Neural Effects of Green Tea Extract on Dorsolateral Prefrontal Cortex

University Hospital Basel

Status: Completed

Conditions: Exploratory Behavior

Treatments: Dietary Supplement: Single intragastric instillation of 250 ml green tea extract; Dietary Supplement: Single intragastric instillation of 500 ml control solution; Dietary Supplement: Single intragastric instillation of 500 ml green tea extract; Dietary Supplement: Single intragastric instillation of 250 ml control solution

Study type: Interventional

Funder types: Other

Identifiers

NCT01615289

EKBB 32/09

Details and patient eligibility

About

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.

Full 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.

Enrollment: 12 patients

Sex: Male

Ages: 18 to 35 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

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

Exclusion criteria

• drug abuse, smoker, left-handed

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Double Blind

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12 participants in 4 patient groups, including a placebo group

Green tea extract, 250 ml

Active Comparator group

Description:

Single intragastric instillation of 250 ml green tea extract

Treatment:

Dietary Supplement: Single intragastric instillation of 250 ml green tea extract

Green tea extract, 500 ml

Active Comparator group

Description:

Intragastric instillation of 500 ml green tea extract solution

Treatment:

Dietary Supplement: Single intragastric instillation of 500 ml green tea extract

Control solution, 250 ml

Placebo Comparator group

Description:

Intragastric instillation of 250 ml control solution

Treatment:

Dietary Supplement: Single intragastric instillation of 250 ml control solution

Control solution, 500 ml

Placebo Comparator group

Description:

Single intragastric instillation of 500 ml control solution

Treatment:

Dietary Supplement: Single intragastric instillation of 500 ml control solution