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Epigallocatechin gallate, cerebral blood flow parameters, cognitive performance and mood in healthy humans: a double‐blind, placebo‐controlled, crossover investigation
Author(s) -
Wightman Emma L.,
Haskell Crystal F.,
Forster Joanne S.,
Veasey Rachel C.,
Kennedy David O.
Publication year - 2012
Publication title -
human psychopharmacology: clinical and experimental
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.461
H-Index - 78
eISSN - 1099-1077
pISSN - 0885-6222
DOI - 10.1002/hup.1263
Subject(s) - crossover study , cerebral blood flow , placebo , mood , effects of sleep deprivation on cognitive performance , anesthesia , hemodynamics , medicine , heart rate , cognition , psychology , blood pressure , psychiatry , alternative medicine , pathology
Objective The aim of the study was to assess the effects of oral ingestion of the ‘green tea’ polyphenol epigallocatechin gallate (EGCG) on cognitive performance, mood and localised cerebral blood flow (CBF) parameters in healthy human adults. Method In this double‐blind, placebo‐controlled, crossover study, 27 healthy adults received placebo and two doses (135 and 270 mg) of EGCG in counterbalanced order on separate days. Following a 45‐min resting absorption period, participants performed a selection of computerised cognitive tasks that activate the frontal cortex for a further 42 min. CBF and haemodynamics, as indexed by concentration changes in oxygenated and deoxygenated haemoglobin, were assessed in the frontal cortex throughout the post‐treatment period using Near‐infrared spectroscopy (NIRS). Results During the post‐dose task performance period, the administration of 135 mg EGCG resulted in reduced CBF in the frontal cortex, as indexed by significantly lower concentrations of both oxygenated and total haemoglobin, in comparison with placebo. Heart rate was significantly reduced from pre dose to post dose across all treatments. No significant differences were observed for the level of deoxygenated haemoglobin or on any of the cognitive performance/mood measures. Conclusions These results demonstrate that a single dose of orally administered EGCG can modulate CBF parameters in healthy humans but that this is not associated with changes in cognitive performance or mood. Copyright © 2012 John Wiley & Sons, Ltd.