Type 2 Diabetes MellitusDiaBEETNCT07560800
Effect of Beetroot Juice on Cardiovascular and Autonomic Responses to Exercise in Adults With Type 2 Diabetes
A study testing Beetroot juice in people with Type 2 Diabetes Mellitus and Hypertension, run by Oxford Brookes University at 1 site in United Kingdom.
Trial summary
This study will investigate whether a single dose of beetroot juice can improve cardiovascular responses and recovery after exercise in adults with Type 2 Diabetes. Type 2 Diabetes is associated with higher blood pressure, impaired blood vessel function, and reduced autonomic control of the heart, all of which… Read more about this study
- Who is it for?
- Ages 40 to 65 years
- Conditions the study is for
- Type 2 Diabetes Mellitus, Hypertension, Autonomic Nervous System Diseases
- What is being tested?
- Beetroot juice
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 20 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 2 Apr 2026to 31 Jul 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 40 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Clinically diagnosed Type 2 Diabetes Mellitus
- Aged 40 to 65 years
- Not treated with insulin
- Stable diabetes medication regimen for at least 3 months
- Able to understand the study information and provide informed consent
- Able to safely perform light-to-moderate cycling exercise
Who cannot join
- Current or recent use of insulin
- Use of organic nitrates (e.g., glyceryl trinitrate) or phosphodiesterase-5 inhibitors (e.g., sildenafil, tadalafil)
- Use of systemic antibiotics within the specified preparation period or regular use of antiseptic/antibacterial mouthwash during study participation
- Use of supplements known to interfere with nitric oxide metabolism within the defined preparation period
- Unstable or clinically significant cardiovascular disease
- Uncontrolled hypertension or any condition that makes exercise unsafe
Show all 11Show fewer
- Chronic kidney disease, history of kidney stones, or other relevant renal conditions
- Neurological, musculoskeletal or systemic disorders that impair safe participation
- Known or suspected allergy or intolerance to beetroot, lemon or any component of the study products
- Pregnancy or breastfeeding
- Inability to comply with study preparation requirements
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United Kingdom1 site
Clinical Physiology Laboratory, Oxford Brookes University
Oxford, Oxfordshire, OX3 0BP
Bruno M Candeloro, MSc, +447523113252, diabeet.study@brookes.ac.uk
About this study
Official title: Effect of Beetroot Juice on Cardiovascular and Autonomic Responses During and After Exercise in Adults With Type 2 Diabetes
This study will investigate whether a single dose of beetroot juice can improve cardiovascular responses and recovery after exercise in adults with Type 2 Diabetes.
Type 2 Diabetes is associated with higher blood pressure, impaired blood vessel function, and reduced autonomic control of the heart, all of which increase cardiovascular risk and may affect how the body responds to and recovers from physical activity. Beetroot juice is naturally rich in dietary nitrate, which is converted in the body into nitric oxide, a molecule that helps blood vessels relax and improve blood flow. While these effects have been demonstrated in healthy individuals, less is known about their impact in people with Type 2 Diabetes.
Read more
In this study, approximately 16 to 20 adults aged 40 to 65 years with Type 2 Diabetes will take part. After an online screening and consent process, eligible participants will attend two laboratory visits at Oxford Brookes University. In a randomised, double-blind, placebo-controlled crossover design, participants will receive beetroot juice during one visit and a nitrate-depleted placebo during the other visit.
During each visit, participants will undergo physiological measurements, including blood pressure, heart rate, oxygen saturation, and capillary blood glucose. Participants will then complete a short session of supervised, light-to-moderate cycling exercise. Measurements will continue during the recovery period to assess how quickly the cardiovascular system returns to resting levels.
The main outcomes are systolic blood pressure and heart rate variability during recovery, which reflect cardiovascular regulation and autonomic function. Secondary outcomes include diastolic blood pressure, heart rate, blood glucose, and markers related to nitric oxide availability.
This study may help determine whether a simple, dietary-based intervention such as beetroot juice can support cardiovascular function and improve recovery after exercise in people living with Type 2 Diabetes.
Read the detailed description
Type 2 diabetes mellitus (T2DM) is characterised by endothelial dysfunction, elevated blood pressure and impaired autonomic regulation, all of which contribute to increased cardiovascular risk. In particular, reduced cardiovagal modulation and delayed recovery of cardiovascular parameters following exercise are associated with adverse clinical outcomes. These disturbances are closely linked to reduced nitric oxide bioavailability.
