The number of people with food allergies in America has doubled in each of the last decades. Children with food allergies are more likely to have another atopic condition, such as eczema or asthma, and often are bullied because of their allergy.
Food sensitivities are poorly defined but usually involve immunoglobulin G (IgG)-mediated or cell-mediated reactions. Foods can also trigger other types of reactions. To make things even murkier, symptoms can appear hours or even days after food exposure.
It’s crucial that practitioners know how to systematically screen for and manage food reactions. This is why we invited our two leading experts on food allergies and sensitivities to join us on Nutramedica today.
Defining Allergies, Sensitivities And Intolerances
In conventional medicine, food allergies are considered IgE-mediated reactions. There are eight foods that are most commonly related to IgE-mediated reactions, including milk, eggs, peanuts, tree nuts, wheat, crustacean shellfish and soy. There's also an increasing concern about including sesame seeds.
Food sensitivities are poorly defined, but usually involve IgG-mediated or cell-mediated reactions. Symptoms can appear hours or even days after food exposure.
Food intolerance refers to a food reaction that occurs because of an enzyme deficiency related to digestion or metabolism. The classic example is lactose intolerance.
IgG Mediated Food Sensitivities Controversy
If controversy exists over this, it’s only among people who are not aware of the research. We can minimize the controversy by being clear with our terms.
There is a common misunderstanding about what the test is actually testing for. Also, the terms get used incorrectly. So there's a lot of education that takes place with the patient base to make sure that they're aware when they get the results back.
As long as we reserve the term “food allergy” to refer to a classic IgE-mediated response, and refer to other reactions as food sensitivities, there should be no controversy.
There is good evidence that foods can trigger an IgG-mediated immune response. It is a normal physiological response to produce IgG antibodies to foods. Oral tolerance is the normal state but it is NOT a normal reaction to develop high levels of antibodies to foods that are consumed regularly.
Evidence For Clinical Relevance Of IgG-Mediated Food Sensitivities
Human clinical trials have demonstrated the clinical relevance of IgG-mediated food reactions in irritable bowel syndrome (IBS), migraine headaches, eosinophilic esophagitis and Crohn’s disease.
Here is a brief list of studies: Atkison et al. showed in 2004 with a randomized, controlled trial that food elimination based on IgG testing was effective at reducing the symptoms of IBS.
Alpay et al. showed in 2010 with a double-blind, randomized, crossover trial that dietary restriction based on IgG antibodies was an effective strategy to reduce the frequency of migraine headaches.
Clayton et al. showed in 2014 that eosinophilic esophagitis was not associated with IgE, but was associated with IgG-mediated food reactions.
Wang et al. found in 2018 that the number of IgG-mediated food reactions may have the potential as a diagnostic marker of Crohn’s disease. This study also showed that patients who removed IgG-reactive foods were more likely to stay in remission from Crohn’s disease.
Key Signs That A Patient Might Have Food Allergies Or Sensitivities
There are three ways to look at whether a patient might have food allergies or sensitivities: you would look for classic signs of an allergy. The second consideration is in a patient who has another atopic condition. The third is in a patient who has an unresolved chronic condition. In the case of a classic allergy, the person will typically show signs immediately after consuming the food. They may develop itching in the mouth or throat or a constriction in their throat or swelling of the lips or eyelids or a hive may appear instantly.
In cases of atopic disease foods commonly play a role in the pathogenesis of other atopic conditions, like allergic rhinitis, eczema, asthma and urticaria. In patients with an unresolved chronic condition - you might find the patient presents with overt GI symptoms but in some cases food sensitivities might be suspected in cases of chronic headaches or mood disorders like anxiety or difficulty concentrating or unexplained fatigue. In some cases you might see bladder symptoms or an aggravation of interstitial cystitis with consumption of an IgG reactive food.
Food allergies and sensitivities can affect almost any system in the body, and can be associated with a wide array of symptoms, including constipation, bloating, gassy, urinary irritation, worsening symptoms of interstitial cystitis or overactive bladder, and fatigue.
The Most Common Food Allergies And Intolerances
- Lactose, a sugar found in milk
- Casein, a protein found in milk
- Gluten, a protein found in grains such as wheat, rye, and barley.
