Efficacy Evaluation of SmarTea™ Green Tea Powder Mix for Cognitive Performance Improvement
TCI Co., Ltd
Efficacy, Value, Experience
The purpose of the study is to evaluate the efficacy of SmarTea™ Green Tea Powder Mix on cognitive performance improvement.
A. Product info:
1. Sample: SmarTea™ Green Tea Powder Mix (4 g/sachet)
2. Instruction: Add 1 sachet of SmarTea™ Green Tea Powder Mix to 150 ml of cold water
1. Number: 8 subjects
2. Inclusion criterion: office workers with age of 25-40 years old
C. Examination items:
1. Perceptual ability:
Perceptual ability can be easily tested by fast counting (subitizing) test. Subitizing is
the direct perceptual apprehension of the numerosity of a group executed without
involving mathematical calculation. Participants recognize and quantify the presented
dots (ranging from 4 to 8 dots) as soon as possible, and the times needed for
quantifications are recorded to represent the speed of attention in perceptual ability.
2. Executive ability:
The Stroop test is designed to measure selective attention, cognitive flexibility
and processing speed and also used as a tool in the evaluation of executive functions.
In the test, a series of color coded words that describe colors (e.g., red, green, yellow,
blue) are presented. These color describing words are coded with either matching or
non-matching colors. The participants are to identify the code of the color being
presented and disregard the nature of the color describing words. The time requires
for color identification will naturally take longer if the coded color doesn’t match
with the color described by the word.
3. Memory ability:
Paced auditory serial addition task (PASAT) involves working memory, attention
and arithmetic capabilities. In the test single digits are presented every 3 seconds
and the participants add each new digit to the one immediately prior to it. The
reaction time of PASAT is recorded to further analyze the improvement of memory
A single-blind, cross-over, placebo-controlled study was conducted. The subjects
consumed 1 sachet of SmarTea™ Green Tea Powder Mix or placebo with 150 ml cold water.
On each day of the study (separated by a 1-week washout), cognitive performance was
evaluated prior and 1 hour after the consumption.
A. Effect on perceptual ability
After consuming SmarTea™ Green Tea Powder Mix, reaction time in fast counting test
was significantly decreased 6.4% (p < 0.05) compared to baseline (Figure 1). Reaction time of the placebo group showed no significant difference during the trial. The population ratio of subjects who had significant improvement on speed of perceptual ability was 6/8.
B. Effect on executive ability
After consuming SmarTea™ Green Tea Powder Mix, normal and interfered reaction
time in Stroop test were significantly decreased 12.0% (p < 0.01) and 9.2% (p < 0.05), respectively, compared to baseline (Figure 2 and 3). Normal and interfered reaction time of the placebo group showed no significant difference during the trial. The population ratio of subjects who had significant improvement on speed of executive ability was 4/8.
C. Effect on memory ability
After consuming SmarTea™ Green Tea Powder Mix, reaction time in PASAT was
decreased 11.7% (p = 0.052), while the reaction time in placebo group was decreased 5.0% (Figure 4). The population ratio of subjects who had effective improvement on speed of memory ability was 4/8.
SmarTea™ Green Tea Powder Mix resulted in improvement on the speed of cognitive
performance in comparison to placebo.