WHEN you have a child with food allergies, the fear of a severe reaction is always there, says Emma Amoscato. “It’s not just mealtimes, it’s going to nursery, family events, soft play. It’s not something you can ever take a day off from.”
She is frustrated that some children, such as hers, could perhaps have avoided developing their allergies at all. A growing body of evidence, including findings that emerged last month, suggests that the earlier babies eat foods like peanuts and eggs, the less likely they are to develop allergies to them.
But in some countries, such as the UK, weaning babies onto solid food early runs counter to official advice to avoid giving infants any solid food until they are 6 months old. Parents face conflicting information from allergy specialists and the healthcare staff they see most often such as family doctors and midwives. “You don’t know who to trust,” says Amoscato, who is author of Living with Allergies: Practical tips for all the family.
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The stakes are high, as was highlighted last year by two UK cases in the headlines in which teenagers died from allergic reactions, both caused by meals from a shop or restaurant they thought were safe.
Food allergies are now common. In the UK, for instance, 7 per cent of children now have one, and the number of hospital admissions for severe allergic reactions has risen six-fold in the past 20 years.
Changes in how babies are fed can’t be the only explanation, because other allergies such as hay fever and asthma are also on the rise. One idea is a modern take on the hygiene hypothesis, and suggests that this may be because modern life prevents us from encountering many friendly and important microbes during our childhood.
But weaning practices are also under suspicion, because they have changed a lot in the past few decades. It was once common for parents to start giving babies solid food as early as possible to fatten them up, sometimes at just a couple of months old or earlier.
By the 1990s, this was becoming frowned on, partly because doctors thought the gut was too immature. There was also growing concern about the move away from breastfeeding, especially in developing countries where there is higher risk of infections from formula milk made with unsterilised water.
As more was discovered about the beneficial substances in breast milk, such as antibodies that protect against microbes, the World Health Organization released guidelines in 2001 recommending that babies should ideally have nothing but breast milk for their first six months. These were adopted by many countries, including the UK.
At the time, this advice wasn’t expected to affect allergies, because the thinking was that we should delay giving potentially risky foods like peanuts to infants for as long as possible. Children known to be at high risk of peanut allergy, such as those with affected siblings, were advised to avoid them until they were 3 years old. Pregnant women were even told not to eat peanuts.
“It was once common for parents to start babies on solids as early as possible to fatten them up”
Then in 2015 came the first randomised trial to look at this question. In 530 children, those who ate peanut snacks before the age of 11 months were much less likely to get peanut allergy than those who waited until the age of 5; the .
It looked like a wrong turn may have been taken. “All this advice to delay is not just neutral, it’s actually harmful,” says Gideon Lack at King’s College London.
Why would timing matter? The idea is that the immune system learns not to react to things we eat when it first encounters food proteins in the gut. If weaning is delayed and babies first encounter food proteins through their skin, the immune system can become sensitised to these proteins.
There are several strands of evidence for this. One is that babies who have moisturisers or nappy creams based on peanut oil rubbed on their skin have a . Another is that infants get more allergies if they have , in which skin is inflamed and cracked – although that could just be because eczema is also an allergic condition.
It isn’t just babies with eczema who are at risk, says Helen Brough, also at King’s. Peanut dust stays on the skin for hours, she says. “If the parents have eaten a bowl of peanuts before a nappy change, they’re applying [peanut dust] to the skin.”
At her clinic, she warns parents against using creams based on peanut, almond or sesame oil, for instance. “We say no food on skin.”
Weaning advice has started to change. Multiple US and European bodies, such as the American Academy of Pediatrics and the European Food Safety Authority, now , with the proviso that infants should never be given whole nuts in case they choke.
But the UK hasn’t. One factor is that early weaning clashes with efforts to promote exclusive breastfeeding for a child’s first six months, which is a major focus of child health promotion.
“People may think once you introduce solids you might as well stop breastfeeding,” says Amy Brown at Swansea University, UK. Population studies show a link between early weaning and formula use – although this may just be a correlation.
Some studies have suggested that breastfeeding brings a wider range of health benefits than just cutting infections, such as reducing obesity and diabetes, although this has been contested. “There are known benefits of exclusive breastfeeding for around the first six months of a child’s life and this is best for overall health,” says Adrienne Cullum at Public Health England.
“7%
The proportion of children in the UK with a food allergy”
One UK body that takes a different tone is the British Society for Allergy and Clinical Immunology (BSACI), which has issued guidance urging parents of children at higher risk of allergies, such as those with eczema, to .
BSACI president Adam Fox says this isn’t at odds with official advice, as the full government guidelines say people should aim to introduce food at 6 months old, but not before 4 months, and that higher-risk families should consult their doctor. Those nuances can be lost in advice from healthcare staff and , which tend to state a blanket 6 months, although many families do start before then. “Parents are feeling quite lost and confused,” says Amoscato.
To help cut through the noise, parents of high-risk children would ideally get tailored advice from specialists, but they are unlikely to get an appointment in time. “If they’re on a waiting list for three or four months, then we have missed that window,” says Lucy Upton, a paediatric dietitian and a spokesperson for the British Dietetic Association. She recommends high-risk families follow the BSACI guidance .
Upton hopes that UK weaning advice will be reconsidered after a further , which found that high-risk children given six potentially allergic foods between the ages of 3 and 6 months developed fewer allergies than those who got them later. With its clear finding that benefits arise from starting before 6 months, the clash with official advice couldn’t be starker.
When Â鶹´«Ă˝ asked Public Health England if this changed things, a spokesperson said: “We wouldn’t change our advice based on one study – we need to look at the totality of the evidence.”
For Amoscato, the delays are frustrating. “They have done the studies. The delay in the government passing the information on could be putting children’s lives at risk.”
Can allergies be reversed?
Parents can try to reduce the risk of their babies developing allergies (see main story), but once an allergy has developed, there is nothing you can do about it, right? Perhaps not.
One approach being investigated is immunotherapy. This involves giving people gradually increasing amounts of the substance they are allergic to in an effort to reduce their body’s sensitivity to it. It starts off with microscopic amounts and must be done under medical supervision for safety.
Some studies have found that this helps some people, but others have suggested that in the case of peanut allergy, it raises the risk of anaphylaxis, a serious reaction requiring an injection of adrenaline to keep people breathing.
Recent research suggests why: the treatment doesn’t take away the allergy, it just encourages the body to make antibodies against the immune cells that cause the reaction. Protection may also , so people would need to keep taking small doses of allergens every day.