Dietary inorganic nitrate, abundant in beetroot juice, is converted via the entero-salivary nitrate-nitrite-nitric oxide pathway into nitric oxide, promoting vasodilation, improved endothelial function and reductions in blood pressure. Acute supplementation with nitrate-rich beetroot juice has been shown to enhance nitric oxide bioavailability within approximately 2 to 3 hours after ingestion, making it suitable for investigating short-term physiological responses. However, evidence in individuals with T2DM remains limited, particularly regarding post-exercise autonomic recovery.
This study is designed as a randomised, double-blind, placebo-controlled crossover trial to evaluate the acute effects of nitrate-rich beetroot juice on cardiovascular and autonomic responses to exercise in adults with T2DM not treated with insulin. Each participant will complete two experimental conditions, receiving nitrate-rich beetroot juice and a nitrate-depleted placebo in random order, separated by an adequate washout period. Randomisation will be performed using a computer-generated sequence by an independent researcher, and both participants and investigators will remain blinded to allocation.
All procedures will be conducted in a controlled laboratory environment under supervision by trained research staff. Continuous physiological monitoring will be performed to capture cardiovascular responses at rest, during exercise and throughout the recovery period. The exercise protocol consists of a standardised, light-to-moderate intensity cycling task designed to provide a consistent physiological stimulus while minimising risk.
The primary focus of the study is on post-exercise recovery, with particular emphasis on heart rate variability as an index of autonomic (vagal) modulation and systolic blood pressure as a marker of haemodynamic regulation. The crossover design allows each participant to serve as their own control, improving statistical efficiency and reducing inter-individual variability.
Safety procedures are integrated throughout the protocol, including pre-participation screening, standardised preparation requirements and continuous monitoring during all experimental phases. The study is conducted as a low-risk laboratory protocol, with predefined procedures for the management of any adverse or unexpected physiological responses.
The findings of this study are expected to contribute to the understanding of whether acute dietary nitrate supplementation can improve cardiovascular regulation and autonomic recovery following exercise in individuals with T2DM, providing mechanistic insight and potential implications for non-pharmacological strategies to support cardiovascular health in this population.
- Being tested
- Beetroot juice, Nitrate-depleted Beetroot Juice Placebo
- Keywords
- Beetroot juice, Dietary nitrate, Nitric oxide, Heart rate variability, Autonomic function, Blood pressure, Exercise recovery, Submaximal exercise, Endothelial function, Crossover trial
- Medical subject headings
- Diabetes Mellitus, Type 2, Hypertension, Autonomic Nervous System Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Beetroot juiceDietary supplement
Also called Nitrate-rich beetroot juice
A single dose of approximately 70 mL of nitrate-rich beetroot juice providing approximately 400 mg of inorganic nitrate will be administered. The product consists of concentrated beetroot juice with a small amount of lemon juice and is consumed prior to exercise testing. The timing of ingestion is standardized to allow peak nitrate-nitrite-nitric oxide conversion within approximately 2 to 3 hours. This intervention is intended to increase nitric oxide bioavailability and assess its acute effects on cardiovascular and autonomic responses.
Nitrate-depleted Beetroot Juice PlaceboDietary supplement
Also called Placebo beetroot juice
A nitrate-depleted beetroot juice placebo matched for appearance, taste and packaging will be administered in a single dose of approximately 70 mL. The placebo is identical to the active intervention in all aspects except for nitrate content. It is consumed under the same standardized conditions and timing as the active intervention to maintain blinding and allow controlled comparison of physiological responses.
| Study group | Role | What they receive |
|---|---|---|
| Beetroot Juice Then Placebo | Experimental | Participants receive nitrate-rich beetroot juice during the first visit and a nitrate-depleted placebo during the second visit, with a washout period of at least 48 hours between visits. Receives: Dietary Supplement: Beetroot juice; Dietary Supplement: Nitrate-depleted Beetroot Juice Placebo |
| Placebo Then Beetroot Juice | Experimental | Participants receive a nitrate-depleted placebo during the first visit and nitrate-rich beetroot juice during the second visit, with a washout period of at least 48 hours between visits. Receives: Dietary Supplement: Beetroot juice; Dietary Supplement: Nitrate-depleted Beetroot Juice Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Systolic Blood Pressure During Post-Exercise Recovery
Systolic blood pressure will be measured continuously during the post-exercise recovery period following submaximal cycling using beat-to-beat monitoring. This measure will be used to assess haemodynamic regulation after exercise under each intervention condition.
