Cracking open home truths on peanut allergy

Three per cent of all one-year-old children throughout our ‘lucky country’ are unable to eat foods with peanuts or traces of peanuts because they are allergic, according to the 2011 HealthNuts study.

The good news is that for some children, allergic severity will lessen with age.

However, around 20 per cent of cases will become worse over time and up to 75 per cent of kids will endure a peanut allergy for the rest of their life.

President of Allergy and Anaphylaxis Australia, Maria Said, describes these figures as a “real concern”.

“What we know from fatality studies is that the majority of people who die from a severe reaction to a food – anaphylaxis – die as a result of consuming peanuts or other nuts when they have an allergy to them,” explains Said.

Peanut allergy trends
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Research shows there has been a three-fold increase in hospital presentations due to food allergies over recent decades, with the biggest increase among children under five years of age.

Australia Society of Clinical Immunology and Allergy (ASCIA) also estimate there are around 31,000 new cases of food allergies each year, including an estimated 9,000 new cases of peanut allergy alone.

But it’s not just children who develop peanut allergies. Around 1.5 per cent of adults aged 20-45 years have a food allergy, with peanut allergy being the most common.

"We just hope that researchers can one day find a cure.”

“I have known many people who have developed allergies later in life,” states Said.  

“They have no allergies one day and then the next day, they have a prawn and experience a life-threatening reaction…We just hope that researchers can one day find a cure.”

Why are prevalence rates so high in children?
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The short answer is that we don’t know. However, this month Victorian-based researchers found that babies with hyperactive immune cells at birth were more likely to develop food allergies in their first year of life.

The research team discovered that babies at risk of developing food allergies in early life are born with a pattern of immune activation.

One of the study’s researchers, pediatrician, Associate Professor Peter Vuillermin from Barwon Health said more investigation is needed to determine why this happens.

“Environment might be at play,” he says. “But it could also have something to do with the composition of the mother’s gut flora during pregnancy, vitamin D or their diet.”

Babies and food allergies: Behind the discovery
Australian researchers have discovered that some babies are already ‘primed’ to have food allergies by the time they are born. SBS spoke to one of the researchers behind the ground-breaking science to learn more about food allergies in babies and understand what the findings mean for bubs, mothers and mums-to-be around Australia.

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How peanut allergies develop: 5 theories
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Scientists around the globe have spent many hours and dollars investigating why so many people are currently allergic to peanuts.

Although there are still no definitive answers, there are a number of evidence-based theories (warranting further investigation) that explain the current health dilemma facing the world.

 

1. Animal exposure

According to a 2015 study published in the Journal of Allergy and Clinical Immunology, dog ownership in early life could play a protective role in the development of allergy and asthma.

Children in households with at least two dogs or cats are also 70 per cent less likely to develop serologic or skin prick test reactivity to common respiratory antigens (Ownby et al., 2002).

In Europe, a 2011 study found that the risk for allergy is also lower for children on farms.

On the flip side, it's inferred that children who haven't been exposed to dogs or farm animals are more likely to develop allergy.

 

2. Peanut exposure

Evidence states that introducing allergenic foods after a child’s first year of life may decrease the risks of developing food allergy, particularly for those who are at already at risk of food allergies.

This theory was examined in the Learning Early about Peanut Allergy (LEAP) trial and its findings were published in the New England Journal of Medicine in 2015. The trial found that children aged 4-11 months who were randomly assigned to consume peanuts up to 60 months (five years) of age showed significantly reduced frequency of peanut allergy development and modulated immune responses to peanuts.

The findings suggest children are not predestined to allergy and if they develop an allergy to peanuts before they turn one, it can be reversed through dietary inclusions.

 

3. Hygiene

The 'hygiene' or 'microbiome' hypothesis states that, unlike our ancestors, modern humans live in an environment that is too clean. As a result, our immune system does not have to do the work it used to do to fight bacteria and is now weakened.

A 2015 paper published in the Journal of Allergy and Clinical Immunology looked at the cleanliness of the common home, medical practices, and human behaviors and states that the markers of a “protective microbial environment” have changed with modern hygiene practices. This could contribute to the development of allergies and asthma in children.

A/Prof Vuillermin also explains this theory: "if a mouse is born into a sterile environment and doesn’t colonise, its bowel goes on to get disease. We can prevent that early on if we can get in during that window of opportunity. We are just not sure how big that window is in humans”.

 

4. Pesticides

Methods of food processing have changed over the years. Some scientists believe that chemicals and pesticides now used to grow crops, which didn't exist in the past, are responsible for allergic reactions.

Dichlorophenol-containing pesticides were identified as being partially to blame for peanut allergy in a study published in the December 2012 issue of Annals of Allergy, Asthma and Immunology.

The findings reported that high levels of dichlorophenols – the chemical used in pesticides, consumer insect and weed control products, as well as tap water – were associated with food allergies when found in the human body.

The chemical showed up in the urine of individuals with food allergies, suggesting a possible link between the two in the study. Those with the highest levels of dichlorophenols were more likely to have an allergy to milk, eggs, peanuts, or shrimp.

