Food – intolerances vs. allergies

Gluten free, dairy free and nut free have become commonplace on menus around the nation, as  the prevalence of food intolerances and allergies are at an all-time high. To find out the difference between the two and why they are on the rise, we consult Doctor Scott Horsburgh, AMA Queensland GP Representative.

What does it mean to have a food intolerance?

A food intolerance is a reaction to certain foods that can cause a physical illness, such as migraines, stomach upsets, and irritable bowel.

What does it mean to have a food allergy?

A food allergy involves the body’s immune system and can range in severity from mild up to and including anaphylaxis.

What are the different types of reactions people can have when intolerant to food?

Food intolerance can cause problems like migraines, irritable bowel syndrome, hives, toxic reactions such as Scombroid fish toxin or reactions to sulphite that can occur from red wine at times. The treatment of food intolerance is essentially eliminating the food from the diet to prevent the medical condition that causes it. 

What are the different types of reactions people can have when allergic to food?

Food allergy can cause swelling of the face, lips or eyes; hives or welts; tingling mouth; abdominal pain or vomiting; and eczema or rashes. It can also cause anaphylaxis, which can lead to difficulty breathing, swelling of the tongue, swelling or tightness in the throat, difficulty talking or a hoarse voice, wheeze or persistent cough, dizziness or collapse 

Why does it seem the lines hAVE become ‘blurred’ in recent years?

Food allergy and intolerance may be confused because the symptoms at times can be similar. However, food intolerance does not involve the immune system and cannot lead to anaphylaxis. The exact mechanism behind food intolerance is not always clear.

How do you find out if you have a food intolerance?

There are no reliable tests to confirm food intolerance and the diagnosis is based on a careful history from a medical practitioner. The only reliable way to confirm if a food intolerance is causing a certain medical problem is to follow an elimination diet; this is often done under the guidance of a dietitian or general practitioner.

How do you detect a food allergy?

A diagnosis of food allergies involves a careful history in conjunction with skin testing or specialised blood tests. There are subtypes of food allergies that may not be picked up by a blood or skin prick test due to them being activated by a different part of the immune system. To diagnose these subtypes we often do elimination diets or an oral food allergen challenge. 

Why does it seem that allergies and intolerances to food are more prevalent than they were a decade ago?

We are not sure why allergies and food intolerance appear to be increasing. 

There are a number of theories about why it may be the case:

• Decreased exposure to infections or microbes in early life

• Delayed introductions of allergic food such as nuts or eggs

• Different methods of preparing foods can increase allergenicity, such as roasting peanuts makes them more allergic than boiling them

• Altered gut bacteria due to low fibre diets may alter the body’s immune function and create an allergy

Can you grow out of food intolerances and allergies?

Many children will grow out of their food allergies and intolerances but not all. Introduction of any allergic or intolerance food should only be done under medical guidance. 

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Did you know?

Food allergy occurs in around one in 20 children and in about two in 100 adults. The most common triggers are egg, cow’s milk, peanut, tree nuts, seafood, sesame, soy, fish and wheat. 

Allergies on the rise

Studies have shown that food allergy affects 10 per cent of children up to one year of age; between four to eight per cent of children aged up to five years of age and approximately two per cent of adults. Hospital admissions for severe allergic reactions (anaphylaxis) have doubled over the last decade in Australia, the USA and UK. In Australia, admissions for anaphylaxis due to food allergy in children aged zero to four years have increased five-fold over the same period.