Measured: During post-exercise recovery mean value at 0-10 minutes, 10-20 minutes, 20-30 minutes, and 50-60 minutes.
Heart Rate Variability (RMSSD) During Post-Exercise Recovery
Heart rate variability, expressed as the root mean square of successive differences (RMSSD), will be derived from continuous electrocardiogram recordings during the post-exercise recovery period following submaximal cycling. This measure will be used to assess autonomic (vagal) recovery after exercise under each intervention condition.
Measured: During post-exercise recovery at 0-10 minutes, 10-20 minutes, 20-30 minutes, and 50-60 minutes.
Secondary outcomes (5)
Diastolic Blood Pressure During Post-Exercise Recovery
Diastolic blood pressure will be measured continuously during the post-exercise recovery period following submaximal cycling using beat-to-beat monitoring. This measure will be used to assess haemodynamic responses and vascular regulation after exercise under each intervention condition.
Measured: During post-exercise recovery mean value at 0-10 minutes, 10-20 minutes, 20-30 minutes, and 50-60 minutes.
Heart Rate During Post-Exercise and Recovery
Heart rate will be measured continuously during submaximal cycling exercise and throughout the post-exercise recovery period using electrocardiogram monitoring. This measure will be used to assess cardiovascular response to exercise and the rate of recovery toward resting levels under each intervention condition.
Measured: During post-exercise recovery mean value at 0-10 minutes, 10-20 minutes, 20-30 minutes, and 50-60 minutes.
Capillary Blood Glucose Response
Capillary blood glucose will be measured using finger-prick sampling at predefined time points, including pre-ingestion, 15, 30, 45, 60, 90 and 120 minutes post-ingestion, and at 5 and 60 minutes post-exercise. These measurements will be used to assess glycaemic response to the intervention and exercise under each experimental condition.
Measured: Pre-ingestion; 15, 30, 45, 60, 90, and 120 minutes post-ingestion; and 5 and 60 minutes post-exercise
Salivary Nitric Oxide-Related Response
Salivary nitric oxide-related response will be assessed using test strips that estimate nitrate and nitrite concentrations in saliva. Measurements will be performed at baseline, 1 hour post-ingestion, and 2 hours post-ingestion. This measure will be used as an indicator of nitric oxide bioavailability following dietary nitrate supplementation under each experimental condition.
Measured: Baseline, 1 hour post-ingestion, and 2 hours post-ingestion.
Perceived Exertion During Exercise
Perceived exertion will be assessed during the submaximal cycling ramp test using the Borg Rating of Perceived Exertion (6-20 scale). The scale ranges from 6 (no exertion) to 20 (maximal exertion), with higher scores indicating greater perceived effort. Ratings will be collected every minute during the exercise test and at peak exercise under each intervention condition.
Measured: On both test days (beetroot juice and placebo days) perceived exertion will be recorded every minute during the submaximal cycling ramp test from timepoint M3 (2 hours post-ingestion) to timepoint M4 (peak exercise)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 May 2026
- Study start2 Apr 2026 (estimated)
- Primary completion31 Jul 2026 (estimated)
- Study completion31 Jul 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (12)Papers the sponsor has linked to this study.
- Other trials for Type 2 Diabetes MellitusStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- This is a randomized, double-blind, placebo-controlled crossover study in which each participant completes two experimental conditions. Participants receive nitrate-rich beetroot juice in one visit and a nitrate-depleted placebo in the other visit, in a randomized order. The two conditions are separated by a washout period of at least 48 hours. Each participant serves as their own control to reduce inter-individual variability.
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Oxford Brookes University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Dr. Shakeeb H Moosavi, Oxford Brookes University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07560800
- Sponsor's protocol ID
- UREC-261968
- Acronym
- DiaBEET
- Status last verified
- Apr 2026
- First submitted
- 2 Apr 2026
- Last updated
- 1 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: The de-identified IPD used in the results publication will be made available on the Oxford Brookes University Research And Digital Assets Repository (RADAR)
Publications
Zunkovic B, Kejzar N, Bajrovic FF. Standard Heart Rate Variability Parameters-Their Within-Session Stability, Reliability, and Sample Size Required to Detect the Minimal Clinically Important Effect. J Clin Med. 2023 Apr 25;12(9):3118. doi: 10.3390/jcm12093118.