 

5. Vitamin D

Vitamin D might also play a role in protecting or exposing children to peanut allergy, according to research.

A 2013 study published in Journal of Allergy and Clinical Immunology shows that children with Australian-born parents who had a vitamin D insufficiency were more likely to be food allergic. However, infants of parents born outside of Australia did not have the same risk.

Scientists are not definitely sure why but it is believed that vitamin D might offer some protection against food allergy.

 

Although these theories are all based on fact, at the end of the day no one knows what makes one child allergic and another child healthy as every person’s situation and body is different.

But, as one study put it: “Food allergy is a complex immune-mediated disease consisting of numerous environmental, genetic, and epigenetic risk factors”. However, it adds, management and interventions to prevent an attack are “likely to be simple and cost-effective”.

Allergy or intolerance?
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“There’s a lot of confusion in society and – dare I say it – among health professionals over the difference between an intolerance and allergy,” comments Said.

She explains that the differentiating between the two health conditions is an immune system response, present in allergies and absent in an intolerance.

“To better understand the difference between an allergy and intolerance, think for a moment about someone with a milk allergy versus someone with lactose intolerance,” she says.

“There’s a lot of confusion in society and – dare I say it – among health professionals over the difference between an intolerance and allergy."

“Neither person can drink milk. But an intolerance exists because you are missing an enzyme needed to digest the lactose. It has nothing to do with the immune system.”

An allergy can also come on suddenly, be triggered everytime you consume the allergen (peanuts) and can be life threatening.

Meanwhile a peanut intolerance, while uncomfortable, is not life-threatening. It usually comes on gradually and may only happen when you eat peanuts a lot, often.

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Peanut v nut allergy
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The difference between a peanut and general nut allergy may sound obvious: if you have a peanut allergy, you are allergic to peanuts and nothing else. If you have a nut allergy, you might be allergic to a range of nuts.

But the real difference stems from how the nut is grown. Peanuts come from the ground while most other nuts – almonds, pine nuts and walnuts – are grown on trees.

That means that peanuts are legumes like peas, lentils and chickpeas, and have different proteins compared to those contained in tree nuts.

“You can be allergic to peanuts and eat tree nuts however about 30 per cent of people are allergic to both peanuts and one or two other tree nuts,” Said explains.

“So it’s important to follow the advice of a doctor when you are considering whether to eat a tree nut or peanut.”

Symptoms
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The tell-tale sign that you have a peanut allergy is that you exhibit some of the following symptoms upon eating (or sometimes touching) a peanut or trace elements of a peanut.

  • Mild: hives, swollen face (lips and eyes), abdominal pains, vomiting and tingling in the mouth.

  • Severe: Difficulty breathing, wheezing, coughing, unable to talk, a hoarse voice or a change in the tone of your voice and dizziness.

Anaphylaxis is the most severe form of allergic reaction that usually involves more than one body system (skin, respiratory, gastro-intestinal and cardiovascular). It typically occurs within 20 minutes to two hours of exposure to the trigger and can rapidly become life-threatening.

“If you have any symptoms that are severe, that’s a sign of a life-threatening reaction,” warns Said. “Don’t stand up or walk. You need to lie down, use your Epipen if you have one with you and call an ambulance.”

Diagnosis
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An accurate and timely diagnosis of peanut allergy is essential to avoid a mild or severe allergic outbreak.

Said advises anyone concerned about a food allergy to contact their GP and ask for a referral to a specialist for extensive testing because allergies aren’t “always as black and white as some people think”.

How to shop
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One of the big annoyances related to peanut allergies is finding out what food products you can and can’t eat. Eating food that contains whole peanuts or trace elements or ingredients that are cross-contaminated with peanuts could warrant a deadly reaction.

People with peanut allergies to exercise due caution when eating out and buying pre-prepared food, Said advises.

She also adds that consumers with allergies should always read labels when grocery shopping. Legally, all labels on food sold in Australia (whether the product is imported or made in Australia) are supposed to say if it contains peanuts. But there are cases where specific brands don’t.

“My advice to people with a peanut allergy is to stick to the brands you know and trust, manufactured in Australia,” Said adds.  

“But if you do want to purchase imported foods, buy food from English-speaking countries where the ingredient list didn’t need to be translated. That leaves no room for errors.”

Allergy management at school
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Said explains that most schools around Australia already have education and management programs, guidelines and policies in place dealing with all types of food allergies. Resources are readily available for teachers and school communities so if you feel a school isn’t as prepared as you like, contact Allergy and Anaphylaxis Australia for support.

“Parents also need to disclose their child’s allergy to the school early on. They need to work with the school at the start of each year to recap training, look at health programs again and come up with a refined system of [issues] management.”

Live life to the full
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Said encourages people with peanut allergies to manage the condition as best as they can so that they can maintain a good quality of life.

“You need to find that right balance of care so you are not petrified of living life because you fear a potentially life-threatening allergic reaction,” concludes Said.

“Education and support is what makes the world of difference when it comes to all food allergies.”