Children under eight should avoid drinking slushies, as doctors warn of serious consequences

12 March 2025, 09:58

Children under the age of eight should avoid consuming slush ice drinks containing the sweetening agent glycerol, researchers suggest.

It comes as a study highlighted a number of youngsters becoming unwell as a result of so-called "glycerol intoxication syndrome", which caused symptoms like decreased consciousness and low blood sugar.

Glycerol is a naturally occurring alcohol and sugar substitute which helps slush drinks maintain their texture by preventing liquid from freezing solid.

In the UK, slush drinks - also known as slushies - containing the ingredient are not recommended for children under the age of four.

However, academics have called for the public health advice to be revisited.

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For the review, published in Archives of Disease in Childhood, researchers at University College Dublin looked at the medical notes of 21 children in the UK and Ireland who fell ill after consuming a slushie.

Most cases took place between 2018 and 2024, with children's ages ranging between two and almost seven.

The youngsters were initially diagnosed with hypoglycaemia, or low blood sugar, after arriving at emergency departments.

Researchers suggest drinking slushies containing glycerol "may cause a clinical syndrome of glycerol intoxication in young children".

Symptoms included decreased consciousness, hypoglycaemia, lactic acidosis, which occurs when the body produces too much lactic acid, and hypokalaemia, or low potassium.

They added: "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 Food Standards Agency (FSA) advises against children under four consuming slush ice drinks containing glycerol.

It also recommends consumption is limited to no more than one slush per day for children aged between five and 10 years.

The time between drinking the slushie and becoming ill was known for 15 children, with 14 becoming unwell within an hour, according to the review.

All 21 children recovered quickly and were discharged with advice not to drink slushies, according to the study.

Of the group, 20 children followed this advice and had no further episodes of low blood sugar.

However, one child had another slushie at the age of seven and developed symptoms within an hour.

Researchers said: "There is poor transparency around slush ice drink glycerol concentration; estimating a safe dose is therefore not easy.

"It is also likely that speed and dose of ingestion, along with other aspects such as whether the drink is consumed alongside a meal or during a fasting state, or consumed after high-intensity exercise, may be contributing factors."

They added that "there are no nutritional or health benefits from these drinks" and "they are not recommended as part of a balanced diet".

"Recommendations on their safe consumption therefore need to be weighted towards safety," academics said.

"To ensure safe population-level recommendations can be easily interpreted at the individual parental level, and given the variability across an age cohort of weight, we suggest that recommendations should be based on weight rather than age.

"Alternatively, the recommended age threshold may need to be higher (eight years), to ensure the dose per weight would not be exceeded given normal population variation in weight."