The March 2014 issue of Psychopharmacology reported on a study from Switzerland suggesting a link between green tea consumption and memory.
In this University of Basel study, participants were given a 250 or 500 ml soft drink of milk whey, which contained 13.75 grams, 27.5 grams or no grams at all of green tea extract. The study subjects did not know which they were consuming.
The people in the study were then put through a range of tests. In one, they were shown a series of letters for one second at a time. When the letter “X” appeared, they were to press a button. In subsequent tests they were asked to report if it was the same letter shown in the previous test. Magnetic resonance imaging (MRI) was conducted on the participants to assess brain connectivity.
There was a statistically significant difference between the two groups, with those consuming green tea extract scoring higher on working memory at the neural level, according to the report by study leader Stefan Borgwardt, MD, PhD.
It is important to recognize that this study included only twelve participants. The study leaders believe that this small number prevented the real impact on performance from emerging clearly. In addition, the research used a green tea extract rather than steeped loose leaf so the effect of drinking green tea has not been assessed.
Regardless of those limitations, this is not the first study to suggest a cognitive impact from green tea consumption. Past studies suggested that the tea could strengthen memory and attention, improve cognition and possibly protect against some of the effects of dementia. This is the first time, however, that the actual mechanisms within the brain have been assessed by MRI.
