Swiss researchers have found first evidence that green tea extract enhances the cognitive functions, in particular the working memory. (Agencies)
The findings suggest promising clinical implications for the treatment of cognitive impairments in psychiatric disorders such as dementia, researchers said.
In the past, the main ingredients of green tea have been thoroughly studied in cancer research.
Recently, scientists have also been enquiring into the beverage's positive impact on the human brain. Different studies were able to link green tea to beneficial effects on the cognitive performance.
However, the neural mechanisms underlying this cognitive enhancing effect of green tea remained unknown.
In a new study, researchers led by Professor Christoph Beglinger from the University Hospital of Basel and Professor Stefan Borgwardt from the Psychiatric University Clinics found that green tea extract increases the brain's effective connectivity, meaning the causal influence that one brain area exerts over another.
This effect on connectivity also led to improvement in actual cognitive performance: Subjects tested significantly better for working memory tasks after the admission of green tea extract.
For the study, healthy male volunteers received a soft drink containing several grammes of green tea extract before they solved working memory tasks. The scientists then analysed how this affected the brain activity of the men using magnetic resonance imaging (MRI).
The MRI showed increased connectivity between the parietal and the frontal cortex of the brain. These neuronal findings correlated positively with improvement in task performance of the participants.
"Our findings suggest that green tea might increase the short-term synaptic plasticity of the brain," said Borgwardt. The research results suggest promising clinical implications, researchers said.
Modelling effective connectivity among frontal and parietal brain regions during working memory processing might help to assess the efficacy of green tea for the treatment of cognitive impairments in neuropsychiatric disorders such as dementia, they said.
Swiss researchers have found first evidence that green tea extract enhances the cognitive functions, in particular the working memory.