This week, the UK’s Standard published an article about why drinking tea in the morning is good for you. Among these reasons was evidence that tea can help reduce stress levels.
Several years ago, researchers at the University College of London found that people who consumed black tea were able to destress more quickly than those who didn’t drink tea. They enrolled 75 men in the study and asked them to stop the consumption of all caffeine. Half the group was asked to drink a fruit-flavored beverage four times a day that was caffeinated and included the major antioxidants and other chemical components of tea. The other half of the group consumed a beverage that tasted the same and also had caffeine, but did not have the tea components. The researchers subjected the group to high levels of different kinds of stress. Their blood pressure and heart rate were checked and they were asked to report on their stress levels. Fifty minutes later, stress levels had dropped 27% in the control group but 47% in the study group.
The structure of the study was important for several reasons. One, it eliminated the possibility that the difference was just in the warmth and comfort of the ritual of consuming the beverage. Second, it answered the question of whether or not caffeine was the sole influence. Other tea components, including L-theanine and catechins, have been credited with reducing overall stress. Catechins, polyphenols and amino acids can affect the brain’s neurotransmitters. But it doesn’t mean the caffeine isn’t important.
Studies continued at other institutions, including the University of Coimbra in Portugal. This team of American, Brazilian and Portuguese researchers focused on the caffeine component specifically and did note that it could help calm mice by blocking the impact of a chemical related to stress.
Researchers at Germany’s University Medical School Schleswig-Holstein looked particularly at green tea and how it could help lower stress levels. They conducted an in-vitro study using liver cells and introducing green tea extracts (as well as black tea and white tea extracts). The green tea extracts, particularly the EGCG and GC components, helped stop cortisone in the body from converting to cortisol. Cortisol is often called “the stress hormone.”
SOURCE: Standard UK