People talk to naturopaths a lot about their food allergies and intolerances, many people get kind of get confused and think that "all food reactions are allergies", when in fact, many reactions are intolerances and not actually food allergies. So how do you distinguish between them both? How do you know if you are actually allergic to something, or can’t tolerate a food? Let me explain...
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Food Allergy and Food Intolerance
Are They The Same?
There are lots of people who are talk to me about their food allergies and intolerances, and many people kind of get confused and think that all food reactions are allergies, when in fact, many reactions are intolerances and not actually food allergies. So how do you distinguish between them both?
How do you know if you are actually allergic to something, or can’t tolerate food?
A food allergy is one type of adverse food reaction that is mediated by the immune system. An adverse food reaction may comprise any symptom following the intake of food. Symptoms may be any perceptible change in how we feel and/or function. A symptom may present, for example, as a rash, achy joint, or fatigue.
We Classify Adverse Food Reactions Into 3 Subgroups
Toxic, commonly known as food poisoning and results from contaminants in the food.
We relate psychological or food aversion to a former ill experience and is psychosomatic.
Non-toxic reaction: divided into two groups, immune (allergy) and non immune mediated responses.
Non-immune-mediated reactions to food. Or food intolerance can mimic allergic inflammation and may occur from food additives, pharmacological compounds, or enzymatic deficiency (i.e., lactose intolerance).
Immune-mediated reactions or food allergies. We divide them into IgE- and IgG (or non-IgE mediated) reactions. Here is a simple diagram to put all of this into visual perspective, as defined by the European Academy of Allergy and Clinical Immunology (EAACI).
A true food allergy is not as common as you may think. Food intolerances are much more common in my experience. A food allergy is immune mediated and involves a reaction to a food or drink, which involves the immune system. We categorise food allergies into two groups: those which are more immediate (IgE immune response), and those which are more delayed (IgG immune response).
Let’s look at both:
Immediate Food Allergy the Type 1 or IgE Response
Food allergies are immediate or delayed. With an immediate reaction, it will be quite noticeable and could take place within minutes to a few hours after ingestion of the offending substance.
The best known and most studied form of food allergies is called a Type 1 immune reaction, or IgE mediated response. Type 1 food allergies occur in less than 5 percent of the population, and mostly in children. They are also called “immediate onset”, or “atopic” food allergies. These types of allergies usually occur in the genetically predisposed individual. One or both parents have an allergy. The immune system creates a specific type of antibody called IgE (immunoglobulin IgE) to certain foods.
An IgE reaction occurs immediately after exposure to the allergen, a food or inhalant. The early phase reaction usually occurs as little as 15 minutes after exposure to the allergen. Other types of IgE reactions may occur 4-6 hours later and persist for days with increased inflammation, including symptoms such as swelling, puffiness, redness and itching. I’ve heard many patients tell me that upon expose to a certain allergen, like pollen or some food, within hours they would experience a reaction. This reaction could range from mildly itchy skin to feeling completely disabled and needing to go to the emergency room at the hospital.
So what happens with these immediate responses? One side of the IgE antibody will recognise and firmly bind to the allergic food, while the other side of the antibody becomes attached to a specialised immune cell called a mast cell, packed with histamine. Ready and waiting for action, the IgE antibody now only has to wait for re-exposure to the food allergen.
When you eat the allergic food the next time, IgE antibodies hungrily latch onto the food. Almost instantly, histamine and other allergy-related chemicals (called chemical mediators) become liberated from the mast cell, bringing on many signs and symptoms rapidly.
The RAST Skin Prick Test
Since this pathway occurs immediately, it is very easy to recognise a Type 1 allergy as a problem after an exposure to the irritant. This is the immunological pathway behind seasonal allergies, such as hay fever. The most common test for this type of reaction is the “scratch” or “RAST” test, which is performed by doctors or specialists. This involves scratching the skin and applying a test substance and then waiting for a “wheal and flare response”, often a skin reaction.
The problem I’ve found with this test is that it’s not always a reliable sign of an allergy, with many patients showing a “false negative” test or even an exaggerated positive response. The test substance may be too old to invoke a reaction, or the test substance may not be specific enough to the particular person and therefore does not invoke the reaction. There are simply too many reasons this test can fail, and it does, so don’t rely on it to be “100% positive”.
