Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12619001384145
Ethics application status
Approved
Date submitted
27/08/2019
Date registered
10/10/2019
Date last updated
5/03/2021
Date data sharing statement initially provided
10/10/2019
Date results information initially provided
5/03/2021
Type of registration
Retrospectively registered

Titles & IDs
Public title
Effect of prior consumption of gymnema sylvestre on desire for sugar-sweetened products in adults
Scientific title
Effect of prior consumption of gymnema sylvestre on desire for sugar-sweetened products in adults
Secondary ID [1] 299123 0
Nil known
Universal Trial Number (UTN)
U1111-1239-2873
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Sugar intake 314184 0
Condition category
Condition code
Metabolic and Endocrine 312543 312543 0 0
Normal metabolism and endocrine development and function

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Upon arrival to the sensory laboratory, participants will be provided one muesli bar (standard serve) each to reduce hunger (45 min prior to testing). During the 45 minutes prior to the sensory testing, participants will then complete a Food Frequency Questionnaire, body composition measures and demographic questionnaire.


Participants will record their hunger and desire for sugar-sweetened product (confectionery). They will then consume a small standardised serving (13g) of their favourite confectionary (from 6 popular brands; which will be provided by the research team), and we will record pleasantness ratings as well as desire for consuming a second serving.


They will then randomly be given the tablet (by the research assistant) containing gymnema sylvestre (4mg per tablet) or isocaloric placebo, and asked to ingest the product. Participants and research assistants will be blinded to the tablets provided.

Participants will then rate their desire for another serving (i.e. 13 g) of their preferred confectionary and will be offered up to five servings, which will be given one after the other (after consumption, they will be given 1 minute before selecting a subsequent serving). They will be asked to rate desire for consuming another serving and pleasantness of the confectionary after each serving has been consumed.

If an offering is accepted, it will be consumed and perceptual ratings will be recorded. If an offering is declined, testing and data collection for that participant will end.

This is a crossover trial; there will be a minimum of three days between trials (the effects of one gymnema-containing tablet last between 30-60 min).

This is an acute trial, so participants will not need to record consumption/adherence.
Intervention code [1] 315395 0
Treatment: Other
Comparator / control treatment
Placebo mint will be used (contains exactly the same ingredients apart from gymnema sylvestre)
Control group
Placebo

Outcomes
Primary outcome [1] 321191 0
Number of servings of sugar-sweetened confectionary consumed post ingestion of gymnema sylsvestre-containing mint/tablet.

The research assistant will count how many servings are consumed by the participant at each visit (and verify consumption by the empty confectionary wrapper).
Timepoint [1] 321191 0
Acute (within 30-40 min of consuming the mint/tablet
Secondary outcome [1] 374260 0
Perceived hunger level
Timepoint [1] 374260 0
Assessed using Likert scale within 30-40 min of consuming the mint/tablet containing gymnema sylvestre.
Secondary outcome [2] 374261 0
Effect of body fat percentage on changes to amount of confectionery eaten and sensory ratings, following consumption of gymnema sylvestre-containing mint/tablet

Body fat (%) will be assessed using bio-electrical impedance analysis (BIA)
Timepoint [2] 374261 0
Will be assessed using bio-electrical impedance analysis (BIA) prior to consuming gymnema-containing mint/tablet
Secondary outcome [3] 374262 0
Effect of 'super-tasting' ability on changes to amount of confectionery eaten and sensory ratings, following consumption of gymnema sylvestre-containing mint/tablet

Participants’ taster status will be determined using propylthiouracil (PROP) solution. Participants will be asked to taste this solution and indicate the perceived bitterness intensity. This will be used to classify subjects as either super-tasters, tasters or non-tasters. This information will be useful in interpreting the sensory data based on individual differences in taste sensitivity.
Timepoint [3] 374262 0
Will be assessed using PROP prior to consuming gymnema-containing mint/tablet
Secondary outcome [4] 374263 0
Effect of having a 'sweet tooth' (assessed using food frequency questionnaire; composite analysis) on changes to amount of confectionery eaten and sensory ratings, following consumption of gymnema sylvestre-containing mint/tablet
Timepoint [4] 374263 0
A food frequency questionnaire will be used (composite analysis) to assess 'sweet tooth' prior to consuming gymnema-containing mint/tablet
Secondary outcome [5] 375383 0
Desire to eat another sugar-sweetened product (confectionery)
Timepoint [5] 375383 0
Will be assessed using a Likert scale within 30-40 minutes of consuming gymnema-containing mint/tablet
Secondary outcome [6] 375384 0
Pleasantness ratings of confectionary
Timepoint [6] 375384 0
Will be assessed using a Likert scale within 30-40 minutes of consuming gymnema-containing mint/tablet

Eligibility
Key inclusion criteria
Healthy adults aged 18-45 years old
Non-smoking
Non-diabetic
English-speaking
Minimum age
18 Years
Maximum age
45 Years
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Known allergies to gymnema sylvestre

