The Effects of a Single Dose of Wild Blueberries on Mood and Cognition in Healthy Young Adults

NCT04935099 | Completed

• 1 other identifier: 21/09
• Study Type: interventional
• Target: 33
• Locations: 1 country
• Sites: 1

Brief Summary

This study aims to investigate whether consuming a drink containing powdered blueberries (equivalent to 150 g fresh fruit) can improve mood and cognition in healthy young adults. Blood biomarkers of inflammation and neurotransmitter turnover will be analyzed as well as responses to computer-based cognitive tasks designed to measure verbal memory, executive function, and emotional processing.

Conditions

Mood; Affect; Cognition

Keywords

blueberry; anthocyanins; flavonoids

Outcome Measures

Primary Outcomes (10)

• Global transient mood as measured by PANAS-X

  The Positive and Negative Affect Schedule - Expanded Form (PANAS-X) is a validated, self-rated measure of affective state, encompassing two general dimensions (positive and negative affect). These will be calculated separately by adding the values of the individual items (21 positive and 25 negative items). Thus, the scales will range from 0 to 84 points for positive affect and from 0 to 100 for negative affect, with a higher score indicating greater positive or negative affect. Positive affect will be considered the primary measure.

  baseline

• Global transient mood as measured by PANAS-X

  The Positive and Negative Affect Schedule - Expanded Form (PANAS-X) is a validated, self-rated measure of affective state, encompassing two general dimensions (positive and negative affect). These will be calculated separately by adding the values of the individual items (21 positive and 25 negative items). Thus, the scales will range from 0 to 84 points for positive affect and from 0 to 100 for negative affect, with a higher score indicating greater positive or negative affect. Positive affect will be considered the primary measure

  2 hours post-ingestion

• Negative interpretation bias

  A negative interpretation bias is defined as a tendency to interpret ambiguous information in a consistently threatening or negative manner, thus serving as an objective indicator of affective state. In this task, participants will be asked to categorize facial expressions of anger, happiness, and surprise as either positive or negative. Interpretation bias will be operationalized as the percent of trials in which surprised faces were rated as negative, out of the total number of surprise trials (48 trials).

  baseline

• Negative interpretation bias

  A negative interpretation bias is defined as a tendency to interpret ambiguous information in a consistently threatening or negative manner, thus serving as an objective indicator of affective state. In this task, participants will be asked to categorize facial expressions of anger, happiness, and surprise as either positive or negative. Interpretation bias will be operationalized as the percent of trials in which surprised faces were rated as negative, out of the total number of surprise trials (48 trials).

  2 hours post-ingestion

• Cognitive flexibility (accuracy on post-switch trials)

  A task-switching test will be used to assess cognitive performance when switching between two predictable tasks requiring simple numerical decisions. The main outcome of interest is the average accuracy of responses to post-switch trials (those immediately following a switch to a new task).

  baseline

• Cognitive flexibility (accuracy on post-switch trials)

  A task-switching test will be used to assess cognitive performance when switching between two predictable tasks requiring simple numerical decisions. The main outcome of interest is the average accuracy of responses to post-switch trials (those immediately following a switch to a new task).

  2 hours post-ingestion

• Delayed verbal memory on RAVLT

  The Rey Auditory Verbal Learning Test (RAVLT) is a standard neuropsychological assessment designed to evaluate verbal memory. The participant hears a list of 15 words and is asked to recall as many words as possible. This procedure is repeated five times. The main outcome of interest is the number of correctly recalled words 20 minutes after the last presentation of the list of words (Trial A7).

  baseline

• Delayed verbal memory on RAVLT

  The Rey Auditory Verbal Learning Test (RAVLT) is a standard neuropsychological assessment designed to evaluate verbal memory. The participant hears a list of 15 words and is asked to recall as many words as possible. This procedure is repeated five times. The main outcome of interest is the number of correctly recalled words 20 minutes after the last presentation of the list of words (Trial A7).

  2 hours post-ingestion

• Serum brain-derived neurotrophic factor (BDNF)

  Serum levels of BDNF will be analyzed using enzyme-linked immunosorbent assay (ELISA).

  baseline

• Serum brain-derived neurotrophic factor (BDNF)

  Serum levels of BDNF will be analyzed using enzyme-linked immunosorbent assay (ELISA).

  2 hours post-ingestion

Secondary Outcomes (34)

• Distinct affective states as measured by PANAS-X subscales

  baseline

• Distinct affective states as measured by PANAS-X subscales

  2 hours post-ingestion

• Reaction time to positive stimuli

  baseline

• Reaction time to positive stimuli

  2 hours post-ingestion

• Reaction time to negative stimuli

  baseline

Other Outcomes (2)

• Recognition memory on RAVLT

  baseline

• Recognition memory on RAVLT

  2 hours post-ingestion

Study Arms (2)

Blueberry/Placebo

EXPERIMENTAL

In this arm, participants will receive the blueberry intervention first, followed by the placebo one week later.

Dietary Supplement: Wild blueberry powder; Dietary Supplement: Placebo powder

Placebo/Blueberry

EXPERIMENTAL

In this arm, participants will receive the placebo first, followed by the blueberry intervention one week later.

Dietary Supplement: Wild blueberry powder; Dietary Supplement: Placebo powder

Interventions

Wild blueberry powder DIETARY_SUPPLEMENT

22 g freeze-dried wild blueberry (Vaccinium angustifolium) powder, mixed with 250 ml water, and served in an opaque container.

Blueberry/Placebo; Placebo/Blueberry

Placebo powder DIETARY_SUPPLEMENT

22 g placebo powder matched for macronutrients and flavor, mixed with 250 ml water, and served in an opaque container.

Blueberry/Placebo; Placebo/Blueberry

Eligibility Criteria

• Age: 18 Years - 25 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• to 25 years of age
• Willingness to provide blood samples

You may not qualify if:

• Allergy to blueberries or any other Vaccinium species
• Diagnosis or symptoms of anxiety, depression, or other mental health conditions
• Any medically significant condition (e.g. anemia, gastrointestinal disorders, diabetes)
• Use of psychoactive medication or recreational drugs in the last two weeks
• Current use of medication that could interact with the intervention (e.g. antibiotics)
• Obesity or underweight
• Participation in other interventional studies in the last month
• Pregnancy or lactation

Sponsors & Collaborators

• University of Reading: lead
• Wild Blueberry Association of North America: collaborator

Study Sites (1)

School of Psychology and Clinical Languages, University of Reading

Reading, Berkshire, RG6 6AL, United Kingdom

Location

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Study Record Dates

• First Submitted: May 27, 2021
• First Posted: June 22, 2021
• Study Start: May 26, 2021
• Primary Completion: August 27, 2021
• Study Completion: August 27, 2021
• Last Updated: September 21, 2021

Record last verified: 2021-09

Data Sharing

• IPD Sharing: Will share
• Shared Documents: SAP

Locations

GB (1)