Investigating the Effects of Daily Consumption of Blueberry (Poly)Phenols on Vascular Function and Cognitive Performance

Overview

Foods rich in certain (poly)phenols, particularly flavonoids, such as berries and cocoa, have been shown to improve measures of vascular function as well as cognitive performance in human intervention studies. This is a randomized, double-blind, placebo controlled, parallel trial investigating the effects of daily blueberry (poly)phenol consumption on vascular function and cognitive performance in healthy elderly individuals. The study will be conducted at King's College London, Franklin-Wilkins Building.

Eligible subjects will be healthy males and females aged 65-80.

Full Title of Study: “Randomised, Double-blind, Placebo Controlled, Parallel Trial Investigating the Daily Effects of Blueberry (Poly)Phenol Consumption on Vascular Function and Cognitive Performance in Healthy Elderly Individuals”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Randomized
    • Intervention Model: Parallel Assignment
    • Primary Purpose: Basic Science
    • Masking: Double (Participant, Investigator)
  • Study Primary Completion Date: September 2020

Detailed Description

To date no study has investigated whether daily blueberry consumption can induce an increase in cerebral blood flow, with subsequent improvements in vascular and cognitive function. In this study, the investigators aim to directly link daily blueberry consumption with improved vascular function, increased cerebral blood flow and positive cognitive outcomes in healthy elderly individuals. The investigators will use a large group of elderly individuals' representative of a healthy population, both males and females, aged 65-80 years to evaluate the health effects of daily blueberry consumption.

The main aim is to investigate whether improvements in vascular and cognitive function previously seen after blueberry consumption can be seen following 3-months daily consumption in elderly individuals, and whether enhanced cognitive performance is correlated with increased cerebral blood flow. The investigators hypothesise that daily consumption of an anthocyanin rich blueberry drink will improve cognitive performance and vascular function, increasing cerebral blood flow, in healthy older individuals.

Interventions

  • Dietary Supplement: Wild Blueberry powder
    • Powdered extract obtained from wild blueberries. A daily administration of 27g wild blueberry powder will be administered.
  • Dietary Supplement: Placebo
    • Identical formulation as the treatment matched for fibre and vitamin C

Arms, Groups and Cohorts

  • Placebo Comparator: Placebo
    • Matched for macronutrients, micronutrients and fibre
  • Active Comparator: Wild Blueberry Powder
    • Formulation of a 100% blueberry (freeze-dried whole fruit) drink

Clinical Trial Outcome Measures

Primary Measures

  • Endothelial Function
    • Time Frame: Baseline and 12 weeks
    • Changes in flow-mediated dilation of the brachial artery (FMD) from baseline after 12-week consumption of blueberry vs control
  • Cognitive function
    • Time Frame: Baseline and 12 weeks
    • Changes in cognitive function from baseline after 12-week consumption of blueberry vs control.Cognitive testing involves the participant conducting tasks administered on a tablet-style laptop. The participants will be conducting these tasks whilst cerebral blood flow measurements are taking place. The cognitive testing battery will consist of 4 tasks which are Audiroty Verbal learning task, Corsi Blocks, Switching task and Serials 3′s and 7′s, including a mood assessment (PANAS).

