Food intolerance and Food Allergy

IBS share symptoms with other gastrointestinal conditions and may sometimes be confused with a range of diseases and disorders, including food intolerance, food allergy, irritable bowel disease (IBD), celiac disease, gluten sensitivity, anxiety, depression and even stomach or colon cancer.

Clinicians knows how to give the correct diagnose and it is important to get a proper diagnosis to get the correct treatment. Even if several conditions share common symptoms like pain, bloating, diarrhoea, nausea, headache and constipation there are usually other clinical signs that can be used to differentiate between them like for example inflammation and other physical signs.

IBS patients usually become well informed when it comes to gastrointestinal pathology, but IBS should be diagnosed by a doctor. Below you’ll find a summary of food intolerance and food allergies that can have symptoms similar to IBS.

Food Intolerances and Food Allergies

More and more expensive products that cater to people with various food allergies or food intolerances are showing up on the shelves of our grocery stores. Here’s a summary of the most common forms of food allergies and food intolerances, how they differ and how they can affect the stomach and intestines through for example stomach ache and bloated stomach etc.

About 5 to 10% of the population around the world including both children and adults are believed to suffer from some kind of allergy or non-allergic hypersensitivity to some food. The foods that most commonly cause allergies or intolerances include milk, fish, shellfish, eggs, legumes (eg. peanuts and soy), nuts, seeds and wheat.

To begin with, it is important to distinguish between allergic reactions (food allergies) and non-allergic hypersensitivity (food intolerance).

Allergies

An allergy is an unwanted immune reaction. Our immune system which protects us against disease-causing bacteria, viruses and other substances suddenly begins to react strongly against harmless substances. These substances are called allergens (allergy-causing substance). Allergies can commonly be divided into two groups – IgE-mediated and non-IgE-mediated allergies.

IgE-mediated allergy

IgE-mediated allergy which is the most common form of food allergy causes an immediate reaction which can take from a few seconds to hours. In an IgE-mediated allergy, the body forms and accumulates immune system components known as IgE antibodies against substances found in food that the body cannot tolerate. For example in a peanut allergy, IgE antibodies are formed against allergens in peanut and in case of an egg allergy IgE antibodies are formed against proteins in the egg. The presence of these antibodies in the blood can lead to rapid and powerful reactions in the blood vessels for example in the eye, nose, throat, respiratory tract or gastrointestinal tract. The reaction is often rapid and the allergen causes the tissue to become irritated and swollen.

Non-IgE mediated allergy

In a non-IgE mediated allergy our immune system reacts without producing these antibodies.

Allergens

The allergen can be anything that circulates in the air around us such as in the case of pollen, fur allergy and dust allergy. But the body can also react strongly to substances, usually proteins, which are naturally part of our diet, causing what was then called a food allergy. Some common food allergies are nut allergies, fish, shellfish allergy and allergy to eggs. These can cause damage or even pose a danger to life. Symptoms of food allergy often appear immediately after a meal, but they can also show up after a few hours or even days. It may especially take more time in non-IgE-mediated allergic reactions.

Causes

It is not exactly known why some people suffer from allergies while others do not. There is however, many times a chance that people may inherit and develop allergies from their parents. Allergies can occur at any age, even though it is more common that they occur during the early years. Sometimes food allergies can even disappear with age. However, some allergies such as peanut allergy and allergies to shellfish that often crop up later in life rarely disappear.

Food Intolerance (Other non-allergic hypersensitivity)

In a non-allergic hypersensitivity or food intolerance no response occurs by the body’s immune system. Instead, a substance in the diet causes the problem in other ways, for example in the case of lactose intolerance, where the body cannot break down lactose in full, which may cause local discomfort in the digestive tract. It may also be that the diet contains substances that give direct reactions similar to those you may have in an allergy. For example, histamines which are also released in an allergic reaction can come from consumption of certain foods such as cheese, mackerel, tuna and red wine. Other substances that can cause hypersensitivity reactions are acetylsalicylic acid, benzoic acid, azo dyes, sulfites and antioxidants.

Symptoms

The most common symptoms of an allergic or non-allergic hypersensitivity reaction come from the gastrointestinal tract (nausea, stomach pain, diarrhea, small children; colic and vomiting), skin (hives, eczema) or respiratory tract (asthma, cough, phlegm, runny nose). Itching of the mouth, swelling (lips and throat) and watery eyes is also common. Anaphylactic (allergic) shock is rare but also a life threatening condition that can affect people with allergies. At anaphylactic shock requires immediate intensive care.

Below we have given some examples of some different food allergies and food intolerances.

Lactose intolerance

Lactose intolerance, also called lactase deficiency is the inability to digest lactose which is a sugar found in milk and to a lesser extent in milk-derived dairy products.

As mentioned above, lactose intolerance is not the same thing as allergy to cow’s milk. It is the deficiency or inability to produce the enzyme lactase which breaks down lactose. The lactose if not broken down can then serve as a source of energy for bacteria in the intestines that can help us break down the lactose, but also potentially cause problems such as flatulence.

All mammals usually cease to produce lactase, becoming lactose intolerant, once they switch from their mother’s milk to a proper diet. We humans have however evolved to develop what is called lactase persistence and continue to produce lactose into our adulthood.

Saying that, to a limit we are all lactose intolerant. That is, for all of us there is a limit to how much lactose we can break down and depending on our genetic inheritance and the diets we have, we can either break down and tolerate less or more lactose. In Sweden we are as a population unusually tolerant to lactose. However, in many parts of the world, especially Africa and Asia people cannot withstand drinking large amounts of milk because they largely lack the enzyme lactase.

A person who is lactose intolerant must limit their consumption of normal milk, cream, and also milk products to some extent. Luckily our grocery stores are now filed with lactose free products which can be consumed by lactose intolerant people. Completely excluding lactose could potentially result in even more intolerance so it is usually recommended to try to find out how much you tolerate and limit, not exclude if lactose intolerant.

Hypersensitivity to fruits and vegetables

Various fruits, berries and vegetables can sometimes cause hypersensitivity reactions such as itching in the throat and around the mouth and hives. It is common, for example, that people who suffer from allergy to birch pollen also react to raw apples and stone fruits (fruits where in each fruiting body there is only a single seed, such as cherry, peach and plum).

Did you know that …

….food that contains any of the following ingredients (which may be allergenic) must be stated on the packaging? (Usually written in bold text in the ingredient list, Please note: Legislation differs depending on country)

Peanuts, nuts (cashew, hazelnut, macadamia nut, pistachio, almond, Brazilian nuts, pecan and walnut), lupine, mollusk (squid, snail etc.), crustaceans, fish, milk, celery, mustard, sesame seeds, soybeans, grains with gluten, eggs, and sulfur dioxide and sulphites (at 10 mg/kg or more sulphite in the product)

Are you allergic? Remember to always read the ingredient list carefully even on products that you usually buy, the content may have changed.

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