What are food allergies

It’s no surprise that the increasing number of children with food allergies is a concern for many parents. But what causes food allergies, and what can you do about them?

Food allergies occur when the body’s immune system reacts to a food (or a substance in the food) that would normally be harmless. This immune response results in the release of antibodies, which in turn causes inflammation. It’s the inflammation that leads to most of the symptoms of allergy.

What does a food allergy look like?

Many food allergies result in symptoms that include stomach and bowel problems, like vomiting and diarrhoea, but they can also cause skin rashes, a sore throat, itchy and watery eyes, and swelling of the tongue or throat that can lead to breathing difficulties. Sometimes the reaction can be severe and life threatening, needing immediate medical attention.

The most common foods that cause allergic reactions in infants are peanuts, raw eggs, sesame and milk. A recent study conducted at The Royal Children’s Hospital in Melbourne found that more than one in 10 infants had a proven allergy to one of these foods. (You can read more about the study here.) Many of these children may outgrow their allergies by the time they’re five or six years old. However, this needs to be monitored by your child’ medical team.

What can we do to manage and prevent food allergies?

When a food allergy exists, strict elimination of the food that causes the allergy is required, so it’s very important to get medical help to diagnose and manage food allergies.

If someone in a baby’s immediate family has an allergy – especially one or both of the parents – the baby has an increased risk of developing a food allergy. If you suspect your baby is at risk, or if you think your little one is showing signs of allergy, you should seek medical attention immediately.

To try and prevent allergies in their babies, some women avoid eating foods that commonly cause allergies during their pregnancy. Some new mothers also delay the introduction of common allergy-causing foods into their baby’s diet. Both of these strategies are unproven, and in fact they may even increase the risk of allergies. If this sounds like you, it is a good idea to chat to your medical professional.

According to the Australian Society of Clinical Immunology and Allergy, consuming foods that commonly cause allergies during pregnancy is likely to be protective against allergies. (ASICA has some great information here.)

Similarly, slowly the introduction of common allergy-causing foods into a baby’s diet at around six months of age and continuing to breastfeed during weaning may be protective (see more here).

What about food intolerance?

It’s been estimated that food intolerance affects around 20% of the general population. Some of the symptoms of food intolerance can resemble those of food allergy, so it’s important to distinguish between the two.

Food intolerance does not involve the immune system. The symptoms, such as bloating, mouth ulcers and headaches, tend to occur some time after eating, and severe reactions don’t occur. Sometimes the symptoms only last for 10 minutes, and sometimes they may last for days.

In short, it can be harder to recognise a direct link between the symptoms and food intolerance than it is with food allergy.

But unlike food allergies, a food that triggers an intolerance doesn’t need to be avoided altogether. A qualified dietitian can help families determine the best way to manage food intolerances.

Food intolerances tend to be triggered by an element in a food. In babies, intolerances have been observed in food elements including:

  • Salicylates – found in many fruits and vegetables, tea, herbs and spices
  • Amines – found in some fruits and vegetables, baked meats, some cheeses and chocolate
  • Monosodium glutamate (MSG) – naturally present in many sauces, but also added as a flavour enhancer to some packaged foods

Although it hasn’t been scientifically proven, it is thought that many of these food intolerance compounds, or their by-products, may be present in breast milk. Some infants may therefore benefit from their mother changing their diet, but it’s important to consult a healthcare professional or qualified dietitian first.

Seek advice

Whether you suspect your baby has a food allergy or food intolerance, seek the advice of your GP or specialist for further investigation. Food allergies require strict elimination whereas food intolerances do not, so distinguishing between the two is very important to ensure the issues are managed in the best way possible.

Find out more

The Murdoch Children’s Research Institute AllergyPal has just launched a new podcast series called Allergies, produced by  PodcastOne. The nine part series featuring Professor Katie Allen and Professor Mimi Tang is information rich for anyone interested in prevention, management and future cures for food allergies and food intolerance. Allergies is a terrific tool to assist with prevention and maintenance of food allergies and intolerances. Download Allergies free from PodcastOne or your favourite podcast store today.

Article provided by:

Dr Jaci Barrett
Accredited Practising Dietitian