On the back of food allergy awareness week and rising numbers of people affected by allergies and intolerances, it’s something worth discussing. So, what’s the difference between a food allergy and a food intolerance? Food allergies and intolerances are often confused as their symptoms can be similar. But in fact, they are quite different.

Food Allergy

A food allergy is an immune reaction to a protein component in a specific food. The body produces antibodies against the food allergen. Consequently, there is a release of histamine and related inflammatory chemicals which may cause symptoms such as hives, swelling, vomiting, diarrhoea, shortness of breath, and itching. Reactions are usually immediate. It’s possible that even a tiny amount of the trigger food can cause a severe reaction.

The most common food allergens are:
– eggs
– cow’s milk
– wheat (gluten)
– soy, peanuts
– tree nuts
– fish and shellfish


Food Intolerance

Different to food allergies, food intolerances are either an inability to properly digest a food component, or a sensitivity to a food chemical. Food intolerances can irritate nerve endings but do not involve the immune system.

Symptoms of food intolerances may include:
Skin: eczema, hives, rashes
Gastrointestinal: IBS (Irritable Bowel Syndrome: alternating constipation/diarrhoea, gas, bloating), nausea, reflux
Airways: sinus problems, wheeze, chronic cough
Nervous system: migraine, headaches, hyperactivity or behavioural problems, irritability, foggy brain/difficulty concentrating, restless legs

The most common food intolerances are:
– Natural food chemicals (amines, glutamate, salicylates)
– Food additives (preservatives, artificial colours, and flavourings)
– FODMAPs (certain fermentable carbohydrates including wheat, fructose and lactose)

Interestingly, different people will react individually to food that they are intolerant to. Some may be able to tolerate greater amounts than others – its very individual.

To support health and wellbeing, it is important to identify the presence of both food allergies and intolerance. Unlike food allergies, which can be diagnosed by blood and skin prick tests, there is no specific test to diagnose a food intolerance. The most reliable way to identify a food intolerance is to follow an elimination diet under the guidance of an Accredited Practising Dietitian. Following an elimination diet takes a small amount of will-power, but is generally easy to follow with the right advice. The benefits of identifying your specific food triggers cannot be understated. An elimination diet usually involves 3 key steps:
1. Elimination phase: where a number of key potential trigger foods are eliminated from the diet
2. Challenge phase: where individual foods/food groups are gradually re-introduced and symptoms are monitored
3. Individualised diet phase: where your dietitian will provide you with fulfilling meal and snack options to ensure your diet is as liberal as possible, without the burden of experiencing your symptoms.

Remember, both food intolerances and allergies require a proper diagnosis. It’s important not to cut out food groups without professional advice as you could be missing out on key nutrients – and not to mention key delicious foods!

Want to know more? Book a Gap-Free or reduced cost initial consult with Accredited Practising Dietitian Ellie Starkey via this link: Click to book with Ellie. Just type Food Intolerance in the comments section. Or, give the clinic a call on 02 6646 3766.


Written by: Ellie Starkey – Accredited Practicing Dietitian.