Licorice presents a unique concern for pregnant individuals due to its active compound. The licorice discussed refers specifically to the extract from the Glycyrrhiza glabra root, distinct from many licorice-flavored candies. Consumption of true licorice during pregnancy has raised questions about potential developmental effects on the fetus. High intake may be associated with adverse outcomes, prompting health organizations to issue warnings.
The Key Compound: Glycyrrhizin
Licorice consumption is scrutinized during pregnancy due to the presence of glycyrrhizin, a natural compound. Glycyrrhizin is responsible for the characteristic sweet flavor of licorice root and possesses powerful biological activity. It works by interfering with a specific enzyme that plays a protective role during gestation.
The enzyme is 11-beta hydroxysteroid dehydrogenase type 2 (11β-HSD2), which is highly expressed in the placenta. The function of 11β-HSD2 is to act as a barrier, quickly inactivating maternal cortisol, a stress hormone, as it crosses into the fetal circulation. Glycyrrhizin inhibits this enzyme, which effectively reduces the placenta’s ability to shield the fetus from high levels of maternal cortisol.
An excess of cortisol reaching the fetus is problematic; while the hormone is necessary for proper development, high concentrations are detrimental to the developing brain. Prenatal exposure to increased cortisol levels has been linked to potential long-term developmental implications. Studies show that children whose mothers consumed large amounts of licorice performed poorer on cognitive tests, including memory and reasoning, and had a higher likelihood of attention deficit/hyperactivity disorder (ADHD)-like problems.
Varying Risks Across Licorice Products
The risk associated with consuming licorice products varies significantly based on their glycyrrhizin concentration. True black licorice products, especially those sold in European countries, contain a high concentration of licorice root extract and thus a substantial amount of glycyrrhizin. These products carry the highest potential risk to pregnant individuals and the developing fetus.
Many licorice-flavored products sold in the United States and other regions do not contain true licorice extract at all. Instead, they often use anise oil to mimic the flavor, which does not contain glycyrrhizin and poses virtually no risk. It is important to check ingredient labels, as “licorice flavor” does not always equate to the presence of the licorice root compound.
Herbal teas require caution, as many marketed as “licorice root tea” can contain significant amounts of the active ingredient. Herbal remedies and teas made from licorice root extract should be treated with the same concern as concentrated candy. Highly concentrated forms, such as supplements, tinctures, or extracts used in traditional medicine, present the greatest risk because they deliver a potent dose of glycyrrhizin. Pregnant individuals should avoid using these concentrated forms without specific medical guidance.
Official Recommendations for Consumption
Given the potential risks, many health organizations recommend that pregnant individuals avoid licorice products containing glycyrrhizin. Studies have linked high consumption—defined as 500 mg or more of glycyrrhizin per week—to adverse outcomes, including a more than twofold increased risk of preterm delivery. This quantity is roughly equivalent to eating 250 grams of licorice confectionery weekly.
Some international guidelines have suggested a consumption limit of no more than 100 mg of glycyrrhizin per day for the general population. However, data concerning pregnant women suggest negative effects could be observed even below this level, and a definitive safe consumption limit for the developing fetus has not been established. Due to the uncertainty and the potential for serious developmental issues, the safest approach is to avoid licorice root extract and products known to contain high levels of glycyrrhizin entirely during pregnancy.
Pregnant individuals should also be aware that licorice consumption can cause maternal risks, such as high blood pressure and electrolyte imbalances, which are already health concerns during gestation. Consulting a healthcare provider is important for anyone who has consumed licorice products or is considering using herbal remedies or supplements. This consultation is particularly important for individuals with pre-existing conditions like high blood pressure or heart issues.