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Trial registered on ANZCTR

Registration number

ACTRN12624000373572

Ethics application status

Approved

Date submitted

29/01/2024

Date registered

2/04/2024

Date last updated

15/09/2024

Date data sharing statement initially provided

2/04/2024

Type of registration

Prospectively registered

Titles & IDs

Public title

Effects of Rooibos Extract on Anxiety Levels

Scientific title

The Effects of Green Rooibos Tea Extract on Anxiety Levels (REAL) Study in adults with mild to moderate anxiety

Secondary ID [1]

Nil known

Universal Trial Number (UTN)

U1111-1301-6151

Trial acronym

REAL

Linked study record

Health condition

Health condition(s) or problem(s) studied:

Anxiety

Condition category

Condition code

Mental Health

Anxiety

Alternative and Complementary Medicine

Other alternative and complementary medicine

Intervention/exposure

Study type

Interventional

Description of intervention(s) / exposure

Designed as a pilot double blind, randomised, placebo controlled, parallel trial, enrolled participants will be randomised into either the active or control group. The study incorporates a one week baseline period, 8-week intervention period and 2-week follow up. After baseline measurements, participants in the active group will receive "active" capsules containing 250mg of green rooibos extract (19.25mg of Aspalathin). Participants will consume one capsule/day for the first week of the intervention period and increase this to two capsules per day for the remaining 7 weeks of the intervention period (trial intervention period = 8 weeks).

Participants will be asked to return any unused capsules at each clinic visit. Unused capsules will be counted to determine compliance.

Intervention code [1]

Treatment: Other

Comparator / control treatment

The control group will be receive placebo capsules which will contain a standardised inert compound commonly used in these types of studies (such as maltodextrin, capsule filler, or similar). Placebo capsules will be colour- and size-matched to the active capsules. Participants will be instructed to consume the placebo capsule in the same manner as in the active group.

Control group

Placebo

Outcomes

Primary outcome [1]

Self-reported anxiety levels

Timepoint [1]

Administered for completion on the day before Clinic 2 (Day 7 pre-treatment commencement), Clinic 3 (Day 27 post-treatment commencement) and Clinic 4 (Day 55 post-treatment commencement)

Secondary outcome [1]

Dietary intake

Timepoint [1]

Administered for completion on the day before Clinic 2 (Day 2, Day 4 and Day 6 pre-treatment commencement), Clinic 3 (Day 22, Day 24, and Day 26 post-treatment commencement) and Clinic 4 (Day 50, Day 52 and Day 54 post-treatment commencement)

Secondary outcome [2]

Alcohol consumption

Timepoint [2]

Administered for completion on the day before Clinic 2 (Day 7 pre-treatment commencement), Clinic 3 (Day 27 post-treatment commencement) and Clinic 4 (Day 55 post-treatment commencement)

Secondary outcome [3]

Chronotype

Timepoint [3]

Administered for completion on the day before Clinic 2 (Day 7 pre-treatment commencement), Clinic 3 (Day 27 post-treatment commencement) and Clinic 4 (Day 55 post-treatment commencement)

Secondary outcome [4]

Immunological status

Timepoint [4]

Administered for completion on the day before Clinic 2 (Day 7 pre-treatment commencement) and Clinic 4 (Day 55 post-treatment commencement)

Secondary outcome [5]

Sleep onset latency

Timepoint [5]

Data collection for one week prior to Clinics 2 (Days 1 - 7 pre-treatment commencement) and 4 (Days 49 - 55 post-treatment commencement)

Secondary outcome [6]

Sleep Quality (Qualitative)

Timepoint [6]

Administered for completion on the day before Clinic 2 (Day 7 pre-treatment commencement), Clinic 3 (Day 27 post-treatment commencement) and Clinic 4 (Day 55 post-treatment commencement)

Secondary outcome [7]

Physical Activity Levels

Timepoint [7]

Data collection for one week prior to Clinics 2 (Days 1 - 7 pre-treatment commencement) and 4 (Days 49 - 55 post-treatment commencement)

Secondary outcome [8]

Body weight

Timepoint [8]

During Clinic 1 - Screening (Day 1 pre-treatment commencement) and Clinic 4 (Day 56 post-treatment commencement)

Secondary outcome [9]

Heart Rate Variability (HRV)

Timepoint [9]

Measured during Clinics 2 (Day 1 of treatment commencement), 3 (Day 28 post-treatment commencement) and 4 (Day 56 post-treatment commencement)

Secondary outcome [10]

Resting blood pressure

Timepoint [10]

Measured during Clinics 1 - Screening [Day 1 (of 7) pre-treatment commencement], 2 (Day 1 of treatment commencement), 3 (Day 28 post-treatment commencement) and 4 (Day 56 post-treatment commencement).