The following foods cause most food intolerances and allergies:
- Nuts such as peanuts, walnuts, pecans, and almonds, which contain salicylate
- Eggs, particularly yolks
Red wine, beer, and certain foods which contain sulfites used as a preservative. Foods that contain monosodium glutamate (MSG).
Preferred Testing To Identify Food Allergies And Sensitivities
ELISA testing is the most commonly used test among integrative practitioners to evaluate food allergies and sensitivities. It gives semi-objective data about food reactions but needs to be followed with elimination-challenge for confirmation.
The elimination-challenge diet is considered the gold standard for identifying food reactions, but it can be time-consuming and people can influence the results.
Once they eliminate the foods for a period of time, do a systematic introduction of each food item and track their symptoms. It usually makes that connection for the person between, “I'm eating this and these are the symptoms that are coming up”.
Now, for some people it can get a little bit muddy, or if there is a concern about compliance, then it's not a very effective tool because you're not really getting good information coming back.
So it has to be done very systematically and it can take a long time. With IgG-mediated reactions, avoidance of highly reactive foods for six months is recommended. Then, have the patient reintroduce each food in a systematic way.
Skin-prick testing and patch testing are the most commonly used tests in conventional medical practice, but they only test for IgE-mediated reactions.
Food sensitivity testing needs to be taken with a grain of salt. It's a good screen. It's not 100% accurate. It can generate both false positives and false negatives.
Also, when interpreting IgG tests, consider that antibodies to the Epstein-Barr Virus can cross-react with up to 40 different food antigens.
Newer High Tech Testing For Food Allergies And Sensitivities
There is a really novel technology using microchip technology that is done by a lab called Vibrant Wellness, and it has higher sensitivity and specificity than the ELISA testing.
Vibrant has developed a specific test platform to test antigenic foods such as corn, dairy, eggs, lectins, nuts, peanuts, seafood, soy, and wheat. In addition, Vibrant also offers a 180 extract level food sensitivity panel.
Cyrex is a clinical immunology laboratory specializing in functional immunology and autoimmunity. They offer multi-tissue antibody testing for the early detection and monitoring of complex autoimmune conditions as well as immunologic testing for both raw and cooked foods, and can also test for reactions to lectins implicated in food reactions.
How To Minimize A Child's Risk Of Developing Food Allergies And Sensitivities
A child's exposure to dirt and microbes will help develop their immune system over time if they have pets in the house or live on a farm. A healthy immune system is developed by exposure. Living in a sterilized environment is detrimental to a child’s immune development.
The “hygiene hypothesis” proposes that childhood exposure to germs and certain infections helps the immune system develop. This teaches the body to differentiate harmless substances from the harmful substances.
Early introduction of cow’s milk and peanuts reduces risk of developing allergies and sensitivity to those foods. Eating fish during pregnancy lowers the risk of the child developing eczema and that eating fast food increases the risk by 70%.
Exposure to environmental chemicals such as bisphenol-A (BPA) and phthalates may increase the risk of developing food allergies.
“What we're talking about here is referred to as a hygiene hypothesis. And it's no longer just a hypothesis. It's been substantiated over 20, 30 years now that environmental influences are essential to the healthy development of the immune system.
When I was first practicing, we had a practice of recommending that certain foods not be introduced to children until they were a certain age on the theory that their digestive system really wasn't able to handle things like dairy and wheat.
And now we find out that early introduction of cow’s milk and peanuts reduces risk of developing allergies and sensitivity to those foods. So it's just turned 180 degrees. We also know that eating fish during pregnancy lowers the risk of the child developing eczema and that eating fast food increases the risk by 70%.”
Dr Michael Traub ND FABNO
“I would say that food allergies and sensitivities affect many patients. There is research that substantiates the use of (food allergy and sensitivity testing) and not to be afraid of using them.
It could be super helpful to get to the root of what the underlying issue that's preventing them from getting better.”
Dr Barbara Weiss ND
The opinions expressed in this Nutramedica program are those of the guests and contributors. They do not necessarily reflect the opinions of Nutritional Fundamentals For Health Inc.
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