Food allergies and intolerances: the differences
We hear a lot in the media about food allergies. In fact, food allergies are uncommon. And the good news is that most children who have allergies grow out of them.
What is a food allergy?
When you’re allergic to a food substance, your immune system reacts to that substance as though the substance is toxic. Your immune system tries to protect your body by releasing chemicals (such as histamines) into the body’s tissues. The resulting effect on the body can be quite major, even with tiny amounts of food.
Researchers estimate that only 6-8% of children and 1-2% of adults have a food allergy.
What is a food intolerance?
A food intolerance is a reaction to a substance in the food you’re eating. Unlike allergies, intolerances aren’t caused by your immune system reacting to the food.
Intolerance reactions are generally less severe than allergic reactions. They can still cause a lot of discomfort, though. Some people can cope with small amounts of foods they’re intolerant of, and they generally have fewer symptoms than people with allergies.
Common food allergies
About 90% of food allergies are caused by seven foods:
- cow’s milk
- hen’s eggs
- tree nuts (almond, brazil, cashew and so on)
- fish and shellfish.
The remaining 10% of allergies are caused by a wide variety of other foods.
Common food intolerances
The most common food intolerances are caused by:
- dairy products (for more information, see our article on lactose intolerance)
- food additives (including flavour enhancers such as monosodium glutamate or MSG)
- citrus fruit
- red wine and other foods containing histamines.
How long do food allergies and intolerances last?
Most children grow out of their food allergies by adolescence, especially children who are allergic to milk, egg, soybean or wheat.
Allergies to peanuts, tree nuts, fish and shellfish are more likely to be lifelong.
Giving a child even a small amount of a food she’s still allergic to can
cause a severe or life-threatening reaction. It’s best to only do this under
appropriate guidance from your doctor or allergist.
If you think your child might have grown out of an allergy, see a doctor or an allergist for an assessment. Do not experiment at home to see whether your child has outgrown the allergy.
Whether a food intolerance is a temporary or lifelong problem depends on the particular food and the reason your child’s body is reacting to it. It’s best to speak to your health professional about whether your child’s food intolerance can be treated.
Allergy risk facts and factors
If a child’s parents have allergies, the child has a 40–80% risk of developing any one of the allergy problems, such as asthma, eczema or hay fever. The particular risk for developing food allergy is less clear.
The allergy that a child develops might not necessarily be the same as the parents’ allergies. For example, a father with hay fever and asthma might have a child with egg allergy and eczema.
Most children with food allergy don’t have parents with food allergy. There might be a slightly higher risk, though, that siblings of a child with food allergy will also have a food allergy.
How to reduce your child’s risk of allergies
If you have a family history of allergic disease, you can take some simple steps that might help reduce your child’s risk of developing allergies, while maintaining a healthy diet.
Eat a well-balanced and nutritious diet while pregnant or breastfeeding
This might sound like commonsense advice for all pregnant or breastfeeding women. But some women who have allergic diseases wonder whether they can prevent their child developing an allergy by avoiding things that cause allergies.
In general, avoiding potential allergy-causing substances while you’re pregnant or breastfeeding won’t reduce the risk of your baby developing allergies. In fact, avoiding too many foods can be dangerous, because the baby won’t receive important nutrients.
The Australasian Society of Clinical Immunology and Allergy recommends that you don’t restrict your diet to avoid potential allergens while you’re pregnant or breastfeeding.
The Australian Government recommends breastfeeding for babies until they’re at least six months old. Babies can continue to be breastfed for as long as it suits mother and baby while water and solids are also introduced.
Use a partially hydrolysed infant formula
If you can’t breastfeed or your baby is weaned before six months of age, use a partially hydrolysed milk formula. This formula contains milk proteins that have been broken down into smaller proteins. Studies have found that using partially hydrolysed milk formula might prevent the development of allergies in children with a high risk of developing an allergic disease.
This type of formula should not be used if your child already has an allergy to cow’s milk, though. In that instance, see your health professional.
Introduce solids from around six months of age
The current Australian recommendation on infant feeding is to introduce solid foods from around the age of six months. You can introduce new foods gradually (every 2-3 days). There are no particular allergenic foods that need to be avoided. The introduction of solids before four months can be associated with an increased risk of food allergy.