Health Benefits of Tea

Excerpt

The health benefits ascribed to the consumption of teas may be related to the high content of bioactive ingredients such as polyphenols. Polyphenols have been reported to possess antioxidant, antiviral, and anti-inflammatory activities; modulate detoxification enzymes; stimulate immune function and decrease platelet aggregation (Lampe 2003; Frankel and Finley 2008). Among all tea polyphenols, epigallocatechin gallate (EGCG) has been found to be responsible for much of the health-promoting ability of GT (Khan et al. 2006). In general, GT has been found to be superior to black tea (BT) in terms of health effects, owing to the higher content of EGCG, although the role of thearubigins and theaflavins contained in BT have not been properly investigated. In vitro and animal studies provide strong evidence that polyphenols derived from tea possess bioactivity to delay the onset of risk factors associated with disease development (Cabrera, Artacho, and Giménez 2006; Wolfram 2007; Yang et al. 2007; Yang et al. 2009; Yang, Lambert and Sang 2009). Studies conducted on cell cultures and animal models indicate a potentially modulating effect of tea on gene transcription, cell proliferation, and other molecular functions (McKay and Blumberg 2002). Over the last few years, clinical studies have revealed several physiological responses to tea that may be relevant to the promotion of health and the prevention or treatment of some chronic diseases (Crespy and Williamson 2004; Cabrera, Artacho, and Giménez 2006). This chapter covers recent findings on the medicinal properties and health benefits of tea with special reference to antioxidant and anti-inflammatory actions as key mechanisms for cancer and CVD prevention.