Study design
Purpose of the study
Treatment
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
All participants will be given the control/placebo treatment first trial; they will then have the experimental condition in the second trial
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Non-randomized; all will take part in control trial first (followed by experiential condition in second trial)
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
Crossover
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
Statistical analyses will be completed using the Statistical Package for the Social Sciences (SPSS, Chicago, IL). All data will be inspected visually and statistically for normality. Normally distributed data will be described using mean ± SD and non-normally distributed data using median and ranges. Two-way analysis of variance (ANOVA) will be used to determine the difference between conditions at each time point evaluated. A suitable post-hoc test (Holm-Bonferroni adjusted paired t-test) will be used to ascertain differences between time points. Pearson’s correlation will be used to examine relationships between outcome measures. P<0.05 will be considered indicative of statistical significance. Furthermore, effect sizes (Cohen’s d) will be calculated (where applicable) to show practical significance.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
1/10/2019
Date of last participant enrolment
Anticipated
29/11/2019
Actual
10/10/2019
Date of last data collection
Anticipated
6/12/2019
Actual
10/10/2019
Sample size
Target
50
Accrual to date
Final
56
Recruitment outside Australia
Country [1] 21814 0
New Zealand
State/province [1] 21814 0
AUCKLAND

Funding & Sponsors
Funding source category [1] 303664 0
Commercial sector/Industry
Name [1] 303664 0
Nu Brands Ltd
Country [1] 303664 0
United States of America
Primary sponsor type
University
Name
Massey University
Address
Private Bag 11222
Palmerston North 4442
Country
New Zealand
Secondary sponsor category [1] 303765 0
None
Name [1] 303765 0
Address [1] 303765 0
Country [1] 303765 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 304185 0
Massey University Human Ethics Committee
Ethics committee address [1] 304185 0
Massey University
Private Bag 11222
Palmerston North 4442
Ethics committee country [1] 304185 0
New Zealand
Date submitted for ethics approval [1] 304185 0
29/07/2019
Approval date [1] 304185 0
20/09/2019
Ethics approval number [1] 304185 0
MUHEC SOA 19/47

Summary
Brief summary
Gymnema sylvestre (gymnema) is a plant-derived sweetness inhibitor which impairs one’s ability to taste sugar by temporarily blocking sweet receptors on the tongue. It is therefore a taste modulator which interferes with the ability of sucrose to activate the sweet receptors on the tongue leading to a decrease in sweetness perception without affecting the other basic tastes. This effect is reversible and lasts between 30-60 minutes.
Gymnema is popular not only due to its anti-saccharine effect, but also because of its hypoglycemic effect and hence its use in diabetes management. To demonstrate its sucrose perception suppressing ability, tea is prepared from gymnema leaves and panellists asked to swish and amount in their mouths prior to tasting foods and sweet products (Noel et al. 2017; Hudson et al., 2018). Utilization of this plant is expanding from Ayurvedic medicine to applications in food product development (Perera and Pavitha, 2017). There is some uncertainty about observing this kind of effect (Shroeder and Flannery-Schroeder, 2005) when the leaves are processed as the case will be if the active ingredient is used in the formulation of a tablet. There is therefore the need to determine if the doses of the active ingredient used in the tablets reduces perception of sweetness. But, most importantly for this project, whether this decrease in sugar perception leads to an aversion to sugar-sweetened products. Therefore, the aim of the study is to determine whether prior consumption of gymnema is associated with a decrease in perceived hunger ratings, desire for sugar-sweetened products and pleasantness ratings of sugar-sweetened products.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 96074 0
A/Prof AJMOL ALI
Address 96074 0
School of sport, Exercise and Nutrition
Massey University
Private Bag 102904
North Shore, Auckland
Country 96074 0
New Zealand
Phone 96074 0
+64 9 213 6414
Fax 96074 0
Email 96074 0
a.ali@massey.ac.nz
Contact person for public queries
Name 96075 0
A/Prof AJMOL ALI
Address 96075 0
School of sport, Exercise and Nutrition
Massey University
Private Bag 102904
North Shore, Auckland
Country 96075 0
New Zealand
Phone 96075 0
+64 9 213 6414
Fax 96075 0
Email 96075 0
a.ali@massey.ac.nz
Contact person for scientific queries
Name 96076 0
A/Prof AJMOL ALI
Address 96076 0
School of sport, Exercise and Nutrition
Massey University
Private Bag 102904
North Shore, Auckland
Country 96076 0
New Zealand
Phone 96076 0
+64 9 213 6414
Fax 96076 0
Email 96076 0
a.ali@massey.ac.nz

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
Only mean and standard deviation data will be available (via the subsequent publications)


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
TypeIs Peer Reviewed?DOICitations or Other DetailsAttachment
Study results articleYes Turner S, Diako S, Kruger R, Wong M, Wood W, Ruthe... [More Details] 378254-(Uploaded-14-09-2020-08-50-28)-Journal results publication.pdf

Documents added automatically
SourceTitleYear of PublicationDOI
EmbaseConsuming gymnema sylvestre reduces the desire for high-sugar sweet foods.2020https://dx.doi.org/10.3390/nu12041046
N.B. These documents automatically identified may not have been verified by the study sponsor.