UMIN-CTR Clinical Trial

Public title

Psychological stress-reducing effect by single or continual ingestion of gamma-aminobutyric acid (GABA): a systematic review with meta-analysis.

Acronym

Psychological stress-reducing effect by single or continual ingestion of gamma-aminobutyric acid (GABA)

Scientific Title

Psychological stress-reducing effect by single or continual ingestion of gamma-aminobutyric acid (GABA): a systematic review with meta-analysis.

Scientific Title:Acronym

Psychological stress-reducing effect by single or continual ingestion of gamma-aminobutyric acid (GABA)

Region

Japan

Condition

This study will be restricted to all original articles of healthy adults (people not suffering from any diseases). We will exclude minors, pregnant women, those planning a pregnancy, and lactating women.

Classification by specialty

Adult

Classification by malignancy

Others

Genomic information

NO

Narrative objectives1

The objective of this review is to assess psychological stress-reducing effect by single or continual ingestion of GABA.

Basic objectives2

Efficacy

Basic objectives -Others

Trial characteristics_1

Others

Trial characteristics_2

Others

Developmental phase

Not applicable

Primary outcomes

We will evaluate the effect by single or continual ingestion of GABA on brain waves, heart rate variability (HRV) and salivary markers (cortisol, alpha-amylase, chromogranin A (CgA)) reported as assessment indices of psychological stress.

Key secondary outcomes

We will evaluate the effect by single or continual ingestion of GABA on biochemical markers (body surface temperature and reaction of the eye pupil towards a flash of light, et al.), physiological markers (blood markers (cortisol and adrenocorticotropic hormone (ACTH), et al.) and salivary markers, et al.) and subjective assessment (the Profile of Mood States (POMS) and visual analogue scale (VAS), et al.) reported as assessment indices of psychological stress.

Study type

Others,meta-analysis etc

Basic design

Randomization

Randomization unit

Blinding

Control

Stratification

Dynamic allocation

Institution consideration

Blocking

Concealment

No. of arms

Purpose of intervention

Type of intervention

Interventions/Control_1

Interventions/Control_2

Interventions/Control_3

Interventions/Control_4

Interventions/Control_5

Interventions/Control_6

Interventions/Control_7

Interventions/Control_8

Interventions/Control_9

Interventions/Control_10

Age-lower limit

20

years-old

<=

Age-upper limit

Not applicable

Gender

Male and Female

Key inclusion criteria

(Study design)
We will include randomized controlled trials (RCT), quasi randomized controlled trials (qRCT), non-randomized controlled trials (nonRCT), crossover trials, cohort studies, and case-control studies.
We will include scientific papers and reports which give us enough research details.

(A) SR on single ingestion of GABA
(PICO)
Participant:
We will include people not suffering from any diseases. We will exclude minors, pregnant women, those planning a pregnancy, and lactating women.

Intervention:
We define a single ingestion of test food containing GABA as an intervention.
Comparison:
We define ingestion of test food not containing GABA or maintaining daily life as controls.

Outcome measurement:
We will evaluate brain waves, HRV and salivary markers (cortisol, alpha-amylase, CgA) as assessment indices of psychological stress.
The secondary outcomes are biochemical markers (body surface temperature and reaction of the eye pupil towards a flash of light, et al.), physiological markers (blood markers (cortisol and ACTH, et al.) and salivary markers, et al.) and subjective assessment (POMS and VAS, et al.).

(B) SR on continual ingestion of GABA
(PI(E)CO)
Participant:
Same as (A)

Intervention:
We define continual ingestion of test food containing GABA as an intervention.
Comparison 1:
Same as (A)

Exposure:
We define continual ingestion of food containing GABA as an exposure.
Comparison 2:
We define eating no food containing GABA as non-exposure. If subgroup analysis of GABA intake amount has been conducted in a study, we define the least intake group as a non-exposure group.

Outcome measurement:
Same as (A)

(Language)
Eligibility is not restricted by language.

Key exclusion criteria

We will exclude cross-sectional studies because it will be difficult to interpret causal relationships between exposure and outcome. We will also exclude proceedings and unpublished studies.

Target sample size

100

Name of lead principal investigator

1st name	Koichi
Middle name
Last name	Aizawa

Organization

Kagome Co., Ltd.

