What Foods Am I Allergic To?
Ways to Diagnose Food Allergies
Types of allergic response
In lay terms, the word “allergy” often means some negative response to food or some other substance which normally would be considered harmless. However technically an allergy refers certain types of immune system reactions.
Allergic can be categorized by type of immunoglobulin response. Immunoglobulins are compounds which tag onto potentially harmful substances (antigens) and tells the immune system to attack.
IgE mediated allergies represent sudden acute symptoms. This includes rashes, hives, coughs, sneezing or a swollen tongue. Emergency or anaphylactic reactions that are treated with epi pens are IgE.
IgG allergies happen in the blood. IgG is involved in long term resistance to infection. For example, long terms immunity to an infection after recovery is due to the presence of IgG immunoglobulins.
IgE mediated food allergies commonly show symptoms immediately. IgG allergies are often delayed for hours or even several days after exposure.
.IgA is a type of immunoglobulin that is secreted across the digestive traction (and other mucous membranes where out body has contact with the outside world).
IgE, IgG and IgA allergy tests
The skin prick allergy test administered by allergists can help to identify IgE responses to both environmental and food allergies. The problem is that such tests are only designed to diagnose IgE response and not other types of allergies. We don't eat through the skin. Just because the skin doesn't respond with an IgE allergy that doesn't mean there are no other types of allergies when that food is eaten.
IgE allergies are mediated by histamine. The commonly used over the counter medications for allergies are anti-histamines. These are primarily used against environmental or seasonal allergies. IgG allergies however are not mediated by histamine.
IgE allergies are often genetic. IgG and IgA allergies may be acquired do to factors such as always eating the same foods or poor digestive system health. Some people gradually develop more and more allergies as they go through life, causing them to eat an ever restricting diet.
Both IgG and IgE panels are available through conventional labs such as Quest Diagnostics. Additionally many natural health care practitioners such as Naturopathic doctors may use panels from specialty labs such as: Alletess, Genova, Immunolabs, Cyrex labs, Diagnostechs and more.
A positive results on either a IgE, IgG, or IgA test indicates an allergic reactions. However, these tests are not perfect. False negatives are possible. The problem is that foods contain many different proteins, each of which can trigger numerous types of immune system or allergic response. The various immunoglobulin tests simple do not definitively rule out allergic response.
In order to combat this problem we see panels such as the following from Cyrex labs in order to diagnose gluten sensitivity:
Wheat Germ Agglutinin IgG
Wheat Germ Agglutinin IgA
Native + Deamidated Alpha-Gliadin-33-mer IgG
Native + Deamidated Alpha-Gliadin-33-mer IgA
Alpha-Gliadin-17-mer IgG Alpha-Gliadin-17-mer IgA Gamma-Gliadin-15-mer IgG Gamma-Gliadin-15-mer IgA Omega-Gliadin-17-mer IgG Omega-Gliadin-17-mer IgA
Glutenin-21-mer IgAGluteomorphin+Prodynorphin IgG Gluteomorphin+Prodynorphin IgA Gliadin-Transglutaminase IgG Gliadin-Transglutaminase IgA Transglutaminase-2 IgG Transglutaminase-2 IgA Transglutaminase-3 IgG Transglutaminase-3 IgA Transglutaminase-6 IgG Transglutaminase-6 IgA
However, despite measuring so many proteins for just one food (wheat) even this test is not 100%. The problem is that there are still many other potentially allergenic proteins. For this reason, when it comes to testing for gluten sensitivity and celiac disease gentic tests are the best. More information is available about this at glutenfreesociety.com.
Alcat has a blood draw allergy that is slightly different. This test does not look for immunoglobulins against various potential antigens. Instead WBC's are challenged with various substances including foods, additives, colorings, chemicals, medicinal herbs, functional foods, molds and pharmaceutical compounds. The patient's unique set of responses help to identify substances that may trigger potentially harmful immune system reactions.
Alcat tests can be helpful. However, upon seeing test results of people who have had both Alcat and IgG or IgA tests, it is not perfect. At times a IgG or IgA test will pick up an allergen missed on Alcat or vice versa.
The bottom line is that there is no such thing as a perfect allergy test. They can all potentially give false negative.
The most common allergens are the foods people eat the most. This includes wheat, dairy, corn, soy and eggs. Many people will feel better by simply avoiding these foods (although that means basically avoiding all artificial processed foods that come in boxes). Sometimes practitioners may recommend allergy tests because they feel patients are more likely to comply with a diet is they see proof for it on a lab test.
