Licorice and Home Blood Pressure
Study Details
Study Description
Brief 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. The aim of this study is to analyze the association between licorice intake and home blood pressure.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
N/A |
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
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Other: Intervention first, control after ("Sweet then salty") 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. |
Other: Sweet licorice
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.
Other Names:
Other: Salty licorice
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.
|
| Other: Control first, intervention after ("Salty then sweet") 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. |
Other: Sweet licorice
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.
Other Names:
Other: Salty licorice
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.
|
Outcome Measures
Primary Outcome Measures
- Systolic home blood pressure (mmHg) [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) [Mean at the end of 14 days of intervention compared with mean during run-in period]
Diastolic home blood pressure (mmHg)
Secondary Outcome Measures
- Body weight (kg) [Mean at the end of 14 days of intervention compared with mean during run-in period]
Body weight (kg)
- Plasma potassium (mmol/L) [Mean at the end of 14 days of intervention compared with mean during run-in period]
Plasma potassium (mmol/L)
- Plasma sodium (mmol/L) [Mean at the end of 14 days of intervention compared with mean during run-in period]
Plasma sodium (mmol/L)
- Plasma renin (mIU/L) [Mean at the end of 14 days of intervention compared with mean during run-in period]
Plasma renin (mIU/L)
- Serum aldosterone (μmol/L) [Mean at the end of 14 days of intervention compared with mean during run-in period]
Serum aldosterone (μmol/L)
Eligibility Criteria
Criteria
Inclusion Criteria:
- Age 18 to 30 years
Exclusion Criteria:
-
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
Contacts and Locations
Locations
No locations specified.Sponsors and Collaborators
- Linkoeping University
Investigators
- Study Director: Fredrik H Nyström, MD, PhD, Linkoeping University
Study Documents (Full-Text)
None provided.More Information
Publications
- Deutch 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.
- Parati 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.
- Rizzato 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.
- Spinks 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.
- 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. Erratum In: J Hypertens. 2019 Jan;37(1):226.
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