Division name

Innovation Division

Zip code

329-2762

Address

17 Nishitomiyama, Nasushiobara-shi, Tochigi

TEL

0287-36-2935

Email

g167_0@kagome.co.jp

Name of contact person

1st name	Koichi
Middle name
Last name	Aizawa

Organization

Kagome Co., Ltd.

Division name

Innovation Division

Zip code

329-2762

Address

17 Nishitomiyama, Nasushiobara-shi, Tochigi

TEL

0287-36-2935

Homepage URL

Email

g167_0@kagome.co.jp

Institute

Kagome Co., Ltd.

Institute

Department

Personal name

Organization

None

Organization

Division

Category of Funding Organization

Self funding

Nationality of Funding Organization

Co-sponsor

Review Team
Professor Hiroharu Kamioka, Department of Ecological Symbiotic Science, Tokyo University of Agriculture
Dr. Takahiro Yoshizaki, Department of Food and Nutritional Sciences, Toyo University
Ms. Mari Makishi, NARASHINO Media Center for Research & Education, Media Net Center, TOHO University.
Mr. Takuro Inoue, Innovation Division,
Kagome Co., Ltd.
Ms. Tomoka Okame, Innovation Division, Kagome Co., Ltd.
Ms. Ayaka Tsutsumi, Innovation Division, Kagome Co., Ltd.

Name of secondary funder(s)

Organization

-

Address

Nihonbashi-Hamacyo F Tower 3-21-1, Nihonbashi-Hmacyo, Chuo-ku, Tokyo

Tel

03-5623-8501

Email

toshika_okuni@kagome.co.jp

Secondary IDs

NO

Study ID_1

Org. issuing International ID_1

Study ID_2

Org. issuing International ID_2

IND to MHLW

Institutions

Date of disclosure of the study information

2018

Year

12

Month

31

Day

URL releasing protocol

Publication of results

Published

URL related to results and publications

Number of participants that the trial has enrolled

244

Results

Results date posted

Results Delayed

Results Delay Reason

Date of the first journal publication of results

Baseline Characteristics

Participant flow

Adverse events

Outcome measures

Plan to share IPD

IPD sharing Plan description

Recruitment status

Main results already published

Date of protocol fixation

2017

Year

07

Month

27

Day

Date of IRB

2017

Year

07

Month

27

Day

Anticipated trial start date

2017

Year

07

Month

28

Day

Last follow-up date

2019

Year

06

Month

07

Day

Date of closure to data entry

Date trial data considered complete

Date analysis concluded

2020

Year

12

Month

31

Day

Other related information

(Searches)
A hospital librarian (e.g., MM) will search 19 databases for studies from the beginning of each database to the search date.

(Data extraction)
Two authors (e.g., TI and TO, or TI and AT) will independently apply all criteria to the full text of articles that have passed the first eligibility screening. Then they will independently extract data from the included studies and cross-check the data.

(Risk of bias assessment)
In order to ensure that variation is not caused by systematic errors in the study or execution, two authors (e.g., TI and TO, or TI and AT) will independently assess the quality of articles. A full quality appraisal of these papers will be made using modified check list (12 items) of Cochrane Handbook for interventional trials, or modified check list (5 items) of GRADE Handbook for observational trials. We will exclude papers with high risk of bias.

Disagreement and uncertainties will be resolved by discussion with another author (e.g., KA). In addition, we will calculate agreement rate and kappa coefficient.

(Inconsistency evaluation)
We will evaluate inconsistency of evidence according to the value of I square and by a statistical test for heterogeneity of effect estimates in a meta-analysis.

(Imprecision assessment)
We will assess imprecision based on the total number of participants in all included studies.

(Meta-analysis)
Only when we will not find heterogeneity in RCT, qRCT, nonRCT, and crossover trials, TY will conduct a meta-analysis using RevMan 5. If we will find missing data, we will make contact with the author to obtain the data.
We will assess heterogeneity according to the value of I square in Forest plot and assess publication bias using Funnel plot.
We will conduct subgroup analyses:
i) restricting to randomized controlled parallel-group trials.
ii) restricting to people burdened with stress-inducing task or not.
iii) excluding trials whose sample sizes are predominantly large compared with the other trials.

Registered date

2017

Year

07

Month

27

Day

Last modified on

2023

Year

01

Month

11

Day

Link to view the page

Value
https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000032511