Calming Influence

A soothing cup of tea

Calm Down!

Usually that phrase is spoken in such a way that’s not very calming at all. So if you’re coming off a stressful day, rather than chewing the scenery and ordering yourself to calm down, you might try fixing a beverage that, according to a new study, really does have the ability to smooth out stress.

As an added bonus, this calming technique may help keep your heart healthy and your memory sharp.

Working on your last nerve

In the e-Alert “Swedish Message” (8/2/05), I told you about a study that examined the effects of cortisol, a hormone known as a “stress hormone.”

Researchers at the Laboratory of Human Stress Research at McGill University conducted six years of memory tests on a cohort that included young and older adults. Results showed that long-term stress creates sustained high levels of cortisol, which may impair learning ability in young people, while weakening memory among the elderly.

Older subjects who had consistently high cortisol levels were actually found to have a smaller hippocampus (the area of the brain where memory is stored) compared to older subjects who did not experience prolonged stress.

When released in small amounts, cortisol can sometimes briefly improve memory, and even supply a burst of energy. But when levels of the hormone remain high with only brief periods of relaxation, the resulting chronic stress may help trigger problems with blood sugar imbalance, high blood pressure, and decreased bone density and muscle tissue.

Smoothing out the kinks

In a recent study from University College London (UCL), researchers recruited 75 nonsmoking men.


  • For one month prior to the study period, all subjects abstained from drinking caffeinated beverages

  • Subjects were randomly divided into two groups

  • For six weeks, one group drank four cups of black tea each day, and one group drank a caffeinated drink that contained none of the other active components of tea

  • During the trial period, each subject was confronted with two extended, stressful tasks

  • Before, during, and immediately after the tasks, researchers measured cardiovascular responses

  • Cortisol levels were checked before and after the tasks

  • Results showed that the tasks triggered substantial blood pressure and heart rate increases among all subjects

  • In less than one hour after the tasks, cortisol levels dropped by nearly 50 percent in the tea group, compared to less than 30 percent in the placebo group

  • Before and after the tasks, blood platelet activation (which plays a role in blood clots) was lower in the tea group

UCL lead researcher Professor Andrew Steptoe told NutraIngredients-USA that this research is significant because chronic conditions (such as heart disease) have been linked with slow recovery after acute stress.

The study didn’t reveal which components in tea may have produced the positive effects, but Prof. Steptoe noted that tea is a complex mix, containing “catechins, polyphenols, flavonoids and amino acids have been found to have effects on neurotransmitters in the brain.”

“The Effects of Tea on Psychophysiological Stress Responsivity and Post-Stress Recovery: A Randomised Double-Blind Trial” Psychopharmacology, Published on-line ahead of print, 9/30/06,
“Black Tea May Speed Up Recovery from Stress” Stephen Daniells, NutraIngredients-USA, 10/5/06,