Positive response on allergy tests do help people figure out some hidden allergies they may have. So eve if the tests are not perfect. they can be useful. Whether or not to do a test depends upon severity of symptoms, and financial concerns. Allergy tests from specialty labs may not always be covered by insurance, and could be a $300 plus out of pocked expense.
Dairy and wheat are such common allergens that they generally warrant elimination regardless of what people see on allergy tests.
Regardless what side of the fence someone is on when it comes to raw, unadulterated dairy (the only product that should reasonably be called milk), conventional dairy is more industrial waste product than food. Contents of dairy contain blood, pus and antibiotics. Milk is then homogenized and pasteurized, which have their own problem. Pasteurization does not sterilize milk (or else it will never go bad), it simple lowers bacteria levels enough so milk is safe to drink for a while. A detailed review of why all these steps created a harmful product is beyond the scope of this article. The point is that virtually anyone in natural health field (Naturopathic doctor, nutritionist, nutritionally minded chiropractors, or MD) will not recommend patients consume conventional dairy as it well known to be a very allergenic food. The real purpose of testing for diary allergies is to convince certain patient to give up milk. These are often the ones who love milk the most, are most allergenic and often will not comply with dietary changes.
Thankfully many more people are aware of these particularly allergenic foods. I often don't have to tell new clients to go dairy and gluten free, because they already have become coming into see me.
If someone wants a lab to test for allergies to wheat, corn, soy and egg, Diagnostechs has a saliva IgA allergy test. This is a good test that can be used as an inexpensive, initial screen. Patients just need to be away that a negative saliva IgA test does not prove that there are no other sorts of allergic reactions happening.
Allergy Elimination Challenge Diet
An allergy elimination diet uses no labs tests. Instead patients remove the most common allergens from their diet. This includes wheat and the other commonly regarded glutenous grains (barley, rye, spelt oats - technically all grains have some gliadins), soy, corn, dairy, eggs, peanuts, citrus fruits and artificial foods. After a month the patient then reintroduces each of these foods one at a time and then tracks all symptoms for 3 days before adding back another food. Any worsening of symptoms indicates an allergy.
Safe foods for the most part include meats (not shellfish), fruits, vegetables and most nuts. This is essentially a whole foods diet.
There are several problems with this diet. First of all, even commonly non-allgergenic foods will be allergenic to some people. For example, other grains such as rice and quinoa will typically be part of allergy elimination diet. But what if someone is allergic to those safe foods?
For this reason there are many variations of what constitutes a non-allergenic diet. Some may exclude all grains for example.
Another problem with this is it's tedious. In years of practice I have given many clients this diet and reintroduction instructions and while many people will eliminate the major allergens, few follow this diet perfect, and almost no one bothers to reintroduce potentially allergenic foods one at a time while charting all symptoms for changes over the next 3 days.
In office allergy tests
There are different methods by which practitioners may test patients in office.
Some of these include:
- Carroll Food Intolerance Assessment - blood sample is placed in circuit and exposed to various foods in contact with reagent
- Electrodermal screening
- Applied Kinesiology
Since the method I use is Applied Kinesiology I write some more about it.
This tests the clients muscle strength against various foods. If there muscle strength remains strong then that indicates the body can tolerate a food or substance. Weakening of muscle strength indicates lack of tolerance and thus food or other substance should be avoided.
Technically when performing this test I say we're looking for a lack of tolerance and not an allergy. Since Applied Kinesiology does not actually test and sample for immunoglobulins, technically it's not an allergy test. Tolerance refers to the body's ability to cope with a foreign agent. In high enough doses any substance (including air and water) will can illness or death. For example an apple may be considered healthy, but eating a dozen apples would be beyond most people's ability to tolerate it, and thus will have symptoms. So I say using Applied Kinesiology we are looking for substance that there is low tolerance to.
Clinically, the testing matches up well to the allergies or sensitivities people know they have. When people follow the results of this testing they feel better.
Advantages to testing with Applied Kinesiology over lab tests:
- Immediate results
- Test isn't dependant on finding the right immunoglobulin, or else giving a false negative.
There are a few drawbacks. Some people may need to see a lab test before following through with dietary change. If that's the case then I'm happy to discuss those options, although it will be a large out of pocket expense. They must also understand that certain foods are very allergenic and at least a trial elimination is warranted even if the lab tests come back negative.