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Trial registered on ANZCTR


Registration number
ACTRN12621001590853
Ethics application status
Approved
Date submitted
2/11/2021
Date registered
22/11/2021
Date last updated
6/11/2023
Date data sharing statement initially provided
22/11/2021
Type of registration
Prospectively registered

Titles & IDs
Public title
The effect of supplementation with a blackcurrant drink containing L-theanine and pine bark extract in supporting cognitive performance in healthy older adults
Scientific title
Investigating the effect of acute and long-term supplementation with a blackcurrant beverage containing L-theanine and pine bark extract in supporting cognitive performance in healthy older adults.
Secondary ID [1] 305705 0
Nil known
Universal Trial Number (UTN)
U1111-1269-9473
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Cognitive function 324175 0
Condition category
Condition code
Neurological 321649 321649 0 0
Studies of the normal brain and nervous system

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
This is a double-blind, placebo controlled, cross-over design intervention study that will allow us to evaluate whether acute or long-term supplementation with a New Zealand blackcurrant beverage containing L-theanine and pine bark extract extract supports cognitive function. Prospective participants who have passed the study’s inclusion/exclusion criteria will be asked to attend a familiarisation session where they will meet with the study’s principal investigator. During this session the study’s trial coordinator (Research Associate, approx. 6 years experience in human studies) and principal investigator (Research Scientist, PhD) who will explain the logistics of the trial to them and introduce them to the visual analogue scales for mood and mental fatigue that they will be asked to complete to during their trial days. Participants will also be instructed on how to complete the five cognitive tasks that will make up the cognitive battery that they will undergo during their trial days. These tasks are stroop, digit vigilance, serial sevens, symbol digit substitution and rapid visualisation information processing.

The study will require participants to attend a total of five trial days where their cognitive function will be assessed. Participants will be given a list of foods (e.g. berry-derived foods, dark chocolate) to abstain from consuming 24 hours prior each trial day. They will also be required to complete a 3-day food diary (2 week days and 1 week end) the week before their trial day. Participants initially attend a baseline trial day, which can be one week after their familiarisation session, where their cognitive function prior to consuming any of the nutrition intervention will be assessed. For the first arm of this study, recruited participants will be evenly randomised into two treatment groups: (1) blackcurrant (780 mg blackcurrant anthocyanins, 200 mg L-theanine and 150 mg pine bark extract) and (2) placebo. At the start of the study arm the trial coordinator will give participants their allocated intervention (blackcurrant or placebo) packaged in opaque 250 mL drink bottles. They will be instructed to consume the contents of one drink bottle daily for four weeks. The trial coordinator will meet with each participant weekly to track their compliance.

On the first day of the first trial arm, participants will arrive at the research facility to complete a trail day to assess the acute effects of their allocated intervention on their cognitive function. They will given their allocated intervention drink to consume then asked to rest for an hour. After 60 minutes rest, participants will be presented with a 15-item word list to commit to memory then complete a mood and mental fatigue questionnaire. They will then undergo a 45-minute cognitive battery which consists of the five cognitive tasks that they have been previously familiarised to. After completing the cognitive battery, their mental fatigue and mood will be assessed using the same questionnaires they completed prior to their cognitive battery. They will also be asked to recall the words list presented to them prior to the cognitive battery.

At the end of the first day of their first trial arm, participants will undergo their 4-week supplementation period with their allocated intervention. The day after their supplementation period, participants complete another trial day to assess the effect of long-term supplementation with their allocate intervention on cognitive function. The logistics of this trial will be the same as their previous trial day. However, they will not be given an intervention beverage to consume prior to cognitive assessment on this trial day.

After the first trial arm, participants will be required to undergo a two week washout prior to starting the second arm of this study. In this arm, they will be asked to consume the intervention that they did not receive during the first arm. Similar to the first trail arm, participants will undergo a trial day at the beginning of trial arm to assess the acute effects of their allocated intervention on their cognitive function. They will then consume a dose of their allocated intervention daily for four weeks then return for a final trial day to assess the effect of long-term supplementation with their intervention on their cognitive function.
Intervention code [1] 322093 0
Treatment: Other
Comparator / control treatment
The placebo is a commercially produced beverage that will contain similar (but not matched) amount of sugars to the blackcurrant intervention. The placebo drink will also be colour matched and flavoured with commercial blackcurrant flavouring and food acids to be as similar in flavour as possible to the blackcurrant intervention.
Control group
Placebo

