Abstract
Rationale: It has been proposed that green tea extract may have a beneficial impact on cognitive functioning, suggesting promising clinical implications. However, the neural mechanisms underlying this putative cognitive enhancing effect of green tea extract still remain unknown. Objectives: This study investigates whether the intake of green tea extract modulates effective brain connectivity during working memory processing and whether connectivity parameters are related to task performance. Material and methods: Using a double-blind, counterbalanced, within-subject design, 12 healthy volunteers received a milk whey-based soft drink containing 27.5 g of green tea extract or a milk whey-based soft drink without green tea as control substance while undergoing functional magnetic resonance imaging. Working memory effect on effective connectivity between frontal and parietal brain regions was evaluated using dynamic causal modeling. Results: Green tea extract increased the working memory induced modulation of connectivity from the right superior parietal lobule to the middle frontal gyrus. Notably, the magnitude of green tea induced increase in parieto-frontal connectivity positively correlated with improvement in task performance. Conclusions: Our findings provide first evidence for the putative beneficial effect of green tea on cognitive functioning, in particular, on working memory processing at the neural system level by suggesting changes in short-term plasticity of parieto-frontal brain connections. Modeling 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 psychiatric disorders such as dementia.
| Original language | English |
|---|---|
| Journal | Psychopharmacology |
| Volume | 231 |
| Issue number | 19 |
| Pages (from-to) | 3879-3888 |
| Number of pages | 10 |
| ISSN | 0033-3158 |
| DOIs | |
| Publication status | Published - 10.2014 |
Funding
This study was supported by grants from the Rivella. All authors have agreed to its submission in this form and we do not have any conflict of interests that might be interpreted as influencing its content. The sponsor of the study had no role in study design, collection, analysis, interpretation of data, writing of this report, and in the decision to submit the paper for publication. We would like to acknowledge the infrastructural support of the Medical Image Analysis Centre, University Hospital Basel.
