CognitionPACVANNCT06900452
The Effect of Pistachio-Rich Breakfast Meals on Cognitive Function in Healthy Older Adults
A study testing 0.5 serving of pistachios, 1 serving of pistachios and 2 servings of pistachios in people with Cognition, run by University of Reading at 1 site in United Kingdom.
Trial summary
This study aims to investigate the effect of a breakfast meal containing varying serving sizes (doses) of pistachio nuts on cognitive function throughout the course of the day in healthy ageing adults aged 65-80. Read more about this study
- Who is it for?
- Ages 65 to 80 yearsHealthy volunteers can take part
- Conditions the study is for
- Cognition
- What is being tested?
- 0.5 serving of pistachios, 1 serving of pistachios and 2 servings of pistachios
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 52 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 6 Mar 2025to Feb 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 65 to 80 years
- All sexes
- Healthy volunteers accepted
- Older adult
Who may be able to join
- 65 - 80 years old
- Fruit \& veg intake less than or equal to 4 servings per day
- Not regularly consuming more than 3 servings of fish per week
- Adequate English language and visual \& auditory acuity to perform the cognitive tasks
- Normal BMI for age
- Normal MMSE performance between 26-30
Who cannot join
- Being diagnosed with psychological or psychiatric disorders
- ADHD or dyslexia
- Any food allergy or intolerance
- Use of medications and dietary supplements that may impact study results
- Antibiotic use within the last 3 months
- Adherence to vegan or vegetarian diets, or other specific diets that may impact study outcomes
- Being diagnosed with cardiometabolic disease (including type II diabetes and cardiovascular disease), or suffer from untreated hypertension or thrombosis related disorders
- Taking blood thinners
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United Kingdom1 site, 1 recruiting
- Recruiting
Nutrition, Cognition & Health Lab, School of Psychology and Clinical Language Sciences, University of Reading
Reading, Berkshire, RG6 6ES
About this study
Official title: A Randomized Controlled Trial to Investigate the Cognitive, Vascular, Neural and Biochemical Effects of Acute Pistachio Intervention in Older Adults
This study aims to investigate the effect of a breakfast meal containing varying serving sizes (doses) of pistachio nuts on cognitive function throughout the course of the day in healthy ageing adults aged 65-80.
Read the detailed description
This crossover RCT investigates the acute postprandial effect (over a 6-hour period) of a breakfast meal containing varying serving sizes (doses) of pistachio nuts on the cognitive behaviour in healthy adults aged 65-80 years old. The study will also assess markers of inflammation and brain health by taking blood samples, and explore brain function (EEG) and blood flow (FMD) to understand how pistachio nuts may positively influence cognitive health. The study will involve a screening visit and four testing visits, with a week interval between each. On the evening prior to each test visit, participants are asked not to consume any food or drinks expect water, including tea/coffee and alcohol, after 8.30pm, and on the morning of test visits to only consume one slice of buttered white toast and a glass of water prior to attending the visit. During the four testing visits, cognitive and mood battery tests will be taken at baseline and then at 2-, 4- and 6-hour intervals following the consumption of the intervention meal. Blood draws are taken at the end of the day. For the subset of participants taking part in FMD, this will be measured at baseline, 2, 4 and 6 hours prior to cognitive testing. For those taking part in EEG, this data will be collected at 6 hours.
- Conditions
- Cognition
- Being tested
- 0.5 serving of pistachios, 1 serving of pistachios, 2 servings of pistachios, Placebo
- Keywords
- Cognition, Pistachios, Vascular, Neural, Inflammation, Mood
- Medical subject headings
- Inflammation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
0.5 serving of pistachiosDietary supplement
The equivalent of 0.5 servings (15g) of shelled, roasted pistachio nuts, crushed and mixed into a muesli-based breakfast meal for consumption.
Ingredients: 15g pistachio, 35g muesli base, 150g full fat natural yoghurt, 15g unsalted butter (melted), 10g unflavoured whey powder
1 serving of pistachiosDietary supplement
The equivalent of 1 serving (30g) of shelled, roasted pistachio nuts, crushed and mixed into a muesli-based breakfast meal for consumption.
Ingredients: 30g pistachio, 35g muesli base, 150g full fat natural yoghurt, 10g unsalted butter (melted), 5g unflavoured whey powder
2 servings of pistachiosDietary supplement
The equivalent of 2 servings (60g) of shelled, roasted pistachio nuts, crushed and mixed into a muesli-based breakfast meal for consumption.
