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Trial registered on ANZCTR


Registration number
ACTRN12617000319370
Ethics application status
Approved
Date submitted
10/02/2017
Date registered
28/02/2017
Date last updated
22/02/2019
Date data sharing statement initially provided
22/02/2019
Date results information initially provided
22/02/2019
Type of registration
Prospectively registered

Titles & IDs
Public title
The effect of blackcurrant juice consumption on motivation to exercise
Scientific title
The relationship between blackcurrant juice consumption and motivation to maintain a moderate intensity exercise in healthy sedentary individuals
Secondary ID [1] 291100 0
None
Universal Trial Number (UTN)
U1111-1187-2933
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Motivation to exercise 301918 0
Condition category
Condition code
Mental Health 301578 301578 0 0
Studies of normal psychology, cognitive function and behaviour

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
This is a double-blind, placebo controlled parallel design intervention study that will allow us to test the effect of the consumption of blackcurrant juice on the modulation of dopaminergic/noradrenergic nerve pathways and motivation to maintain a moderate intensity exercise. All prospective participants will be asked to attend a familiarisation session which will take approximately 1 hour. During the familiarisation session, participants will be introduced to the subjective scales and questionnaire that they will be asked to respond to during the main trial day. Participants will also be asked to perform a moderate intensity treadmill exercise that will allow us to estimate the intensity of the exercise they will be required to perform on the main trial day that is customised to their fitness level.

On the main trial day, participants will be randomised into one of two treatment groups: (1) Blackcurrant group and (2) Placebo group. On the main trial day, participants will be asked to consume 200 mL of blackcurrant (adjusted to a dose of 500 mg polyphenol per 60 kg body weight) or placebo drink within 2 minutes. After consuming the their treatment drink, participants will be asked to sit in the waiting room provided in the facility and refrain from any exercise for 1 hr. Following this, participants will be asked to perform a moderate intensity exercise with their motivation and exertion subjectively measured at regular intervals. We estimate that participants will be required to be on-site for approximately 4-5 hours during the main trial day.
Intervention code [1] 297089 0
Lifestyle
Intervention code [2] 297159 0
Treatment: Other
Comparator / control treatment
The placebo drink will contain the equivalent amount of sugar (glucose and fructose) that would be in be present in 500 mg polyphenol per 60 kg body weight of blackcurrant juice made up to 200 mL volume. Because our treatment intervention is normalised to each individual’s body weight, the quantities of sugar will vary for each individual. All treatment drinks (Blackcurrant and Placebo) will contain equivalent amounts of artificial blackcurrant flavouring, colouring and artificial sweetener so that both treatments will look and taste as identical as possible.
Control group
Placebo

Outcomes
Primary outcome [1] 300986 0
Primary exercise/physicial activity parameters will include exercise duration (time and distance).
Timepoint [1] 300986 0
Exercise duration (time and distance) will be determined at the end of the moderate intensity treadmill exercise at the main trial day from data gathered from the treadmill ergometer.
Primary outcome [2] 300987 0
The primary subjective motivation measure will be measured by scores on the Feeling Scale (FS) given by participants.
Timepoint [2] 300987 0
Participants will be familiarised to the FS measures during the familiarisation session. On the main trial day, participants will be asked to give subjective ratings of their motivation using the FS at the start and every 3-5 minutes after the commencement of the treadmill exercise until the end of the exercise trial. After a two minute warm down from the treadmill exercise, participants will be asked to give a final FS score.
Primary outcome [3] 300988 0
Biochemical motivation biomarkers including neurotransmitters (serotonin, 4-dihydroxyphenylglycol (DHPG), 3-methoxy-4-hydroxyphenylglycol (MHPG), homovanillic acid and normetadrenaline), plasma prolactin, B-endorphins, cortisol and platelet MAO-A and B activity will be measured using commercial assay kits or assays developed in-house.
Timepoint [3] 300988 0
All biochemical motivation markers will be measured from blood samples collected prior to consuming the treatment drink, 1 hour after treatment consumption and after the exercise intervention.
Secondary outcome [1] 331344 0
Heart rate during exercise will measured as a secondary measure of exercise/physical activity.
Timepoint [1] 331344 0
Participant's resting, exercising and recovery heart rate will be measured continuously the during the familiarisation and main trial day using chest-worn heart rate monitor.
Secondary outcome [2] 331661 0
The Rate of Percieved Exertion (RPE) as a secondary subjective measure of motivation and effort by scores given by participants will be measured.
Timepoint [2] 331661 0
Similar to the FS measures, participants will be asked to provide a RPE score using an RPE scale at the start and every 3-5 minutes after the commencement of the treadmill exercise until the end of the exercise trial. After a two-minute warm down period, participants will be asked to provide a final RPE score.
Secondary outcome [3] 331663 0
Plasma ATP and blood glucose will be measured as composite secondary biological measures of energy.
Timepoint [3] 331663 0
Plasma ATP will be measured from blood samples collected prior to treatment consumption, 1 hour after treatment consumption and immediately after exercise during the main trial day using a commercial assay kit. Blood glucose will be measured using a "point of care" biosensor from finger prick blood samples at these same timepoints.
Secondary outcome [4] 331977 0
Plasma anthocyanin and polyphenol levels will be measured in blood samples collected from participants as composite measurements of bioavailabilty.
Timepoint [4] 331977 0
These will be measured from blood samples collected prior to treatment consumption and 1 h after treatment consumption from the main trial day using validated in-house high performance liquid chromotography (HPLC) methods.
Secondary outcome [5] 331978 0
Plasma oxidative capacity and lipid peroxidation will also be measured as composite measurements of oxidative stress.
Timepoint [5] 331978 0
These will be measured from blood samples collected before treatment consumption, 1 hr after treatment consumption and immediately after the exercise during the main trial day using validated assays developed in-house.
Secondary outcome [6] 331979 0
Ferric reducing capacity of plasma (FRAP) will be measured as a parameter of plasma antioxidant capacity.
Timepoint [6] 331979 0
This will be measured using blood samples collected before treatment consumption, 1 hr after treatment consumption and immediately after exercise during the main trial day using a validated in-house assay.