PubMed 37176559Yang DR, Wang MY, Zhang CL, Wang Y. Endothelial dysfunction in vascular complications of diabetes: a comprehensive review of mechanisms and implications. Front Endocrinol (Lausanne). 2024 Apr 5;15:1359255. doi: 10.3389/fendo.2024.1359255. eCollection 2024.
PubMed 38645427Colberg SR, Sigal RJ, Yardley JE, Riddell MC, Dunstan DW, Dempsey PC, Horton ES, Castorino K, Tate DF. Physical Activity/Exercise and Diabetes: A Position Statement of the American Diabetes Association. Diabetes Care. 2016 Nov;39(11):2065-2079. doi: 10.2337/dc16-1728. No abstract available.
PubMed 27926890Benjamim CJR, Porto AA, Valenti VE, Sobrinho ACDS, Garner DM, Gualano B, Bueno Junior CR. Nitrate Derived From Beetroot Juice Lowers Blood Pressure in Patients With Arterial Hypertension: A Systematic Review and Meta-Analysis. Front Nutr. 2022 Mar 15;9:823039. doi: 10.3389/fnut.2022.823039. eCollection 2022.
PubMed 35369064Tyler AP, Linder BA, Ricart K, Behrens CE Jr, Ovalle F, Patel RP, Fisher G. The Effects of Acute Beetroot Juice Intake on Glycemic and Blood Pressure Responses When Controlling for Medication in Individuals with Type 2 Diabetes: A Pilot Study. Nutrients. 2024 Aug 10;16(16):2636. doi: 10.3390/nu16162636.
PubMed 39203773Sun H, Saeedi P, Karuranga S, Pinkepank M, Ogurtsova K, Duncan BB, Stein C, Basit A, Chan JCN, Mbanya JC, Pavkov ME, Ramachandaran A, Wild SH, James S, Herman WH, Zhang P, Bommer C, Kuo S, Boyko EJ, Magliano DJ. IDF Diabetes Atlas: Global, regional and country-level diabetes prevalence estimates for 2021 and projections for 2045. Diabetes Res Clin Pract. 2022 Jan;183:109119. doi: 10.1016/j.diabres.2021.109119. Epub 2021 Dec 6.
PubMed 34879977Liu S, Cui Y, Chen M. Heart rate variability: a multidimensional perspective from physiological marker to brain-heart axis disorders prediction. Front Cardiovasc Med. 2025 Nov 6;12:1630668. doi: 10.3389/fcvm.2025.1630668. eCollection 2025.
PubMed 41282340Lara J, Ashor AW, Oggioni C, Ahluwalia A, Mathers JC, Siervo M. Effects of inorganic nitrate and beetroot supplementation on endothelial function: a systematic review and meta-analysis. Eur J Nutr. 2016 Mar;55(2):451-459. doi: 10.1007/s00394-015-0872-7. Epub 2015 Mar 13.
PubMed 25764393Fejes R, Lutnik M, Weisshaar S, Pilat N, Wagner KH, Stuger HP, Peake JM, Woodman RJ, Croft KD, Bondonno CP, Hodgson JM, Wolzt M, Neubauer O. Increased nitrate intake from beetroot juice over 4 weeks affects nitrate metabolism, but not vascular function or blood pressure in older adults with hypertension. Food Funct. 2024 Apr 22;15(8):4065-4078. doi: 10.1039/d3fo03749e.
PubMed 38546454Eleftheriadou A, Spallone V, Tahrani AA, Alam U. Cardiovascular autonomic neuropathy in diabetes: an update with a focus on management. Diabetologia. 2024 Dec;67(12):2611-2625. doi: 10.1007/s00125-024-06242-0. Epub 2024 Aug 9.
PubMed 39120767Benjamim CJR, S Junior FW, de Figueiredo MILS, Benjamim CJR, Cavalcante TCF, da Silva AAM, Monteiro LRL, Santana MDR, Garner DM, Valenti VE. Beetroot (Beta Vulgaris L.) Extract Acutely Improves Heart Rate Variability Recovery Following Strength Exercise: A Randomized, Double-Blind, Placebo-Controlled Crossover Trial-Pilot Study. J Am Coll Nutr. 2021 May-Jun;40(4):307-316. doi: 10.1080/07315724.2020.1774441. Epub 2020 May 29.
