What is the difference between a food allergy and food intolerance?
A food allergy is an adverse reaction to the protein component of a food. It occurs when the body’s immune system mistakenly identifies a protein in the food as harmful, an invading organism like a bacteria or virus. Some proteins or fragments of proteins are resistant to digestion. Those that are incompletely digested before being absorbed are more likely to be tagged by our immune defences, specifically Immunoglobulin E (IgE) [immunoglobulin G (IgG) may be a tag for food intolerance reactions]. These tags fool the immune system into thinking that the protein fragment is an invader.
The immune system, thinking you are under attack, sends white the blood cells, and an allergic reaction is triggered. These reactions can range from mild to severe. A food allergy can cause symptoms such as an itchy sensation in the mouth or throat, an itchy skin rash (urticaria or nettle rash), gastrointestinal distress (vomiting and/or diarrhoea), or more seriously swelling of the lips, tongue or airways.
Anaphylaxis is a severe, potentially life-threatening allergic reaction that can develop swiftly. If someone is experiencing the symptoms of anaphylaxis, such as breathing difficulties and swollen lips, dial 999 immediately for an ambulance. Anaphylaxis should always be treated as a medical emergency.
Since food allergens tend to cause noticeable symptoms very quickly they are usually easy to identify. Common food allergens include peanuts (nuts generally), egg white, cow’s milk, soya bean, strawberries, certain fish and seafood.
Food intolerances are usually milder, and cause more broad ranging symptoms. The reaction is delayed, often 24 hours to 4 days, making identification of the allergen difficult. Food intolerances appear to be very common. They have been estimated by specialist doctors in the UK to affect perhaps as many as 25% of the population.
Many people have adverse reactions to foods, which do not show up with allergy (IgE) tests. It is now known that the underlying mechanisms responsible for ‘allergies’ or food intolerances are not restricted to IgE-mediated reactions. There are many different mechanisms that can give rise to these ‘allergy’-like symptoms. There is therefore a marked discrepancy between those displaying allergy reactions, and those with traditionally diagnosed food allergy.
Contact Intelligent Nutrition for more information.
Food Intolerance: a variety of symptoms
Food intolerance can cause or be a contributing factor to a wide range of symptoms such as those listed below.
|chronic fatigue syndrome
Food intolerances: difficult to identify without help
Food intolerances can be difficult to track down for several reasons. It is often difficult to identify problem foods partly because there is a delay between eating the food and symptoms developing, which may vary from a few hours to two or three days.
This problem is compounded by the fact that there is usually more than one food, sometimes several, triggering symptoms. Add to this the fact that many symptoms, such as fatigue, are very general and may have more than one cause and you can begin to see the problem.
How can problem foods be identified?
Food elimination and reintroduction diets are one way to identify food intolerances, but these can be cumbersome to perform and problematic to interpret.
If you are lucky, sometimes identifying the problem foods is quite straightforward, even without laboratory tests, as certain symptoms are more likely to be triggered by specific foods.
However, identifying food intolerances is often a complex process. At Intelligent Nutrition we can help you through this. If you are intolerant to particular foods we will advise you how your current diet needs to change and which foods you can substitute so that you maintain an enjoyable, varied and balance diet. We will also help you identify which type of laboratory test is the most appropriate for you.
We are able to offer laboratory tests as part of our service to you. The most appropriate tests are indicated below. Please see our Laboratory Tests page for more details.
Food allergy (IgE)
FACTest (Food Allergen Cellular Test): identifies which foods trigger an immediate inflammatory response (leukotrienes)
IgG antibody test: identifies which foods are tagged with IgG antibodies (more of an historic record)
The Nutrition Clinic, Leeds
Although we are based in Leeds, we see clients from all over Yorkshire including Harrogate, York, Bradford, Huddersfield, Halifax, Wakefield and much further afield. For those living too far to travel we also offer telephone consultations.