Study on black tea against stress
According to researcher Andrew Steptoe, one of those responsible for the study carried out by the University of London, it is still not possible to know which properties of black tea promote this stress reduction in its consumers, given that the drink is “very complex”. However, through the test, it was possible to verify this beneficial action.
The study, carried out with 75 young men, was published in psychopharmacology and outlined as follows: the group was divided into two and both made use of beverages produced by the researchers. The volunteers were observed for six weeks, and during this period, they could not use any other beverage that had caffeine.
One of the teams drank daily a caffeinated fruit-flavored drink that had the properties present in black tea. Meanwhile, the other group received a caffeinated placebo that tasted identical but did not contain the substances of the main ingredient. In addition, both the drinks of one and the other had similar colors, flavors and smells, so as not to run the risk of these factors influencing the conclusion of the study.
After drinking the drinks by the groups, the volunteers were placed in three stressful situations, they were: threat of unemployment, accusation of shoplifting or an incident in an old people’s home. For each circumstance, the participant would have to create a verbal response to a camera. These simulations increased blood pressure, platelet and cortisol levels, which consequently increased the level of stress.
Results of tests performed by the research
The surprise came just after an hour of stressful tasks. The group that drank the drink that contained the properties of black tea had their cortisol levels decreased by 47%. The people on the team who drank the liquid without the substances in the tea, lowered the level by only 27%. In addition, the first group reported feeling more relaxed after the stressful situation.