The Chemical Culprit: How Glycyrrhizin Causes Problems
The root of the liquorice plant, Glycyrrhiza glabra, contains a potent compound called glycyrrhizin, which is responsible for the distinct sweet flavour. While harmless in small, occasional doses, chronic or excessive intake of glycyrrhizin mimics the effects of the hormone aldosterone in the body.
Inside the body, glycyrrhizin is converted into glycyrrhetinic acid by intestinal bacteria. This acid then inhibits an enzyme, 11-beta-hydroxysteroid dehydrogenase type 2 (11β-HSD2), which normally inactivates the stress hormone cortisol in the kidneys. With the enzyme blocked, cortisol acts like a powerful mineralocorticoid, causing the kidneys to retain sodium and water while excreting potassium. This cascading hormonal effect is known as pseudohyperaldosteronism, as it mimics the symptoms of excess aldosterone, such as high blood pressure and low potassium.
Serious Health Consequences of Excessive Liquorice Consumption
The most well-documented and dangerous consequences of eating too much liquorice stem from the imbalance of electrolytes, particularly the severe depletion of potassium (hypokalemia). This can lead to a host of debilitating and potentially life-threatening conditions. A 2020 case in the New England Journal of Medicine described the death of a 54-year-old man whose cardiac arrest was directly linked to his habit of eating multiple bags of black liquorice daily.
Other symptoms that can arise from licorice toxicity include:
- Cardiovascular issues: High blood pressure (hypertension), irregular heart rhythms (arrhythmias), congestive heart failure, and swelling (oedema) due to fluid retention.
- Neuromuscular problems: Extreme muscle weakness (myopathy), muscle cramps, lethargy, and in severe cases, paralysis.
- Kidney-related damage: Over time, the strain on the kidneys can lead to or worsen existing kidney disease.
- Other symptoms: Headaches, fatigue, and for men, a drop in testosterone levels leading to reduced libido.
Who is at a Higher Risk?
While anyone can experience negative effects from excessive liquorice, certain individuals are at a higher risk of developing serious complications.
- Older adults: Individuals over 40 may be more susceptible to the hypertensive and cardiac effects of glycyrrhizin.
- People with pre-existing conditions: Those with a history of heart disease, high blood pressure, kidney disease, or liver problems are at a much greater risk of experiencing severe symptoms.
- Pregnant women: Large amounts of liquorice are unsafe during pregnancy and have been linked to an increased risk of premature birth.
- Individuals on certain medications: Those taking diuretics (water pills), corticosteroids, or other medications that affect potassium levels or blood pressure should avoid liquorice.
Liquorice vs. Anise-Flavoured Products
Many sweets that taste like liquorice do not contain actual liquorice root extract and thus pose no risk of glycyrrhizin poisoning.
| Feature | Real Black Liquorice | Anise-Flavoured Sweets (e.g., Red Liquorice) |
|---|---|---|
| Key Ingredient | Contains licorice root extract with glycyrrhizin. | Flavoured with anise oil, not licorice root. |
| Health Risk | High risk of health complications if consumed excessively over time. | Generally considered safe, but still high in sugar. |
| Taste Profile | Distinct, complex, and earthy liquorice taste. | Similar flavour to black liquorice, but without the harmful compound. |
| Ingredients Label | Lists 'licorice extract' or 'glycyrrhizic acid'. | Lists 'anise oil' or flavouring, without licorice root. |
| Regulatory Warnings | Health authorities issue warnings for excessive consumption. | No specific warnings related to glycyrrhizin toxicity. |
Conclusion
While an occasional, small serving of real black liquorice is unlikely to cause harm, eating large quantities or consuming it regularly can lead to serious health problems, including potentially fatal heart complications. The active compound, glycyrrhizin, disrupts the body's delicate electrolyte balance, causing high blood pressure, low potassium, and other dangerous side effects. It is crucial for high-risk individuals, such as those over 40 or with pre-existing conditions, to be especially cautious and moderate their intake. Always check product labels for 'licorice extract' or 'glycyrrhizic acid' to distinguish between real liquorice and anise-flavoured alternatives. For those concerned about potential health risks, consulting a healthcare provider is the safest course of action. More information on the health effects of excessive intake can be found on sites like Medscape, which provides details on the clinical presentation of licorice poisoning.
What to Do If You Suspect Liquorice Toxicity
If you have been eating a lot of black liquorice and experience symptoms such as irregular heart rhythm, muscle weakness, or severe swelling, stop consumption immediately and contact a health care provider. In severe cases, prompt medical attention is necessary to correct the electrolyte imbalances and prevent life-threatening complications.
How to Enjoy the Flavour Safely
For those who love the taste of liquorice but want to avoid the health risks, consider these alternatives:
- Choose anise-flavoured products: As noted in the table above, anise oil offers a similar flavour profile without the glycyrrhizin.
- Look for 'DGL' (Deglycyrrhizinated Liquorice): Some dietary supplements and health products contain DGL, which has had the glycyrrhizin removed.
- Limit your intake: Stick to very small, occasional amounts of real liquorice to minimize risk. Health authorities suggest staying well below 100 mg of glycyrrhizin per day, which is equivalent to roughly 60-70 grams of many liquorice sweets.
Conclusion
In conclusion, the key takeaway is moderation. Real black liquorice, while a beloved treat, contains a potent compound that can have significant and serious health consequences if consumed in excess. Understanding the distinction between true liquorice and its anise-flavoured counterparts is essential for enjoying this flavour safely. Always be mindful of your intake, particularly if you have underlying health concerns, and consult a medical professional if you experience any adverse symptoms.
The Recovery Process after Cessation
If liquorice consumption is stopped, the body will usually correct its electrolyte balance over time. Potassium levels may normalise within a few weeks, while blood pressure and hormonal imbalances may take longer, often several months, to fully return to normal. The recovery period and necessary treatments depend on the severity of the toxicity and the individual's overall health.
Regulations and Awareness
Due to the potential for harm, regulatory bodies in many countries require products containing liquorice extract to carry warnings, particularly for people with hypertension. However, as the glycyrrhizin content can vary widely between products, it can be difficult for consumers to know their exact intake. This highlights the need for greater public awareness of the risks associated with chronic, excessive consumption of this seemingly harmless confection.
