Researchers have warned that children under eight should avoid ‘slushies’, saying the popular brightly coloured icy drinks can cause “glycerol intoxication syndrome” in youngsters, which leads to loss of consciousness and low blood sugar.
The University College Dublin study team said other potential symptoms can include lactic acidosis, which occurs when the body produces too much lactic acid, and hypokalaemia, or low potassium.
Glycerol is a naturally occurring alcohol and sugar substitute which helps slush drinks maintain their texture by preventing liquid from freezing solid.
While glycerol is found in some other foods, it is added at much lower quantities than in slush ice drinks, reports Sky News.
The Food Standards Agency (FSA) currently advises against children under four consuming slush ice drinks containing glycerol, and also recommends children between five and 10 are limited to no more than one slushie a day.
However, the researchers have urged children under eight to avoid them altogether.
“Clinicians and parents should be alert to the phenomenon, and public health bodies should ensure clear messaging regarding the fact that younger children, especially those under eight, should avoid slush ice drinks containing glycerol,” said their review, published in Archives of Disease in Childhood.
“There are no nutritional or health benefits from these drinks,” they added, “and are not recommended as part of a balanced diet.”
The study looked at the medical notes of 21 children aged between two and seven in the UK and Ireland who fell ill after consuming the drinks between 2009 and 2024.
All of the youngsters needed treatment in accident and emergency (A&E) departments, with 14 of the children becoming unwell within an hour of drinking slushies.
All 21 children recovered quickly and were discharged with advice not to drink slushies, according to the study. Only one child from the group did not follow the advice and again developed symptoms an hour after drinking one, at the age of seven.
Researchers said there was “poor transparency” around slush ice drink glycerol concentration, so estimating a safe dose was not easy.
They said factors, including speed of ingestion, and whether the drink was consumed with a meal or during high-intensity exercise, may be contributing factors.
Study details
Glycerol intoxication syndrome in young children, following the consumption of slush ice drinks
Shona Brothwell, Patricia E Fitzsimons, Adam Gerrard et al.
Published in BMJ Archives of Disease in Children in March 2025
Abstract
Introduction
Slush ice drinks are commonly available refreshments, aimed at children and young people. Glycerol is used to maintain the slush effect in the absence of a high sugar content.
Objective
To describe a series of children who became acutely unwell shortly after consuming a slush ice drink; their presentation mimics specific inherited metabolic diseases (IMDs).
Methods
A retrospective case review of 21 children who presented to centres across the UK and Ireland from 2009 through 2024 was carried out.
Results
Almost all of the children (93%) became unwell within 60 min of slush ice drink consumption. None had any relevant past medical history. The median age at presentation was 3 years 6 months (range 2 years – 6 years 9 months). Presenting features include acute decrease in consciousness (94%), hypoglycaemia (95%), metabolic (lactic) acidosis (94%), pseudohypertriglyceridaemia (89%) and hypokalaemia (75%). Glyceroluria was present in all acute urine organic acid samples. No underlying IMD was found in the 14 patients who underwent further enzymatic or genetic testing. The majority (95%) subsequently avoided slush ice drinks and did not have reoccurrence.
Conclusion
Consumption of slush ice drinks containing glycerol may cause a clinical syndrome of glycerol intoxication in young children, characterised by decreased consciousness, hypoglycaemia, lactic acidosis, pseudohypertriglyceridaemia and hypokalaemia. This mimics inherited disorders of gluconeogenesis and glycerol metabolism. Clinicians and parents should be alert to the phenomenon, and public health bodies should ensure clear messaging regarding the fact that younger children, especially those under 8 years of age, should avoid slush ice drinks containing glycerol.