Black Tea Flavonoids: A Focus on Thearubigins and their Potential Roles in Diet & Health

Abstract

The potential health benefits of black tea are well documented but the specific roles of thearubigins are less widely published. We undertook a review to identify human observational studies and laboratory studies investigating inter-relationships between thearubigin intakes and health. Twenty-two publications were identified-five observational studies and 17 laboratory/mechanistic studies. Evidence from observational studies demonstrates that black tea is a major dietary provider of thearubigins, with reported intakes of 327 mg/d in the UK, a nation of tea drinkers but lower in Europe (156 mg/d). A growing body of evidence (from laboratory/cell studies) signifies that thearubigins could have potential health roles, including antioxidant, antimutagenic and anticancer properties, along with the ability to reduce inflammation and improve gastrointestinal motility. Well-designed human trials are now needed to further investigate thearubigin intakes from dietary sources in relation to specific health outcomes.