Hypertension,EssentialNCT05661721
Licorice and Home Blood Pressure
A study testing Sweet licorice and Salty licorice in people with Hypertension,Essential, run by Linkoeping University at 1 site in Sweden.
Trial summary
Out-of-office blood pressure is more strongly associated with cardiovascular risk than office blood pressure. Licorice is known to raise blood pressure, but no previous studies have measured the effects on home blood pressure. Read more about this study
- Who is it for?
- Ages 18 to 30 yearsHealthy volunteers can take part
- Conditions the study is for
- Hypertension,Essential
- What is being tested?
- Sweet licorice and Salty licorice
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 28 participants
- Where
- 1 siteSweden
- Study dates
- 30 Jan 2023to 30 Jun 2023
- 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 18 to 30 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Age 18 to 30 years
Who cannot join
- known hypertension, cardiovascular disease, kidney disease, liver disease, hormonal disease, peanut allergy, eating disorder or headache disease (including tension headache and migraine)
- known alcohol abuse or drug abuse (including cannabis and anabolic steroids)
- treatment with hormonal drugs (including oral contraceptives
- known intolerance to licorice intake
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Licorice and Home Blood Pressure: a Randomized Crossover Trial
Out-of-office blood pressure is more strongly associated with cardiovascular risk than office blood pressure. Licorice is known to raise blood pressure, but no previous studies have measured the effects on home blood pressure. The aim of this study is to analyze the association between licorice intake and home blood pressure.
Read the detailed description
Healthy volunteers will be invited to participate in a randomized, non-blinded, cross-over study. Participants will be randomized to either of two groups with a 1:1 allocation ratio, stratified by sex. Intervention will be sweet licorice and control will be salty licorice. A run-in period of 1 week will be followed by a 2-week intervention/control, a 2-week washout period, another 2-week control/intervention period and again a 2-week washout period. Home blood pressure will be measured continuously, and blood samples (including potassium and aldosterone) will be collected every two weeks. Analyses will be made comparing baseline characteristics of the two groups, intervention/control and washout period results of the two groups to look for potential carry-over effects, and finally comparing intervention and washout period results respectively to the baseline data to look for the effects of licorice.
- Conditions
- Hypertension,Essential
- Being tested
- Sweet licorice, Salty licorice
- Medical subject headings
- Essential Hypertension
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Sweet licoriceOther
Also called Glycyrrhiza glabra
Ecologic, vegan and gluten free, low-sodium sweet licorice pastilles made from Glycyrrhiza glabra, with a manufacturer specified content of 4% sugars, 2% glycyrrhizin and 0.03% salt, will be used as intervention. The exact glycyrrhizin content will be determined before the study begins, and participants will be instructed to consume a daily licorice dose that is equivalent to 100 mg of glycyrrhizin.
Salty licoriceOther
A vegan and gluten free salty licorice without glycyrrhizin, flavored with ammonium chloride, with a manufacturer specified content of 0% sugars and 0.05% salt, will be used as control. The amount of salty licorice will be the same as for sweet licorice, and thus determined after the glycyrrhizin content analysis of the sweet licorice.
| Study group | Role | What they receive |
|---|---|---|
| Intervention first, control after ("Sweet then salty") | Other | This arm will be divided into the following periods:
Run-in period: 7 days without any licorice intake Intervention period: 14 days with sweet licorice intake First wash-out period: 14 days without any licorice intake Control period: 14 days with salty licorice intake Second wash-out period: 14 days without any licorice intake. Receives: Other: Sweet licorice; Other: Salty licorice |
| Control first, intervention after ("Salty then sweet") | Other | This arm will be divided into the following periods:
Run-in period: 7 days without any licorice intake Control period: 14 days with salty licorice intake First wash-out period: 14 days without any licorice intake Intervention period: 14 days with sweet licorice intake Second wash-out period: 14 days without any licorice intake. Receives: Other: Sweet licorice; Other: Salty licorice |
What is being measured
The primary outcome is the main question the study is designed to answer.
Systolic home blood pressure (mmHg)
Systolic home blood pressure (mmHg)
Measured: Mean at the end of 14 days of intervention compared with mean during run-in period
Diastolic home blood pressure (mmHg)
Diastolic home blood pressure (mmHg)
Measured: Mean at the end of 14 days of intervention compared with mean during run-in period
Secondary outcomes (5)
Body weight (kg)
Body weight (kg)
Measured: Mean at the end of 14 days of intervention compared with mean during run-in period
Plasma potassium (mmol/L)
Plasma potassium (mmol/L)
Measured: Mean at the end of 14 days of intervention compared with mean during run-in period
Plasma sodium (mmol/L)
Plasma sodium (mmol/L)
Measured: Mean at the end of 14 days of intervention compared with mean during run-in period
Plasma renin (mIU/L)
Plasma renin (mIU/L)
Measured: Mean at the end of 14 days of intervention compared with mean during run-in period
Serum aldosterone (μmol/L)
Serum aldosterone (μmol/L)
Measured: Mean at the end of 14 days of intervention compared with mean during run-in period
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Dec 2022
- Study start30 Jan 2023
- Primary completion30 Jun 2023
- Study completion30 Jun 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (6)Papers the sponsor has linked to this study.
- Other trials for Hypertension,EssentialStudies of the same condition, open and under way.
- More trials run by Linkoeping UniversityThe 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
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 28 participants (actual)
Sponsor and investigators
- Lead sponsor
- Linkoeping University
- Sponsor type
- Other government
- Responsible party
- Principal investigator, Peder af Geijerstam, Linkoeping University
- Investigators
- Fredrik H Nyström, MD, PhD, Study director, Linkoeping University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05661721
- Sponsor's protocol ID
- licorice2023
- Status last verified
- Aug 2023
- First submitted
- 12 Dec 2022
- Last updated
- 28 Aug 2023
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: As specified below.
Publications
Williams B, Mancia G, Spiering W, Agabiti Rosei E, Azizi M, Burnier M, Clement DL, Coca A, de Simone G, Dominiczak A, Kahan T, Mahfoud F, Redon J, Ruilope L, Zanchetti A, Kerins M, Kjeldsen SE, Kreutz R, Laurent S, Lip GYH, McManus R, Narkiewicz K, Ruschitzka F, Schmieder RE, Shlyakhto E, Tsioufis C, Aboyans V, Desormais I; Authors/Task Force Members:. 2018 ESC/ESH Guidelines for the management of arterial hypertension: The Task Force for the management of arterial hypertension of the European Society of Cardiology and the European Society of Hypertension: The Task Force for the management of arterial hypertension of the European Society of Cardiology and the European Society of Hypertension. J Hypertens. 2018 Oct;36(10):1953-2041. doi: 10.1097/HJH.0000000000001940.
PubMed 30234752Deutch MR, Grimm D, Wehland M, Infanger M, Kruger M. Bioactive Candy: Effects of Licorice on the Cardiovascular System. Foods. 2019 Oct 14;8(10):495. doi: 10.3390/foods8100495.
PubMed 31615045Parati G, Stergiou GS, Bilo G, Kollias A, Pengo M, Ochoa JE, Agarwal R, Asayama K, Asmar R, Burnier M, De La Sierra A, Giannattasio C, Gosse P, Head G, Hoshide S, Imai Y, Kario K, Li Y, Manios E, Mant J, McManus RJ, Mengden T, Mihailidou AS, Muntner P, Myers M, Niiranen T, Ntineri A, O'Brien E, Octavio JA, Ohkubo T, Omboni S, Padfield P, Palatini P, Pellegrini D, Postel-Vinay N, Ramirez AJ, Sharman JE, Shennan A, Silva E, Topouchian J, Torlasco C, Wang JG, Weber MA, Whelton PK, White WB, Mancia G; Working Group on Blood Pressure Monitoring and Cardiovascular Variability of the European Society of Hypertension. Home blood pressure monitoring: methodology, clinical relevance and practical application: a 2021 position paper by the Working Group on Blood Pressure Monitoring and Cardiovascular Variability of the European Society of Hypertension. J Hypertens. 2021 Sep 1;39(9):1742-1767. doi: 10.1097/HJH.0000000000002922.
PubMed 34269334Spinks EA, Fenwick GR. The determination of glycyrrhizin in selected UK liquorice products. Food Addit Contam. 1990 Nov-Dec;7(6):769-78. doi: 10.1080/02652039009373939.
PubMed 2079112Rizzato G, Scalabrin E, Radaelli M, Capodaglio G, Piccolo O. A new exploration of licorice metabolome. Food Chem. 2017 Apr 15;221:959-968. doi: 10.1016/j.foodchem.2016.11.068. Epub 2016 Nov 17.
