The consumption of licorice during pregnancy may be associated with long-lasting risks for the developing child. The study, “Maternal licorice consumption during pregnancy and pubertal, cognitive and psychiatric outcomes in children” by Katri Räikkönen et al. was published today in the American Journal of Epidemiology, along with an invited commentary, “An Ingenious Approach to Examining the Relationship Between Maternal Stress and Offspring Health?” by Drs Keyes and Susser.
In our study, those 12-year-olds whose mothers ate large amounts of licorice during pregnancy scored lower on tests of general cognitive ability and memory and had more ADHD symptoms, compared with children whose mothers had consumed little or no licorice during pregnancy. Girls whose mothers had consumed a lot of licorice during pregnancy also entered puberty earlier.
Based on animal studies, the natural sweetener of licorice called glycyrrhizin strongly interferes with placental metabolism of cortisol, sometimes called the “stress hormone”. During pregnancy, the placenta acts as an active barrier between the mother and the fetus, but maternal consumption of glycyrrhizin disrupts this barrier, causing the fetus to be over-exposed to maternal cortisol. This is likely to explain why licorice consumption during pregnancy may harm the developing fetus.
The study was carried out as part of the Glaku longitudinal study project, which was funded by the Academy of Finland and private foundations. We compared 51 Finnish children whose mothers reported consuming at least 500 mg of glycyrrhizin peer week (roughly equivalent to 250 grams of licorice) with 327 children whose mothers reported they had consumed less than 250 mg of glycyrrhizin per week.
In light of the findings from Glaku and other recent studies, the Finnish nutritional guidelines for pregnant women were recently revised.
As the amount of glycyrrhizin one can safely consume during pregnancy is unknown, women are advised to avoid sweet and salty licorice throughout pregnancy.
/ Sara Sammallahti