Children should avoid drinking slushies with glycerol as experts warn of health risk
14 March 2025
Children under eight should not drink slushies containing glycerol, warns a new study led by University College Dublin and (opens in a new window)Children’s Health Ireland.
The brightly coloured drinks can cause "glycerol intoxication syndrome" in young children, a condition that causes headaches, nausea, and vomiting, and in severe cases, loss of consciousness and low blood sugar (hypoglycaemia).
Publishing their findings in the British Medical Journal’s (opens in a new window)Archives of Disease in Childhood, experts at Children’s Health Ireland (CHI) Temple Street and the UCD School of Medicine have urged parents not to give under-eights the icy drinks after examining the cases of 21 children across Britain and Ireland who became sick soon after drinking the beverages.
"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 years of age, should avoid slush ice drinks containing glycerol," the study states.
The review team at University College Dublin was led by consultant metabolic paediatrician Professor Ellen Crushell, with Dr Shona Brothwell, Paediatric Metabolic Specialist Registrar at Birmingham Children’s Hospital, and Patricia Fitzsimons, Chief Medical Scientist at CHI’s National Metabolic Laboratory.
(opens in a new window)Speaking to RTÉ, Professor Crushell said that it currently isn’t known how much glycerol is in a regular 500ml slushie as there is currently no requirement to label the amount used.
“If a young child takes a large dose of glycerol, such as you might find in a slushie, that’s absorbed straight away into the system and that big dose of glycerol, the metabolism of a small child can’t really cope with it. It interferes with their glucose metabolism and that’s how your body keeps your blood sugar normal,” she said.
She continued: “What’s needed is more transparency around glycerol because at the moment it doesn’t need to be declared or measured. Its use is becoming more ubiquitous as we need less sugar in our diets.”
All but one of the cases looked at in the study took place between 2018 and 2024, with the children aged between two and almost seven years old. In each case examined the child became acutely unwell with a series of shared symptoms soon after drinking a slushie.
These symptoms included headaches, nausea, and vomiting, followed by reduced consciousness' referred to as drowsiness or coma, and very low blood sugar levels with high lactic acid levels, with glycerol being found in their urine.
A naturally occurring alcohol and sugar substitute and an EU-approved additive, glycerol helps slushies maintain their texture by preventing liquid from freezing solid.
The Food Safety Authority of Ireland (FSAI) advises parents to limit young children’s consumption of slushies that contain glycerol due to potentially negative side-effects – including headaches, nausea, and vomiting, and that older children and adults should have no more than one a day.
However, such guidance could go further, according to Professor Crushell, who said there may be a spectrum of milder illness in young children being caused by icy drinks containing glycerol.
“To be safe, and to account for normal variations in children’s weights, the guidance not to consume could potentially be extended to children under eight years of age.”
"It should also be noted that all slush ice drinks, whether containing sugar or glycerol, convey no health benefits, and are not part of a healthy diet for children of any age,” added Dr Abigail Collins, National Clinical Lead for the HSE's Child Health Public Health Programme.
By: David Kearns, Digital Journalist / Media Officer, UCD University Relations
To contact the UCD News & Content Team, email: newsdesk@ucd.ie
