Diluted apple juice 'as good as' rehydration drinks for children

"Scientists have revealed which fruit can stop toddlers crying due to stomach pains," says the Daily Mirror, missing the point of the study it reports on.

The study looked at the use of diluted apple juice to prevent dehydration in children with upset stomachs.

When children get diarrhoea or vomiting, the main danger is that they will lose too much fluid (become dehydrated). Severe dehydration can be life-threatening and can happen quickly in young children.

To prevent this, doctors often recommend giving them specially made rehydration drinks, with a mixture of salts and sugars designed to keep fluid levels stable. However, the drinks are expensive and some children don't like the taste.

The researchers wanted to see if rehydration drinks were actually better, or if drinking diluted apple juice followed by children's usual preferred drinks would work just as well for children aged over six months.

The study found that children given apple juice were less likely to need additional treatments – possibly because they were happier with the taste and more willing to drink the juice.

However, this may not work for all children, as the study didn't include any babies under six months, children with more serious stomach upsets or other conditions, and those who were already severely dehydrated.

The advice from the National Institute for Health and Care Excellence (NICE) is still to give your child rehydration solution if you're worried they may become dehydrated and to seek medical advice if they don't get better. Fruit juice could make their diarrhoea worse and the current advice is that it should be avoided.

Where did the story come from?

The study was carried out by researchers from the University of Calgary, the University of Toronto and the Hospital for Sick Children and Child Health Evaluative Services in Toronto, all in Canada. It was funded by the Physician Services Incorporated Foundation.

No apple juice producers were involved in the funding of this study and the authors reported no conflict of interests.

The study was published in the peer-reviewed Journal of the American Medical Association (JAMA), on an open-access basis, meaning it is free to read online.

The study seems to have confused the UK media. The Daily Express says "an apple a day" might cure children's tummy aches, the Daily Mirror says apples "could stop toddlers crying", while the Daily Mail says apples "could keep tummy bugs at bay".

All the headlines miss the point that the apple juice was tested as a treatment to prevent dehydration when a child has a bug, not to prevent stomach aches or infections. There's no evidence in the study to back up these headline claims.

What kind of research was this?

Researchers carried out a single-blind randomised controlled trial (RCT), to see whether diluted apple juice followed by the child's normal preferred drinks (such as milk, water or juice) worked as well to prevent dehydration as rehydration solutions.

RCTs are a good way to see which of two treatments works best. But in this case, the study was designed to see whether apple juice worked as well as rehydration solutions, not to say for certain which works best.

What did the research involve?

Researchers from a specialist children's hospital recruited 647 children aged from six months to five years who'd been brought into the emergency department with an upset stomach. Children were randomly divided into two groups and assigned to the different treatments.

The children were given their allocated fluids, designed to look the same, as soon as they'd been seen by the nurse. Their parents were told to start giving them sips of the fluid straight away. They were then seen by a doctor, who could change the treatment if necessary.

When they went home, parents were told to either keep on using the rehydration salts to replace fluid lost by diarrhoea or vomiting, or to use the diluted apple juice followed by the child's normal preferred drink. A research nurse phoned daily to check how they got on.

At the end of the study, researchers compared how many children had either needed additional treatment (such as fluids given through an IV drip) or to switch to the other treatment, or had long-lasting illness, dehydration or weight loss, or needed to go back to hospital or see the doctor with the same episode of upset tummy, within seven days.

A combination of any of these factors was called a "treatment failure".

They analysed the results to see if apple juice worked as well as rehydration salts, and to look for patterns that might explain it, such as the child's age.

What were the basic results?

Children who had apple juice followed by their preferred drinks did at least as well as those who had rehydration drinks:

• 16.7% of children who'd had apple juice had treatment failure, and 2.5% needed fluids given through a drip
• 25% of children who'd had rehydration drinks had treatment failure, and 9% needed fluids given through a drip

There were no significant differences between the two treatments in terms of frequency of diarrhoea and vomiting, weight loss and admission to hospital.

How did the researchers interpret the results?

The researchers say that diluted apple juice "may be an appropriate alternative" to rehydration drinks for children with mild tummy upsets in high income countries such as Canada, where few children get serious infections and there's easy access to healthcare.

They warn the results may not be relevant to low and middle income countries where children are more likely to get serious infections and to become dangerously dehydrated.

They point out that parents have been discouraged from giving children with stomach upsets sugary drinks like fruit juice, because it could make diarrhoea worse. However, they say their results provide evidence that "in children with minimal dehydration, promoting fluid consumption is more important" than how much sugar is in the fluid.

They say that children over two years of age seemed to get most benefit from apple juice, perhaps because they were more used to drinking sweetened drinks and were fussier about taste.

Conclusion

This study shows that diluted apple juice may work as well as rehydration salts for children with mild stomach upsets in preventing dehydration. But it might not work for all children, especially those with more serious stomach upsets, babies under six months, or children who are already more severely dehydrated.

It's important to remember that the children in this study were seen by a doctor before being allowed to continue with the diluted apple juice. They were all over six months old, didn't have other conditions that might have made the stomach upset more serious (such as diabetes) and had been checked for dehydration or other signs of serious illness.

There is also some missing information from the study that could have affected the results. We don't know whether parents continued to use apple juice or rehydration drinks as directed when they got home, or whether the child was receiving any treatment other than the hydration or anti-sickness tablets.

Most of the study results came from databases recording treatments given and visits to doctors or hospitals, or from phone calls by research nurses to the families after they'd left hospital. Not many parents returned the diary they'd been given to record their child's symptoms and whether the parents were happy with the treatment, so we don't know for sure if the parents were happy with the advice and their child's recovery.

If other studies also show that diluted apple juice works well for children with mild stomach upsets, doctors might decide to start recommending it instead of rehydration drinks.

For now, NICE advice is to encourage your child to drink fluids when they have a tummy bug, but to avoid giving your child fruit juice. See a doctor if you're worried your child is losing too much fluid.