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Completed

NCT Number: NCT05661721

Licorice and Home Blood Pressure

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.

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Key information

Conditions

Hypertension,Essential Cardiovascular Diseases Essential Hypertension Hypertension Vascular Diseases

Age range

18 year–30 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Cityhälsan Centrum

Norrköping, Östergötland County, 60239, Sweden

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Sweet licorice

Other

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: Glycyrrhiza glabra

Salty licorice

Other

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.

Primary outcomes

  1. 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)

  2. 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)

Secondary outcomes

  1. Body weight (kg)

    Time frame: Mean at the end of 14 days of intervention compared with mean during run-in period

    Body weight (kg)

  2. Plasma potassium (mmol/L)

    Time frame: Mean at the end of 14 days of intervention compared with mean during run-in period

    Plasma potassium (mmol/L)

  3. Plasma sodium (mmol/L)

    Time frame: Mean at the end of 14 days of intervention compared with mean during run-in period

    Plasma sodium (mmol/L)

  4. Plasma renin (mIU/L)

    Time frame: Mean at the end of 14 days of intervention compared with mean during run-in period

    Plasma renin (mIU/L)

  5. Serum aldosterone (μmol/L)

    Time frame: Mean at the end of 14 days of intervention compared with mean during run-in period

    Serum aldosterone (μmol/L)

Sponsors and collaborators

Lead sponsor

Linkoeping University

Other Gov

Registry information

Official study title

Licorice and Home Blood Pressure: a Randomized Crossover Trial

Important dates

Study start
2023
Primary completion
2023
Study completion
2023
First posted
Dec 22, 2022
Registry last updated
Aug 28, 2023

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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