It is interesting that a conventional New Zealand medical allergy clinic states: “A negative prick skin or RAST test predicts with about 97% accuracy that the test food was not the cause of symptoms but only in atopic disorders and where immediate hypersensitivity food reactions are involved”. I have not found this to be the case and have frequently discovered that the RAST test was not “97%” accurate at all. There are NO guarantees in this life, certainly not in immune testing, so never rely entirely on RAST food allergy testing. It’s just not worth getting paralysis from false analysis.
Type 1 Food Allergy Symptoms
The allergen and resulting symptoms are unique to the individual affected. Symptoms can be very individual. Some people don’t have any idea that they have food allergies.
Once the potentially allergenic foods become digested, broken down protein particles enter the bloodstream. The body rejects some of these food nutrients or other food components because of the immune system’s response. The immune system produces antibodies and other related elements that fight the protein particles. And that’s when the symptoms start.
Not long after the response, allergy symptoms become apparent, sometimes including swollen hands, itchy and swollen eyes, sensations of the lungs, and, if acute, even the closing of the larynx or throat. Anaphylaxis is the most alarming response. It means you can’t breathe; you have a fast heart rate, and there could be feelings of panic. Other symptoms may include stomach cramping, diarrhoea, hives, swelling, itching and various skin rashes.
Immediate Food Allergy (IgE) Summary
We call these the “Type One” toxic immune reactions, and they are quite obvious. You know when you have one because your body suffers a notable and almost instant reaction, some people can die from consuming fish or crab meat. More people die in Australia from bee stings (an IgE response) than from snake bites annually.
At most, only 1 or 2 foods (rarely more) are involved in causing these allergic symptoms.
Small, even the tiniest trace amounts of food can trigger these intense allergic reactions, including anaphylaxis, in which a fatal reaction can occur within minutes.
Allergic symptoms commonly appear 2 hours or fewer after consumption of offending foods, but may occur within minutes.
Primarily affects the skin, airway and digestive tract manifesting in such “classical” allergies as asthma, rhinitis, urticaria, angioedema, eczema, vomiting, diarrhoea and anaphylaxis.
Common in children, these reactions do occur in adults, albeit less commonly than the delayed (IgG) allergies.
Some leading experts claim that addictive cravings and withdrawal symptoms are rare to nonexistent in children with IgE allergies, but this is certainly not my experience!
Except for infants and young children, due to single food and the immediate appearance of allergic symptoms, the offending food is commonly self -diagnosed. As a result, many patients never see a physician.
Allergic food is food that is rarely eaten.
Commonly a permanent, fixed food allergy, but again, I have seen with some patients that no allergies are permanent. Even the most virulent IgE allergies sometimes become rather mold, on a rare occasion actually disappear entirely. The only certainty with immunity is change.
Frequently, IgE “RAST” positive and skin test positive, but not necessarily so. It all depends on the experience of the person doing the testing, and the conditions they performed the test under. For example, if the patient was taking drugs like antihistamines beforehand or even how much Vitamin C the patient took that morning. As you can see, many variables can cause a “false negative” test result, and you’d better believe it. It happens a lot. False reports.
Although mixed immediate/delayed onset allergic reactions can occur (e.g., eczema), the IgG antibody is not characteristically involved in IgE responses.
Mast cells, basophils, histamine and tryptase release are all commonly involved in this type of reaction.
Delayed Food Allergies – Type 3 or IgG Response
Non-IgE-mediated allergies involve antibodies other than IgE (e.g.: IgG). Symptoms of an IgG-dependent reaction may occur hours to days following exposure to the allergen. When foods are involved, we often refer to these as “delayed food reactions”.
Much more complex mechanisms are involved in the delayed response. Here, the IgG antibody will bind to the food antigen and form an immune complex. An immune complex, sometimes called an antigen-antibody complex or antigen-bound antibody, is a molecule formed from the binding of multiple antigens to antibodies. The bound antigen and antibody act as a single object, effectively becoming an antigen of its own. Let’s leave it at that, or I’ll lose too many readers…
What happens to these “complexes”, is that they travel in the bloodstream throughout the body. They eventually deposited in various tissues and trigger inflammatory reactions. It is most unfortunate, but conventional medicine does not really recognise these types of immune responses.
According to the American Academy of Allergy, Asthma & Immunology (AAAAI), IgG food allergy testing test has “never been scientifically proven to accomplish what it reports doing” and “the scientific studies to support the use of this test are out of date, in non-reputable journals.” A 2016 study of IgG and food allergies, however, reports a different narrative. But because it was from the Annals of Saudi Medicine (ASM), they perhaps viewed it as “non-reputable” science. Rather sad.
