HypertensionDINONCT02916615
Effects of Nitrate in Vegetables on Blood Pressure in Subjects With Prehypertension
A study testing High nitrate vegetables, Low nitrate vegetables + nitrate and Low nitrate vegetables in people with Hypertension and Cardiovascular Disease, run by Karolinska Institutet at 1 site in Sweden.
Trial summary
The purpose of this study is to examine the effect of different vegetables on cardiovascular function in subjects with moderately increased blood pressure. Specifically we are comparing the effects of vegetables with a high natural content of inorganic nitrate with those of vegetables with a low nitrate content. Read more about this study
- Who is it for?
- Ages 50 to 70 yearsHealthy volunteers can take part
- Conditions the study is for
- Hypertension, Cardiovascular Disease
- What is being tested?
- High nitrate vegetables, Low nitrate vegetables + nitrate and Low nitrate vegetables
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 225 participants
- Where
- 1 siteSweden
- Study dates
- Jan 2016to 30 Jan 2019
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 50 to 70 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Age 50-70 years Systolic blood pressure >130 at screening visit 2
Who cannot join
- Systolic blood pressure <120 or >159 mm Hg at screening 2 Systolic blood pressure > 169 mm Hg at screening 1 Chronic kidney disease Chronic rheumatic disease Insulin treated diabetes mellitus Atrial fibrillation Major cardiovascular event within 6 months Inflammatory bowel disease Malignancy, actively treated within 6 months Hepatitis Polycytemia Vera
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Diet and Nitric Oxide (DINO): A Study on the Effects of Dietary Nitrate on Blood Pressure in Subjects With Prehypertension
The purpose of this study is to examine the effect of different vegetables on cardiovascular function in subjects with moderately increased blood pressure. Specifically we are comparing the effects of vegetables with a high natural content of inorganic nitrate with those of vegetables with a low nitrate content.
Read the detailed description
Recent studies indicate that dietary-derived inorganic nitrate can affect blood pressure in humans by converting into nitric oxide bioactivity. Here we will study if vegetables that naturally contain high amounts of nitrate (green leafy vegetables) can lower blood pressure and whether any effect is attributed to the nitrate anion. High nitrate vegetables are compared with vegetables low in nitrate (e.g. tomatoes, sweet pepper). After a 2 week run in period where all subjects receive vegetables low in nitrate, the participants are randomized to one of three interventions. One third of the patients receive high-nitrate vegetables + a placebo pill (KCl), one third receives low-nitrate vegetables + placebo and the third group receives low-nitrate vegetables + a nitrate pill (KNO3). The nitrate content in the pill is precisely matched to the nitrate content in the high-nitrate vegetable group.
- Conditions
- Hypertension, Cardiovascular Disease
- Being tested
- High nitrate vegetables, Low nitrate vegetables + nitrate, Low nitrate vegetables
- Medical subject headings
- Hypertension, Cardiovascular Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
High nitrate vegetablesOther
vegetables naturally high in nitrate
Low nitrate vegetables + nitrateDietary supplement
Also called potassium nitrate (KNO3)
pill containing KNO3
Low nitrate vegetablesOther
vegetables naturally low in nitrate
| Study group | Role | What they receive |
|---|---|---|
| High nitrate vegetables | Active comparator | During 5 weeks subjects receive 100-150 g of a leafy green vegetable (High nitrate vegetables) per day and placebo pills containing 300 mg KCl (2 x 150 mg). Receives: Other: High nitrate vegetables |
| Low nitrate vegetables | Placebo comparator | During 5 weeks subjects receive 100-150 g of tomatoes/sweet pepper (Low nitrate vegetables) per day and placebo pills containing 300 mg KCl (2 x 150 mg). Receives: Other: Low nitrate vegetables |
| Low nitrate vegetables + nitrate | Active comparator | During 5 weeks subjects receive 100-150 g of tomatoes/sweet pepper (Low nitrate vegetables) per day and nitrate pills containing 300 mg KNO3 (2 x 150 mg). Receives: Dietary Supplement: Low nitrate vegetables + nitrate |
What is being measured
The primary outcome is the main question the study is designed to answer.
