There is an abundance of foods that should be avoided during pregnancy, and a new study suggests that licorice should sit firmly in this category. Researchers have found that children born to mothers who consume large amounts of licorice during pregnancy may be more likely to develop behaviors associated with attention deficit hyperactivity disorder.
Study co-author Katri Räikkönen, from the University of Helsinki in Finland, and colleagues hypothesize that glycyrrhizin (the active ingredient in licorice) may interfere with fetal neurodevelopment by increasing levels of "the stress hormone" cortisol.
The researchers recently reported their findings in the American Journal of Epidemiology.
Though licorice is often hailed for its medicinal benefits - such as the alleviation of peptic ulcers and canker sores - studies have indicated that the plant-derived product has some downsides.
A study reported by Medical News Today in November, for example, associated licorice intake with reduced fertility for women, and studies have also suggested that licorice consumption during pregnancy may lead to poorer birth outcomes, such as a lower birth weight.
For this latest study, Räikkönen and team investigated how licorice intake during pregnancy might influence cognitive functioning and behavior in offspring.
The researchers explain that licorice's active ingredient, glycyrrhizin, is a strong inhibitor of placental 11β-hydroxysteroid dehydrogenase type 2 (11βHSD2), which is an enzyme known to block the production of glucocorticoids such as cortisol.
As such, glycyrrhizin may increase glucocorticoid production, and research has suggested that prenatal exposure to excess glucocorticoids is associated with psychiatric illness.