Many people are confused about the difference between allergies and being intolerant to a food or something in its makeup.

What is food intolerance?

The main difference between food intolerance and food allergy is that intolerances do not involve the immune system and are generally not life-threatening. Food intolerances may happen only when you eat a lot of the food or if you eat it often, whereas in a true allergic reaction the immune response happens even if you have a small amount of the food.

Food intolerances are often a reaction (pharmacological or enzymatic) to natural substances in food, such as food additives and sulphites [1].

There is a large range of symptoms which result from being intolerant and this can happen straight after a food is eaten or sometime later, depending on the person.

Common causes of intolerance include:

• lactose (found mainly in milk and milk products)[2]
• vaso-active amines (found in blue cheese, red wine, tuna, mackerel, pork products and other foods)
• salicyclate and glutamate (naturally occurring chemicals in food
• food preservatives (particularly sulphite, benzoate and monosodium glutamate)[1]

Some 75% of adults globally suffer from lactose intolerance, but New Zealand rates are probably closer to 25% [2].

How do I know if I have a food intolerance?

Detecting a food intolerance usually means taking a detailed record of the foods you suspect and symptoms associated with this food, and also recording the time it takes to notice the discomfort. Symptoms of being intolerant can range quite widely, from feeling bloated and having gas, to feeling slightly nauseous and getting headaches.

Keeping a diary of what you have eaten, when, and the reaction can then be worked through with a healthcare professional, who will help to understand and diagnose the situation. Some food intolerances are easier to detect than others such as lactose intolerance [2].

Listening to our bodies and how we feel is an important step in working out what foods you may be intolerant to.

References
1. British Dietetic Association. Food Allergies and Intolerances. 2015 – [cited on 15 September 2017]. PEN Database

2. Auckland Allergy Clinic. Lactose Intolerance and Milk Allergy. 2014- [cited on 15 September 2017]. Available from: http://www.allergyclinic.co.nz/lactose_intolerance.aspx