Eligibility
Key inclusion criteria
Healthy individuals who are not involved in any regular exercise routine and do not have a high habitual acitivy but can complete the physical requirements of this trial will be selected for this study. Participants will be required to complete a health questionnaire and provide written consent for this study.
Minimum age
18 Years
Maximum age
60 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Participants will be excluded if they are unwilling or unable to provide informed written consent or comply with the study's procedures. Participants will also be excluded if they (1) have known hypersensitivity or intolerance to blackcurrants or berry fruit-derived products, (2) have health conditions that impair ability to perform a treadmill walking task (e.g. injury, hernia, back or joint pain, cardiovascular and breathing problems), (3) exceed a certain fitness level, assessed by a Baecke questionnaire, or (4) are unable to perform the study walking exercise to the standard required by the trial coordinator in the familiarisation session. In addition, participants will be excluded if they are pregnant, planning to get pregnant in the near future or have any of the following conditions: (i) blood borne diseases (e.g. Hepatitis), (ii) clinically diagnosed high/low blood pressure, (iii) recent bacterial or viral illness, (iv) are taking any mediation that affects the properties of blood (e.g. blood clotting).

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)
This is a double-blind, placebo controlled, parallel design intervention study. Participants will be randomly allocated into one of two groups: Group 1 - Blackcurrant group and Group 2 - Placebo group. Study investigators and participants will be blinded from the dietary intervention. Treatment allocation for each participant will be undertaken by a fellow scientist not involved in this study. Participant treatment allocation is held and concealed until completion of the trial and analysis of the data is finished. Furthermore, the placebo treatment drink will be matched to have a similar colour and sweetness as the blackcurrant drink and participants will be asked to consume the treatment juice as quickly as they can.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Allocation of participants into one of the two treatment groups will be performed using a spreadsheet random function.
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
Data will be expressed as mean +/- standard error. Interaction between consumption of blackcurrant juice and parameters of exercise/physical performance and subjective measures of motivation and interactions between these will be determined. Likewise, interaction between consumption of blackcurrant juice and modulation of biomarkers detailed in this study and how these relate to physiological and subjective measures will be determined. Statistical significance for the comparison between Blackcurrant and Placebo groups will be assessed using Student's two-sample t-test. Multiple comparisons will be assessed by two-way ANOVA. Where appropriate, the original data will be transformed to achieve normality and constant variance in the residuals. Statistical significance for all indices will be set at P < 0.05 with a confidence level of 95%.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment outside Australia
Country [1] 8638 0
New Zealand
State/province [1] 8638 0
Manawatu

