Neural Effects of Green Tea Extract on Dorsolateral Prefrontal Cortex

Not Applicable

Completed

• Conditions: Exploratory Behavior
• Interventions: Dietary Supplement: Single intragastric instillation of 500 ml green tea extract; Dietary Supplement: Single intragastric instillation of 500 ml control solution; Dietary Supplement: Single intragastric instillation of 250 ml green tea extract; Dietary Supplement: Single intragastric instillation of 250 ml control solution

• Registration Number: NCT01615289
• Lead Sponsor: University Hospital, Basel, Switzerland

Brief Summary

Green tea is being recognized as a beverage with potential benefits for human health and on cognitive function. In vitro and in vivo studies provide preliminary evidence that green tea intake may play a positive role in improving effects on cognitive functions. The investigators aim to examine the neural effects of green tea extract on brain activation in humans.

Detailed Description

As functional neuroimaging provides a means of examining how green tea extract acts on the brain, we used functional magnetic resonance imaging (fMRI) to study healthy volunteers while they performed a working memory task following intra-gastric administration of either 250 ml or 500 ml Rivella green® (RG), a milk whey based green tea extract containing soft drink, or Rivella blue® (RB), a milk whey based soft drink without green tea extract as sham condition in a double-blind, controlled design. Based on the literature on pharmacological and behavioural effects of green tea, we hypothesized - a priori - that green tea extract would subtly modulate the engagement of the dorsolateral prefrontal cortex (DLPFC), a brain region critically involved in many cognitive functions such as working memory processing.

A double-blind, controlled, within-subject study with counterbalanced order of substance administration using an established protocol (6-8) was conducted over 4 sessions (250 ml or 500 ml Rivella green® (including green tea extract; RG), 250 or 500 ml Rivella blue® (RB). Each participant was scanned four times with a one-week interval between scans. The order of substance administration across sessions was counterbalanced across subjects, such that equal numbers followed each substance sequence.

Study Timeline

• Study Start: 2010-07
• Primary Completion: 2011-01
• Study Completion: 2012-01
• Status Verified: 2012-06
• Study First Submitted: 2012-06-05
• Study First Submitted QC: 2012-06-07
• Last Update Submitted: 2012-06-07
• Study First Posted: 2012-06-08
• Last Update Posted: 2012-06-08

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 12

Inclusion Criteria

• right-handed healthy males, no drugs, non-smoking

Exclusion Criteria

• drug abuse, smoker, left-handed

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Green tea extract, 500 ml	Single intragastric instillation of 500 ml green tea extract	Intragastric instillation of 500 ml green tea extract solution
Control solution, 500 ml	Single intragastric instillation of 500 ml control solution	Single intragastric instillation of 500 ml control solution
Green tea extract, 250 ml	Single intragastric instillation of 250 ml green tea extract	Single intragastric instillation of 250 ml green tea extract
Control solution, 250 ml	Single intragastric instillation of 250 ml control solution	Intragastric instillation of 250 ml control solution

Primary Outcome Measures

Name	Time	Method
Functional magnetic resonance imaging (fMRI) in healthy volunteers while they performed a working memory task	0 and 45 min	Whole brain analysis with a cluster-level threshold was followed by an a priori defined region of interest analysis of the dorsolateral prefrontal cortex including a cluster-level threshold and family-wise error adjustment for multiple comparisons.

Trial Locations

Locations (1)

University Hospital; 🇨🇭 Basel, Switzerland