A Review on the Weight-Loss Effects of Oxidized Tea Polyphenols

Abstract

The mechanistic systems in the body through which tea causes weight loss are complex and multi-dimensional. Additionally, the bioactive components in tea such as catechins, caffeine, and products of tea polyphenol oxidation vary greatly from one major tea type to the next. Green tea has been the primary subject of consideration for investigation into the preventative health effects of tea because it contains the highest levels of phenolic compounds and retains the highest antioxidant capabilities of any major tea type. However, recent research suggests decreasing body fat accumulation has little to do with antioxidant activity and more to do with enzyme inhibition, and gut microbiota interactions. This paper reviews several different tea polyphenol-induced weight-loss mechanisms, and purposes a way in which these mechanisms may be interrelated. Our original ‘short-chain fatty acid (SCFA) hypothesis’ suggests that the weight-loss efficacy of a given tea is determined by a combination of carbohydrate digestive enzyme inhibition and subsequent reactions of undigested carbohydrates with gut microbiota. These reactions among residual carbohydrates, tea polyphenols, and gut microbiota within the colon produce short-chain fatty acids, which enhance lipid metabolism through AMP-activated protein kinase (AMPK) activation. Some evidence suggests the mechanisms involved in SCFA generation may be triggered more strongly by teas that have undergone fermentation (black, oolong, and dark) than by non-fermented (green) teas. We discussed the mechanistic differences among fermented and non-fermented teas in terms of enzyme inhibition, interactions with gut microbiota, SCFA generation, and lipid metabolism. The inconsistent results and possible causes behind them are also discussed.

Metabolome and Transcriptome Analysis Reveals Putative Genes Involved in Anthocyanin Accumulation and Coloration in White and Pink Tea (Camellia sinensis) Flower

“…Tea (Camellia sinensis (L.) O. Kuntze) is the most popular beverage in the world, largely because of its beneficial health attributes [1,2]. Additionally, it is recognized as one of the most central economic crops in China, India and other developing countries, functioning as a powerful driver of poverty reduction in poor mountainous regions and underdeveloped rural economies.…”

In Vitro Characterization, Modelling, and Antioxidant Properties of Polyphenon-60 from Green Tea in Eudragit S100-2 Chitosan Microspheres

“…Green tea is obtained from the fresh leaves of Camellia sinensis, a plant from the Theaceae family which has been used for centuries as a natural antioxidating beverage. Its polyphenolic constituents provide it with additional therapeutic benefits in the modulation of oxidative stress-induced cardiovascular diseases associated with diabetes, already confirmed in clinical trials [1][2][3][4][5][6]. Green tea extracts, rich in antioxidant polyphenols (e.g., epigallocatechin-3-gallate), have been reported for reducing lipid peroxidation, oxidized low-density lipoproteins (LDL), cholesterol levels, and anti-hypertensive effects, factors that are relevant to reduce cardio-metabolic disease risk [7].…”

Effect of green tea on obesity and serum lipid profiles in both normo- and hyper-cholesterolemic rabbits

“…There are several mechanisms to explain the mechanism of action of green tea in weight reduction, but the most accepted hypothesis is that green tea inhibits the expression and activity of enzymes involved in carbohydrate metabolism, and also it plays a significant role in the interaction of these undigested carbohydrates with the gut microbiome. These interactions among the polyphenols present in green tea, undigested carbohydrates, and gut microbiome generate short-chain fatty acids that improve lipid metabolism by activating AMP-activated protein kinase (AMPK) (Rothenberg et al, 2018).…”

“…Green tea has been inspected broadly for its role in the management of several systemic diseases like metabolic disorders, obesity, diabetes, and growth (Yang et al, 2018). Existing investigations according to the function of green tea in weight reduction have been conflicting in indicating an advantageous potential of green tea consumption on weight reduction (Quinhoneiro et al, 2018;Rothenberg et al, 2018).…”