Ingredients: 60g pistachios, 25g muesli base, 150g low fat natural yoghurt
PlaceboDietary supplement
Macronutrient-matched placebo breakfast meal. Ingredients: 40g muesli base, 150g full fat natural yoghurt, 25g unsalted butter (melted), 15g unflavoured whey powder
| Study group | Role | What they receive |
|---|---|---|
| Placebo | Placebo comparator | Macronutrient-matched placebo breakfast meal Receives: Dietary Supplement: Placebo |
| 0.5 servings of pistachio | Experimental | 0.5 servings of pistachio (15g) administered in breakfast meal Receives: Dietary Supplement: 0.5 serving of pistachios |
| 1 serving of pistachio | Experimental | 1 serving of pistachio (30g) administered in breakfast meal Receives: Dietary Supplement: 1 serving of pistachios |
| 2 servings of pistachio | Experimental | 2 servings of pistachio (60g) administered in breakfast meal Receives: Dietary Supplement: 2 servings of pistachios |
What is being measured
The primary outcome is the main question the study is designed to answer.
Delayed recall (Rey Auditory Verbal Learning Task)
The RAVLT is a verbal learning task that presents participants with 15 words (list A) 5 times, giving participants one minute after each presentation to recall as many words as they can from the list. After 5 presentations, a new list (list B) is presented and recalled, and finally participants are asked (without hearing list A again) to recall as many words as they can from list A. After a 30 minute period, participants are asked to think back to the task and recall as many words as possible from list A only, providing a measure of delayed recall.
Measured: Baseline
Delayed recall (Rey Auditory Verbal Learning Task)
The RAVLT is a verbal learning task that presents participants with 15 words (list A) 5 times, giving participants one minute after each presentation to recall as many words as they can from the list. After 5 presentations, a new list (list B) is presented and recalled, and finally participants are asked (without hearing list A again) to recall as many words as they can from list A. After a 30 minute period, participants are asked to think back to the task and recall as many words as possible from list A only, providing a measure of delayed recall.
Measured: 2 hours
Delayed recall (Rey Auditory Verbal Learning Task)
The RAVLT is a verbal learning task that presents participants with 15 words (list A) 5 times, giving participants one minute after each presentation to recall as many words as they can from the list. After 5 presentations, a new list (list B) is presented and recalled, and finally participants are asked (without hearing list A again) to recall as many words as they can from list A. After a 30 minute period, participants are asked to think back to the task and recall as many words as possible from list A only, providing a measure of delayed recall.
Measured: 4 hours
Delayed recall (Rey Auditory Verbal Learning Task)
The RAVLT is a verbal learning task that presents participants with 15 words (list A) 5 times, giving participants one minute after each presentation to recall as many words as they can from the list. After 5 presentations, a new list (list B) is presented and recalled, and finally participants are asked (without hearing list A again) to recall as many words as they can from list A. After a 30 minute period, participants are asked to think back to the task and recall as many words as possible from list A only, providing a measure of delayed recall.
Measured: 6 hours
Secondary outcomes (36)
Rate of learning (Rey Auditory Verbal Learning Task)
The RAVLT is a verbal learning task that presents participants with 15 sequential words (list A) 5 times, giving participants one minute after each presentation to recall as many words as they can from the list. Scores are recorded as a percentage of accuracy, and the rate of learning is determined through change in accuracy across the 5 recalls.
Measured: Baseline
Rate of learning (Rey Auditory Verbal Learning Task)
The RAVLT is a verbal learning task that presents participants with 15 sequential words (list A) 5 times, giving participants one minute after each presentation to recall as many words as they can from the list. Scores are recorded as a percentage of accuracy, and the rate of learning is determined through change in accuracy across the 5 recalls.
Measured: 2 hours
Rate of learning (Rey Auditory Verbal Learning Task)
The RAVLT is a verbal learning task that presents participants with 15 sequential words (list A) 5 times, giving participants one minute after each presentation to recall as many words as they can from the list. Scores are recorded as a percentage of accuracy, and the rate of learning is determined through change in accuracy across the 5 recalls.
Measured: 4 hours
Rate of learning (Rey Auditory Verbal Learning Task)
The RAVLT is a verbal learning task that presents participants with 15 sequential words (list A) 5 times, giving participants one minute after each presentation to recall as many words as they can from the list. Scores are recorded as a percentage of accuracy, and the rate of learning is determined through change in accuracy across the 5 recalls.