Secondary outcome [11]

Grip Strength

Timepoint [11]

Measured during Clinics 2 (Day 1 of treatment commencement) and 4 (Day 56 post-treatment commencement)

Secondary outcome [12]

Stool Metagenomics

Timepoint [12]

Collected a day prior to Clinic 2 (Day 7 pre-treatment commencement) and Clinic 4 (Day 55 post-treatment commencement)

Secondary outcome [13]

Percent sleep efficiency

Timepoint [13]

Data collection for one week prior to Clinics 2 (Days 1 - 7 pre-treatment commencement) and 4 (Days 49 - 55 post-treatment commencement)

Secondary outcome [14]

Sleep Duration

Timepoint [14]

Data collection for one week prior to Clinics 2 (Days 1 - 7 pre-treatment commencement) and 4 (Days 49 - 55 post-treatment commencement)

Secondary outcome [15]

Total Sleep Time

Timepoint [15]

Data collection for one week prior to Clinics 2 (Days 1 - 7 pre-treatment commencement) and 4 (Days 49 - 55 post-treatment commencement)

Secondary outcome [16]

Wake after sleep onset

Timepoint [16]

Data collection for one week prior to Clinics 2 (Days 1 - 7 pre-treatment commencement) and 4 (Days 49 - 55 post-treatment commencement)

Secondary outcome [17]

Body fat %

Timepoint [17]

During Clinic 1 - Screening (Day 1 pre-treatment commencement) and Clinic 4 (Day 56 post-treatment commencement)

Secondary outcome [18]

Body fat mass

Timepoint [18]

During Clinic 1 - Screening (Day 1 pre-treatment commencement) and Clinic 4 (Day 56 post-treatment commencement)

Secondary outcome [19]

Fat free mass

Timepoint [19]

During Clinic 1 - Screening (Day 1 pre-treatment commencement) and Clinic 4 (Day 56 post-treatment commencement)

Secondary outcome [20]

Muscle mass

Timepoint [20]

During Clinic 1 - Screening (Day 1 pre-treatment commencement) and Clinic 4 (Day 56 post-treatment commencement)

Secondary outcome [21]

Total body weight

Timepoint [21]

During Clinic 1 - Screening (Day 1 pre-treatment commencement) and Clinic 4 (Day 56 post-treatment commencement)

Secondary outcome [22]

Total body water

Timepoint [22]

During Clinic 1 - Screening (Day 1 pre-treatment commencement) and Clinic 4 (Day 56 post-treatment commencement)

Secondary outcome [23]

Total body water %

Timepoint [23]

During Clinic 1 - Screening (Day 1 pre-treatment commencement) and Clinic 4 (Day 56 post-treatment commencement)

Secondary outcome [24]

Bone mass

Timepoint [24]

During Clinic 1 - Screening (Day 1 pre-treatment commencement) and Clinic 4 (Day 56 post-treatment commencement)

Secondary outcome [25]

Basal metabolic rate

Timepoint [25]

During Clinic 1 - Screening (Day 1 pre-treatment commencement) and Clinic 4 (Day 56 post-treatment commencement)

Secondary outcome [26]

Visceral fat rating

Timepoint [26]

During Clinic 1 - Screening (Day 1 pre-treatment commencement) and Clinic 4 (Day 56 post-treatment commencement)

Secondary outcome [27]

Body mass index

Timepoint [27]

During Clinic 1 - Screening (Day 1 pre-treatment commencement) and Clinic 4 (Day 56 post-treatment commencement)

Secondary outcome [28]

Biomarkers of anxiety

Timepoint [28]

Collected for Clinic 2 [once the night before (Day 7 pre-treatment commencement) and twice on the morning (upon waking and 45 minutes following the initial morning collection)} of treatment commencement (Day 1 of treatment commencement), Clinic 3, [once the night before (Day 27 post-treatment commencement) and twice on the morning of Clinic 3 (upon waking and 45 minutes following the initial morning collection -- Day 28 post-treatment commencement)] and Clinic 4 [once the night before (Day 55 post-treatment commencement) and twice on the morning of Clinic 4 (upon waking and 45 minutes following the initial morning collection -- Day 56 post-treatment commencement)}.

Eligibility

Key inclusion criteria

Healthy participants with mild to moderate anxiety levels that score between 11 and 25 (inclusive) on the Beck Anxiety Inventory (screening measure). Participants will be in general good health, willing to comply with all study procedures, and avoid consumption of rooibos tea/extract in any other form throughout the trial (other than through the intervention).

Minimum age

18 Years

Maximum age

65 Years

Sex

Both males and females

Can healthy volunteers participate?

