title: Epigallocatechin gallate, cerebral blood flow parameters, cognitive performance and mood in healthy humans: a double-blind, placebo-controlled, crossover investigation.
abstract: 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.
  
  
  METHODS
  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.
authors.affiliation: Brain, Performance and Nutrition Research Centre, Northumbria University, Newcastle upon Tyne, United Kingdom.
authors.forename: Emma L
authors.initials: EL
authors.lastname: Wightman
authors.forename: Crystal F
authors.initials: CF
authors.lastname: Haskell
authors.forename: Joanne S
authors.initials: JS
authors.lastname: Forster
authors.forename: Rachel C
authors.initials: RC
authors.lastname: Veasey
authors.forename: David O
authors.initials: DO
authors.lastname: Kennedy
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000339:Affect / Q000187:drug effects*; D002392:Catechin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D002540:Cerebral Cortex / Q000098:blood supply / Q000187:drug effects*; D003071:Cognition / Q000187:drug effects*; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008297:Male; D018696:Neuroprotective Agents / Q000008:administration & dosage / Q000494:pharmacology; D010108:Oxyhemoglobins / Q000378:metabolism; D019265:Spectroscopy, Near-Infrared; D055815:Young Adult
chemical_list: D006454:Hemoglobins; D018696:Neuroprotective Agents; D010108:Oxyhemoglobins; D002392:Catechin; C045651:epigallocatechin gallate