Tea and Herbal Infusions, Psychological Stress, Anxiety & Sleep Health: A Systematic Review of Human Trials & Mechanistic Studies

Abstract

Tea is popular global beverage and abundant provider of biologically active plant molecules which have been attributed to its health properties. Relationships between tea drinking and certain aspects of health have been the subject of past reviews. The present systematic review focuses on tea consumption in relation to psychological stress and the challenges of stress and anxiety on sleep health. Publications were searched up to 21st September 2022, in the PubMed database along with references of original articles. Thirty-three publications were included in the main review-17 human trials and 16 mechanistic studies. Human trials were graded to assess quality using the Jadad scale. Overall, a growing body of evidence suggests that tea (including green and oolong) and herbal infusions, at relatively low intakes (around 1 to 2 cups daily), could help to facilitate sleep, alleviate psychological stress and anxiety, primarily by facilitating relaxation. Evidence for black tea, German Chamomile, Lavender, Rose, Jasmine, and Passionflower tea is emerging and looks promising. Ongoing research is needed in the form of randomised controlled trials to build on these provisional findings.