Key exclusion criteria

Participants will be excluded from the study if they:
• have a BMI >= 35kg/m2,
• have blood pressure >= 160/95 mmHg,
• take or have taken within 8 weeks prior to enrollment any anti-anxiety or antidepressant medication or supplement (e.g. St. John's wort, valerian, ashwagandha, CBD oil, etc.),
• take sleep, gastrointestinal, cardiovascular or other medication or supplement deemed to interfere with measured parameters,
• have taken antibiotics within 8 weeks prior to enrollment,
• have taken probiotics/prebiotics/postbiotics within 2 weeks prior to enrollment,
• are receiving or have received any kind of formal psychological treatment for anxiety within 8 weeks prior to enrollment,
• have a known allergy or hypersensitivity to any of the components of the study product,
• are pregnant or lactating,
• are currently participating in other intervention studies,
• have any chronic diseases, including but not limited to CVD, diabetes (Type I and Type II), cancer, kidney disease, gastrointestinal disease, clinically diagnosed mental illness or are severely immunocompromised,
• have planned surgical procedures during the course of the study;
• have any physical injuries preventing the participation in exercise testing.

Study design

Purpose of the study

Treatment

Allocation to intervention

Randomised controlled trial

Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)

Participants will be assigned a pre-determined and unique seven digit participant code during enrollment
which will be non-identifiable. All participants will be randomly allocated either the active or control groups. Method of allocation will be located within a sealed envelope and broken when they study is completed (all participants data) is final. The person randomising the participants will not know the allocation.

Methods used to generate the sequence in which subjects will be randomised (sequence generation)

Sequence generation will be block randomised 1:1 using an online randomizer tool (https://www.randomizer.org/).

Masking / blinding

Blinded (masking used)

Who is / are masked / blinded?

The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data

Intervention assignment

Parallel

Other design features

Phase

Not Applicable

Type of endpoint/s

Efficacy

Statistical methods / analysis

Recruitment

Recruitment status

Recruiting

Date of first participant enrolment

Anticipated

17/05/2024

Actual

30/04/2024

Date of last participant enrolment

Anticipated

2/12/2024

Actual

Date of last data collection

Anticipated

28/02/2025

Actual

Sample size

Target

Accrual to date

Final

Recruitment in Australia

Recruitment state(s)

ACT,NSW

Funding & Sponsors

Funding source category [1]

Commercial sector/Industry

Name [1]

ADM WILD Valencia

Address [1]

Partida La Coma s/n, Postal Code E-46740, Carcaixenet (Valencia)

Country [1]

Spain

Primary sponsor type

University

Name

University of Canberra

Address

11 Kirinari Street, Bruce ACT 2617

Country

Australia

Secondary sponsor category [1]

None

Name [1]

Address [1]

Country [1]

Ethics approval

Ethics application status

Approved

Ethics committee name [1]

University of Canberra Human Research Ethics Committee

Ethics committee address [1]

11 Kirinari Street, Bruce ACT 2617

Ethics committee country [1]

Australia

Date submitted for ethics approval [1]

08/11/2023

Approval date [1]

20/12/2023

Ethics approval number [1]

Summary

Brief summary

The REAL study is a pilot randomised, placebo-controlled clinical trial investigating the effects of green rooibos tea extract supplementation (dose = 500mg of rooibos extract) on anxiety levels in mildly to moderately anxious adults. The study incorporates a one week baseline period, 8-week intervention period and 2-week follow up.

Trial website

Trial related presentations / publications

Public notes

Contacts

Principal investigator

Name

Prof Nenad Naumovski

Address

University of Canberra, PO Box 5018, Bruce ACT, 2617

Country

Australia

Phone

+61 2 62068719

Fax

[email protected]

Contact person for public queries

Name

Dr Katie Speer

Address

University of Canberra, PO Box 5018, Bruce ACT, 2617

Country

Australia

Phone

+61 4 03844963

Fax

[email protected]

Contact person for scientific queries

Name

Prof Nenad Naumovski

Address

University of Canberra, PO Box 5018, Bruce ACT, 2617

Country

Australia

Phone

+61 2 62068719

Fax

[email protected]

Data sharing statement

Will individual participant data (IPD) for this trial be available (including data dictionaries)?

No/undecided IPD sharing reason/comment

Participants have not consented to provide IPD

What supporting documents are/will be available?

Doc. No.	Type	Citation	Link	Email	Other Details	Attachment
21218	Clinical study report				A clinical study report will be provided when the ... [More Details]

Results publications and other study-related documents

Documents added manually

No documents have been uploaded by study researchers.

Documents added automatically

No additional documents have been identified.

Trial Review

Documents added manually

Documents added automatically