It was a story that was as baffling as it was shocking. Last week, a four-year-old became the second child this year to be hospitalised after consuming a slushy.
The brightly-coloured iced drinks are sold in corner shops, cinemas and fun fairs – and are seen as a family-favourite sweet treat.
Albie Green from Warwickshire reportedly became severely unwell – ‘hallucinating’ and ‘clawing at his face’ – after downing a small strawberry-flavoured slushy at an after-school bowling party.
It was suggested his illness was an adverse reaction to glycerol, the artificial sweetener used in the drinks which help keep them from freezing solid.
Although Albie recovered, many parents have been understandably wondering whether their children are at risk.
Now, The Mail can reveal that scientists are exploring an intriguing theory: that some children carry a genetic mutation which makes glycerol toxic to them.
A major supplier of slushies, the British firm Nichols, which produces two of the most popular brands Slush Puppie and Starlush, has now removed the sweetener from their products for the safety of children, we have learned.
Beth Green faced a parent’s worst nightmare when her four-year-old son Albie became unresponsive after drinking a small strawberry-flavoured slushy
However, glycerol is still present in the majority of slushies available on British high streets and used in a wide variety of confectionary as well as cereal bars.
Experts are now calling on local health authorities to warn parents of the dangers of slushies, which contain a large amount of glycerol, in order to prevent further hospitalisations and even possible deaths.
Alongside glycerol, or E422, slushies typically also include citric acid used a preservative, artificial fruit flavouring, food colouring, salt, and water.
But experts agree that glycerol is most likely to blame for the two recent cases of children falling unwell – and last year the Government’s Food Standards Agency advised retailers not to sell slushies to children under four, and not offer free refill promotions to under 10s.
It came after two previous cases of children in Scotland being hospitalised after drinking slushies, in 2021 and 2022.
So just how worried should parents be?
Beth, 24, from Nuneaton, Warwickshire, feared unconscious Albie would die an hour after downing the iced slushy drink
Alongside its use as a sugar substitute glycerol is used in medical treatments – taken to help tackle eye disease glaucoma and alleviate constipation.
Experts believe that glycerol in food and drinks is essentially harmless for adults.
Jaffa Cakes, Angel Slices, and Cherry Bakewells all contain small amounts of glycerol – which is also listed in the ingredients as glycerine – to ensure the outside of these treats remains moist and soft.
Cereal bars like Nature Valley and Alpen – which are often promoted as a natural alternative to sweet treats – also contain glycerol for the same purpose.
The majority of these food items appear to contain very small traces of glycerol but companies are not required to state how much appears in their products.
However, the additive has become more common in beverages since 2018, when the Government introduced the sugar tax on soft drinks.
The tax is estimated to have saved thousands of children from tooth extractions, as sugar is one of the main causes of tooth decay in children.
However, the concentration of glycerol now in soft drinks such as slushies can be dangerous for some younger children.
Last month, three-year-old Angus Anderson was taken to hospital when he unexpectedly collapsed 30 minutes after drinking a raspberry-flavoured slushy bought from a local corner shop.
His mother, 29-year-old Victoria from Inverclyde, Scotland, described how Angus’s eyes rolled into the back of his head and his body went ‘stone cold’.
Angus was the third child in Scotland to be hospitalised after drinking a slushy, where the beverage appears to particularly popular.
In 2022, the supermarket SPAR Scotland announced a partnership with the frozen dessert brand Calippo to install glycerol-containing slushy machines in all its 320 shops across the nation.
Ms Anderson, who has since called for a ban on slushies, was told by doctors at Glasgow Children’s Hospital that her son had suffered glycerol toxicity – where overconsumption of glycerol can trigger headaches, sickness, and loss of consciousness.
However, why this condition occurs is debated amongst experts.
In August 2023, the Food Standards Agency said that, in rare circumstances, slushies can be dangerous for under-fours. Just one 350ml drink could tip them over the safe threshold
One argument is that glycerol leaves children dehydrated and lowers their blood-sugar.
‘Glycerol is very effective at absorbing excess water in the body, that’s why it’s used to treat glaucoma, which is caused by a build-up of fluid in the eye,’ says Professor James Caulson, a toxicology expert at Cardiff University.
‘This water is then carried with the glycerol out of the body. However, glycerol can sometimes also absorb a lot of sugar from the bloodstream during this process.
‘That sudden loss of water can leave people with headaches and the loss of sugar can have a significant effect on the body.’
Prof Caulson says that children who consume a large amount of glycerol can suffer hypoglycaemia – a low blood sugar condition usually associated with diabetes which leads to trembling, dizziness and even seizures.
He added: ‘So it’s no surprise that small children can end up unwell from consuming a lot of glycerol.’
Worryingly, experts also say slushies can significantly vary in glycerol content depending on where they are sold.
According to the Food Standards Agency most slushies contain around 16 grams – or around four teaspoons – of glycerol.
However, there is no maximum amount of glycerol that manufacturers have to legally adhere to. Most brands also do not state how much glycerol is in each slushy.
‘These products can really vary in how much glycerol ends up in them,’ says Professor Caulson.
‘There have been reports in the past of factory errors that have led to similar products containing far more glycerol than expected, which have put children in the hospital.’
But other experts say this theory does not explain why only some children have ended up severely unwell from products which are consumed by thousands of young people every day.
‘Lots of children drink slushies, but these horrible side effects appear to be quite rare,’ says Prof Alan Boobis, a toxicology expert at Imperial College London and Government advisor.
Instead, Prof Boobis argues that it is possible that the children who have suffered severe reactions after drinking slushies may have a rare genetic disorder which means their bodies cannot process glycerol.
For example, some children are born with a condition called fructose-1,6-bisphosphatase deficiency, which means they cannot produce enough of a certain enzyme that the body uses to break down glycerol and turn it into glucose – or sugar.
The rare condition can occur at any point in life and can lead to a range of symptoms depending on its severity, including drowsiness, hypoglycaemia and seizures.
Many people may never realise they have the problem.
Prof Boobis believes that a small child with this condition could become severely unwell if they consumed a large portion of glycerol.
‘In this situation, consuming a lot of glycerol could overwhelm the body and cause a health crisis,’ he says.
‘Because the body could not process the glycerol, this could block the production of all glucose in the body, and the child would experience severe hypoglycaemia.’
Prof Boobis stresses that his assessment is currently only a theory and wants more research to be carried out to see if it explains the rise in slushy-related hospitalisations, particularly in Scotland.
‘It’s feasible that all those affected might share the same genes or be related in some way,’ he says.
If he is right, given the rarity of this genetic disorder, a significant rise in reports of children suffering severe reactions to slushies is unlikely.
However, he warns that the majority of children with the condition would be undiagnosed, meaning there is no way for parents to know if their children are at risk or not.
‘Banning slushies would be an extreme measure because you’d be depriving thousands of people something that, for them, is safe and enjoyable, to protect a small handful of children who are at risk,’ says Prof Boobis.
‘However, it should be the responsibility of local health authorities to warn parents of the risks of the beverages.
‘If [the adverse reactions] are triggered by a genetic disorder, then it’s unlikely you’ll know your child is at risk until they get sick.’