Measured: 6 hours
Word recognition (Rey Auditory Verbal Learning Task)
Following the delayed word recall, words from list A, list B and novel words are displayed sequentially on the screen and participants are asked to indicate which words were from list A only.
Measured: Baseline
Word recognition (Rey Auditory Verbal Learning Task)
Following the delayed word recall, words from list A, list B and novel words are displayed sequentially on the screen and participants are asked to indicate which words were from list A only.
Measured: 2 hours
Word recognition (Rey Auditory Verbal Learning Task)
Following the delayed word recall, words from list A, list B and novel words are displayed sequentially on the screen and participants are asked to indicate which words were from list A only.
Measured: 4 hours
Word recognition (Rey Auditory Verbal Learning Task)
Following the delayed word recall, words from list A, list B and novel words are displayed sequentially on the screen and participants are asked to indicate which words were from list A only.
Measured: 6 hours
Modified Attention Network Task (MANT)
This task examines execution function, attention and inhibition. Participants respond to a centrally presented target arrow pointing to the left or the right by pressing the corresponding key on the keyboard. The target arrow is flanked by arrows that point in the same (congruent) or opposite (incongruent) direction. Previous studies have found that participants show larger latencies and more errors on incongruent trials when compared with congruent trials due to the conflicting interference of the incongruently facing arrows. Response latencies to congruent trials reflect processing speed, while errors on incongruent trials indicate susceptibility to interference. In this study participants will be presented with two blocks of the MANT - one normal block, and one block with the addition of serial 3s. In the serial 3s block, participants will be asked to count backwards in 3s out loud while continuing to perform the MANT, increasing the level of cognitive demand.
Measured: Baseline
Modified Attention Network Task (MANT)
This task examines execution function, attention and inhibition. Participants respond to a centrally presented target arrow pointing to the left or the right by pressing the corresponding key on the keyboard. The target arrow is flanked by arrows that point in the same (congruent) or opposite (incongruent) direction. Previous studies have found that participants show larger latencies and more errors on incongruent trials when compared with congruent trials due to the conflicting interference of the incongruently facing arrows. Response latencies to congruent trials reflect processing speed, while errors on incongruent trials indicate susceptibility to interference. In this study participants will be presented with two blocks of the MANT - one normal block, and one block with the addition of serial 3s. In the serial 3s block, participants will be asked to count backwards in 3s out loud while continuing to perform the MANT, increasing the level of cognitive demand.
Measured: 2 hours
Modified Attention Network Task (MANT)
This task examines execution function, attention and inhibition. Participants respond to a centrally presented target arrow pointing to the left or the right by pressing the corresponding key on the keyboard. The target arrow is flanked by arrows that point in the same (congruent) or opposite (incongruent) direction. Previous studies have found that participants show larger latencies and more errors on incongruent trials when compared with congruent trials due to the conflicting interference of the incongruently facing arrows. Response latencies to congruent trials reflect processing speed, while errors on incongruent trials indicate susceptibility to interference. In this study participants will be presented with two blocks of the MANT - one normal block, and one block with the addition of serial 3s. In the serial 3s block, participants will be asked to count backwards in 3s out loud while continuing to perform the MANT, increasing the level of cognitive demand.
Measured: 4 hours
Modified Attention Network Task (MANT)
This task examines execution function, attention and inhibition. Participants respond to a centrally presented target arrow pointing to the left or the right by pressing the corresponding key on the keyboard. The target arrow is flanked by arrows that point in the same (congruent) or opposite (incongruent) direction. Previous studies have found that participants show larger latencies and more errors on incongruent trials when compared with congruent trials due to the conflicting interference of the incongruently facing arrows. Response latencies to congruent trials reflect processing speed, while errors on incongruent trials indicate susceptibility to interference. In this study participants will be presented with two blocks of the MANT - one normal block, and one block with the addition of serial 3s. In the serial 3s block, participants will be asked to count backwards in 3s out loud while continuing to perform the MANT, increasing the level of cognitive demand.
