Tea and human health: biomedical functions of tea active components and current issues

Abstract

Originating in China, tea and tea planting have spread throughout the world since the middle of the Tang dynasty. Now people from 160 countries in the world are accustomed to tea drinking. A brief history of tea's medicinal role in China and its spread to the world are introduced. The effectiveness of tea active components and tea drinking on major human diseases, including cancer, metabolic syndrome, cardiovascular disease, and neurodegenerative diseases, is discussed. Also presented are some related issues, such as the bioavailability of tea active components, the new formulations of tea polyphenols, and the safety for consumers of dietary supplements containing tea polyphenols.

Tea polyphenols dominate the short-term tea (Camellia sinensis) leaf litter decomposition

“…Tea is widely cultivated in Southeast Asia as a commercial crop, especially in China (Chen and Lin, 2015), and it uniquely contains a lot of phenolic compounds. Tea polyphenols are distributed in almost every part of the plant, but are particularly prevalent in the leaves accounting for approximately 18%-34% of the dry leaf weight (Wan, 2008).…”

Biosorption of green and black tea polyphenols into Saccharomyces cerevisiae improves their bioaccessibility

“…During the oxidative processing in the manufacturing of oolong and black teas, derivatives of flavan-3-ols, theaflavins and thearubigins are formed (Daglia, Antiochia, Sobolev, & Mannina, 2014). Tea bioactive compounds have attracted much attention as potential beneficial agents as their consumption has been associated with reduced incidence of cancer, cardiovascular and coronary heart diseases (Chen & Lin, 2015;da Silva Pinto, 2013;Vertoli et al, 2013). Moreover, scientific evidence supports the health benefits of GT consumption and closely relates these benefits to catechins which have antioxidative, anticarcinogenic, antimicrobial, anti-viral, anti-inflammatory and anti-diabetic properties (Bancirova, 2010;Khan & Mukhtar, 2007).…”

Chemical characterization and bioactivity of phenolics from Tieguanyin oolong tea

“…Tea ( Camellia sinensis ) is becoming an increasingly popular beverage worldwide mainly because of its potential benefits for human health(Vyas & Kumar, ). In the past 30 years, tea polyphenols, especially catechins, have attracted much attention due to their extensive bioactivities and are considered the most effective component in tea (Chen & Lin, ). Although tea catechin monomers are sensitive to temperature and oxygen and are easily oxidated during manufacture (especially becoming fermented), alterations in polyphenols seem to have no negative effect on the bioactivities of related tea products because black tea (fully fermented) and pu‐erh tea (post fermented), as well as green tea, have demonstrated several health‐promoting functions.…”