If you drink black tea you will de-stress faster because your levels of cortisol, a stress hormone, will go down more quickly, say researchers from the University College London. This study applies only to black tea.

You can read about this study in the journal Psychopharmacology.

The researchers observed 75 volunteers. They were all male, non-smoking, regular tea drinkers. For a period of six weeks one group was given 4 cups of black tea per day while the other was given a placebo that tasted, looked and smelt the same. Both groups had to refrain from drinking other teas, coffees and herbal and/or caffeinated beverages during this period.

All the volunteers were exposed to stressful tasks while the researchers monitored their cortisol levels, blood pressure, blood platelet levels, and how they subjectively rated their levels of stress.

The scientists found both groups experienced similar increases in heart rate and blood pressure during the stress-inducing situations. Levels of cortisol 50 minutes after each stressful task dropped 47% among the black tea drinkers and just 27% among the placebo drinkers. The black tea drinkers also had lower levels of blood platelet activation. The black tea drinkers also expressed themselves in a more relaxed way 50 minutes after a stressful task, when compared to the placebo drinkers.

The scientists are unsure which black tea ingredients help people recover from stress.

The team emphasized that black tea does not lower stress levels while the stressful event is taking place. It helps you get over it more quickly.

Comment by Editor of Medical News Today

The researchers only studied people who had been regular tea drinkers. One could conclude from this study that they had become dependent on tea and that those on the placebo were not recovering as fast because of this. The study would have been more informative if they had split the study into four groups: 1. Two placebo groups - one with regular tea drinkers and the other with non-tea drinkers. 2. Two black tea groups - one with regular tea drinkers and the other with non-tea drinkers.

The effects of tea on psychophysiological stress responsivity and post-stress recovery: a randomised double-blind trial
Andrew Steptoe, E. Leigh Gibson, Raisa Vounonvirta, Emily D. Williams, Mark Hamer, Jane A. Rycroft, Jorge D. Erusalimsky and Jane Wardle
Psychopharmacology DOI 10.1007/s00213-006-0573-2
Click here to see the abstract online

Written by: Christian Nordqvist
Editor: Medical News Today