Green tea catechin: does it lower blood cholesterol?

Abstract

Tea is one of the most popular beverages in the world, especially in Asian societies. Green, oolong and black tea are three main types of tea products. Catechin is the principal polyphenol compound in all tea products including four major subgroup compounds, epigallocatechin gallate (EGCG), epicatehin (EC), epigallocatechin (EGC) and epicatechin gallate (ECG). Green tea contains highest amount of catechin compared to oolong and black tea since fermentation process can significantly reduce the amount of catechin in tea product, which polyphenol oxidase can convert catechins to theaflavins and thearubigins during fermentation process. Therefore, green tea catechin is becoming more and more attractive to nutritionists since it can provide several health benefits to human body. Cholesterol lowering effect is one of the health benefits been studied and proposed over decade. There are well documented evidences that suggested green tea catechin, in particular EGCG has the potential to lower blood cholesterol concentrations. Since the pool bioavailability and absorption ability of catechin, researchers believed that green tea catechin may significantly inhibit lipids absorption in intestine. Mechanisms are including inhibition of pancreatic lipase activity, lipids hydrolysis, and emulsification in intestine and precipitation of micellar cholesterol. In vitro studies, animal studies as well as most of human RCT, consistent results been observed that dietary intake of green tea beverages or extracts could significantly lower circulating cholesterol concentration, in particular lower LDL-C and total cholesterol level. However, in 2010, European Food Safety Authority (EFSA) denied the health claim of cholesterol lowering benefits of dietary intake of green tea or green tea catechins. In this presentation, current scientific evidences and EFSA judgment will be reviewed and discussed.