Bioavailability of beetroot compounds in older adults
| ISRCTN | ISRCTN86706442 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN86706442 |
| Secondary identifying numbers | 7985 |
- Submission date
- 08/09/2017
- Registration date
- 24/10/2017
- Last edited
- 08/11/2023
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Nutritional, Metabolic, Endocrine
Plain English summary of protocol
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 years and 60 to 75 years 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
Contact information
Public
4th Floor William Leech Building
Medical School
Newcastle University
Newcastle upon Tyne
NE2 4HH
United Kingdom
Scientific
4th Floor William Leech Building
Medical School
Newcastle University
Newcastle upon Tyne
NE2 4HH
United Kingdom
Study information
| Study design | Acute 4-arm randomized crossover intervention study |
|---|---|
| Primary study design | Interventional |
| Secondary study design | Randomised cross over trial |
| Study setting(s) | Hospital |
| Study type | Other |
| Participant information sheet | ISRCTN86706442_PIS_v4.0_24Oct16.pdf |
| Scientific title | Bioavailability of phenolic compounds, betalain and inorganic nitrate following incremental portions of whole beetroot in older and younger adults |
| Study acronym | Beetroot study |
| Study objectives | 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(s) | Cambridge Central NRES Committee, East of England, 26/09/2016, ref: 16/EE/0376 |
| Health condition(s) or problem(s) studied | 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. 100 g whole pre-cooked beetroot 2. 200 g whole pre-cooked beetroot 3. 300 g whole pre-cooked beetroot 4. 200 ml 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 5 hours. The washout period between each phase will be one week. |
| Intervention type | Supplement |
| Primary outcome measure | Differences in bioavailability of nitrate between incremental doses of beetroot and compared to a standard dose of potassium nitrate at 5 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 5 hours 2. Differences in changes in endothelial function following each dose of nitrate supplementation and compared to a standard dose of potassium nitrate at 5 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 5 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 5 hours |
| Overall study start date | 01/06/2016 |
| Completion date | 22/12/2017 |
Eligibility
| Participant type(s) | Healthy volunteer |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Upper age limit | 75 Years |
| Sex | Male |
| Target number of participants | 30 |
| Total final enrolment | 24 |
| Key inclusion criteria | 1. Non-obese 2. Non-smoker 3. Males aged between 18 and 35 or 60 and 75 years 4. Free of chronic illness |
| Key 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 |
| Date of first enrolment | 01/12/2016 |
| Date of final enrolment | 17/11/2017 |
Locations
Countries of recruitment
- England
- United Kingdom
Study participating centre
NE1 4LP
United Kingdom
Sponsor information
Research organisation
Level 1, Regent Point
Regent Farm Road
Gosforth
Newcastle upon Tyne
NE3 3HD
England
United Kingdom
| Website | http://www.newcastlejro.org.uk/ |
|---|---|
"ROR" |
https://ror.org/05p40t847 |
Funders
Funder type
Industry
No information available
Private sector organisation / Universities (academic only)
- Location
- United Kingdom
Results and Publications
| Intention to publish date | 31/12/2020 |
|---|---|
| Individual participant data (IPD) Intention to share | No |
| IPD sharing plan summary | Not expected to be made available |
| Publication and dissemination plan | Planned publication in a high-impact peer reviewed journal |
| IPD sharing plan | 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. |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Participant information sheet | version v4.0 | 24/10/2016 | 01/04/2019 | No | Yes |
| Basic results | 16/01/2020 | 20/01/2020 | No | No | |
| Basic results | 06/02/2020 | 06/02/2020 | No | No | |
| HRA research summary | 28/06/2023 | No | No | ||
| Results article | 11/01/2022 | 08/11/2023 | Yes | No |
Additional files
- ISRCTN86706442_PIS_v4.0_24Oct16.pdf
- Uploaded 01/04/2019
- ISRCTN86706442_BasicResults_16Jan20.pdf
- uploaded 20/01/2020
- ISRCTN86706442_BasicResults_06Feb20.pdf
- uploaded 06/02/2020
Editorial Notes
08/11/2023: Publication reference and total final enrolment added.
06/02/2020: The basic results of this trial have been corrected and uploaded as an additional file.
20/01/2020: The following changes were made to the trial record:
1. The intention to publish date was changed from 31/12/2019 to 31/12/2020.
2. 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 22/12/2018 to 31/12/2019.
01/04/2019: The participant information sheet has been uploaded