Measured: 6 hours
Task Switching Task
This task requires executive function and sustained attention, and provides a measure of cognitive flexibility. Participants view a circle with 8 equally spaced radii, 2 of which form a bold bisecting line. Numbers are chosen randomly from a set of 1-4 \& 6-9 and displayed sequentially in a clockwise direction. A response of higher or lower than 5 is made for trials below the bold line, and even or odd for numbers above the line. Outcome measures include overall accuracy and reaction time (RT) on correct trials, as well as accuracy and RT on trials where there is a 'switch cost' from stimuli moving from below to above the bold line and vice versa.
Measured: Baseline
Task Switching Task
This task requires executive function and sustained attention, and provides a measure of cognitive flexibility. Participants view a circle with 8 equally spaced radii, 2 of which form a bold bisecting line. Numbers are chosen randomly from a set of 1-4 \& 6-9 and displayed sequentially in a clockwise direction. A response of higher or lower than 5 is made for trials below the bold line, and even or odd for numbers above the line. Outcome measures include overall accuracy and reaction time (RT) on correct trials, as well as accuracy and RT on trials where there is a 'switch cost' from stimuli moving from below to above the bold line and vice versa.
Measured: 2 hours
Task Switching Task
This task requires executive function and sustained attention, and provides a measure of cognitive flexibility. Participants view a circle with 8 equally spaced radii, 2 of which form a bold bisecting line. Numbers are chosen randomly from a set of 1-4 \& 6-9 and displayed sequentially in a clockwise direction. A response of higher or lower than 5 is made for trials below the bold line, and even or odd for numbers above the line. Outcome measures include overall accuracy and reaction time (RT) on correct trials, as well as accuracy and RT on trials where there is a 'switch cost' from stimuli moving from below to above the bold line and vice versa.
Measured: 4 hours
Task Switching Task
This task requires executive function and sustained attention, and provides a measure of cognitive flexibility. Participants view a circle with 8 equally spaced radii, 2 of which form a bold bisecting line. Numbers are chosen randomly from a set of 1-4 \& 6-9 and displayed sequentially in a clockwise direction. A response of higher or lower than 5 is made for trials below the bold line, and even or odd for numbers above the line. Outcome measures include overall accuracy and reaction time (RT) on correct trials, as well as accuracy and RT on trials where there is a 'switch cost' from stimuli moving from below to above the bold line and vice versa.
Measured: 6 hours
Corsi Block Tapping Task
A standardised assessment of visuospatial working memory. The task comprises nine identical squares fixed in a random arrangement on a screen. Participants observe sequences of between two and nine blocks, which they then reproduce as accurately as possible by clicking with the mouse. Outcomes include number of correct sequences identified as a percentage of accuracy, and number of correct blocks identified (not necessarily in the correct sequence). Four versions of each sequence length are presented during the task. A novel sequence will be presented on each occasion, the order of which will be counterbalanced across participants.
Measured: Baseline
Corsi Block Tapping Task
A standardised assessment of visuospatial working memory. The task comprises nine identical squares fixed in a random arrangement on a screen. Participants observe sequences of between two and nine blocks, which they then reproduce as accurately as possible by clicking with the mouse. Outcomes include number of correct sequences identified as a percentage of accuracy, and number of correct blocks identified (not necessarily in the correct sequence). Four versions of each sequence length are presented during the task. A novel sequence will be presented on each occasion, the order of which will be counterbalanced across participants.
Measured: 2 hours
Corsi Block Tapping Task
A standardised assessment of visuospatial working memory. The task comprises nine identical squares fixed in a random arrangement on a screen. Participants observe sequences of between two and nine blocks, which they then reproduce as accurately as possible by clicking with the mouse. Outcomes include number of correct sequences identified as a percentage of accuracy, and number of correct blocks identified (not necessarily in the correct sequence). Four versions of each sequence length are presented during the task. A novel sequence will be presented on each occasion, the order of which will be counterbalanced across participants.
Measured: 4 hours
Corsi Block Tapping Task
A standardised assessment of visuospatial working memory. The task comprises nine identical squares fixed in a random arrangement on a screen. Participants observe sequences of between two and nine blocks, which they then reproduce as accurately as possible by clicking with the mouse. Outcomes include number of correct sequences identified as a percentage of accuracy, and number of correct blocks identified (not necessarily in the correct sequence). Four versions of each sequence length are presented during the task. A novel sequence will be presented on each occasion, the order of which will be counterbalanced across participants.
Measured: 6 hours
N-back task
The N-Back task is a measure of working memory where participants are instructed to monitor a series of stimuli and to respond whenever a stimulus is presented that is the same as the one presented n trials previously. In this simplified 0-back version, participants respond when the target matches a fixed target specified at the beginning of the task (similar to a Go/No-Go task). Data will be analysed for both accuracy and reaction time on correct trials. For a subset of participants, this task will be conducted while recording EEG (6 hours only) in order to monitor change in brain activity in response to target trials. The N-Back was selected as it has been shown in previous work to elicit a strong P300 signal (see EEG as additional outcome).
Measured: Baseline
N-back task
The N-Back task is a measure of working memory where participants are instructed to monitor a series of stimuli and to respond whenever a stimulus is presented that is the same as the one presented n trials previously. In this simplified 0-back version, participants respond when the target matches a fixed target specified at the beginning of the task (similar to a Go/No-Go task). Data will be analysed for both accuracy and reaction time on correct trials. For a subset of participants, this task will be conducted while recording EEG (6 hours only) in order to monitor change in brain activity in response to target trials. The N-Back was selected as it has been shown in previous work to elicit a strong P300 signal (see EEG as additional outcome).
Measured: 2 hours
N-back task
The N-Back task is a measure of working memory where participants are instructed to monitor a series of stimuli and to respond whenever a stimulus is presented that is the same as the one presented n trials previously. In this simplified 0-back version, participants respond when the target matches a fixed target specified at the beginning of the task (similar to a Go/No-Go task). Data will be analysed for both accuracy and reaction time on correct trials. For a subset of participants, this task will be conducted while recording EEG (6 hours only) in order to monitor change in brain activity in response to target trials. The N-Back was selected as it has been shown in previous work to elicit a strong P300 signal (see EEG as additional outcome).
Measured: 4 hours
N-back task
The N-Back task is a measure of working memory where participants are instructed to monitor a series of stimuli and to respond whenever a stimulus is presented that is the same as the one presented n trials previously. In this simplified 0-back version, participants respond when the target matches a fixed target specified at the beginning of the task (similar to a Go/No-Go task). Data will be analysed for both accuracy and reaction time on correct trials. For a subset of participants, this task will be conducted while recording EEG (6 hours only) in order to monitor change in brain activity in response to target trials. The N-Back was selected as it has been shown in previous work to elicit a strong P300 signal (see EEG as additional outcome).
Measured: 6 hours
EEG (ERPs & PSD)
Event related potential (ERP) measure of P300 \& N200 latency and amplitude will be assessed using EEG (electroencephalography) in a subset of participants during resting state (eyes open and closed) and during the N-Back task. Additionally, power for Alpha, Beta, Gamma, Delta, and Theta bands during performance of the N-Back task will be assessed in these participants.
EEG data will be collected using Brain Products software and 16-channel active electrodes.
Measured: 6 hours
Blood markers
Blood samples will be collected 6 hours post-intervention to measure to following serum markers: BDNF, irisin, IGF-1 and cytokines (IL-6, IL-10 and TNF-α). Samples will be analysed using enzyme-linked immunosorbent assays.
Measured: 6 hours
Flow mediated dilation (FMD)
A subset of participants will complete FMD assessment prior to each cognitive task battery (baseline, 2, 4 and 6 hours). FMD is a non-invasive ultrasound technique that measures how the brachial artery dilates in response to increased blood flow following occlusion. Participants are required to lie down for 15 minutes before scanning commences. The procedure then takes 9 minutes: the brachial artery is first scanned for 1 minute, a blood pressure cuff is then inflated on the forearm for 5 minutes, before being released and the artery scanned for a further 3 minutes. This data will be analysed using Cardiovascular Suit. During FMD, laser doppler flowometry (LDF) will also be measured using the index finger of the right arm and analysed for % PORH (post occlusive reactive hyperaemia), measured in flux units .
Measured: Baseline
Flow mediated dilation (FMD)
A subset of participants will complete FMD assessment prior to each cognitive task battery (baseline, 2, 4 and 6 hours). FMD is a non-invasive ultrasound technique that measures how the brachial artery dilates in response to increased blood flow following occlusion. Participants are required to lie down for 15 minutes before scanning commences. The procedure then takes 9 minutes: the brachial artery is first scanned for 1 minute, a blood pressure cuff is then inflated on the forearm for 5 minutes, before being released and the artery scanned for a further 3 minutes. This data will be analysed using Cardiovascular Suit. During FMD, laser doppler flowometry (LDF) will also be measured using the index finger of the right arm and analysed for % PORH (post occlusive reactive hyperaemia), measured in flux units .
