Condition category
Nutritional, Metabolic, Endocrine
Date applied
08/09/2017
Date assigned
24/10/2017
Last edited
10/10/2017
Prospective/Retrospective
Retrospectively registered
Overall trial status
Completed
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
There is a growing interest in the biological activity of the root vegetable, red beetroot (Beta vulgaris rubra) and its health benefits as a functional food. Research is largely focused on the nitrate content of beetroot, which provides a natural means of increasing the availability of nitric oxide (NO). Many age-related degenerative diseases are associated with reduced NO bioavailability, such as hypertension and dementia, and beetroot is being considered as a promising treatment to slow down the progression of these diseases. In addition to nitrate, beetroot is also rich in phenolic compounds and a water-soluble group of phytochemicals called betalains. Betalains and phenolic compounds are potent antioxidants and display anti-inflammatory properties. Ageing is associated with increased oxidative damage and a diminished availability of whole-body NO. The aim of this study is to compare the bioavailability of phenolic compounds, betalain and inorganic nitrate after the ingestion of three incremental portions of whole beetroot in healthy younger and older adults.

Who can participate?
Males aged between 18 to 35 and 60 to 75 who are free of chronic illnesses.

What does the study involve?
Participants are randomly allocated to an order to receive one of four different treatments (100g beetroot, 200g beetroot, 300g beetroot, a dose of inorganic nitrate as a positive control). The duration of each intervention is five hours. The washout period between each phase will be one week. The difference in bioavailability of nitrate, phenolic compounds and betalains between younger and older subjects is assessed. Participants are also assessed for their blood pressure, blood flow, exhaled nitric oxide and tolerability to the interventions.

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?
Royal Victoria Infirmary (UK)

When is the study starting and how long is it expected to run for?
June 2016 to December 2017

Who is funding the study?
1. Gs Fresh Ltd (UK)
2. Newcastle University (UK)

Who is the main contact?
Miss Tess Capper
Professor Emma Stevenson

Trial website

Contact information

Type

Public

Primary contact

Miss Tess Capper

ORCID ID

Contact details

4th Floor William Leech Building
Medical School
Newcastle University
Newcastle upon Tyne
NE2 4HH
United Kingdom

Type

Scientific

Additional contact

Prof Emma Stevenson

ORCID ID

Contact details

4th Floor William Leech Building
Medical School
Newcastle University
Newcastle upon Tyne
NE2 4HH
United Kingdom

Additional identifiers

EudraCT number

ClinicalTrials.gov number

Protocol/serial number

7985

Study information

Scientific title

Bioavailability of phenolic compounds, betalain and inorganic nitrate following incremental portions of whole beetroot in older and younger adults

Acronym

Beetroot study

Study hypothesis

We hypothesise that, due to possible changes in the oral bacteria and microbiome of older adults, the bioavailability of nitrate, betalains and phenolic compounds from whole beetroot will be less in older adults than in younger adults. We do, however, predict a trend towards a dose-response to incremental portions, with higher amounts of beetroot causing an increased bioavailability of the compounds contained within it in both populations, despite an inter-individual variation. Due to a reduction in whole-body NO, it is predicted that the positive effect on vascular function associated with nitrate will be reduced in the older population. We expect that the response to the potassium nitrate will be higher than that of the beetroot, eliciting greater reductions in blood pressure and improved blood flow. We hypothesise that the vascular response to the beetroot will be greater with higher quantities in both populations

Ethics approval

Cambridge Central NRES Committee, East of England, 26/09/2016, ref: 16/EE/0376

Study design

Acute 4-arm randomised crossover intervention study

Primary study design

Interventional

Secondary study design

Randomised cross over trial

Trial setting

Hospitals

Trial type

Other

Patient information sheet

See additional files

Condition

Age-related degenerative diseases

Intervention

Participants are randomised using a Latin-Square method. Participants are allocated in a random order to receive the four interventions.

The four interventions include:
1. 100g whole pre-cooked beetroot
2. 200g whole pre-cooked beetroot
3. 300g whole pre-cooked beetroot
4. 200ml potassium nitrate solution.

Participants are asked to consume the supplement within 15 minutes after baseline testing, and measurements will be taken for 5 hours post-supplementation. The duration of each intervention will be five hours. The washout period between each phase will be one week.

Intervention type

Supplement

Phase

Drug names

Primary outcome measures

Differences in bioavailability of nitrate between incremental doses of beetroot and compared to a standard dose of potassium nitrate at five hours.

Secondary outcome measures

1. Differences in changes in blood pressure following each dose of nitrate supplementation and compared to a standard dose of potassium nitrate at five hours
2. Differences in changes in endothelial function following each dose of nitrate supplementation and compared to a standard dose of potassium nitrate at five hours
3. Differences in changes in exhaled nitric oxide following each dose of nitrate supplementation and compared to a standard dose of potassium nitrate at five hours
4. Differences in bioavailability of betalains and phenolic compounds between incremental doses of beetroot and compared to a standard dose of potassium nitrate at five hours

Overall trial start date

01/06/2016

Overall trial end date

22/12/2017

Reason abandoned

Eligibility

Participant inclusion criteria

1. Non-obese
2. Non-smoker
3. Males aged between 18 and 35 or 60 and 75
4. Free of chronic illness

Participant type

Healthy volunteer

Age group

Adult

Gender

Male

Target number of participants

30

Participant exclusion criteria

1. Vegetarianism
2. High blood pressure
3. Active cancer and any diagnosis of malignant cancer in the last 5 years
4. Diagnosis of chronic and acute metabolic and inflammatory conditions interfering with the study outcome
5. Medications that may have an effect on NO production
6. Hormonal therapies, statins and psychiatric drugs if dose started/changed in previous 3 months
7. Haematological disorders
8. History of repetitive gastric reflux
9. Excessive alcohol intake
10. Allergy or intolerance to the intervention food
11. Under the age of 18
12. Smoker

Recruitment start date

01/12/2016

Recruitment end date

17/11/2017

Locations

Countries of recruitment

United Kingdom

Trial participating centre

Royal Victoria Infirmary
Newcastle upon Tyne
NE1 4LP
United Kingdom

Sponsor information

Organisation

Newcastle upon Tyne Hospitals NHS Foundation Trust

Sponsor details

Level 1
Regent Point
Regent Farm Road
Gosforth
Newcastle upon Tyne
NE3 3HD
United Kingdom

Sponsor type

Research organisation

Website

http://www.newcastlejro.org.uk/

Funders

Funder type

Industry

Funder name

Gs Fresh Ltd

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Funder name

Newcastle University

Alternative name(s)

Funding Body Type

private sector organisation

Funding Body Subtype

academic

Location

United Kingdom

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 is not expected to be made available due to not being able to be made available online.

Intention to publish date

22/12/2018

Participant level data

Not expected to be available

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes