Hypertension,Essential
Conditions
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.
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.
Interventions
OTHERSweet 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.
OTHERSalty 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.
Sponsors
Linkoeping University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 30 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| Plasma sodium (mmol/L) | Mean at the end of 14 days of intervention compared with mean during run-in period | Plasma sodium (mmol/L) |
| Body weight (kg) | Mean at the end of 14 days of intervention compared with mean during run-in period | Body weight (kg) |
| Serum aldosterone (μmol/L) | Mean at the end of 14 days of intervention compared with mean during run-in period | Serum aldosterone (μmol/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) |
| Plasma potassium (mmol/L) | Mean at the end of 14 days of intervention compared with mean during run-in period | Plasma potassium (mmol/L) |
Countries
Sweden
Outcome results
None listed