Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12615000762550
Ethics application status
Approved
Date submitted
29/05/2015
Date registered
22/07/2015
Date last updated
2/11/2015
Type of registration
Prospectively registered

Titles & IDs
Public title
The effects of daily blackcurrant consumption for 6 weeks on cognitive performance before and after exercise-induced physical fatigue.
Scientific title
Daily consumption of blackcurrants on cognitive performance after physical fatigue in healthy adults.
Secondary ID [1] 286829 0
None
Universal Trial Number (UTN)
U1111-1170-6735
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Cognitive fatigue
 295217 0
Physical fatigue 295395 0
Condition category
Condition code
Mental Health 295464 295464 0 0
Studies of normal psychology, cognitive function and behaviour

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
This is a two-arm, double blind intervention feeding trial that will involve volunteers (16-50yrs). We aim to recruit 50 participants who will be split into two groups. In group one the participants will receive blackcurrant extract (240mg anthocyanins via oral capsule, everyday for 6 weeks) and participate in fatiguing/cognitive performance (week 1 and week 7). In group two the participants will receive a matched sugar placebo (240mg fructose and glucose via oral capsule, everyday for 6 weeks) and participate in fatiguing/cognitive performance (week 1 and week 7). The fatiguing sessions is a cycle test for 30 secs intervals. The fatigue threshold is calculated as the intensity where the individual displays a decline in peak cycle power output and a blood lactate level above their lactate threshold. this will vary between participants depending on their fitness level. Participants will complete the 30 secs cycle with 1 minute rest intervals until they are tired. They will complete this cycle test at the beginning of week one twice (once for baseline and to establish fatigue threshold) and then twice at the end of week seven. These sessions will be administrated by a physiotherapist and a qualified first aider will also be present. The cognitive performance will take 15 - 20 minutes (twice at both weeks 1 and 7) and consists of computerized tests. Over the 6 week feeding period the participants will be asked to consume their supplements (blackcurrant or placebo) in the morning at the same time. At the beginning of the week they will be asked to complete an online diet, energy, health and mood (PoMs) questionnaire. This questionnaire will ask them about their adherence to the pill schedule. Furthermore, participants will collect their pills once a week from the trial coordinator, who will also discuss adherence with the participants at that time. Randomization will be performed using a randomization schedule designed by a biostatistician, with study investigators and subjects blind to group allocation.
Intervention code [1] 291991 0
Lifestyle
Intervention code [2] 291992 0
Treatment: Other
Intervention code [3] 291993 0
Behaviour
Comparator / control treatment
Opaque gelatin capsule containing the 240mg sugar (frucose and glucose) present in the blackcurrant extract.
Control group
Placebo

Outcomes
Primary outcome [1] 295191 0
Cognitive performance
Timepoint [1] 295191 0
Cognitive performance will be assessed at the familiarization session and in the main part of the trial. In the main trial, participants will be asked to perform a series of computerised tasks designed to test cognitive functioning. This will occur prior to, and immediately after performing repeated (usually 4-5) 30 second Wingate cycle tests designed to induce physical fatigue. Cognitive performance will be tested using 5 tasks; stroop, digit symbol substitution, trail making and complex reaction time,serial sevens, which examine various aspects of cognitive processing. This will be assessed at week one and at week seven.
Primary outcome [2] 295192 0
Physical exercise performance
Timepoint [2] 295192 0
Exercise performance is assessed on a stationary cycle ergometer, participants will be asked to cycle at maximum speed at braking torque (4% body weight) for 30 seconds. Using the participants physical performance measures: cycle work output (peak/average), physical fatigue index, lactate threshold (anaerobic capacity), blood glucose and ratings of perceived excertion parameters, we aim to assess changes in physical performance in the main trial before and after exercise-induced fatigue. This will be assessed at weeks one and seven of the trial.
Secondary outcome [1] 315011 0
Leukocyte mitochondrial DNA fragility
Timepoint [1] 315011 0
Mitchondrial fragility will be measured (i) pre-treatment; blackcurrant or placebo, (ii) just before and (iii) immediately after exercise induced fatigue or relaxation period, and finally (iv) after 20 minutes recovery period (all measured at week 1 and week 7). We aim to determine the effect of blackcurrant consumption over a 6 week period and/or exercise-induced fatigue on mitochondrial DNA. This involves isolating leukocyte DNA and using 'nested' PCR methodology using specific oligonucleotides that recognise a specific region of mitochondrial DNA that is susceptible to oxidative stress.

