A new study, published in the journal Psychopharmacology, finds another reason to enjoy tea time: green tea can help improve the brain's cognitive functions.
The study, conducted by researchers at the University Hospital of Basel in Switzerland, suggests that green tea could be helpful in treating cognitive impairments—those caused by dementia, for instance.
Tea Is Rich in Antioxidants
Green tea, which comes from the leaves of the Camellia sinensis bush, is made from unoxidized leaves. And it is high in antioxidants.
Previous studies have also found a link between green tea and cognition, but the exact mechanisms that may be causing these effects have not been identified until now.
In the study, 12 healthy volunteers received a milk whey–based soft drink containing either 27.5 grams of green tea extract or the same drink without green tea (as control). As the participants performed several tasks that involved working memory, magnetic resonance imaging (MRI) was used to measure their brain activity.
Improved Performance on Memory Tasks
Participants who drank the green tea extract displayed increased connectivity between the right superior parietal lobule and the frontal cortex of the brain. This activity correlated with improved performance on working memory tasks.
According to the researchers, their study shows that green tea extract enhances functional connectivity from the parietal to the frontal cortex during working memory processing, in healthy subjects.
The researchers found that this effect on effective connectivity was related to the green tea–induced improvement in cognitive performance. “Our findings provide first insights into the neural effect of green tea on working memory processing at the neural network level, suggesting a mechanism on short-term plasticity of interregional brain connections," said the researchers in a statement.
Because green tea appears to increase connectivity between frontal and parietal brain regions during working memory processing, the researchers believe that it would be worthwhile to test green tea's efficacy in treating disorders involving cognitive impairments, such as dementia.
Acknowledging that the study had limitations, the researchers said that compared with the imaging results, there was no significant connection found between green tea consumption and task performance. In addition, subjects didn’t consume a pure green tea extract, so other components, such as caffeine, may have had some impact on participants' cognitive performance.