Understanding the Risks of Excessive Licorice
Licorice root, derived from the Glycyrrhiza glabra plant, has been used for thousands of years in traditional medicine and as a flavoring agent. However, its powerful component, glycyrrhizin, can pose serious health risks when consumed in large quantities over a prolonged period. Glycyrrhizin causes the body to retain sodium and lose potassium, leading to a condition known as pseudohyperaldosteronism. This hormonal effect can be dangerous, especially for individuals with pre-existing health conditions.
The Role of Glycyrrhizin and its Health Impact
Glycyrrhizin is the natural compound responsible for the sweet flavor of licorice, but it also inhibits an enzyme called 11-beta-hydroxysteroid dehydrogenase (11β-HSD). This enzyme is crucial for regulating the mineralocorticoid receptors in the kidneys. By blocking it, glycyrrhizin allows cortisol to bind to these receptors, mimicking the effects of the hormone aldosterone. This results in a series of adverse effects on the body's electrolyte and fluid balance.
Key health impacts of excessive glycyrrhizin intake include:
- High Blood Pressure (Hypertension): The increase in sodium retention and fluid buildup directly contributes to elevated blood pressure. Even relatively modest daily intakes of glycyrrhizic acid have been shown to increase blood pressure in young, healthy individuals in some studies.
- Low Potassium Levels (Hypokalemia): The increased excretion of potassium can lead to dangerously low levels in the blood, causing muscle weakness, fatigue, and abnormal heart rhythms. A 2020 case report detailed the death of a 54-year-old man from cardiac arrest, which was linked to dangerously low potassium levels caused by his extensive black licorice consumption.
- Other Symptoms: Excessive licorice can cause a range of other issues, including swelling (edema), lethargy, and in severe cases, rhabdomyolysis (muscle breakdown).
How Product Type Influences Safe Intake
Not all licorice-flavored products are created equal when it comes to glycyrrhizin content. Many candies in the U.S., for instance, use anise oil for flavoring, which does not contain glycyrrhizin. Genuine licorice root products, however, have highly variable levels of the compound. This variation makes it extremely difficult for consumers to know their exact intake, highlighting the importance of cautious consumption.
For those seeking the flavor or benefits of licorice without the risk, Deglycyrrhizinated Licorice (DGL) is a safe alternative. DGL is processed to have the glycyrrhizin removed, eliminating the risk of side effects like blood pressure elevation and potassium depletion.
Comparison of Licorice Product Glycyrrhizin Levels
| Product Type | Glycyrrhizin Content (Approximate) | Potential Risk of Side Effects | Notes |
|---|---|---|---|
| Genuine Licorice Candy | Varies widely; can be high | High, especially with long-term, regular consumption. | The FDA warns about potential heart rhythm issues in those over 40 with certain levels of consumption. |
| Licorice Root Tea | Varies significantly between brands | Moderate to High, depending on quantity and potency. | Excessive daily intake is strongly cautioned against. |
| Licorice Dietary Supplements | Varies based on concentration; often high in glycyrrhizin. | High, especially with non-DGL versions. | Consult a doctor before use, as potencies are often higher than food products. |
| Deglycyrrhizinated Licorice (DGL) | Glycyrrhizin removed (negligible amounts) | Very Low to None. | A safer option for those sensitive to glycyrrhizin or with risk factors. |
| Anise-Flavored Candies | None | None. | Many U.S. "black licorice" candies fall into this category. |
A Critical Look at Intake Recommendations
The most widely cited benchmark for safe glycyrrhizin intake is the WHO's suggestion of a certain amount per day for the average adult. However, a 2024 study by researchers at Linköping University showed that even a seemingly low daily dose increased blood pressure in young, healthy volunteers. This suggests that previous recommendations may need reconsideration and that some individuals are more sensitive than others. The FDA also advises that people over 40 should be mindful of their intake of black licorice. Given the varying concentrations and individual sensitivities, consistent daily use of any genuine licorice product containing glycyrrhizin is not advised. The risks are particularly elevated for those with high blood pressure, heart disease, or kidney disease.
When to Consider Licorice to be "Too Much"
For most healthy adults, occasional, small servings of genuine licorice candy or tea are unlikely to cause problems. The definition of "too much" is not a fixed threshold but depends on several factors, including the product's glycyrrhizin content, the individual's overall health, and the frequency of consumption. Long-term, consistent daily use, especially of unregulated supplements or teas, is where the risks significantly increase. If you have any underlying health issues, especially those affecting the heart or kidneys, you should consider any consumption to be excessive and consult a healthcare provider.
Conclusion
While licorice has a place in tradition and as an occasional treat, caution is paramount when it comes to regular consumption of products containing glycyrrhizin. The established guideline for limiting intake is a starting point, but recent research suggests even modest amounts can affect blood pressure in some individuals. For those with heart or kidney issues, pregnant women, and anyone on certain medications, licorice should be avoided entirely. The safest approach for anyone concerned about the risks is to opt for Deglycyrrhizinated Licorice (DGL) products or choose anise-flavored alternatives that contain no glycyrrhizin. Always speak with a healthcare professional before incorporating licorice into your regular diet or supplement routine to assess your personal risk.
