None listed
Conditions
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.
Interventions
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 stu
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.
Sponsors
Dr Jocelyn Eason
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
55 Years to 70 Years
Healthy volunteers
Yes
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.
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).
Outcome results
None listed