PubMed 32469260Aliahmadi M, Amiri F, Bahrami LS, Hosseini AF, Abiri B, Vafa M. Effects of raw red beetroot consumption on metabolic markers and cognitive function in type 2 diabetes patients. J Diabetes Metab Disord. 2021 Apr 21;20(1):673-682. doi: 10.1007/s40200-021-00798-z. eCollection 2021 Jun.
PubMed 34222085
Study at a glance
From the registry record, last updated by the sponsor on 1 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Beetroot Juice on Cardiovascular and Autonomic Responses During and After Exercise in Adults With Type 2 Diabetes
- ClinicalTrials.gov ID
- NCT07560800
- Acronym / sponsor ID
- DiaBEET / UREC-261968
- Keywords
- Beetroot juice, Dietary nitrate, Nitric oxide, Heart rate variability, Autonomic function, Blood pressure, Exercise recovery, Submaximal exercise
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- Oxford Brookes UniversityUniversity, hospital or other
- Study start
- 2 Apr 2026 (estimated)
- Primary completion
- 31 Jul 2026 (estimated)
- Study completion
- 31 Jul 2026 (estimated)
- First posted
- 1 May 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study will investigate whether a single dose of beetroot juice can improve cardiovascular responses and recovery after exercise in adults with Type 2 Diabetes.
Type 2 Diabetes is associated with higher blood pressure, impaired blood vessel function, and reduced autonomic control of the heart, all of which increase cardiovascular risk and may affect how the body responds to and recovers from physical activity. Beetroot juice is naturally rich in dietary nitrate, which is converted in the body into nitric oxide, a molecule that helps blood vessels relax and improve blood flow. While these effects have been demonstrated in healthy individuals, less is known about their impact in people with Type 2 Diabetes.
In this study, approximately 16 to 20 adults aged 40 to 65 years with Type 2 Diabetes will take part. After an online screening and consent process, eligible participants will attend two laboratory visits at Oxford Brookes University. In a randomised, double-blind, placebo-controlled crossover design, participants will receive beetroot juice during one visit and a nitrate-depleted placebo during the other visit.
During each visit, participants will undergo physiological measurements, including blood pressure, heart rate, oxygen saturation, and capillary blood glucose. Participants will then complete a short session of supervised, light-to-moderate cycling exercise. Measurements will continue during the recovery period to assess how quickly the cardiovascular system returns to resting levels.
The main outcomes are systolic blood pressure and heart rate variability during recovery, which reflect cardiovascular regulation and autonomic function. Secondary outcomes include diastolic blood pressure, heart rate, blood glucose, and markers related to nitric oxide availability.
This study may help determine whether a simple, dietary-based intervention such as beetroot juice can support cardiovascular function and improve recovery after exercise in people living with Type 2 Diabetes.
Detailed description
Type 2 diabetes mellitus (T2DM) is characterised by endothelial dysfunction, elevated blood pressure and impaired autonomic regulation, all of which contribute to increased cardiovascular risk. In particular, reduced cardiovagal modulation and delayed recovery of cardiovascular parameters following exercise are associated with adverse clinical outcomes. These disturbances are closely linked to reduced nitric oxide bioavailability.
Dietary inorganic nitrate, abundant in beetroot juice, is converted via the entero-salivary nitrate-nitrite-nitric oxide pathway into nitric oxide, promoting vasodilation, improved endothelial function and reductions in blood pressure. Acute supplementation with nitrate-rich beetroot juice has been shown to enhance nitric oxide bioavailability within approximately 2 to 3 hours after ingestion, making it suitable for investigating short-term physiological responses. However, evidence in individuals with T2DM remains limited, particularly regarding post-exercise autonomic recovery.
This study is designed as a randomised, double-blind, placebo-controlled crossover trial to evaluate the acute effects of nitrate-rich beetroot juice on cardiovascular and autonomic responses to exercise in adults with T2DM not treated with insulin. Each participant will complete two experimental conditions, receiving nitrate-rich beetroot juice and a nitrate-depleted placebo in random order, separated by an adequate washout period. Randomisation will be performed using a computer-generated sequence by an independent researcher, and both participants and investigators will remain blinded to allocation.