PubMed 27979300Af Geijerstam P, Joelsson A, Radholm K, Nystrom FH. A low dose of daily licorice intake affects renin, aldosterone, and home blood pressure in a randomized crossover trial. Am J Clin Nutr. 2024 Mar;119(3):682-691. doi: 10.1016/j.ajcnut.2024.01.011. Epub 2024 Jan 20.
PubMed 38246526
Study at a glance
From the registry record, last updated by the sponsor on 28 Aug 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Licorice and Home Blood Pressure: a Randomized Crossover Trial
- ClinicalTrials.gov ID
- NCT05661721
- Acronym / sponsor ID
- licorice2023
- Conditions
- Hypertension,Essential
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 28 participants (actual)
- Lead sponsor
- Linkoeping UniversityOther government
- Study start
- 30 Jan 2023 (actual)
- Primary completion
- 30 Jun 2023 (actual)
- Study completion
- 30 Jun 2023 (actual)
- First posted
- 22 Dec 2022 (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.
Out-of-office blood pressure is more strongly associated with cardiovascular risk than office blood pressure. Licorice is known to raise blood pressure, but no previous studies have measured the effects on home blood pressure. The aim of this study is to analyze the association between licorice intake and home blood pressure.
Detailed description
Healthy volunteers will be invited to participate in a randomized, non-blinded, cross-over study. Participants will be randomized to either of two groups with a 1:1 allocation ratio, stratified by sex. Intervention will be sweet licorice and control will be salty licorice. A run-in period of 1 week will be followed by a 2-week intervention/control, a 2-week washout period, another 2-week control/intervention period and again a 2-week washout period. Home blood pressure will be measured continuously, and blood samples (including potassium and aldosterone) will be collected every two weeks. Analyses will be made comparing baseline characteristics of the two groups, intervention/control and washout period results of the two groups to look for potential carry-over effects, and finally comparing intervention and washout period results respectively to the baseline data to look for the effects of licorice.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Intervention first, control after ("Sweet then salty") | Other | Other: Sweet licorice, Other: Salty licoriceThis arm will be divided into the following periods: Run-in period: 7 days without any licorice intake Intervention period: 14 days with sweet licorice intake First wash-out period: 14 days without any licorice intake Control period: 14 days with salty licorice intake Second wash-out period: 14 days without any licorice intake. |
| Control first, intervention after ("Salty then sweet") | Other | Other: Sweet licorice, Other: Salty licoriceThis arm will be divided into the following periods: Run-in period: 7 days without any licorice intake Control period: 14 days with salty licorice intake First wash-out period: 14 days without any licorice intake Intervention period: 14 days with sweet licorice intake Second wash-out period: 14 days without any licorice intake. |
Who may qualify
- Ages
- 18 to 30 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- Age 18 to 30 years
Key exclusion criteria (4 listed)
- known hypertension, cardiovascular disease, kidney disease, liver disease, hormonal disease, peanut allergy, eating disorder or headache disease (including tension headache and migraine)
- known alcohol abuse or drug abuse (including cannabis and anabolic steroids)
- treatment with hormonal drugs (including oral contraceptives
- known intolerance to licorice intake
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 |
|---|---|---|
| Sweet licoriceAlso: Glycyrrhiza glabraEcologic, vegan and gluten free, low-sodium sweet licorice pastilles made from Glycyrrhiza glabra, with a manufacturer specified content of 4% sugars, 2% glycyrrhizin and 0.03% salt, will be used as intervention. The exact glycyrrhizin content will be determined before the study begins, and participants will be instructed to consume a daily licorice dose that is equivalent to 100 mg of glycyrrhizin. | Other | Control first, intervention after ("Salty then sweet"), Intervention first, control after ("Sweet then salty") |
| Salty licoriceA vegan and gluten free salty licorice without glycyrrhizin, flavored with ammonium chloride, with a manufacturer specified content of 0% sugars and 0.05% salt, will be used as control. The amount of salty licorice will be the same as for sweet licorice, and thus determined after the glycyrrhizin content analysis of the sweet licorice. | Other | Control first, intervention after ("Salty then sweet"), Intervention first, control after ("Sweet then salty") |
Primary outcome
Systolic home blood pressure (mmHg)
Time frame: Mean at the end of 14 days of intervention compared with mean during run-in period
Systolic home blood pressure (mmHg)
Diastolic home blood pressure (mmHg)
Time frame: Mean at the end of 14 days of intervention compared with mean during run-in period
Diastolic home blood pressure (mmHg)
5 secondary outcomes
Body weight (kg)
Time frame: Mean at the end of 14 days of intervention compared with mean during run-in period
Plasma potassium (mmol/L)
Time frame: Mean at the end of 14 days of intervention compared with mean during run-in period
Plasma sodium (mmol/L)
Time frame: Mean at the end of 14 days of intervention compared with mean during run-in period
Plasma renin (mIU/L)
Time frame: Mean at the end of 14 days of intervention compared with mean during run-in period
Serum aldosterone (μmol/L)
Time frame: Mean at the end of 14 days of intervention compared with mean during run-in period
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 28 Aug 2023.
