Writing in a case study published in Pediatric Neurology, the Italian scientists recommend that liquorice sweet manufacturers should clearly label a maximum recommended daily intake level on packaging as a precautionary measure after a 10-year-old who had consumed very high levels of liquorice suffered repeated seizures and high blood pressure as a result of very high glycyrrhizic acid levels.

Glycyrrhizic acid is the chief sweet-tasting constituent of liquorice and is generally considered to be safe for consumption at the low levels found in the sweet root – with a maximum recommended intake of 2 mg per kg set out by the World Health Organization (WHO).

“This boy was hospitalized following a cluster of generalized tonic-clonic seizures. Monitoring his clinical parameters, we detected constant high blood pressure and a brain magnetic resonance scan showed a localized vasogenic edema; these symptoms suggested posterior reversible encephalopathy syndrome (PRES),” ​wrote the research team – led by Dr Davide Tassinari from the University of Bologna.

“The child told the doctors he had been eating at least 20 liquorice sweets a day for the past 4 months,”​ noted the team. “From the data on the packet, each sweet contained 120 mg of liquorice, corresponding to 3.6 mg of glycyrrhizic acid, which amounted to a total daily consumption of 2400 mg of licorice and therefore 72 mg of glycyrrhizic acid.”​

“​Considering the boy's body weight, the total daily intake of glycyrrhizic acid was 2.88 mg/kg. This amount was well above the maximum safety range (2 mg/kg/day) suggested by the World Health Organization,”​ they added.

Case study​

Tassinari and his colleagues reported that investigations on the child were conducted using cranial computed tomography (CT) and magnetic resonance imaging (MRI), to investigate the possibility of posterior reversible encephalopathy syndrome (PRES).

However, the major clinical conditions that lead to PRES were all ruled out, said the team.

During a further medical examination doctors noticed that the boy's teeth were black, and it transpired that he had been eating considerable amounts of liquorice sweets each day for the past four months.

“This excessive consumption had resulted in his development of hypertension (or high blood pressure), and in turn PRES,”​ said the team.

After the child stopped eating the sweets, his anti-hypertensive treatment was gradually reduced and his blood pressure returned to normal, however the case revealed a worry that children with a low body weight may be consuming well over the WHO maximum stated limits for glycyrrhizic acid if they regularly consume a high level of liquorice sweets, said the team.

“As a result of our research, we suggest that liquorice sweet manufacturers indicate a recommended daily amount in relation to maximum safety limits on their packaging,” ​they concluded.

Source: Pediatric Neurology​

Published online ahead of print, doi: 10.1016/j.pediatrneurol.2014.12.001​

“Posterior Reversible Encephalopathy Syndrome Associated with Licorice Consumption: A Case Report in a 10-Year-Old Boy”​

Authors: Davide Tassinari, et al​