People connect drinking tea to calming down, and those who drink tea tend to cope better with stress, Andrew Steptoe says. His study gives proof to the fact that tea induces positive changes in bodily chemistry. The level of the stress hormone Cortisol sank much more rapidly in those test persons who drank tea than in those who were given a placebo beverage to drink.

However, the exact substance responsible for this positive effect has not been identified yet. Tea consists of many different substances (polyphenols, flavonoids, etc.) — all of which have been tested as beneficial to health in previous studies.

(Source: Article in the German magazine Stern)

In a healthy artery system, blood vessels relax if the blood increases. The study showed that black tea improves this so-called flow-mediated dilation (FMD). If, however, milk is added to the tea, the beneficial effects completely vanish. The researchers believe that certain proteins in milk might cause this negative effect.

[Source: Jane Kirby, “Tea, but no milk, please: How to beat heart disease,” The Independent, Online Edition, January 9, 2007.]