- Background: PubMed 30234752Williams B, Mancia G, Spiering W, Agabiti Rosei E, Azizi M, Burnier M, Clement DL, Coca A, de Simone G, Dominiczak A, Kahan T, Mahfoud F, Redon J, Ruilope L, Zanchetti A, Kerins M, Kjeldsen SE, Kreutz R, Laurent S, Lip GYH, McManus R, Narkiewicz K, Ruschitzka F, Schmieder RE, Shlyakhto E, Tsioufis C, Aboyans V, Desormais I; Authors/Task Force Members:. 2018 ESC/ESH Guidelines for the management of arterial hypertension: The Task Force for the management of arterial hypertension of the European Society of Cardiology and the European Society of Hypertension: The Task Force for the management of arterial hypertension of the European Society of Cardiology and the European Society of Hypertension. J Hypertens. 2018 Oct;36(10):1953-2041. doi: 10.1097/HJH.0000000000001940.
- Background: PubMed 31615045Deutch MR, Grimm D, Wehland M, Infanger M, Kruger M. Bioactive Candy: Effects of Licorice on the Cardiovascular System. Foods. 2019 Oct 14;8(10):495. doi: 10.3390/foods8100495.
- Background: PubMed 34269334Parati G, Stergiou GS, Bilo G, Kollias A, Pengo M, Ochoa JE, Agarwal R, Asayama K, Asmar R, Burnier M, De La Sierra A, Giannattasio C, Gosse P, Head G, Hoshide S, Imai Y, Kario K, Li Y, Manios E, Mant J, McManus RJ, Mengden T, Mihailidou AS, Muntner P, Myers M, Niiranen T, Ntineri A, O'Brien E, Octavio JA, Ohkubo T, Omboni S, Padfield P, Palatini P, Pellegrini D, Postel-Vinay N, Ramirez AJ, Sharman JE, Shennan A, Silva E, Topouchian J, Torlasco C, Wang JG, Weber MA, Whelton PK, White WB, Mancia G; Working Group on Blood Pressure Monitoring and Cardiovascular Variability of the European Society of Hypertension. Home blood pressure monitoring: methodology, clinical relevance and practical application: a 2021 position paper by the Working Group on Blood Pressure Monitoring and Cardiovascular Variability of the European Society of Hypertension. J Hypertens. 2021 Sep 1;39(9):1742-1767. doi: 10.1097/HJH.0000000000002922.
- Background: PubMed 2079112Spinks EA, Fenwick GR. The determination of glycyrrhizin in selected UK liquorice products. Food Addit Contam. 1990 Nov-Dec;7(6):769-78. doi: 10.1080/02652039009373939.
- Background: PubMed 27979300Rizzato G, Scalabrin E, Radaelli M, Capodaglio G, Piccolo O. A new exploration of licorice metabolome. Food Chem. 2017 Apr 15;221:959-968. doi: 10.1016/j.foodchem.2016.11.068. Epub 2016 Nov 17.
- Derived from this study: PubMed 38246526Af Geijerstam P, Joelsson A, Radholm K, Nystrom FH. A low dose of daily licorice intake affects renin, aldosterone, and home blood pressure in a randomized crossover trial. Am J Clin Nutr. 2024 Mar;119(3):682-691. doi: 10.1016/j.ajcnut.2024.01.011. Epub 2024 Jan 20.
- Individual participant dataSharing planned: Yes. As specified below.
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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.
Fredrik H Nyström, MD, PhD study director
Linkoeping University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Sweet licorice and Salty licorice in people with Hypertension,Essential, run by Linkoeping University 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 4 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 28 Aug 2023. 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. 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?
Systolic home blood pressure (mmHg) (time frame: Mean at the end of 14 days of intervention compared with mean during run-in period). 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 NCT05661721, which also lists 6 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 28 Aug 2023.