What is Glycyrrhizin?
Real liquorice, from the Glycyrrhiza glabra plant, contains glycyrrhizin, a sweet compound responsible for its distinct flavor and potential side effects. Many sweets do not contain real liquorice but use anise oil, which lacks glycyrrhizin. Checking labels is key to identifying products with real liquorice extract.
The Mechanism of Liquorice's Adverse Effects
The primary issue with liquorice is how glycyrrhizin affects hormones. Its metabolite, glycyrrhetinic acid, hinders the enzyme 11β-HSD2, which converts active cortisol to inactive cortisone. This inhibition raises cortisol levels. Elevated cortisol then activates mineralocorticoid receptors, typically by aldosterone, causing sodium and water retention and potassium excretion, a state called pseudohyperaldosteronism.
Major Health Consequences of Excessive Liquorice
Hypertension and Cardiovascular Issues
Excessive liquorice intake is known to increase blood pressure (hypertension). Glycyrrhizin-induced sodium and water retention significantly raise blood pressure, posing a risk to those with existing hypertension or heart conditions. Severe cases have resulted in heart failure and cardiac arrest.
Hypokalemia and Muscle Weakness
Increased potassium excretion can lead to hypokalemia (low blood potassium). Symptoms include muscle weakness or paralysis, fatigue, abnormal heart rhythms, and fluid retention. Severe hypokalemia has been linked to muscle paralysis and rhabdomyolysis.
Medication Interactions
Liquorice can interfere with several medications, including diuretics, blood pressure drugs, cardiac glycosides (like Digoxin), corticosteroids, and warfarin. It can amplify the potassium-depleting effects of diuretics, reduce the effectiveness of antihypertensives and warfarin, and increase corticosteroid levels.
Comparison of Standard Liquorice and DGL
Deglycyrrhizinated liquorice (DGL) is used in some products to reduce glycyrrhizin-related side effects. Standard liquorice extract contains high levels of glycyrrhizin, which can increase blood pressure and cause low potassium. DGL has trace amounts or no glycyrrhizin, and is generally considered safe for up to 4 months. {Link: Merck Manual https://www.merckmanuals.com/professional/special-subjects/dietary-supplements/licorice}.
Who Should Avoid or Limit Liquorice?
Certain individuals are at higher risk of adverse effects from liquorice:
- Those with high blood pressure, heart, or kidney disease are more sensitive to its effects.
- Pregnant or breastfeeding women should avoid high consumption due to potential risks to offspring.
- The elderly, especially those with existing health issues, may be more vulnerable.
Safe Consumption and Recognising Toxicity
Authorities like the WHO suggest limiting daily glycyrrhizin intake to under 100 mg for average adults. This is roughly equivalent to a small amount of real liquorice sweets for most healthy adults over a short time, though glycyrrhizin content varies widely.
Regular liquorice consumers should watch for signs of toxicity, including headaches, swelling, muscle cramps or weakness, irregular heartbeats, and fatigue. If these occur, stop consumption and see a doctor.
Conclusion
Liquorice's potential health benefits are offset by significant side effects, particularly concerning cardiovascular and electrolyte health due to glycyrrhizin. Excessive or prolonged intake can lead to high blood pressure and low potassium. Understanding these risks, identifying vulnerable individuals, and considering DGL are crucial for responsible consumption. Consulting a healthcare provider is recommended for those with existing conditions or on medication before regular liquorice intake.
For further information on licorice and its safety, you can visit the {Link: National Center for Complementary and Integrative Health website https://www.nccih.nih.gov/health/licorice-root}.
