Anti‐obesity effects of green tea: From bedside to bench

Abstract

During the last decade, the traditional notion that green tea consumption benefits health has received significant scientific attention and, particularly, the areas of cardiovascular disease and cancer were subject to numerous studies. Due to the ever-growing obesity pandemic, the anti-obesity effects of green tea are being increasingly investigated in cell, animal, and human studies. Green tea, green tea catechins, and epigallocatechin gallate (EGCG) have been demonstrated in cell culture and animal models of obesity to reduce adipocyte differentiation and proliferation, lipogenesis, fat mass, body weight, fat absorption, plasma levels of triglycerides, free fatty acids, cholesterol, glucose, insulin and leptin, as well as to increase beta-oxidation and thermogenesis. Adipose tissue, liver, intestine, and skeletal muscle are target organs of green tea, mediating its anti-obesity effects. Studies conducted with human subjects report reduced body weight and body fat, as well as increased fat oxidation and thermogenesis and thereby confirm findings in cell culture systems and animal models of obesity. There is still a need for well-designed and controlled clinical studies to validate the existing and encouraging human studies. Since EGCG is regarded as the most active component of green tea, its specific effects on obesity should also be investigated in human trials.

Purification and Characterization of a Novel Galloyltransferase Involved in Catechin Galloylation in the Tea Plant (Camellia sinensis)

“…The health-promoting effects of galloylated catechins are stronger than those of nongalloylated catechins (16,17).…”

Epigallocatechin-3-gallate (EGCG), A Green Tea Polyphenol, Suppresses Hepatic Gluconeogenesis through 5′-AMP-activated Protein Kinase

“…1,2). EGCG has been shown to be involved in regulation of a variety of metabolic processes and has been used as an anti-obesity reagent in animal models and in humans (3)(4)(5)(6). Although its effectiveness in the treatment of human diabetes has not been established, EGCG has been shown in rodents to be effective in preventing the development of Type I diabetes and treatment of Type II diabetes (7,8).…”

The effects of green tea on weight loss and weight maintenance: a meta-analysis

“…1 The polyphenols in green tea such as epigallocatechin gallate (EGCG), epigallocatechin, and epicatechin gallate, which are responsible for its beneficial effects (such as the anti-oxidant potential and anti-mutagenic capacity) are converted into thearubigins and theaflavins in black tea. 2 Although black tea still can improve one's health, the conversion attenuates the effects reported after intake of green tea. [3][4][5] Since the 1990s, green tea is also seen as a natural herb that can enhance energy expenditure and fat oxidation and thereby induce weight loss (WL).…”