Eligibility
Key inclusion criteria
Healthy individuals (male or female) 16-50 years, who have not taken part in any formal fitness training in the last 4 months and are able to complete the physical fitness requirements of the study will be selected. They will need to be able to complete (i) health (ii) fitness (Baecke) questionnaires and (iii) perform with Wingate cycle test to the standard required. In addition, all participants will provide written consent for this study.
Minimum age
16 Years
Maximum age
50 Years
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Participants will be excluded if they are unable or willing to provide informed written consent or comply with the study procedures. Participants will also be excluded if they have (i) known hypersensitivity or intolerance to blackcurrants or berry fruit and/or berryfruit derived products (ii) have health conditions that impair ability to perform Wingate cycle exercise (e.g. injury, hernia, back or joint pain, cardiovascular and breathing problems or fail to demonstrate a certain fitness level, assessed by a Baecke questionnaire, or are unable to perform the Wingate cycle exercise to the standard required by the trial co-ordinator, and (iii) health conditions that may affect ability to do computerized cognitive tasks (e.g. eye sight problems, colour blindness, aura migraines, epilepsy). In addition, participants will be excluded if they are pregnant or 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 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)
Recruitment. Participants will be recruited from a flyer posted on the appropriate notice boards local research institutes and community gyms. All interested individuals will have an initial chat with the trial coordinator and be provided with information sheet, health and fitness questionnaires and consent forms to take home for discussion with friends, family or whanau. Potential participants will have 2 weeks to decide whether they would like to take part in the study. Allocation concealment will be used. Study investigators and participants will be blinded from the dietary intervention. Allocation of dietary intervention is undertaken by a fellow scientist who is not involved in this study. Participant treatment allocation is held concealed until completion of the trial and analysis of the data is finished.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
This is a two-arm double blind intervention nutritional trial examining changes in cognitive performance after exercise induced fatigue. The participants will be split into two groups. Group one: blackcurrant extract and physical and cognitive fatigue. Group two: placebo and physical and cognitive fatigue. Study investigators and participants will be blinded from dietary intervention. Participants will be given their dietary treatment as an opaque gelatin capsule, which will mask the blackcurrant or placebo. Randomization will be performed using a randomization schedule designed by a biostatistician. This software will create two equal columns of random numbers that were allocated to the participants.
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
The overall aim of this study is to generate results that contribute to the growing meta-analysis data supporting the efficacy of dietary intervention on cognitive performance (Lambourne, & Tomporowski, 2010). In this particular study we examine the effectiveness of a 6-week blackcurrant supplementation on cognitive performance after physical fatigue. Selection of cognitive tasks and calculation of subject power number for this current study are based upon a previous study reported by Haskell and colleagues (2010); “Effects of a multi-vitamin/mineral supplement on cognitive function and fatigue during extended multi-tasking”, Human Psychopharmacology, 2010, DOI: 10.1002/hup.1144, where the results indicate a 5% improvement in a Stroop cognitive test in people who’ve been on multivitamins for 9 weeks compared to those on a placebo. Application of these findings to estimate the power number for our 6-week blackcurrant supplementation intervention study indicates that to detect, say, a 0.04 at p=0.05 (one-tailed) for the same Stroop cognitive task the subject numbers required for 80% power needs to be at least 25 per group. Therefore, in this study we aim to use a total of 50 individuals divided into 2 treatment groups; placebo vs. blackcurrant supplementation. Power calculations for this study design were performed using the Genstat’s ASAMPLESIZE procedure, assuming a one factor ANOVA with blocks.

