LONDON:

Drinking at least four cups of black tea a day could help you fight the stresses of everyday life, evidence shows.

In the study, researchers at London’s University College studied 75 young male regular tea drinkers splitting them into two groups and monitored them for six weeks, states a release posted in the university website.

While one group was given a fruit-flavoured caffeinated tea mixture made up of the constituents of an average cup of black tea, the other was given a caffeinated placebo identical in taste but devoid of the active tea ingredients. 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. The tasks triggered substantial increases in blood pressure, heart rate and subjective stress ratings in both of the 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.

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

This is one of the first studies to assess tea in a double-blind placebo controlled design — neither we nor participants knew whether they were drinking real or fake tea, UCL Professor Andrew Steptoe said.

“We do not know what ingredients of tea were responsible for these effects on stress recovery and relaxation... we cannot tell from this research which ones produced the differences,” he said.

“Nevertheless, our study suggests that drinking black tea may speed up our recovery from daily stresses. Although it does not appear to reduce the actual levels of stress, tea does seem to have a greater effect in bringing stress hormone levels back to normal.”