All procedures will be conducted in a controlled laboratory environment under supervision by trained research staff. Continuous physiological monitoring will be performed to capture cardiovascular responses at rest, during exercise and throughout the recovery period. The exercise protocol consists of a standardised, light-to-moderate intensity cycling task designed to provide a consistent physiological stimulus while minimising risk.
The primary focus of the study is on post-exercise recovery, with particular emphasis on heart rate variability as an index of autonomic (vagal) modulation and systolic blood pressure as a marker of haemodynamic regulation. The crossover design allows each participant to serve as their own control, improving statistical efficiency and reducing inter-individual variability.
Safety procedures are integrated throughout the protocol, including pre-participation screening, standardised preparation requirements and continuous monitoring during all experimental phases. The study is conducted as a low-risk laboratory protocol, with predefined procedures for the management of any adverse or unexpected physiological responses.
The findings of this study are expected to contribute to the understanding of whether acute dietary nitrate supplementation can improve cardiovascular regulation and autonomic recovery following exercise in individuals with T2DM, providing mechanistic insight and potential implications for non-pharmacological strategies to support cardiovascular health in this population.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- This is a randomized, double-blind, placebo-controlled crossover study in which each participant completes two experimental conditions. Participants receive nitrate-rich beetroot juice in one visit and a nitrate-depleted placebo in the other visit, in a randomized order. The two conditions are separated by a washout period of at least 48 hours. Each participant serves as their own control to reduce inter-individual variability.
| Arm | Type | Receives |
|---|---|---|
| Beetroot Juice Then Placebo | Experimental | Dietary Supplement: Beetroot juice, Dietary Supplement: Nitrate-depleted Beetroot Juice PlaceboParticipants receive nitrate-rich beetroot juice during the first visit and a nitrate-depleted placebo during the second visit, with a washout period of at least 48 hours between visits. |
| Placebo Then Beetroot Juice | Experimental | Dietary Supplement: Beetroot juice, Dietary Supplement: Nitrate-depleted Beetroot Juice PlaceboParticipants receive a nitrate-depleted placebo during the first visit and nitrate-rich beetroot juice during the second visit, with a washout period of at least 48 hours between visits. |
Who may qualify
- Ages
- 40 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Clinically diagnosed Type 2 Diabetes Mellitus
- Aged 40 to 65 years
- Not treated with insulin
- Stable diabetes medication regimen for at least 3 months
- Able to understand the study information and provide informed consent
Key exclusion criteria (11 listed)
- Current or recent use of insulin
- Use of organic nitrates (e.g., glyceryl trinitrate) or phosphodiesterase-5 inhibitors (e.g., sildenafil, tadalafil)
- Use of systemic antibiotics within the specified preparation period or regular use of antiseptic/antibacterial mouthwash during study participation
- Use of supplements known to interfere with nitric oxide metabolism within the defined preparation period
- Unstable or clinically significant cardiovascular disease
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Beetroot juiceAlso: Nitrate-rich beetroot juiceA single dose of approximately 70 mL of nitrate-rich beetroot juice providing approximately 400 mg of inorganic nitrate will be administered. The product consists of concentrated beetroot juice with a small amount of lemon juice and is consumed prior to exercise testing. The timing of ingestion is standardized to allow peak nitrate-nitrite-nitric oxide conversion within approximately 2 to 3 hours. This intervention is intended to increase nitric oxide bioavailability and assess its acute effects on cardiovascular and autonomic responses. | Dietary supplement | Beetroot Juice Then Placebo, Placebo Then Beetroot Juice |
| Nitrate-depleted Beetroot Juice PlaceboAlso: Placebo beetroot juiceA nitrate-depleted beetroot juice placebo matched for appearance, taste and packaging will be administered in a single dose of approximately 70 mL. The placebo is identical to the active intervention in all aspects except for nitrate content. It is consumed under the same standardized conditions and timing as the active intervention to maintain blinding and allow controlled comparison of physiological responses. | Dietary supplement | Beetroot Juice Then Placebo, Placebo Then Beetroot Juice |
Primary outcome
Systolic Blood Pressure During Post-Exercise Recovery
Time frame: During post-exercise recovery mean value at 0-10 minutes, 10-20 minutes, 20-30 minutes, and 50-60 minutes.
