Allergies & Intolerances…What’s the difference?

A negative reaction by your body to a particular food or food group is common. This reaction is mostly caused by intolerance to a food or food group rather than an allergy. It’s very common to confuse these two food hypersensitivities as some of the signs and symptoms are the same.

A true food allergy causes your immune system to react to a protein found in particular foods. When your immune system reacts quickly to the protein, it creates cells that can be detected by a blood test. Once these cells are created, they encourage the release of substances that cause your body to physically react. This process usually takes less than 2 hours and the physical reactions to these substances can range from mild symptoms e.g. skin reaction to reactions that can be life-threatening. The sooner these reactions occur, generally the more severe. This is to do with the type of cells and substances that are created. For instance a life-threatening allergic reaction known as anaphylaxis can cause breathing trouble and dangerously low blood pressure instantly.

On the other hand food intolerances are generally less serious. It is thought that they do not involve the immune system and are therefore not fatal. The physical reactions associated by these intolerances usually involve the gut.

Allergies involve an immune reaction, can be life-threatening are actually quite rare (1-10% of the population).
Signs and symptoms may include nausea, vomiting, a tingling mouth, hives, and swelling of the lips, face, tongue and throat. The
reaction is fairly instant (usually within 1 hour). Common allergens include cow’s milk protein, chicken eggs, peanuts, tree nuts and seeds, fish, shellfish, soya & wheat.

Whereas food Intolerancesare not life threatening and are relatively common (>20% population). Signs and symptoms may include nausea, vomiting, cramping and diarrheoa, sinusitis, indigestion, irritable bowel and migraines. The reaction is also a gradual process (few hours to days) which can make them difficult to identify. The most common food intolerances are FODMAPs like lactose as well as MSG (monosodium glutamate) & gluten.

Both allergies and intolerances need to be diagnosed and the food or group of foods avoided. Diet is obviously central. When you have an allergy, you will have to avoid the offending foods completely. If you have an intolerance, you must discover your tolerance level or threshold to the offending food. However, keeping your diet balanced, healthy and full of all necessary nutrients while remaining completely symptom free is no easy task and therefore a qualified dietitian or clinical nutritionist is crucial.