Outcomes
Primary outcome [1] 329425 0
Composite measures of cognitive function parameters will include attention, reaction time, cognitive flexibility, working memory and learning.
Timepoint [1] 329425 0
Cognitive function assessments will be conducted on Trial Day 1 (baseline), and Days 1 and 29 of each supplementation arm.
Primary outcome [2] 329426 0
Subjective measures of mood
Timepoint [2] 329426 0
Participants mood will be assessed using a Bond-Lader Visual Analogue questionnaire comprising of 16 mood descriptors that correspond with three mood factors: alert, calm and content. Mood assessments will be taken immediately before and after the cognitive battery on all Trial Day 1 (baseline) and Days 1 and 29 of each supplementation arm.
Primary outcome [3] 329427 0
Mental fatigue
Timepoint [3] 329427 0
Participants mental fatigue will be assessed using an electronic Visual Analogue Scale anchored at “not at all” on the left hand side of the scale and “extremely” on the right, with higher scores representing more mental fatigue/higher difficulty. Mental fatigue assessments will be taken immediately before and after the cognitive battery on Trial Day 1 (baseline) and Days 1 and 29 of each supplementation arm.
Secondary outcome [1] 402561 0
Composite measures of neurotransmitters - prolactin and plasma concentrations of up to 35 inhibitory and excitatory neurotransmitters and their precursors associated with the tryptophan, tyrosine and glutamate pathways. Analysis will be conducted using a commercial ELISA kit (prolactin) and ultra performance liquid chromatography (UPLC) protocols developed in-house.
Timepoint [1] 402561 0
Neurotransmitter analysis will be measured in plasma separated from venous blood samples collected immediately upon arrival to study site, immediately before cognitive assessment and immediately after cognitive assessment on Trial Day 1 (baseline) and Days 1 and 29 of each supplementation arm.
Secondary outcome [2] 402562 0
Platelet monoamine oxidase-B activity (MAO-B) will be measured in participants platelets using a commercial assay kit.
Timepoint [2] 402562 0
MAO-B enzyme activity will be measured in platelet samples isolated from whole blood collected immediately upon arrival to study site, immediately before cognitive assessment and immediately after cognitive assessment on Trial Day 1 (baseline) and Days 1 and 29 of each supplementation arm
Secondary outcome [3] 402563 0
Plasma anthocyanin and polyphenol levels will be measured in blood samples collected from participants as composite measurements of bioavailabilty and compliance using validated in-house high performance liquid chromotography (HPLC) methods.
Timepoint [3] 402563 0
These will be measured from plasma separated from venous blood samples collected immediately upon arrival to study site, immediately before cognitive assessment and immediately after cognitive assessment on Trial Day 1 (baseline) and Days 1 and 29 of each supplementation arm

Eligibility
Key inclusion criteria
Healthy individuals (males and females) aged 55 - 70 years old, who habitually (self-identified) consume low amounts polyphenolic-rich foods are non-smokers and vapers, do not exhibit meaningful cognitive impairment (Mini-Mental State Examination (MMSE) score below 20 and are not prescribed psychotropic medication or MAO inihibitors.
Minimum age
55 Years
Maximum age
70 Years
Sex
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 procedures. Participants will also be excluded if they (i) have known hypersensitivity or intolerance to blackcurrants, L-theanine or pine bark extract or food products derived from these ingredients, (ii) ? Have health conditions that impair their ability to perform the cognitive tests they are required to complete in this study and (iii) if they are unable to perform the exercises to the standard required during the familiarisation session.

In addition, participants will also be excluded if they have the following health conditions: (i) blood borne diseases (e.g. hepatitis), (ii) clinically diagnosed high/low blood pressure, (iii) recent bacterial or viral illness or (iv) are taking medication 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, cross-over design intervention study consisting of two treatment interventions. In the first arm of this study, participants will be randomly allocated evenly to the two treatment groups (blackcurrant and placebo). The randomisation of participants will be undertaken by a fellow scientist not involved in this study using a computer randomisation function. In the second arm of the study, participants will be assigned the treatment intervention that they did not receive in the first arm. All recruited participants will then be allocated a random participant code (consisting of numerical and alphabetical characters) containing no information on which order of treatment they were allocated to. To conceal the treatment allocation from the study investigators, those preparing and packaging the treatment interventions for the participants will not be involved in any other component of the study. Further, the placebo will be commercially prepared to be as close as possible in appearance and flavour as the blackcurrant treatment. A daily dose of each intervention will be packaged in opaque drink bottles. These measures will be taken to conceal the identity of the interventions to the volunteers and study investigators.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
This is a double-blind, placebo controlled, parallel crossover study. Participants will be evenly randomly allocated into two treatment groups: blackcurrant and placebo. The randomisation of participant treatment allocation for each participant will be undertaken by a fellow scientist not involved in this study using the randomisation function in Microsoft Excel. The key to participant treatment allocation will until completion of the trial and sample analysis.
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
Data will be expressed as mean +/- standard error. Interaction between blackcurrant supplementation and cognitive function following acute and long term supplementation will be determined. Likewise, interaction between blackcurrant and their effects on mood, mental fatigue, plasma neurotransmitters and platelet MAO-B activity will be determined, Statistical significance for the comparison between blackcurrant and placebo groups will be assessed using paired t-tests. Multiple comparisons will be assessed by two-way ANOVA. Statistical significance for all parameters will be set at P < 0.05 with a confidence level of 95%.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
1/12/2021
Actual
8/04/2022
Date of last participant enrolment
Anticipated
31/08/2022
Actual
1/02/2023
Date of last data collection
Anticipated
31/03/2023
Actual
21/04/2023
Sample size
Target
42
Accrual to date
Final
40
Recruitment outside Australia
Country [1] 24289 0
New Zealand
State/province [1] 24289 0
MANAWATU
Country [2] 24290 0
New Zealand
State/province [2] 24290 0
Auckland