Systolic blood pressure will be measured continuously during the post-exercise recovery period following submaximal cycling using beat-to-beat monitoring. This measure will be used to assess haemodynamic regulation after exercise under each intervention condition.
Heart Rate Variability (RMSSD) During Post-Exercise Recovery
Time frame: During post-exercise recovery at 0-10 minutes, 10-20 minutes, 20-30 minutes, and 50-60 minutes.
Heart rate variability, expressed as the root mean square of successive differences (RMSSD), will be derived from continuous electrocardiogram recordings during the post-exercise recovery period following submaximal cycling. This measure will be used to assess autonomic (vagal) recovery after exercise under each intervention condition.
5 secondary outcomes
Diastolic Blood Pressure During Post-Exercise Recovery
Time frame: During post-exercise recovery mean value at 0-10 minutes, 10-20 minutes, 20-30 minutes, and 50-60 minutes.
Heart Rate During Post-Exercise and Recovery
Time frame: During post-exercise recovery mean value at 0-10 minutes, 10-20 minutes, 20-30 minutes, and 50-60 minutes.
Capillary Blood Glucose Response
Time frame: Pre-ingestion; 15, 30, 45, 60, 90, and 120 minutes post-ingestion; and 5 and 60 minutes post-exercise
Salivary Nitric Oxide-Related Response
Time frame: Baseline, 1 hour post-ingestion, and 2 hours post-ingestion.
Perceived Exertion During Exercise
Time frame: On both test days (beetroot juice and placebo days) perceived exertion will be recorded every minute during the submaximal cycling ramp test from timepoint M3 (2 hours post-ingestion) to timepoint M4 (peak exercise)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 May 2026.
- Background: PubMed 37176559Zunkovic B, Kejzar N, Bajrovic FF. Standard Heart Rate Variability Parameters-Their Within-Session Stability, Reliability, and Sample Size Required to Detect the Minimal Clinically Important Effect. J Clin Med. 2023 Apr 25;12(9):3118. doi: 10.3390/jcm12093118.
- Background: PubMed 38645427Yang DR, Wang MY, Zhang CL, Wang Y. Endothelial dysfunction in vascular complications of diabetes: a comprehensive review of mechanisms and implications. Front Endocrinol (Lausanne). 2024 Apr 5;15:1359255. doi: 10.3389/fendo.2024.1359255. eCollection 2024.
- Background: PubMed 27926890Colberg SR, Sigal RJ, Yardley JE, Riddell MC, Dunstan DW, Dempsey PC, Horton ES, Castorino K, Tate DF. Physical Activity/Exercise and Diabetes: A Position Statement of the American Diabetes Association. Diabetes Care. 2016 Nov;39(11):2065-2079. doi: 10.2337/dc16-1728. No abstract available.
- Background: PubMed 35369064Benjamim CJR, Porto AA, Valenti VE, Sobrinho ACDS, Garner DM, Gualano B, Bueno Junior CR. Nitrate Derived From Beetroot Juice Lowers Blood Pressure in Patients With Arterial Hypertension: A Systematic Review and Meta-Analysis. Front Nutr. 2022 Mar 15;9:823039. doi: 10.3389/fnut.2022.823039. eCollection 2022.
- Background: PubMed 39203773Tyler AP, Linder BA, Ricart K, Behrens CE Jr, Ovalle F, Patel RP, Fisher G. The Effects of Acute Beetroot Juice Intake on Glycemic and Blood Pressure Responses When Controlling for Medication in Individuals with Type 2 Diabetes: A Pilot Study. Nutrients. 2024 Aug 10;16(16):2636. doi: 10.3390/nu16162636.
- Background: PubMed 34879977Sun H, Saeedi P, Karuranga S, Pinkepank M, Ogurtsova K, Duncan BB, Stein C, Basit A, Chan JCN, Mbanya JC, Pavkov ME, Ramachandaran A, Wild SH, James S, Herman WH, Zhang P, Bommer C, Kuo S, Boyko EJ, Magliano DJ. IDF Diabetes Atlas: Global, regional and country-level diabetes prevalence estimates for 2021 and projections for 2045. Diabetes Res Clin Pract. 2022 Jan;183:109119. doi: 10.1016/j.diabres.2021.109119. Epub 2021 Dec 6.
