The Effects of a Single Dose of Wild Blueberries on Mood and Cognition in Healthy Young Adults: a Randomized, Double-blind, Placebo-controlled, Crossover Study
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 33
- 试验地点
- 2
- 主要终点
- Negative interpretation bias
研究概览
简要总结
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.
详细描述
The present study will examine the psychological effects of a single dose of freeze-dried wild blueberries using a randomized, double-blind, placebo-controlled, counterbalanced, crossover design. A total of 30 healthy young adults will consume two drinks: one containing 22 g blueberry powder and the other containing 22 g matched placebo powder in counterbalanced order one week apart. The investigators will assess changes in transient mood, cognitive-emotional function, and serum biomarkers of inflammation, neuroplasticity, and monoamine metabolism from baseline to 2 hours post-ingestion.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Treatment
- 盲法
- Triple (Participant, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 25 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •18 to 25 years of age
- •Willingness to provide blood samples
排除标准
- •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
结局指标
主要结局
Negative interpretation bias
时间窗: 2 hours post-ingestion
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).
Global transient mood as measured by PANAS-X
时间窗: 2 hours post-ingestion
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
Cognitive flexibility (accuracy on post-switch trials)
时间窗: 2 hours post-ingestion
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).
Delayed verbal memory on RAVLT
时间窗: 2 hours post-ingestion
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).
Serum brain-derived neurotrophic factor (BDNF)
时间窗: 2 hours post-ingestion
Serum levels of BDNF will be analyzed using enzyme-linked immunosorbent assay (ELISA).
次要结局
- Distinct affective states as measured by PANAS-X subscales(2 hours post-ingestion)
- Reaction time to positive stimuli(2 hours post-ingestion)
- Recall of interference list on RAVLT(2 hours post-ingestion)
- Serum monoamine oxidase B (MAO-B) inhibition(2 hours post-ingestion)
- Reaction time to negative stimuli(2 hours post-ingestion)
- Attentional bias to emotional information(2 hours post-ingestion)
- Choice reaction time (post-switch trials)(2 hours post-ingestion)
- Choice reaction time (remaining trials of task-switching test)(2 hours post-ingestion)
- Cognitive flexibility (accuracy on remaining trials of task-switching test)(2 hours post-ingestion)
- Immediate recall on RAVLT(2 hours post-ingestion)
- Proactive interference on RAVLT(2 hours post-ingestion)
- Retroactive interference on RAVLT(2 hours post-ingestion)
- Final acquisition on RAVLT (Trial 5)(2 hours post-ingestion)
- Retention on RAVLT(2 hours post-ingestion)
- Serum interleukin-6 (IL-6)(2 hours post-ingestion)
- Serum C-reactive protein (CRP)(2 hours post-ingestion)
- Serum 3,4-dihydroxyphenylglycol (DHPG)(2 hours post-ingestion)
研究者
Prof Claire Williams
Professor
University of Reading