Funding & Sponsors
Funding source category [1] 310064 0
Government body
Name [1] 310064 0
Ministry of Business Innovation and Employment - High Value Nutrition
Country [1] 310064 0
New Zealand
Funding source category [2] 310066 0
Commercial sector/Industry
Name [2] 310066 0
AlphaGen NZ Ltd.
Country [2] 310066 0
New Zealand
Primary sponsor type
Individual
Name
Dr Jocelyn Eason
Address
The New Zealand Institute for Plant & Food Research
Batchelar Road
Fitzherbert
Palmerston North 4474
Country
New Zealand
Secondary sponsor category [1] 311118 0
None
Name [1] 311118 0
Address [1] 311118 0
Country [1] 311118 0
Other collaborator category [1] 282054 0
Individual
Name [1] 282054 0
Dr Edward Walker
Address [1] 282054 0
The New Zealand Institute for Plant & Food Research
120 Mt Albert Road
Mt Albert
Auckland 1025
Country [1] 282054 0
New Zealand
Other collaborator category [2] 282055 0
Individual
Name [2] 282055 0
Dr Pramod Gopal
Address [2] 282055 0
The New Zealand Institute for Plant & Food Research
Batchelar Road
Fitzherbert
Palmerston North 4474
Country [2] 282055 0
New Zealand

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 309757 0
Northern B Health and Disability Ethics Committee
Ethics committee address [1] 309757 0
Ministry of Health
133 Molesworth Street
PO Box 5013
Wellington
6011
Ethics committee country [1] 309757 0
New Zealand
Date submitted for ethics approval [1] 309757 0
21/10/2021
Approval date [1] 309757 0
18/11/2021
Ethics approval number [1] 309757 0
2021 EXP 11576

Summary
Brief summary
There is increasing evidence supporting the benefits of anthocyanin-rich blackcurrants on mood and cognition. Randomised placebo-controlled human studies have reported that consuming a single standardised dose of blackcurrants reduced the decline in reaction time during cognitive fatigue and supported a more positive affective response and reduced perceived exertion during a moderate walking exercise. Improvements in cognition following blackcurrant consumption also corresponded with distinct changes in spectral wavelengths measured by electroencephalogram (EEG), indicating increased attention and reduced anxiety in those who consumed blackcurrants during cognitive challenges. Analysis of biological samples from these studies indicate that blackcurrant constituents may regulate the concentrations of neurotransmitters essential for cognitive function and mood. Consuming a single dose of blackcurrants was observed to significantly inhibit peripheral monoamine oxidase (MAO)-B activity within 15 minutes. This effect was observed to last for at least 4 h following blackcurrant consumption. Acute blackcurrant consumption also led to a reduction in dihydroxyphenylglycine, a known marker of MAO-A enzyme inhibition. Aside from MAO-inhibitory effects, blackcurrant consumption has also been reported to lead to reduced prolactin levels, which may reflect increased central dopamine concentrations.

Studies investigating the benefits of blackcurrants on cognitive function have been limited to characterising their benefits after consuming a single dose in healthy adult populations (mean age approx. 25 years). Whether longer-term blackcurrant supplementation leads to further augmentation in cognitive performance in healthy, elderly populations (55+) warrants further investigation. There is evidence from literature for the efficacy of long-term supplementation with other anthocyanin-rich foods in enhancing measures of cognitive function in elderly populations, including those at risk of dementia. In this project, we will investigate the benefits of acute and long-term consumption of a commercial blackcurrant nootropic beverage containing L-theanine and pine bark extract in supporting the cognitive function and mood of healthy elderly individuals in a double-blind, placebo-controlled trial.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 115282 0
Dr Dominic Lomiwes
Address 115282 0
The New Zealand Institute for Plant & Food Research Ltd.
Batchelar Road
Private Bag 11600
Palmerston North 4442
Country 115282 0
New Zealand
Phone 115282 0
+64 6 355 6113
Fax 115282 0
+64 6 351 7050
Email 115282 0
[email protected]
Contact person for public queries
Name 115283 0
Pramod Gopal
Address 115283 0
The New Zealand Institute for Plant & Food Research Ltd.
Batchelar Road
Private Bag 11600
Palmerston North 4442
Country 115283 0
New Zealand
Phone 115283 0
+64 6 953 7678
Fax 115283 0
+64 6 351 7050
Email 115283 0
[email protected]
Contact person for scientific queries
Name 115284 0
Dominic Lomiwes
Address 115284 0
The New Zealand Institute for Plant & Food Research Ltd.
Batchelar Road
Private Bag 11600
Palmerston North 4442
Country 115284 0
New Zealand
Phone 115284 0
+64 6 355 6113
Fax 115284 0
+64 6 351 7050
Email 115284 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
This work is partly industry funded and publicly disclosing individual participant data will violate our confidentiality agreement to protect the intellectual property generated from this study.
Furthermore, ethics guidelines for human clinical studies do not allow us to release data that may risk the disclosure of the identity of participants who took part in this study.


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

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