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.
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.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
DOUBLE
Enrollment
53
Powdered extract obtained from wild blueberries. A daily administration of 27g wild blueberry powder will be administered.
Identical formulation as the treatment matched for fibre and vitamin C
Franklin-Wilkins Building, King's College London
London, United Kingdom
Endothelial Function
Changes in flow-mediated dilation of the brachial artery (FMD) from baseline after 12-week consumption of blueberry vs control
Time frame: Baseline and 12 weeks post-intervention
Cognitive function
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 Auditory Verbal learning task, Corsi Blocks, Switching task and Serials 3's and 7's, including a mood assessment (PANAS).
Time frame: Baseline and 12 weeks post-intervention
Cerebral blood flow velocity (CBFv)
Changes in cerebral blood flow velocity (CBFv) from baseline after 12-week consumption of blueberry vs control. Trans-cranial blood flow will be assessed by Non-imaging transcranial Doppler sonography (TCD). Variables measured include resting and active mean blood flow velocity (cm/s).
Time frame: Baseline and 12 weeks post-intervention
Office systolic blood pressure
Changes from baseline office systolic blood pressure (mmHg) after 12-week consumption of blueberry vs control.
Time frame: Baseline and 12 weeks post-intervention
Pulse wave velocity (PWV)
Determine the changes in Pulse wave velocity (PWV) from baseline after 12-week consumption of blueberry vs control.
Time frame: Baseline and 12 weeks post-intervention
Augmentation Index (AIx)
Changes in augmentation Index (AIx) using a Sphygmocor device post consumption of a placebo or blueberry treatment
Time frame: Baseline and 12 weeks post-intervention
24-hour ambulatory systolic blood pressure
Determine the effect of the blueberry extract vs Placebo on 24-hour systolic blood pressure using a monitor, at 12 weeks post consumption. Variables include mean asleep, awake and total 24 h systolic blood pressure
Time frame: Baseline and 12 weeks post-intervention
Mood
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. Dependent variables are composite positive affect and negative affect scores obtained by summing responses to positive or negative PANAS items, respectively.
Time frame: Baseline and 12 weeks post-intervention
Change in Blood lipids concentration (Total, HDL and LDL cholesterol, triglycerides)
Determine the effect of the blueberry extract vs Placebo on blood lipids (Total, HDL and LDL cholesterol, triglycerides), at 12 weeks post consumption.
Time frame: Baseline and 12 weeks post-intervention
Plasma blueberry (poly)phenol metabolites
Measured by liquid chromotography- mass spectrometry (LC/MS) 0 and 2 hours post consumption
Time frame: Baseline and 12 weeks post-intervention
Microbiome analysis
Stool sample collection involving an all-in-one kit for self-collection and stabilization of microbial DNA from faeces for gut microbiome profiling.
Time frame: Baseline and 12 weeks post-intervention
Urine blueberry polyphenol metabolites
Collected over a 24 hour period. Measured by liquid chromotography- mass spectrometry (LC/MS) 0 and 2 hours post consumption
Time frame: Baseline and 12 weeks post-intervention
Number of volunteers with treatment-related adverse events
The number of volunteers with treatment-related adverse events will be assessed by questionnaires and interviews.
Time frame: Baseline and 12 weeks post-intervention
Pulsatility index (PI)
Changes in pulsatility index (PI) from baseline after 12-week consumption of blueberry vs control. Trans-cranial blood flow will be assessed by Non-imaging transcranial Doppler sonography (TCD). Variables measured include resting and active PI (cm/s.
Time frame: Baseline and 12 weeks post-intervention
Office diastolic blood pressure
Changes from baseline office diastolic blood pressure (mmHg) after 12-week consumption of blueberry vs control.
Time frame: Baseline and 12 weeks post-intervention
24-hour ambulatory diastolic blood pressure
Determine the effect of the blueberry extract vs Placebo on 24-hour diastolic blood pressure using a monitor, at 12 weeks post consumption. Variables include mean asleep, awake and total 24 h diastolic blood pressure
Time frame: Baseline and 12 weeks post-intervention
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.