Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Black tea soothes away stress

04.10.2006
Daily cups of tea can help you recover more quickly from the stresses of everyday life, according to a new study by UCL (University College London) researchers. New scientific evidence shows that black tea has an effect on stress hormone levels in the body.

The study, published in the journal Psychopharmacology, found that people who drank tea were able to de-stress more quickly than those who drank a fake tea substitute. Furthermore, the study participants – who drank a black tea concoction four times a day for six weeks – were found to have lower levels of the stress hormone cortisol in their blood after a stressful event, compared with a control group who drank the fake or placebo tea for the same period of time.

In the study, 75 young male regular tea drinkers were split into two groups and monitored for six weeks. They all gave up their normal tea, coffee and caffeinated beverages, then one group was given a fruit-flavoured caffeinated tea mixture made up of the constituents of an average cup of black tea. The other group – the control group – was given a caffeinated placebo identical in taste, but devoid of the active tea ingredients. All drinks were tea-coloured, but were designed to mask some of the normal sensory cues associated with tea drinking (such as smell, taste and familiarity of the brew), to eliminate confounding factors such as the ‘comforting’ effect of drinking a cup of tea.

Both groups were subjected to challenging tasks, while their cortisol, blood pressure, blood platelet and self-rated levels of stress were measured. In one task, volunteers were exposed to one of three stressful situations (threat of unemployment, a shop lifting accusation or an incident in a nursing home), where they had to prepare a verbal response and argue their case in front of a camera.

The tasks triggered substantial increases in blood pressure, heart rate and subjective stress ratings in both of the groups. In other words, similar stress levels were induced in both groups. However, 50 minutes after the task, cortisol levels had dropped by an average of 47 per cent in the tea drinking group compared with 27 per cent in the fake tea group.

UCL researchers also found that blood platelet activation – linked to blood clotting and the risk of heart attacks – was lower in the tea drinkers, and that this group reported a greater degree of relaxation in the recovery period after the task.

Professor Andrew Steptoe, UCL Department of Epidemiology and Public Health, says: “Drinking tea has traditionally been associated with stress relief, and many people believe that drinking tea helps them relax after facing the stresses of everyday life. However, scientific evidence for the relaxing properties of tea is quite limited. This is one of the first studies to assess tea in a double-blind placebo controlled design – that is, neither we nor the participants knew whether they were drinking real or fake tea. This means that any differences were due to the biological ingredients of tea, and not to the relaxing situations in which people might drink tea, whether they were familiar with the taste and liked it, and so on.

“We do not know what ingredients of tea were responsible for these effects on stress recovery and relaxation. Tea is chemically very complex, with many different ingredients. Ingredients such as catechins, polyphenols, flavonoids and amino acids have been found to have effects on neurotransmitters in the brain, but we cannot tell from this research which ones produced the differences.

“Nevertheless, our study suggests that drinking black tea may speed up our recovery from the daily stresses in life. Although it does not appear to reduce the actual levels of stress we experience, tea does seem to have a greater effect in bringing stress hormone levels back to normal. This has important health implications, because slow recovery following acute stress has been associated with a greater risk of chronic illnesses such as coronary heart disease.”

Jenny Gimpel | alfa
Further information:
http://www.ucl.ac.uk/media/library/tea

More articles from Studies and Analyses:

nachricht Smart Data Transformation – Surfing the Big Wave
02.12.2016 | Fraunhofer-Institut für Angewandte Informationstechnik FIT

nachricht Climate change could outpace EPA Lake Champlain protections
18.11.2016 | University of Vermont

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

IHP presents the fastest silicon-based transistor in the world

05.12.2016 | Power and Electrical Engineering

InLight study: insights into chemical processes using light

05.12.2016 | Materials Sciences

High-precision magnetic field sensing

05.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>