Could we be turning the corner on peanut allergies? A new study offers hope

New research from the United States shows a solid decline in childhood food allergies following changes in infant feeding advice, and there are signs Australia is on a similar path.

A new study, published this week in Pediatrics, found the number of children under three with food allergies fell by 36 per cent – driven largely by a 43 per cent reduction in peanut allergies – in the years after US health authorities scrapped old advice to delay exposure.

In 2017, new guidelines instead encouraged parents to take an early-introduction approach, offering peanut products to infants from around six months of age.

Allergy epidemiologist Associate Professor Rachel Peters from the Murdoch Children’s Research Institute says any sign of falling allergy rates is encouraging.

“Living with allergies has a huge burden on children and their families, and it’s not just about their diet – it affects every aspect of their life,” Peters says.

“There’s constant vigilance, checking every food label, and fear of a severe reaction. Many children also face social isolation, like missing out on school camps or parties, or feeling different because they can’t eat the same food as their friends.”

Australia introduced similar early-introduction advice in 2016. While new local data is expected in coming months, the most recently published studies showed a 16 per cent drop in peanut allergies.

Although the results are not as strong as those seen in the US, Peters says this probably reflects differences in data collection and reporting.

“The findings are helpful for reassuring parents that the guidelines recommending we feed babies allergy-causing foods earlier appear to be effective,” she says.

“New reports will be published soon, but the US study alongside our previous Australian data are pointing towards a reduction in peanut allergy.”

Despite the progress, infant food allergies in Australia remain among the highest in the world – impacting one in 10 one-year-olds – and researchers are still trying to understand why.

“We’ve been trying to answer this over the past 20 years of research,” Peters says. “We think it’s due to a combination of factors – genetics, diet, microbial exposures, and the Australian environment – it’s difficult to pinpoint it to one thing specific to Australia.”

A number of clinical trials are underway in Australia testing strategies for preventing and treating food allergy, including a nationwide peanut oral immunotherapy program.

“The ADAPT OIT program aims to change the way peanut allergy – the most common food allergy among Australian school-aged children – is treated,” says director of the National Allergy Centre for Excellence Prof Kirsten Perrett.

“Rather than strictly avoiding peanuts in diets, this program aims to safely build tolerance to the allergen and hopefully achieve remission.”

Food allergies develop when the immune system reacts to a substance that is normally harmless, such as a peanut.

“One hypothesis is that some children develop food allergies if they are first exposed to food proteins through inflamed or broken skin, such as eczema,” says Peters.

“The food proteins interact directly with immune cells that are designed to detect danger, such as an infection, and may mistakenly treat the food proteins as threats and produce allergy antibodies against them.

“However, when an infant is first exposed to a food through the oral route, immune cells in the digestive tract learn that the food is safe and helps train the body not to react.”

Allowing kids to get a little grubby can also help reduce the risk of food allergies.

“Our research has shown that babies who grow up with older siblings or around pet dogs are less likely to have food allergies,” Peters says.

“It is believed that exposure to microbes and germs in early life helps to promote healthy development of the immune system, making it less likely to overreact to non-harmful foods.”

Current Australian guidelines recommend introducing common allergy-causing foods – including peanuts, eggs, milk and tree nuts such as cashews – in the first year of life, but not before four months, and ideally while still breastfeeding.

Babies should be showing signs they’re ready for solids, such as good head control and interest in food, like reaching out or trying to grab it.

Peters says it’s best to start small and at home, introducing one new food at a time.

“It’s important to make sure these foods are introduced in an age-appropriate form – especially nuts as whole nuts are a choking hazard,” she says.

“Smooth peanut butter or peanut powder mixed into purees is a safe way to begin, and egg should always be well-cooked.”

Peanuts and eggs are the most common food allergies in Australian children. While Peters says parents are getting the messaging around introducing these foods in the first year of life, some forget the risks around lesser known allergies such as tree nuts or shellfish.

“There are a variety of allergy-causing foods, and it’s important to introduce each of them to your baby’s diet early.”

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