Measured: 2 hours
Flow mediated dilation (FMD)
A subset of participants will complete FMD assessment prior to each cognitive task battery (baseline, 2, 4 and 6 hours). FMD is a non-invasive ultrasound technique that measures how the brachial artery dilates in response to increased blood flow following occlusion. Participants are required to lie down for 15 minutes before scanning commences. The procedure then takes 9 minutes: the brachial artery is first scanned for 1 minute, a blood pressure cuff is then inflated on the forearm for 5 minutes, before being released and the artery scanned for a further 3 minutes. This data will be analysed using Cardiovascular Suit. During FMD, laser doppler flowometry (LDF) will also be measured using the index finger of the right arm and analysed for % PORH (post occlusive reactive hyperaemia), measured in flux units .
Measured: 4 hours
Flow mediated dilation (FMD)
A subset of participants will complete FMD assessment prior to each cognitive task battery (baseline, 2, 4 and 6 hours). FMD is a non-invasive ultrasound technique that measures how the brachial artery dilates in response to increased blood flow following occlusion. Participants are required to lie down for 15 minutes before scanning commences. The procedure then takes 9 minutes: the brachial artery is first scanned for 1 minute, a blood pressure cuff is then inflated on the forearm for 5 minutes, before being released and the artery scanned for a further 3 minutes. This data will be analysed using Cardiovascular Suit. During FMD, laser doppler flowometry (LDF) will also be measured using the index finger of the right arm and analysed for % PORH (post occlusive reactive hyperaemia), measured in flux units .
Measured: 6 hours
Raven's Progressive Matrices
The Raven's is a non-verbal intelligence test designed to assess abstract reasoning and fluid intelligence which provides a single score (the sum of correct answers). Ravens will be included in the present study at baseline as a measure of IQ, which may later be utilised as a covariate when analysing the cognitive data.
Measured: Baseline
Epic-Norfolk Food Frequency Questionnaire
The FFQ is a validated tool for gauging the average habitual dietary intake of micro and macronutrients of an individual in the UK. Data will be processed using the FETA software.
Measured: Baseline
Blood pressure
Average (triplicate) resting brachial left arm cuffed systolic and diastolic blood pressure mmHg.
Measured: Baseline
Blood pressure
Average (triplicate) resting brachial left arm cuffed systolic and diastolic blood pressure mmHg.
Measured: 2 hours
Blood pressure
Average (triplicate) resting brachial left arm cuffed systolic and diastolic blood pressure mmHg.
Measured: 4 hours
Blood pressure
Average (triplicate) resting brachial left arm cuffed systolic and diastolic blood pressure mmHg.
Measured: 6 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Mar 2025
- Study start6 Mar 2025
- Primary completionNov 2025 (estimated)
- Study completionFeb 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for CognitionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 52 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Reading
- Sponsor type
- University, hospital or other
- Collaborators
- American Pistachio Growers
- Responsible party
- Principal investigator, Prof Claire Williams, University of Reading
- Investigators
- Claire Williams, PhD, Principal investigator, University of Reading
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06900452
- Sponsor's protocol ID
- 2024-236-CW
- Acronym
- PACVAN
- Status last verified
- May 2025
- First submitted
- 21 Mar 2025
- Last updated
- 7 May 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: All relevant study outcomes described in the Ethics Review Application Form, including demographics, anthropometrics, cognitive performance, blood tests FMD and EEG data, will be preserved and made available via a data repository, such as the University of Reading data repository, in anonymised form, so that they can be consulted and re-used by others.
Study at a glance
From the registry record, last updated by the sponsor on 7 May 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Randomized Controlled Trial to Investigate the Cognitive, Vascular, Neural and Biochemical Effects of Acute Pistachio Intervention in Older Adults
- ClinicalTrials.gov ID
- NCT06900452
- Acronym / sponsor ID
- PACVAN / 2024-236-CW
- Conditions
- Cognition
- Keywords
- Cognition, Pistachios, Vascular, Neural, Inflammation, Mood
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 52 participants (estimated)
- Lead sponsor
- University of ReadingUniversity, hospital or other
- Collaborators
- American Pistachio Growers
- Study start
- 6 Mar 2025 (actual)
- Primary completion
- Nov 2025 (estimated)
- Study completion
- Feb 2026 (estimated)
- First posted
- 28 Mar 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study aims to investigate the effect of a breakfast meal containing varying serving sizes (doses) of pistachio nuts on cognitive function throughout the course of the day in healthy ageing adults aged 65-80.
