Study: Black Tea Eases Stress

A study by University College London researchers published in Psychopharmacology shows that tea-drinkers are able to de-stress more quickly than people drinking a tea substitute and carry less of the stress hormone cortisol in their bloodstreams.

Seventy-five young men were given either a flavored drink containing the contents of a cup of black tea or a caffeinated placebo identical in taste but lacking tea. After ingesting the beverages, both groups underwent stressful tasks. Their blood pressure, heart rate, subjective stress ratings and cortisol levels were then measured.

While initial stress levels were similar between the groups, after 50 minutes, the cortisol in the tea-drinking group was 20 percent lower. The tea-drinkers also had lower blood clot activation levels and reported lower levels of stress.

While tea did help in stress recovery, scientists are not yet able to pinpoint why, says Professor Andrew Steptoe:

"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."