells and tissues.
"If further research confirms that EGCG's ability to bind to such a basic and pervasive protein enables it to extend its protective effect throughout our bodies, it explains a scientific mystery," said Gasiewicz. "Studies that track the diets of human subjects over several years, particularly studies conducted in Asia, where green tea consumption is common, have associated regular usage of green tea with lower risk for cancers that are vastly different from one another."
Scientists suspect that many different mechanisms must be involved to explain Asian data linking green tea to the prevention of such diverse cancers as those of the breast, prostate, bladder, colon, stomach, pancreas, breast and esophagus. But this new finding shows that EGCG may be effective against an important "common denominator" for many different cancers, at the very start of the process.
EGCG Does What Cancer Drugs Can't Do... Yet
The protein called HSP90 is essentially a "helper" or "chaperone" protein, in that it exists to help stabilize other proteins and keep them together. Because it has to bind to so many different proteins it is present, in varying amounts, in all of our cells. In fact, it is referred to as a "promiscuous protein" because it is so pervasive.