Plain English Summary
Background and study aims
A reduction in blood flow to the brain is implicated in cognitive decline into older age, therefore the ability to improve blood perfusion to the brain in older adults is likely to impact on cognitive health in this population. Studies have demonstrated heightened regional blood perfusion in the brain following dietary nitrate consumption, which is present in beetroot and other vegetables. Dietary nitrate is converted to nitric oxide in the body, which helps to widen blood vessels in the body. Researchers have demonstrated acute improvements in cognitive performance after a dose of dietary nitrate, however the longer-term effects are currently poorly understood. Furthermore, supplementing with vegetables such as beetroot may increase dietary fibre intake over a prolonged period, leading to changes in gut microbiota. This can have a positive effect on gut health. This research proposal aims to investigate the link between dietary nitrate and cognitive performance and functional capacity in older adults, and assess the effect of dietary supplementation with beetroot on gut microbiota in this population. The main aim of this randomised, two-arm parallel trial is to assess cognitive test scores before and after intervention with beetroot in healthy older adults.
Who can participate?
Males and females between the ages of 60 and 80 years who are free of chronic illness.
What does the study involve?
Participants are randomly allocated to one of two interventions for a duration of eight weeks (150g beetroot plus one banana every second day or one banana every second day). Changes in cognitive test scores before, during and after the intervention period will be assessed. Participants will also be assessed for changes in gut microbiota and gut functioning, blood pressure, and functional capacity.
What are the possible benefits and risks of participating?
Participants may benefit from monetary reimbursement and from undergoing a body composition analysis. There are minor risks. Beetroot consumption can cause beeturia, discolouration of the urine, which is harmless and perfectly normal. Blood sampling can cause some minor bruising.
Where is the study run from?
NU-Food Research Centre, Newcastle University.
When is the study starting and how long is it expected to run?
22/01/2018 to 23/07/2018.
Who is funding the study?
1. G’s Fresh Ltd (UK)
2. Newcastle University (UK)
Who is the main contact?
Miss Tess Capper, firstname.lastname@example.org
Professor Emma Stevenson, email@example.com
Miss Tess Capper
M4.076 William Leech Building
Newcastle upon Tyne
Investigating the effects of an eight-week intervention with whole beetroot on cognitive function, functional capacity and gut health in older adults
1. Following beetroot consumption, cognitive test scores will improve
2. Following beetroot consumption, gut microbiota will show increased diversity and thus overall gut functioning will be improved
Approved 05/12/2017, Faculty of Medical Sciences Research Ethics Committee (Newcastle University Medical School, Framlington Place, Newcastle upon Tyne, NE2 4HH; 0191 208 6000; firstname.lastname@example.org)
Randomised two-armed open-label parallel intervention trial
Primary study design
Secondary study design
Randomised parallel trial
Quality of life
Patient information sheet
Not available in web format, please use contact details to request a participant information sheet
Eight weeks of supplementation with 150g whole cooked beetroot every second day plus one banana OR one banana every second day as a control.
Participants were randomised online at randomization.com. Participants were allocated in a random order to receive one of two interventions above. Participants were asked to consume the intervention foods every second day for eight weeks and data was collected at baseline, at 5 weeks (midway) and at 9 weeks (end of study).
Primary outcome measure
Changes in cognitive test scores assessed by CogTrack online cognition programme at baseline, 5 and 9 weeks.
Secondary outcome measures
1. Functional capacity measured by timed-up-and-go, grip strength and spirometry at baseline, 5 and 9 weeks
2. Gut microbiome measured by bacterial composition and short-chain fatty acid production at baseline, 5 and 9 weeks
3. Blood pressure measured at baseline, 5 and 9 weeks
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Male or female between the ages of 60 and 80 years
2. In good health i.e. free of chronic illness
3. BMI greater than 20.0kg/m2
Target number of participants
Participant exclusion criteria
2. Vitamin or other dietary supplements – will be stopped for 4 weeks previous
3. Active cancer and any diagnosis of malignant cancer in the last 5 years
4. Excessive alcohol intake
5. Allergy or intolerance to the intervention food
9. Psychoactive medication
10. Mental health issues
11. Repetitive gastric reflux
12. Use of antibiotics in the last month
13. Drugs: corticosteroids, sildenafil, aspirin, anti-hypertensives (Ca2+ channel blockers, ACE inhibitors), diuretics, beta-blockers, antacids, anticoagulants, nitrate-derived agents, and anti-cholinergics. Those on statins and hormone replacement therapy must have had a stable dose over the past 3 months and no changes to dose are to occur during the study
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
NU-Food Research Centre
School of Natural and Environmental Sciences Agriculture Building King's Road Newcastle University
Newcastle upon Tyne
Newcastle upon Tyne
Newcastle upon Tyne
0191 208 6000
G's Fresh Ltd.
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Planned publication in a high-impact peer-reviewed journal
IPD sharing statement:
The datasets generated during and/or analysed during the current study are not expected to be made available
Intention to publish date
Participant level data
Not expected to be available
Basic results (scientific)
See additional file (ISRCTN37389799_BasicResults_16Jan20)
- ISRCTN37389799_BasicResults_16Jan20.pdf uploaded 20/01/2020