Detailed description
This crossover RCT investigates the acute postprandial effect (over a 6-hour period) of a breakfast meal containing varying serving sizes (doses) of pistachio nuts on the cognitive behaviour in healthy adults aged 65-80 years old. The study will also assess markers of inflammation and brain health by taking blood samples, and explore brain function (EEG) and blood flow (FMD) to understand how pistachio nuts may positively influence cognitive health. The study will involve a screening visit and four testing visits, with a week interval between each. On the evening prior to each test visit, participants are asked not to consume any food or drinks expect water, including tea/coffee and alcohol, after 8.30pm, and on the morning of test visits to only consume one slice of buttered white toast and a glass of water prior to attending the visit. During the four testing visits, cognitive and mood battery tests will be taken at baseline and then at 2-, 4- and 6-hour intervals following the consumption of the intervention meal. Blood draws are taken at the end of the day. For the subset of participants taking part in FMD, this will be measured at baseline, 2, 4 and 6 hours prior to cognitive testing. For those taking part in EEG, this data will be collected at 6 hours.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Placebo | Placebo comparator | Dietary Supplement: PlaceboMacronutrient-matched placebo breakfast meal |
| 0.5 servings of pistachio | Experimental | Dietary Supplement: 0.5 serving of pistachios0.5 servings of pistachio (15g) administered in breakfast meal |
| 1 serving of pistachio | Experimental | Dietary Supplement: 1 serving of pistachios1 serving of pistachio (30g) administered in breakfast meal |
| 2 servings of pistachio | Experimental | Dietary Supplement: 2 servings of pistachios2 servings of pistachio (60g) administered in breakfast meal |
Who may qualify
- Ages
- 65 to 80 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Older adult
Key inclusion criteria (6 listed)
- 65 - 80 years old
- Fruit \& veg intake less than or equal to 4 servings per day
- Not regularly consuming more than 3 servings of fish per week
- Adequate English language and visual \& auditory acuity to perform the cognitive tasks
- Normal BMI for age
Key exclusion criteria (8 listed)
- Being diagnosed with psychological or psychiatric disorders
- ADHD or dyslexia
- Any food allergy or intolerance
- Use of medications and dietary supplements that may impact study results
- Antibiotic use within the last 3 months
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| 0.5 serving of pistachiosThe equivalent of 0.5 servings (15g) of shelled, roasted pistachio nuts, crushed and mixed into a muesli-based breakfast meal for consumption. Ingredients: 15g pistachio, 35g muesli base, 150g full fat natural yoghurt, 15g unsalted butter (melted), 10g unflavoured whey powder | Dietary supplement | 0.5 servings of pistachio |
| 1 serving of pistachiosThe equivalent of 1 serving (30g) of shelled, roasted pistachio nuts, crushed and mixed into a muesli-based breakfast meal for consumption. Ingredients: 30g pistachio, 35g muesli base, 150g full fat natural yoghurt, 10g unsalted butter (melted), 5g unflavoured whey powder | Dietary supplement | 1 serving of pistachio |
| 2 servings of pistachiosThe equivalent of 2 servings (60g) of shelled, roasted pistachio nuts, crushed and mixed into a muesli-based breakfast meal for consumption. Ingredients: 60g pistachios, 25g muesli base, 150g low fat natural yoghurt | Dietary supplement | 2 servings of pistachio |
| PlaceboMacronutrient-matched placebo breakfast meal. Ingredients: 40g muesli base, 150g full fat natural yoghurt, 25g unsalted butter (melted), 15g unflavoured whey powder | Dietary supplement | Placebo |
Primary outcome
Delayed recall (Rey Auditory Verbal Learning Task)
Time frame: Baseline
The RAVLT is a verbal learning task that presents participants with 15 words (list A) 5 times, giving participants one minute after each presentation to recall as many words as they can from the list. After 5 presentations, a new list (list B) is presented and recalled, and finally participants are asked (without hearing list A again) to recall as many words as they can from list A. After a 30 minute period, participants are asked to think back to the task and recall as many words as possible from list A only, providing a measure of delayed recall.
