What’s the Difference Between Food Allergy and Food Intolerance?
There has been a lot of coverage in the media about food intolerances and allergies (such as wheat and dairy). But what exactly are they, and what’s the difference between them?
- Food Allergy – an allergy affects your immune system causing your body to go into defence mode. This usually involves the mass production of histamine, leading to symptoms affecting the eyes, throat and skin.
- Food Intolerance – the reaction caused by a food intolerance usually takes place in your gut due to your body’s inability to digest certain food types.
Symptoms of an allergy tend to appear fairly quickly, while the reaction to a food intolerance could take hours.
Here we look at some common food types and their potential effects on the body:
Lactose Intolerance and Milk Allergy
Lactose intolerance is the body’s inability to digest lactose – a sugar found in dairy products. The lactose stays in the gut and starts to ferment. While the majority who suffer from lactose intolerance have inherited it, young children can also acquire it through an infection in their digestive system. The condition can last for life or (especially in the case of young children) just a few weeks.
Milk allergies are similar to lactose intolerance, but not quite the same. Very rarely, a milk allergy can cause anaphylaxis, just like a peanut allergy. In fact, milk is actually the third most common food allergy, after peanuts and tree nuts.
Symptoms of lactose intolerance include:
- bloated stomach
- stomach cramps
Symptoms of a dairy allergy can include:
- and in rare cases, difficulty breathing
Having to avoid milk and dairy can eliminate some major sources of vitamin D and calcium. While there are many substitute products that are dairy or lactose free, using additional supplements can also help you get these important nutrients into your diet.
This is an out-and-out allergy and can be quite severe, causing anaphylaxis in the worst cases. When the body comes into contact with nut allergens, the immune system responds as if facing a threat and releases histamine. Symptoms of anaphylaxis can appear any time, from instantly to in a few hours.
- itchy mouth, throat or ears
- red rash or hives
- swelling of the face, eyes, lips, tongue and mouth
While there is no cure for a nut allergy, you can try to avoid contact with nuts. Ask restaurants if any food has been prepared with, or near, nuts. Peanut dust alone can be enough to cause a reaction in some sufferers. If you do come into contact with an allergen, antihistamines can help reduce the symptoms. If you go into anaphylactic shock, an EpiPen can be used.
Coeliac disease is a digestive condition in which a person has an adverse reaction to gluten. It is an autoimmune condition – and therefore not quite the same as an allergy or food intolerance – in which your immune system mistakes a substance in gluten, called gliadin, as a threat to the body.
The antibodies your body releases in reaction to this cause the surface of your intestine to become inflamed. This flattens out your gut’s villi – tiny tubes that help you digest food. When they’re swollen, they are unable to digest food, and vital nutrients pass right through your body.
Symptoms, which appear as both short term and long term, include:
- bloating and flatulence
- abdominal pain
- weight loss
- slow growth rate in children
The last three of these are due to your body not getting enough nutrients.
Coeliac disease is not the same as gluten intolerance. Coeliac disease is a medical condition that most commonly presents itself in early childhood, while gluten intolerance is a blanket term referring to any sensitivity to gluten that can emerge at any point in your life.
There is no cure for coeliac disease, so excluding foods containing gluten is the best defence. These include barley, rye, wheat, flour, couscous and many pastas and breads. This means no pizza, pies, baked goods, cereals, biscuits or cake unless they are made with gluten-free ingredients. Giving up these foods will improve your symptoms within a few weeks, but repairing the damage done can take years.
People with a mild gluten intolerance may find that they can still consume certain types of gluten in small amounts, as their symptoms will be less severe.
Wheat sensitivity is often confused with coeliac disease or gluten intolerance, since wheat contains gluten. However, gluten-free products can still contain wheat. Little is known about the cause of wheat sensitivity, but it has become a problem for many in recent years.
Like lactose intolerance, symptoms can include:
- stomach cramps
The current recommendation is to give up wheat for a week and see if the symptoms disappear. If they do, you may have a sensitivity to wheat and should try a wheat free diet in the long term. Some people have also found reducing their consumption of fermentable foods (like pears, onions, honey and cabbage) to help the bloating.