Maternal prenatal licorice consumption alters hypothalamic-pituitary-adrenocortical axis function in children.

Overexposure to glucocorticoids has been proposed as a mechanism by which prenatal adversity 'programs' the function of the hypothalamic-pituitary-adrenocortical axis (HPAA), thereby increasing the risk of adult diseases. Glycyrrhizin, a natural constituent of licorice, potently inhibits 11β-hydroxysteroid dehydrogenase type 2, the feto-placental barrier to the higher maternal cortisol levels. We studied if maternal consumption of glycyrrhizin in licorice associates with HPAA function in children. Diurnal salivary cortisol and salivary cortisol during the Trier Social Stress Test for Children (TSST-C) were measured in children (n=321, mean age=8.1, SD=0.3 years) whose mothers consumed varying levels of glycyrrhizin in licorice during pregnancy; exposure-level groups were labeled high (≥500 mg/week), moderate (250-499 mg/week) and zero-low (0-249 mg/week). In comparison to the zero-low exposure group, children in the high exposure group had 19.2% higher salivary cortisol awakening peak, 33.1% higher salivary cortisol awakening slope, 15.4% higher salivary cortisol awakening area under the curve (AUC), 30.8% higher baseline TSST-C salivary cortisol levels, and their salivary cortisol levels remained high throughout the TSST-C protocol (P-values <0.05). These effects appeared dose-related. Our findings lend support to prenatal 'programming' of HPAA function by overexposure to glucocorticoids.