Funding & Sponsors
Funding source category [1] 295540 0
Government body
Name [1] 295540 0
The New Zealand Institute of Plant and Food Research
Address [1] 295540 0
Batchelar Road,
Fitzherbert,
Palmerston North 4474
Country [1] 295540 0
New Zealand
Funding source category [2] 295548 0
Government body
Name [2] 295548 0
Ministry of Business, Innovation and Employment
Address [2] 295548 0
15 Stout Street,
Wellington 6011
Country [2] 295548 0
New Zealand
Primary sponsor type
Individual
Name
Dr. Jocelyn Eason
Address
The New Zealand Institute of Plant and Food Research
Batchelar Road,
Fitzherbert,
Palmerston North 4474
Country
New Zealand
Secondary sponsor category [1] 294366 0
None
Name [1] 294366 0
Address [1] 294366 0
Country [1] 294366 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 296861 0
Health and Disability Ethics Committees
Ethics committee address [1] 296861 0
Ministry of Health
133 Molesworth Street
PO Box 5013
Wellington 6011
Ethics committee country [1] 296861 0
New Zealand
Date submitted for ethics approval [1] 296861 0
31/01/2017
Approval date [1] 296861 0
22/02/2017
Ethics approval number [1] 296861 0
17/NTA/9

Summary
Brief summary
Regular and appropriate exercise is a necessary part of a healthy lifestyle. It is associated with increased physical and mental acuity and the prevention of age-related chronic health problems like heart disease and Type 2 diabetes. An individual's motivation or desire to maintain a regular exercise regime is crucial to gaining these health benefits. Moreover, several human and animal studies have shown that motivation to maintain regular physical activity involves dopaminergic and noradrenergic nerve pathways in the brain that regulate the generation and metabolism of the neurotransmitters dopamine, adrenaline, noradrenaline and serotonin.

There is very limited information available on how a nutritional intervention may improve motivation to exercise. Over recent years, only one publication has reported the effects of a dietary intervention on exercise motivation, with caffeine consumption linked to increase enjoyment from exercise. In a recent clinical trial, we have demonstrated that the consumption of a single dose of blackcurrant juice had an acute, reversible modulatory effect of neurotransmitter oxidation in healthy individuals in vivo. Given the known interaction between brain neurotransmitters and physical exercise and motivation, it is feasible that the consumption of blackcurrants may improve physical activity in humans through their modulatory effects on exercise-related brain neurotransmitters.

In this study, we aim to subjectively measure our participants' motivation to maintain a prescribed moderate intensity exercise following the consumption of blackcurrant juice and how this relates to the regulation of brain neurotransmitters related to motivation. We hypothesise that blackcurrant juice modulates brain neurotransmitter levels leading to higher concentrations of neurotransmitters related to motivation which results in a greater desire and willingness to exercise. This study will generate knowledge supporting the implementation of timed nutritional strategies to maintain motivation during exercise, thus assisting in attaining the health benefits associated with regular and appropriate exercise.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 72258 0
Dr Suzanne Hurst
Address 72258 0
The New Zealand Institute of Plant and Food Research Ltd.
Batchelar Road
Private Bag 11600
Palmerston North 4442
Country 72258 0
New Zealand
Phone 72258 0
+64 6 355 6231
Fax 72258 0
+64 6 351 7050
Email 72258 0
suzanne.hurst@plantandfood.co.nz
Contact person for public queries
Name 72259 0
Dr Dominic Lomiwes
Address 72259 0
The New Zealand Institute of Plant and Food Research Ltd.
Batchelar Road
Private Bag 11600
Palmerston North 4442
Country 72259 0
New Zealand
Phone 72259 0
+64 6 355 6113
Fax 72259 0
+64 6 351 7050
Email 72259 0
dominic.lomiwes@plantandfood.co.nz
Contact person for scientific queries
Name 72260 0
Dr Suzanne Hurst
Address 72260 0
The New Zealand Institute of Plant and Food Research Ltd.
Batchelar Road
Private Bag 11600
Palmerston North 4442
Country 72260 0
New Zealand
Phone 72260 0
+64 6 355 6231
Fax 72260 0
+64 6 351 7050
Email 72260 0
suzanne.hurst@plantandfood.co.nz

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
Individual participant data will not be shared to ensure the anonymity of participants who took part in this study. Collective data of participants will be presented in publications related to this study.
What supporting documents are/will be available?
No other documents available
Summary results
Have study results been published in a peer-reviewed journal?
No
Other publications
Have study results been made publicly available in another format?
Yes
Other publication details
Citation type [1] 1434 0
Conference abstract
Citation/DOI/link/details [1] 1434 0
Lomiwes, D., Hurst, S. M., Ha, B., Ngametua, N., Burr, N. & Hurst, R. D. (2018). The effect of New Zealand blackcurrant juice consumption on motivation to exercise. In Proceedings 1st Innovations in Food Science and Human Nutrition conference, Rome, Italy
Results – basic reporting
Results – plain English summary