Difference in Change in ambulatory Systolic Blood Pressure From Baseline
Measure how 24h ambulatory SBP changes over 5 weeks with the different interventions
Measured: 5 weeks intervention
Secondary outcomes (5)
Difference in Change in ambulatory diastolic Blood Pressure From Baseline
Measure how 24h ambulatory DBP changes over 5 weeks with the different interventions
Measured: 5 weeks intervention
Difference in Change in office diastolic blood pressure (DBP)
BP is measured during a hospital visit every week during intervention
Measured: Once every week for 5 weeks
Difference in Change in flow mediated dilatation (FMD)
FMD is measured before and after the interventions
Measured: 5 weeks intervention
Difference in Change in office Systolic Blood Pressure From Baseline
Measure how clinic SBP changes weekly over 5 weeks with the different interventions
Measured: 5 weeks intervention
Difference in Change in Daytime Ambulatory systolic Blood Pressure From Baseline
Measure how 24h ambulatory daytime SBP changes over 5 weeks with the different interventions
Measured: 5 weeks intervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Sep 2016 (estimated)
- Study startJan 2016
- Primary completion30 Jan 2019
- Study completion30 Jan 2019
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for HypertensionStudies of the same condition, open and under way.
- More trials run by Karolinska InstitutetThe sponsor's other registered studies.
- 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
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 225 participants (actual)
Sponsor and investigators
- Lead sponsor
- Karolinska Institutet
- Sponsor type
- University, hospital or other
- Collaborators
- Karolinska University Hospital
- Responsible party
- Principal investigator, Jon Lundberg, Karolinska Institutet
- Investigators
- Jon Lundberg, MD, PhD, Principal investigator, Karolinska Institutet
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02916615
- Sponsor's protocol ID
- DINO1
- Acronym
- DINO
- Status last verified
- Mar 2019
- First submitted
- 26 Sep 2016
- Last updated
- 25 Mar 2019
- Results posted
- No
- Data monitoring committee
- No
- Individual data sharing
- Undecided
Publications
Bondonno CP, Sundqvist ML, Shinde S, Croft K, Hodgson JM, Carlstrom M, Weitzberg E, Lundberg JO. A clinical study examining the effects of dietary nitrate on urinary N-nitrosamines. Am J Clin Nutr. 2026 May;123(5):101239. doi: 10.1016/j.ajcnut.2026.101239. Epub 2026 Feb 20.
PubMed 41724486Sundqvist ML, Larsen FJ, Carlstrom M, Bottai M, Pernow J, Hellenius ML, Weitzberg E, Lundberg JO. A randomized clinical trial of the effects of leafy green vegetables and inorganic nitrate on blood pressure. Am J Clin Nutr. 2020 Apr 1;111(4):749-756. doi: 10.1093/ajcn/nqaa024.
PubMed 32091599
Study at a glance
From the registry record, last updated by the sponsor on 25 Mar 2019. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Diet and Nitric Oxide (DINO): A Study on the Effects of Dietary Nitrate on Blood Pressure in Subjects With Prehypertension
- ClinicalTrials.gov ID
- NCT02916615
- Acronym / sponsor ID
- DINO / DINO1
- Conditions
- Hypertension, Cardiovascular Disease
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 225 participants (actual)
- Lead sponsor
- Karolinska InstitutetUniversity, hospital or other
- Collaborators
- Karolinska University Hospital
- Study start
- Jan 2016
- Primary completion
- 30 Jan 2019 (actual)
- Study completion
- 30 Jan 2019 (actual)
- First posted
- 27 Sep 2016 (estimated)
- 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.
The purpose of this study is to examine the effect of different vegetables on cardiovascular function in subjects with moderately increased blood pressure. Specifically we are comparing the effects of vegetables with a high natural content of inorganic nitrate with those of vegetables with a low nitrate content.
