Licorice, a flavor in many foods and supplements, often raises questions about its health effects, particularly regarding cancer. This article clarifies the scientific understanding of licorice and its components in relation to cancer, and discusses its broader health implications.
Understanding Licorice Varieties and Components
Licorice varies significantly in form and composition. True licorice comes from the root of the Glycyrrhiza glabra plant, found in parts of Asia, Southern Europe, and the Middle East. It contains nearly 300 compounds, with glycyrrhizin as its main active component. Glycyrrhizin gives the root its distinct sweet taste and some biological properties.
Many licorice-flavored candies, particularly in North America, do not contain true licorice root extract. Instead, they use anise oil for a similar taste and aroma. Red licorice, for example, uses other flavorings like strawberry, cherry, or raspberry, lacking licorice root extract entirely. This distinction is important for understanding potential health effects.
Addressing the Cancer Question: Research Insights
Current scientific evidence does not indicate a causal link between licorice consumption and cancer in humans. Studies investigating this relationship have not found conclusive evidence of carcinogenicity.
While human studies on licorice are limited, some research has explored the potential anti-cancer properties of compounds found in licorice, such as glycyrrhizin and various flavonoids. Animal and laboratory studies suggest certain licorice components might inhibit cancer cell growth or induce programmed cell death in specific cancer types. However, these findings are from controlled laboratory settings and animal models, and their effects on human cancers are not yet established.
Known Health Considerations of Excessive Licorice
While not linked to cancer, excessive consumption of true licorice, due to its glycyrrhizin content, can lead to other health considerations. Glycyrrhizin affects fluid and electrolyte balance. It inhibits an enzyme regulating cortisol, increasing its activity in the kidneys.
Increased cortisol activity can mimic aldosterone, leading to pseudohyperaldosteronism. This causes sodium retention, fluid retention, and elevated blood pressure (hypertension). It can also reduce blood potassium levels (hypokalemia). Severe hypokalemia may cause muscle weakness and irregular heart rhythms. These effects usually reverse once licorice consumption stops.
Guidelines for Licorice Consumption
Given true licorice’s potential health considerations, consume it in moderation. The World Health Organization (WHO) and the European Scientific Committee of Food (SCF) suggest limiting glycyrrhizin intake to 100 mg per day for most healthy adults. This amount is typically found in 60 to 70 grams of licorice sweets, depending on glycyrrhizin content.
Individuals with pre-existing health conditions should exercise caution. Those with high blood pressure, heart disease, or kidney disease are more sensitive to glycyrrhizin and should avoid significant licorice consumption. Pregnant or nursing individuals should also avoid chronic licorice root use. Consulting a healthcare professional is advisable before using licorice as a supplement or for any medicinal purpose, especially when taking other medications, as licorice can interact with certain drugs.