Free audio stream, including stories that are padlocked on our site. Listen on any device, anywhere. Updated twice daily. The audio stream takes several seconds to start on Android devices.Launch Radio player
A new study supports earlier evidence that tea can not only reduce blood pressure but also calm anxiety, despite its caffeine content.
Japanese researchers tested two compounds found in tea – L-theanine, the amino acid contained in tea leaves, and caffeine – and their effect in the body when under stress.
They enlisted 14 subjects who underwent three separate trials, in which they took L-theanine and a placebo, caffeine and a placebo, or a placebo only, the Journal of Physiological Anthropology reports.
The subjects were then asked to complete mental activities under varying degrees of stress, such as solving arithmetic questions with their non-dominant hand submerged in a bucket of ice water.
Ai Yoto and her team from the University of Shizuoka found that L-theanine significantly inhibited the blood pressure increases in a high-response group, which consisted of subjects whose blood pressure rose more than average while performing a mental task after taking a placebo.
Caffeine also had an effect on blood pressure but to a lesser degree than L-theanine.
In addition, the L-theanine was shown to reduce tension-anxiety scores on mood tests.
This article is tagged with the following keywords. Find out more about MyNBR Tags
- 'We've never seen a competitor in any category behave in this manner' — MYOB on Xero man's outburst
- Key, Aussies at odds with Abbott over time-limit on Iraq mission
- Orion CFO Rodney Hyde to leave after company reports earnings in May
- Claudia Batten joins Vend board
- RAW DATA: Patrick Gower interviews Winston Peters