Recruitment
Recruitment status
Active, not recruiting
Date of first participant enrolment
Anticipated
1/08/2015
Actual
7/08/2015
Date of last participant enrolment
Anticipated
8/10/2015
Actual
13/10/2015
Date of last data collection
Anticipated
Actual
Sample size
Target
50
Accrual to date
Final
50
Recruitment outside Australia
Country [1] 6919 0
New Zealand
State/province [1] 6919 0
Palmerston North, Manawatu

Funding & Sponsors
Funding source category [1] 291381 0
Government body
Name [1] 291381 0
New Zealand Institute for Plant and Food Research
Country [1] 291381 0
New Zealand
Primary sponsor type
Government body
Name
New Zealand Institute for Plant and Food Research
Address
Private Bag, 11600, Palmerston North 4442
Country
New Zealand
Secondary sponsor category [1] 290056 0
None
Name [1] 290056 0
Address [1] 290056 0
Country [1] 290056 0
Other collaborator category [1] 278489 0
Individual
Name [1] 278489 0
Assoc. Prof. John Podd
Address [1] 278489 0
School of Psychology, Massey University, Private Bag 11-222, Palmerston North, 4442
Country [1] 278489 0
New Zealand

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 292937 0
Health and Disability Ethics Committee (HDEC), New Zealand
Ethics committee address [1] 292937 0
Ministry of Health
No 1 The Terrance
PO Box 5013
Wellington 6145
Ethics committee country [1] 292937 0
New Zealand
Date submitted for ethics approval [1] 292937 0
29/05/2015
Approval date [1] 292937 0
25/06/2015
Ethics approval number [1] 292937 0

Summary
Brief summary
The influence of physical exercise on cognition is complex and is dependent upon a variety of factors including an individual’s, age; gender and fitness level as well the type, intensity and duration of the exercise. Meta analysis reports show that physical exercise (even after one session) can improve mental acuity, whereas long-term high intensity exercise shows a decline in mental performance. Identifying nutritional intervention strategies that support cognitive performance during and/or after exercise would benefit those individuals taking part in sport training regimes that involve exercise-induced physical fatigue. In an attempt to support mental acuity during and after exercise-induced mental fatigue nutritional intervention studies have focused on reducing oxidative stress associated with physical fatigue. However exercise studies investigating the role of antioxidant supplementation on exercise performance show that long-term consumption of antioxidant supplements have no effect on physical fatigue and may actually delay recovery, thereby augmenting any detrimental effect of physical fatigue on cognitive performance. In contrast, consumption of whole fruit, especially berryfruit appears to facilitate recovery after exercise. In particular, eating blackcurrants prior to exercise has been shown to alleviate not only oxidative stress but also improve blood flow to a variety of tissues; increase oxygen delivery and blood lactate clearance. It is therefore feasible that daily blackcurrant consumption as part of sport training strategies facilitates recovery processes after exercise-induced physical fatigue and support cognitive performance. In this study we explore the effect of daily blackcurrant consumption for 6-week on cognitive performance after acute fatigue induced by exercise.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 57706 0
Dr Suzanne Hurst
Address 57706 0
New Zealand Institute for Plant and Food Research Ltd. Private Bag 11600, Palmerston North 4442
Country 57706 0
New Zealand
Phone 57706 0
+64 (6) 355 6231
Fax 57706 0
+64 (6) 351 7050
Email 57706 0
suzanne.hurst@plantandfood.co.nz
Contact person for public queries
Name 57707 0
Mr Dominic Lomiwes
Address 57707 0
New Zealand Institute for Plant and Food Research Ltd. Private Bag 11600, Palmerston North 4442
new Zealand
Country 57707 0
New Zealand
Phone 57707 0
+64 (6) 953 6224
Fax 57707 0
+64 (6) 351 7050
Email 57707 0
dominic.lomiwes@plantandfood.co.nz
Contact person for scientific queries
Name 57708 0
Dr Suzanne Hurst
Address 57708 0
New Zealand Institute for Plant and Food Research Ltd. Private Bag 11600 Palmerston North 4442
Country 57708 0
New Zealand
Phone 57708 0
+64 (6) 355 6231
Fax 57708 0
+64 (6) 351 7050
Email 57708 0
suzanne.hurst@plantandfood.co.nz

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