- Background: PubMed 41282340Liu S, Cui Y, Chen M. Heart rate variability: a multidimensional perspective from physiological marker to brain-heart axis disorders prediction. Front Cardiovasc Med. 2025 Nov 6;12:1630668. doi: 10.3389/fcvm.2025.1630668. eCollection 2025.
- Background: PubMed 25764393Lara J, Ashor AW, Oggioni C, Ahluwalia A, Mathers JC, Siervo M. Effects of inorganic nitrate and beetroot supplementation on endothelial function: a systematic review and meta-analysis. Eur J Nutr. 2016 Mar;55(2):451-459. doi: 10.1007/s00394-015-0872-7. Epub 2015 Mar 13.
- Background: PubMed 38546454Fejes R, Lutnik M, Weisshaar S, Pilat N, Wagner KH, Stuger HP, Peake JM, Woodman RJ, Croft KD, Bondonno CP, Hodgson JM, Wolzt M, Neubauer O. Increased nitrate intake from beetroot juice over 4 weeks affects nitrate metabolism, but not vascular function or blood pressure in older adults with hypertension. Food Funct. 2024 Apr 22;15(8):4065-4078. doi: 10.1039/d3fo03749e.
- Background: PubMed 39120767Eleftheriadou A, Spallone V, Tahrani AA, Alam U. Cardiovascular autonomic neuropathy in diabetes: an update with a focus on management. Diabetologia. 2024 Dec;67(12):2611-2625. doi: 10.1007/s00125-024-06242-0. Epub 2024 Aug 9.
- Background: PubMed 32469260Benjamim CJR, S Junior FW, de Figueiredo MILS, Benjamim CJR, Cavalcante TCF, da Silva AAM, Monteiro LRL, Santana MDR, Garner DM, Valenti VE. Beetroot (Beta Vulgaris L.) Extract Acutely Improves Heart Rate Variability Recovery Following Strength Exercise: A Randomized, Double-Blind, Placebo-Controlled Crossover Trial-Pilot Study. J Am Coll Nutr. 2021 May-Jun;40(4):307-316. doi: 10.1080/07315724.2020.1774441. Epub 2020 May 29.
- Background: PubMed 34222085Aliahmadi M, Amiri F, Bahrami LS, Hosseini AF, Abiri B, Vafa M. Effects of raw red beetroot consumption on metabolic markers and cognitive function in type 2 diabetes patients. J Diabetes Metab Disord. 2021 Apr 21;20(1):673-682. doi: 10.1007/s40200-021-00798-z. eCollection 2021 Jun.
- Individual participant dataSharing planned: Yes. The de-identified IPD used in the results publication will be made available on the Oxford Brookes University Research And Digital Assets Repository (RADAR)
Related trials for Type 2 Diabetes Mellitus
Not yet recruitingPhase 3
Efficacy and Safety of Once-Weekly SHR-3167 Compared With Once-Daily Insulin Glargine in Adults With Insulin-Naive Type 2 Diabetes
Type 2 Diabetes
Active, not recruiting
Digital Reinforcement of Motivational Interviewing Micro-Skills Among Primary Care Healthcare Professionals
Hypertension (Without Type 2 Diabetes Mellitus)
Recruiting
Investigating Vascular Properties of HEMI and SPG Signals in Individuals With or at Risk for Chronic Kidney Disease
Chronic Kidney Disease, Hypertension (HTN)
Not yet recruitingPhase 3
A Study to Evaluate the Effectiveness and Safety of the Drug AZD6234 for Managing Weight in Adults Who Are Obese or Overweight. These Participants May or May Not Also Have Type 2 Diabetes
Obesity, Overweight
Not yet recruiting
Impact of Endoscopic Sleeve Gastroplasty (ESG) in Obese Adults With Type 2 Diabetes (T2D)
Type 2 Diabetes Mellitus (T2D), Obesity (BMI>30)
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Beetroot juice in people with Type 2 Diabetes Mellitus and Hypertension, run by Oxford Brookes University at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 1 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Bruno M Candeloro, MSc (+447523113252, diabeet.study@brookes.ac.uk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Systolic Blood Pressure During Post-Exercise Recovery (time frame: During post-exercise recovery mean value at 0-10 minutes, 10-20 minutes, 20-30 minutes, and 50-60 minutes.). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07560800, which also lists 12 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 1 May 2026.