The beneficial effects of green tea on human health: an updated review

Abstract

Green tea is un-fermented product of Camellia species. The leaves of both Camellia sinensis and Camellia assamica, are used for the production of green tea, but C. assamica is mainly used for the production of black tea. Green tea is widely produced from the leaves of C. sinensis, now a day’s which is one of the most popular beverages worldwide. Over the past 50 years or more, scientists have studied this plant with respect to potential health benefits. Research has shown that the main components of green tea that are associated with health benefits are the catechins. The four main catechins found in green tea are: (-)-epicatechin (EC), (-)-epicatechin-3-gallate (ECG), (-)-epigallocatechin (EGC), and (-)-epigallocatechin-3-gallate (EGCG). Of these four, EGCG is present in the largest quantity, and so has been used in most of the researches. Among the important health benefits of green tea are: anticarcinogenic, anti-inflammatory, antioxidant, and antimicrobial properties, and benefits in cardiovascular disease and oral health. Research has been carried out using various animal models and cells lines, and is now more and more being carried out in humans. This type of research will help us to better understand the direct benefits of green tea. This review will focus primarily on researches conducted on human subjects to investigate the health benefits of green tea.