Secondary Measures

  • Cerebral blood flow (CBF)
    • Time Frame: Baseline 0 and 2 hours (post-consumption) and 12 weeks 0 and 2 hours post consumption
    • Changes in cerebral blood flow (CBF) from baseline after 12-week consumption of blueberry vs control. Trans-cranial blood flow will be assessed by Non-imaging transcranial Doppler sonography (TCD)
  • Ambulatory blood pressure
    • Time Frame: Baseline 0 and 2 hours (post-consumption) and 12 weeks 0 and 2 hours post consumption
    • Changes from baseline ambulatory blood pressure after 12-week consumption of blueberry vs control. Systolic and diastolic will be recorded.
  • Pulse wave velocity (PWV)
    • Time Frame: Baseline 0 and 2 hours (post-consumption) and 12 weeks 0 and 2 hours post consumption
    • Determine the changes in Pulse wave velocity (PWV) from baseline after 12-week consumption of blueberry vs control.
  • Augmentation Index (AIx)
    • Time Frame: Baseline 0 and 2 hours (post-consumption) and 12 weeks 0 and 2 hours post consumption
    • Changes in augmentation Index (AIx) using a Sphygmocor device post consumption of a placebo or blueberry treatment
  • 24-hour heart rate
    • Time Frame: Baseline and 12 weeks
    • Determine the effect of the blueberry extract vs Placebo on 24-hour heart rate, using a monitor, at 12 weeks post consumption
  • Blood flow velocity
    • Time Frame: Baseline and 12 weeks
    • Determine the effect of the Blueberry extract vs Placebo on blood flow velocity at 12 weeks post consumption.
  • Mood
    • Time Frame: Baseline (0 and 2 hours) and 12 weeks (0 and 2 hours)
    • Assessment using a self-reported questionnaire using the Positive and Negative Affect Schedule (PANAS).PANAS (The Positive and Negative Affect Schedule) to measure mood, where the participants will need to answer 20 questions using a 5-point likert scale that ranges from (1) not at all to (5) extremely
  • Change in Blood lipids concentration (Total, HDL and LDL cholesterol, triglycerides)
    • Time Frame: Baseline (0 and 2 hours) and 12 weeks (0 and 2 hours).
    • Determine the effect of the blueberry extract vs Placebo on blood lipids (Total, HDL and LDL cholesterol, triglycerides), at 12 weeks post consumption.
  • Plasma blueberry (poly)phenol metabolites
    • Time Frame: Baseline (0 and 2 hours) and 12 weeks (0 and 2 hours)
    • Measured by liquid chromotography- mass spectrometry (LC/MS) 0 and 2 hours post consumption
  • Microbiome analysis
    • Time Frame: Baseline and 12 weeks
    • Stool sample collection involving an all-in-one kit for self-collection and stabilization of microbial DNA from faeces for gut microbiome profiling.
  • Change in blood cortisol levels
    • Time Frame: Baseline and 12 weeks
    • Determine the changes on blood cortisol levels after 12 weeks consumption of blueberry vs control.
  • Number of volunteers with treatment-related adverse events
    • Time Frame: Baseline and 12 weeks
    • The number of volunteers with treatment-related adverse events will be assessed by questionnaires and interviews.
  • Urine blueberry polyphenol metabolites
    • Time Frame: Baseline and 12 weeks
    • Collected over a 24 hour period. Measured by liquid chromotography- mass spectrometry (LC/MS) 0 and 2 hours post consumption
  • Acute effects of treatment on endothelial function
    • Time Frame: Baseline and 2 hours post consumption
    • Changes in flow-mediated dilation of the brachial artery (FMD) 2 hours post consumption of blueberry vs control
  • Acute effects of treatment on cognitive function
    • Time Frame: Baseline and 2 hours post consumption
    • Changes in cognitive function from baseline after 2 hours consumption of blueberry treatment. Cognitive testing involves the participant conducting tasks administered on a tablet-style laptop. The participants will be conducting these tasks whilst cerebral blood flow measurements are taking place. The cognitive testing battery will consist of 4 tasks which are Auditory Verbal learning task, Corsi Blocks, Switching task and Serials 3′s and 7′s, including a mood assessment (PANAS).

Participating in This Clinical Trial

Inclusion Criteria

  • Participants will include 60 healthy male and female volunteers, aged 65-80.
  • Volunteers will be able to understand the nature of the study and able to give signed written informed consent.
  • Subjects willing to maintain their normal eating/drinking habits and exercise habits to avoid changes in body weight over the duration of the study.

Exclusion Criteria

  • Manifest cardiovascular diseases including coronary artery disease, cerebrovascular disease and peripheral artery disease.
  • Hypertensive, as defined as SBP superior or equal to 140 mmHg or DBP superior or equal to 90 mmHg.
  • Obese participants, defined as BMI superior or equal to 30.
  • Diabetes mellitus and metabolic syndrome.
  • Acute inflammation, terminal renal failure or malignancies.
  • Allergies to berries or another significant food allergy.
  • Subjects under medication or on vitamin/dietary supplements (within 2 weeks of baseline).
  • Subjects who have lost more than 10% of their weight in the past 6 months or are currently on a diet.
  • Subjects who reported participant in another study within one month before the study starts.
  • Subjects who smoke cigarettes irregularly.
  • MCI or dyslexic or unable to complete the cognitive function tasks for any reason such as visual impairments.
  • Subjects who require chronic antimicrobial or antiviral treatment.
  • Subjects with unstable psychological condition.
  • Subjects with history of cancer, myocardial infarction, cerebrovascular incident.
  • Any reason or condition that in the judgment of the clinical investigator(s) may put the subject at unacceptable risk or that may preclude the subject from understanding or complying with the study's requirements.

Gender Eligibility: All

Minimum Age: 65 Years

Maximum Age: 80 Years

Are Healthy Volunteers Accepted: Accepts Healthy Volunteers

Investigator Details

  • Lead Sponsor
    • King’s College London
  • Collaborator
    • University of Reading
  • Provider of Information About this Clinical Study
    • Principal Investigator: Dr Ana Rodriguez-Mateos, Principal Investigator – King’s College London
  • Overall Contact(s)
    • Ana Rodriguez-Mateos, PhD, +44 (0)20 7848 4349, ana.rodriguez-mateos@kcl.ac.uk

Clinical trials entries are delivered from the US National Institutes of Health and are not reviewed separately by this site. Please see the identifier information above for retrieving further details from the government database.

At TrialBulletin.com, we keep tabs on over 200,000 clinical trials in the US and abroad, using medical data supplied directly by the US National Institutes of Health. Please see the About and Contact page for details.