7 June 2006

New Theory On Green Tea's Medicinal Properties

by Kate Melville

Scientists have for some time been puzzled about the lower incidence of cardiovascular disease and cancer in Asian countries where the population smokes heavily. A preventative effect from green tea has been thought to be responsible and now a new study from Yale has found what could be the key chemical component.

"We do not yet have a full explanation for the 'Asian paradox', which refers to the very low incidence of both heart disease and cancer in Asia, even though consumption of cigarettes is greater than in most other countries," said Yale's Bauer Sumpio, "but we now have some theories."

According to Sumpio, writing in the Journal of the American College of Surgeons, the average 1.2 liters of green tea consumed daily by many people in Asia offers the anti-oxidant protective effects of the polyphenolic epigallocatechin-3-gallate (EGCG). Sumpio said that EGCG may prevent LDL oxidation, which has been shown to play a key role in the pathophysiology of arteriosclerosis. EGCG also reduces the amount of platelet aggregation, regulates lipids, and promotes proliferation and migration of smooth muscle cells, which are all factors in reducing cardiovascular disease. Sumpio added that other reports show that EGCG prevents growth of certain tumors.

"More studies are necessary to fully elucidate and better understand green tea's method of action, particularly at the cellular level," Sumpio concluded. "The evidence is strong that green tea consumption is a useful dietary habit to lower the risk for, as well as treat, a number of chronic diseases."

Source: Yale University