Allergies and Intolerances

What causes allergies and intolerances? 

An allergy is an inappropriate response by the body’s immune system to a substance that is not normally harmful. The body mistakenly produces antibodies to ‘fight-off’ the substance, releasing histamine and other chemicals in the body which subsequently cause inflammation.

Food intolerances, on the other hand, do not involve the immune system. They happen when your digestive system can’t break down a particular food or your stomach is irritated by it. 

This could be because of enzyme deficiency, sensitivity to additives in the food or reaction to naturally occurring chemicals in the food.  

What are the symptoms of allergies and intolerances?

Food allergies cause immediate, distressing and often severe allergic reactions (known as anaphylaxis). Symptoms can be rash, wheezing or itching. Food allergy is actually quite rare, affecting about 2% of the adult UK population and up to 8% of children

Intolerances cause delayed reactions (a few hours or even several days) that usually have milder symptoms, such as migraine, bloating, diarrhoea or stomach cramp - but can nonetheless have a major impact on your health, both physical and emotional.

How can I identify if I have a Food allergy or Food intolerance?

Food allergy and food intolerance are commonly confused, as symptoms are often similar (migraines, headaches, rashes or digestive upset). 

Food intolerance can be an especially difficult concept to understand – even for doctors. The confusion has promoted a growing industry for inappropriately trained people selling many alternative tests purported to diagnose various allergies and intolerances. 

Food allergies can be detected through skin prick tests and blood tests, whereas food intolerances do not show up in allergy testing and are best identified through food exclusion diets, as well as keeping food diaries.

Before commencing on an exclusion diet, you should consult your GP.

Which foods should I watch out for?

Some of the most common allergenic foods are:

• dairy products
• eggs
• shellfish
• peanuts
• tree nuts (eg walnuts, hazelnuts and brazil nuts)
• soy
• wheat. 

No one knows why some people are allergic to certain substances, but some allergies have a genetic component. 

The foods that tend to cause intolerance reactions in sensitive people include dairy products (lactose intolerance), gluten (in wheat, rye and barley), chocolate, eggs, flavour enhancers and food additives, some types of fish, strawberries, citrus fruits, tomatoes and wine. 

It is important to note that food intolerance can lead to allergy if particles of undigested food mange to get into the bloodstream. This can happen in leaky gut syndrome, a condition in which the intestinal lining becomes inflamed and porous, allowing tiny particles of partially digested food to enter the bloodstream and cause an allergic reaction. 

Emotional factors such as stress and anger may aggravate allergies, especially if the immune system is not functioning properly.

How does healthy nutrition help treat allergies and intolerances naturally? 

Food intolerance or sensitivities can contribute to many different problems, either directly or indirectly. Indeed, a growing body of evidence indicates that they can trigger a wide range of unwanted symptoms, including asthma and allergies, autoimmune disorders, skin conditions, arthritis, atherosclerosis and other cardiovascular diseases, neurodegenerative diseases such as dementia, mood disorders, ADD/ADHD, narcolepsy, addiction and migraines.

While there is no known simple “cure” for food allergies and intolerances, there are a number of dietary measures that can help avoid and lessen the symptoms and correct the underlying causes. Managing allergies and intolerances focuses on identifying allergenic foods, avoiding food triggers and elimination and reintroduction diets, as well as the appropriate use of nutritional supplements. 

Find out more about the Allergies and Intolerances Program