Detailed description
Recent studies indicate that dietary-derived inorganic nitrate can affect blood pressure in humans by converting into nitric oxide bioactivity. Here we will study if vegetables that naturally contain high amounts of nitrate (green leafy vegetables) can lower blood pressure and whether any effect is attributed to the nitrate anion. High nitrate vegetables are compared with vegetables low in nitrate (e.g. tomatoes, sweet pepper). After a 2 week run in period where all subjects receive vegetables low in nitrate, the participants are randomized to one of three interventions. One third of the patients receive high-nitrate vegetables + a placebo pill (KCl), one third receives low-nitrate vegetables + placebo and the third group receives low-nitrate vegetables + a nitrate pill (KNO3). The nitrate content in the pill is precisely matched to the nitrate content in the high-nitrate vegetable group.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| High nitrate vegetables | Active comparator | Other: High nitrate vegetablesDuring 5 weeks subjects receive 100-150 g of a leafy green vegetable (High nitrate vegetables) per day and placebo pills containing 300 mg KCl (2 x 150 mg). |
| Low nitrate vegetables | Placebo comparator | Other: Low nitrate vegetablesDuring 5 weeks subjects receive 100-150 g of tomatoes/sweet pepper (Low nitrate vegetables) per day and placebo pills containing 300 mg KCl (2 x 150 mg). |
| Low nitrate vegetables + nitrate | Active comparator | Dietary Supplement: Low nitrate vegetables + nitrateDuring 5 weeks subjects receive 100-150 g of tomatoes/sweet pepper (Low nitrate vegetables) per day and nitrate pills containing 300 mg KNO3 (2 x 150 mg). |
Who may qualify
- Ages
- 50 to 70 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Age 50-70 years Systolic blood pressure >130 at screening visit 2
Key exclusion criteria (1 listed)
- Systolic blood pressure <120 or >159 mm Hg at screening 2 Systolic blood pressure > 169 mm Hg at screening 1 Chronic kidney disease Chronic rheumatic disease Insulin treated diabetes mellitus Atrial fibrillation Major cardiovascular event within 6 months Inflammatory bowel disease Malignancy, actively treated within 6 months Hepatitis Polycytemia Vera
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 |
|---|---|---|
| High nitrate vegetablesvegetables naturally high in nitrate | Other | High nitrate vegetables |
| Low nitrate vegetables + nitrateAlso: potassium nitrate (KNO3)pill containing KNO3 | Dietary supplement | Low nitrate vegetables + nitrate |
| Low nitrate vegetablesvegetables naturally low in nitrate | Other | Low nitrate vegetables |
Primary outcome
Difference in Change in ambulatory Systolic Blood Pressure From Baseline
Time frame: 5 weeks intervention
Measure how 24h ambulatory SBP changes over 5 weeks with the different interventions
5 secondary outcomes
Difference in Change in ambulatory diastolic Blood Pressure From Baseline
Time frame: 5 weeks intervention
Difference in Change in office diastolic blood pressure (DBP)
Time frame: Once every week for 5 weeks
Difference in Change in flow mediated dilatation (FMD)
Time frame: 5 weeks intervention
Difference in Change in office Systolic Blood Pressure From Baseline
Time frame: 5 weeks intervention
Difference in Change in Daytime Ambulatory systolic Blood Pressure From Baseline
Time frame: 5 weeks intervention
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 Mar 2019.
- Derived from this study: PubMed 41724486Bondonno CP, Sundqvist ML, Shinde S, Croft K, Hodgson JM, Carlstrom M, Weitzberg E, Lundberg JO. A clinical study examining the effects of dietary nitrate on urinary N-nitrosamines. Am J Clin Nutr. 2026 May;123(5):101239. doi: 10.1016/j.ajcnut.2026.101239. Epub 2026 Feb 20.
- Derived from this study: PubMed 32091599Sundqvist ML, Larsen FJ, Carlstrom M, Bottai M, Pernow J, Hellenius ML, Weitzberg E, Lundberg JO. A randomized clinical trial of the effects of leafy green vegetables and inorganic nitrate on blood pressure. Am J Clin Nutr. 2020 Apr 1;111(4):749-756. doi: 10.1093/ajcn/nqaa024.
- Individual participant dataSharing planned: Undecided
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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. This study is not recruiting at the moment.
Jon Lundberg, MD, PhD principal investigator
Karolinska Institutet
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing High nitrate vegetables, Low nitrate vegetables + nitrate and Low nitrate vegetables in people with Hypertension and Cardiovascular Disease, run by Karolinska Institutet at 1 site in Sweden.
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 1 inclusion and 1 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: finished, as of the sponsor's last update on 25 Mar 2019. 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 Sweden. 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. Some participants in this study may receive a placebo. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Difference in Change in ambulatory Systolic Blood Pressure From Baseline (time frame: 5 weeks intervention). 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 NCT02916615, which also lists 2 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 25 Mar 2019.