Food intolerance vs. food allergy: What is the difference?


Food intolerances and food allergies can be unpleasant and complicate everyday life. In the worst cases food allergies can be life threatening. However, having a food intolerance or allergy can be managed when you know which foods are the culprits.

Who doesn’t like to enjoy some delicious ice cream when the days are sunny and warm? But for some people that scoop of creamy chocolate ice cream can cause uncomfortable symptoms: less than 30 minutes after eating they suffer from abdominal pain and bloating. Some even experience vomiting and diarrhoea. When they drink their Latte in the morning they start to feel sick; when they eat a cream cheese bagel in the afternoon diarrhoea strikes again. They are intolerant to lactose, a carbohydrate found in milk.

What is a food intolerance?

Food is composed of carbohydrates, protein, fat and various nutrients and chemicals. Sometimes these naturally occurring molecules can trigger symptoms in individuals. There are many different types of food that people can be intolerant to. One of the most common food intolerances is lactose intolerance.

In lactose intolerance, the body cannot digest milk sugar (lactose) found in milk and dairy products. But lactose can also be found in soups, fast food, desserts and even prescription drugs. To digest lactose the body utilises the enzyme lactase. Lactase splits the lactose into two smaller sugars, glucose and galactose. These smaller sugars are absorbed by your body to provide energy. 

Lactose intolerance means that there is simply not enough of the lactase enzyme to break down the lactose. The undigested lactose passes through the small intestine to the colon where natural bacteria ferment the lactose and produce acids and gas. This can cause the symptoms of lactose intolerance such as abdominal pain and bloating. With the cerascreen Lactose Intolerance Test and a visit to your doctor you can find out if you are intolerant to lactose or not.

The difference between food intolerance and food allergy

Food intolerance and allergy are both types of ‘food sensitivity’ and both can make you feel unwell. Food allergies involve the immune system. Food intolerances are adverse reactions to certain food components but these do not involve an immune response.

If you have a food allergy your immune system reacts to a particular food protein that is harmless to most people. This is because your body produces antibodies against a specific protein in the food (the allergen). So when you eat the food a chemical reaction in the body causes inflammation. If someone has a severe food allergy the symptoms can be life-threatening. The symptoms of food intolerance, however, can be very unpleasant but are generally not life-threatening.

Food allergy and food intolerance are commonly confused as symptoms of food allergies and intolerances can be quite similar. Both food intolerance and allergy can cause headaches and migraines, skin conditions, general feelings of weakness, runny nose and an upset stomach and bowel. Other severe symptoms of food allergy include swelling or tightness in the throat, a swollen tongue, watering eyes and a persistent cough. 

Use the cerascreen Food Reaction Test to find out if you have food intolerances and food allergies. The test is easy to handle allowing you to do it at home. A comprehensive IgE (immune globulins of the subclass E) and IgG4 (immune globulins of the subclass G) screening of your blood is performed in our human diagnostic laboratory.

The difference between IgE food allergy and IgG food allergy

There are different types of food allergies.

When allergy symptoms appear right away it is called a type 1 allergy. A classic type 1 allergy is when the immune system produces specific IgE antibodies. The symptoms of a type 1 food allergy can be severe and even life-threatening.

A delayed IgG food allergy is when the immune system produces specific IgG antibodies and these antibodies lead to inflammatory processes. The symptoms appear up to 48 hours after the consumption of meal and it is difficult to pinpoint which foods caused these symptoms.