Condition category
Digestive System
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

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,
Professor Emma Stevenson,

Trial website

Contact information



Primary contact

Miss Tess Capper


Contact details

M4.076 William Leech Building
Framlington Place
Newcastle University
Newcastle upon Tyne
United Kingdom

Additional identifiers

EudraCT number

Nil known number

Nil known

Protocol/serial number


Study information

Scientific title

Investigating the effects of an eight-week intervention with whole beetroot on cognitive function, functional capacity and gut health in older adults


Study hypothesis

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

Ethics approval

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;

Study design

Randomised two-armed open-label parallel intervention trial

Primary study design


Secondary study design

Randomised parallel trial

Trial setting


Trial type

Quality of life

Patient information sheet

Not available in web format, please use contact details to request a participant information sheet


Digestive health


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 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).

Intervention type



Drug names

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

Participant type

Healthy volunteer

Age group




Target number of participants


Participant exclusion criteria

1. Vegetarianism
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
6. Smoking
8. Epilepsy
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

United Kingdom

Trial participating centre

NU-Food Research Centre
School of Natural and Environmental Sciences Agriculture Building King's Road Newcastle University
Newcastle upon Tyne
United Kingdom

Sponsor information


Newcastle University

Sponsor details

Newcastle upon Tyne
Newcastle upon Tyne
United Kingdom
0191 208 6000

Sponsor type




Funder type


Funder name

G's Fresh Ltd.

Alternative name(s)

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)

Publication list

Publication citations

Additional files

Editorial Notes

20/01/2020: The basic results of this trial have been uploaded as an additional file. 04/10/2019: The following changes have been made: 1. The public contact's details have been updated. 2. The intention to publish date has been changed from 15/04/2019 to 31/12/2019. 19/03/2019: Trial’s existence confirmed by IRB