A popular summertime treat could contain hidden dangers to kids’ health, a new study cautions.

Researchers at University College Dublin conducted a review of 21 children who became ill between 2009 and 2024 after consuming a “slush ice drink.”

A vast majority of the children, none of whom had preexisting medical conditions, became ill within an hour of having the drink.

The patients, who ranged in age from 2 to 6 years old, all received medical treatment in the UK and Ireland.

The findings, which were published in the journal Archives of Disease in Childhood, indicated the most prevalent symptoms as an acute decrease in consciousness, hypoglycaemia (low blood sugar), metabolic acidosis (lactic acid build-up in the bloodstream), pseudohypertriglyceridaemia (falsely elevated triglycerides), and hypokalaemia (low potassium levels).

According to lead study author Ellen Crushell, a pediatrician at Children’s Health Ireland and a clinical professor at University College Dublin, the children exhibited very low blood sugar levels, were unconscious (with one having a seizure), and had high levels of lactate in their blood.

The children also had high levels of glycerol in their blood and urine while ill, which disappeared upon recovery. Although they recuperated well, hospitalization and intravenous fluids were necessary for their treatment.

The researchers concluded that consumption of slush ice drinks containing glycerol may cause a syndrome called glycerol intoxication.

The majority of the children (95%) did not have continued symptoms after avoiding the drinks.

What is glycerol?

“Glycerol is used as a sweetener and to maintain the semi-frozen texture of some (not all) slush ice drinks,” Crushell said.

“It is being used more often in recent years as a sugar substitute,” she noted. “Large doses can be harmful to small children.”

The effect of sudden illness after consuming a slush drink had never been reported in the medical literature, Crushell noted.

This study did have some limitations, the researchers acknowledged.

“The numbers are small and include only the sickest children who were brought to emergency departments and who were referred on to specialists in inherited metabolic disorders,” Crushell said.

“They were referred because their symptoms were similar to those of some rare metabolic diseases. We do not know the extent of children who may develop milder symptoms.”

The other limitation is that the amount of glycerol ingested in the various slush drinks is unknown, she added.

Recommendations for parents

Crushell said slush ice drinks “do not convey health benefits at any age” and are not recommended as part of a healthy, balanced diet. 

The UK Food Standards Agency and the Food Safety Authority of Ireland (FSAI) have both issued guidance recommending that children age 4 and under avoid consuming slush ice drinks containing glycerol, and that children 5 and up should only drink them in moderation.

“The use of slush ice machines by children in the home should be monitored,” Crushell advised. “Parents and guardians should check the ingredients of syrups used to make slush ices in the home for the presence of glycerol and follow the manufacturer’s instructions for use.”

The researchers hope this new study could lead to the development of new policies and guidance related to glycerol ingestion.   

Fox News Digital reached out to the US Food and Drug Administration and to a leading manufacturer of slush drinks requesting comment.