Delayed recall (Rey Auditory Verbal Learning Task)
Time frame: 2 hours
The RAVLT is a verbal learning task that presents participants with 15 words (list A) 5 times, giving participants one minute after each presentation to recall as many words as they can from the list. After 5 presentations, a new list (list B) is presented and recalled, and finally participants are asked (without hearing list A again) to recall as many words as they can from list A. After a 30 minute period, participants are asked to think back to the task and recall as many words as possible from list A only, providing a measure of delayed recall.
Delayed recall (Rey Auditory Verbal Learning Task)
Time frame: 4 hours
The RAVLT is a verbal learning task that presents participants with 15 words (list A) 5 times, giving participants one minute after each presentation to recall as many words as they can from the list. After 5 presentations, a new list (list B) is presented and recalled, and finally participants are asked (without hearing list A again) to recall as many words as they can from list A. After a 30 minute period, participants are asked to think back to the task and recall as many words as possible from list A only, providing a measure of delayed recall.
Delayed recall (Rey Auditory Verbal Learning Task)
Time frame: 6 hours
The RAVLT is a verbal learning task that presents participants with 15 words (list A) 5 times, giving participants one minute after each presentation to recall as many words as they can from the list. After 5 presentations, a new list (list B) is presented and recalled, and finally participants are asked (without hearing list A again) to recall as many words as they can from list A. After a 30 minute period, participants are asked to think back to the task and recall as many words as possible from list A only, providing a measure of delayed recall.
36 secondary outcomes
Rate of learning (Rey Auditory Verbal Learning Task)
Time frame: Baseline
Rate of learning (Rey Auditory Verbal Learning Task)
Time frame: 2 hours
Rate of learning (Rey Auditory Verbal Learning Task)
Time frame: 4 hours
Rate of learning (Rey Auditory Verbal Learning Task)
Time frame: 6 hours
Word recognition (Rey Auditory Verbal Learning Task)
Time frame: Baseline
Word recognition (Rey Auditory Verbal Learning Task)
Time frame: 2 hours
Word recognition (Rey Auditory Verbal Learning Task)
Time frame: 4 hours
Word recognition (Rey Auditory Verbal Learning Task)
Time frame: 6 hours
Modified Attention Network Task (MANT)
Time frame: Baseline
Modified Attention Network Task (MANT)
Time frame: 2 hours
Modified Attention Network Task (MANT)
Time frame: 4 hours
Modified Attention Network Task (MANT)
Time frame: 6 hours
Task Switching Task
Time frame: Baseline
Task Switching Task
Time frame: 2 hours
Task Switching Task
Time frame: 4 hours
Task Switching Task
Time frame: 6 hours
Corsi Block Tapping Task
Time frame: Baseline
Corsi Block Tapping Task
Time frame: 2 hours
Corsi Block Tapping Task
Time frame: 4 hours
Corsi Block Tapping Task
Time frame: 6 hours
N-back task
Time frame: Baseline
N-back task
Time frame: 2 hours
N-back task
Time frame: 4 hours
N-back task
Time frame: 6 hours
EEG (ERPs & PSD)
Time frame: 6 hours
Blood markers
Time frame: 6 hours
Flow mediated dilation (FMD)
Time frame: Baseline
Flow mediated dilation (FMD)
Time frame: 2 hours
Flow mediated dilation (FMD)
Time frame: 4 hours
Flow mediated dilation (FMD)
Time frame: 6 hours
Raven's Progressive Matrices
Time frame: Baseline
Epic-Norfolk Food Frequency Questionnaire
Time frame: Baseline
Blood pressure
Time frame: Baseline
Blood pressure
Time frame: 2 hours
Blood pressure
Time frame: 4 hours
Blood pressure
Time frame: 6 hours
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 May 2025.
- Individual participant dataSharing planned: Yes. All relevant study outcomes described in the Ethics Review Application Form, including demographics, anthropometrics, cognitive performance, blood tests FMD and EEG data, will be preserved and made available via a data repository, such as the University of Reading data repository, in anonymised form, so that they can be consulted and re-used by others.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Claire Williams, PhD principal investigator
University of Reading
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing 0.5 serving of pistachios, 1 serving of pistachios and 2 servings of pistachios in people with Cognition, run by University of Reading at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 7 May 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Claire Williams, PhD (0118 378 7540, claire.williams@reading.ac.uk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Delayed recall (Rey Auditory Verbal Learning Task) (time frame: Baseline). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 7 May 2025.