Delayed Food Allergy (IgG) – Good Summary
These delayed food reactions are not immediate, and this can make them almost impossible to detect without sophisticated blood testing. I find it rather hard to believe that many conventional immunologists virtually ignore the IgG response, citing “lack of scientific evidence” as the main reason they won’t test for it.
More allergic responses typically occur here in the person suffering from an IgG food allergy, anywhere from 3 to 10 food allergens may be clinically involved, and they have reported sometimes even up to 20 foods sometimes.
It is more rare for a person to be only allergic to one or two foods in this category.
Unlike IgE allergies, typically larger amounts of food is often required, and in multiple feedings are required to provoke these types of allergic reactions. Reactions may not sometimes even occur after a single food challenge.
Allergic symptoms commonly appear 2 to 24 hours after consuming the offending foods, but in my clinical experience, symptoms often appear 48 to 72 hours later.
What makes it hard for the doctor or skin specialist to distinguish between an IgE and an IgG allergic response is that virtually any tissue, organ, or system of the human body can be affected, even the so-called “classical” allergic areas.
Very common in children and adults, and well over 50 medical conditions and 200 symptoms can be provoked, worsened or caused by IgG allergic reactions to foods.
We have estimated that addictive cravings and withdrawal symptoms can be clinically significant in 20 to 30% of patients suffering from this type of allergy.
Because of multiple foods and delayed onset of symptoms, the offending foods are rarely self-diagnosed. Multiple doctor visits involving different physicians are the rule, not the exception, before proper diagnosis and treatment can happen.
Allergic foods are commonly favourite foods, frequently eaten, and eaten in larger amounts.
Allergy to foods is commonly reversible. Symptoms often clear following 3-6 months of avoidance and nutritional therapy.
Skin test negative, IgE “RAST” negative. This is a non-IgE antibody-mediated allergic reaction to foods.
IgG ELISA (Type II) positive; IgG food immune complex (Type III) and/or cellular (Type IV) reactions may be involved as well.
Sensitised lymphocytes, eosinophils, platelets, release of PAF and leukotrienes may be more prevalent.
Food Allergies – Learning What To Do
They often interrelate food allergies with chronic illnesses such as arthritis, asthma, diabetes, and ADHD (Attention Deficit Hyperactivity Disorder). I’ve often seen changes in patient’s behaviours and emotions once they overcame the chronic allergic reactions. It is important to learn to prevent and deal with food allergies, whether the condition is mild or severe. It includes learning the causes of allergic reactions, how to recognise the onset of symptoms cause by foods or inhaled allergens, the best options for preventing and fighting food allergies, and integrating ways into your lifestyle to avoid food allergies.
The Hypo-Allergenic Diet FREE Handout
Major allergens may include eggs, dairy, gluten or wheat, corn, peanuts, shellfish, fish, oranges, bananas and chocolate.
My Hypo Allergenic Diet Sheet will give you good indications as to the most allergenic and least allergenic of foods. It is a handout I have used in my clinic for over twenty-five years and it has helped thousands of patients over the years. Why not download it and laminate it & hang it on your refrigerator!
Sufferers from food allergies can in time still eat the food they love, especially if they work on avoidance, food rotation and in particular to help build up their digestive system to avoid the small bowel from being too permeable to those dietary proteins which are often the real culprits in allergic responses.
Babies and food allergies
It is striking how many women I have seen in my clinic who come in with a child covered in eczema; it happens on a weekly basis. The child can be covered in a red, itchy rash and will be miserable.In many of such cases, they have placed the child on a cow’s milk formula after having been breastfed for a few weeks. This is in most all instances too young to be introduced to cow’s milk protein. Once the child develops the rash, he or she will become itchy and scratch the skin. This may well result in a skin infection and they then prescribed an antibiotic. Before you know it, the digestive system becomes even more affected (as the gut bacteria die) by the prime dietary antigens such as milk proteins, ice cream, peanut butter, chocolate, bananas, oranges, etc. By utilising the Hypo Allergenic Diet and dramatically improving the mother’s diet (if the child is being breastfed only), you will be well on the way to helping your child overcome eczema.
Keep An Open Mind!
Always keep an open mind and use common sense (and sixth sense) with your health care practitioner. If he or she is irresolute and dogmatic and refuses to believe that you are interested in your treatment options, both conventional and natural, particularly if you are not getting the results you wish, then it’s time to move on. I’ve always believed that minds are like parachutes. They function at their best when they are open.