Daily Liquorice Consumption for Two Weeks Increases Augmentation Index and Central Systolic and Diastolic Blood Pressure

Abstract

BackgroundLiquorice ingestion often elevates blood pressure, but the detailed haemodynamic alterations are unknown. We studied haemodynamic changes induced by liquorice consumption in 20 subjects versus 30 controls with average blood pressures of 120/68 and 116/64 mmHg, respectively.MethodsHaemodynamic variables were measured in supine position before and after two weeks of liquorice consumption (daily glycyrrhizin dose 290–370 mg) with tonometric recording of radial blood pressure, pulse wave analysis, and whole-body impedance cardiography. Thirty age-matched healthy subjects maintaining their normal diet were studied as controls.ResultsTwo weeks of liquorice ingestion elevated peripheral and central systolic and diastolic blood pressure (by 7/4 and 8/4 mmHg, 95% confidence intervals [CI] 2-11/1-8 and 3-13/1-8, respectively, P<0.05), and increased extracellular volume by 0.5 litres (P<0.05 versus controls). Also augmentation index adjusted to heart rate 75/min (from 7% to 11%, 95% CI for change 0.3-7.5, P<0.05) and aortic pulse pressure (by 4 mmHg, 95% CI 1-7, P<0.05) were elevated indicating increased wave reflection from the periphery. In contrast, peripheral (−3/−0.3 mmHg) and central blood pressure (−2/−0.5 mmHg), aortic pulse pressure (−1 mmHg), and augmentation index adjusted to heart rate 75/min (from 9% to 7%) decreased numerically but not statistically significantly without changes in extracellular volume in the control group. Heart rate, systemic vascular resistance, cardiac output, and pulse wave velocity did not differ between the groups.ConclusionsTwo weeks of daily liquorice consumption increased extracellular volume, amplified pressure wave reflection from the periphery, and elevated central systolic and diastolic blood pressure.Trial RegistrationEU Clinical Trials Register EudraCT 2006-002065-39</url>ClinicalTrials.gov NCT01742702

Expert panel consensus recommendations for ambulatory blood pressure monitoring in Asia: The HOPE Asia Network

“…Specific agents such as non‐steroidal anti‐inflammatory drugs (NSAIDs) and Kanzo [liquorice] increase the circulating volume, resulting in a non‐dipping pattern and nocturnal hypertension …”

Voluntary liquorice ingestion increases blood pressure via increased volume load, elevated peripheral arterial resistance, and decreased aortic compliance

“…Exclusion criteria were office BP >140/90 mmHg, cardiovascular disease with regular medication, pregnancy, and consumption of liquorice >300 grams per week. Subject recruitment and data collection have been described previously 8 . The liquorice group consisted of 22 subjects (14 women and 8 men), and the aged-matched control group of 30 subjects (17 women and 13 men).…”

“…We recently reported that daily liquorice consumption in normotensive subjects for two weeks elevated peripheral and central systolic and diastolic BP, increased extracellular fluid volume, and amplified pressure wave reflection from the peripheral arterial tree 8 . However, increased peripheral arterial resistance and large arterial stiffness, and changes in cardiac function and autonomic tone could also contribute to the elevation of BP following liquorice ingestion.…”

“…The elevation of BP after liquorice ingestion is well-known 6 – 8 . The active metabolite in liquorice, glycyrrhetinic acid (GA) that resembles the structure of cortisone, inhibits the enzyme 11β-HSD2 6 .…”

An Unexpected Cause of Severe Hypokalemia

“…The USA Food and Drug Administration (FDA) advises avoiding eating large amounts of black licorice at one time [ 7 ]. An increase in extracellular volume and elevation of central systolic and diastolic blood pressure after two weeks of daily licorice consumption have been reported [ 8 ]. However, it has been suggested that individual factors may predispose to pseudoaldosteronism in certain patients, since some patients develop neither hypokalemia nor hypertension even after long time consuming licorice.…”