Do you have a Corn (Maize) Allergy or a Corn (Maize) Intolerance?
Confused? Well so are we.
Actually I think the entire world is confused. The more I read up on this subject in order to shed some light on this confusing debate, the more confused I became. So don't worry, you're not alone in the head scratching.
It seems that when it comes to food intolerance, no one can agree on specifics. About the only agreement is this:
For it to be a food allergy, the immune system (IgE) is involved. Food intolerance the immune system isn't involved.
However that's about where the agreement separates. Some sites will tell you that if your food allergy doesn't show up on tests, then it has to be a food intolerance. We tend to disagree.
How reliable are Corn Allergy tests?
According to a study from March 2004, posted on Allergy Advisor.com "Traditionally, skin-specific and serum-specific IgE tests to maize are used to diagnose maize allergy. It is generally assumed that a negative result indicates the absence of maize allergy. However, it was recently shown that a negative skin-specific IgE and serum-specific IgE to maize flour had no clinical significance for most of the patients studied, and that food allergy to maize has to be proved by double-blind placebo-controlled food challenge studies"
The same study also states: "Many allergens have been isolated from maize, but the majority of them have not been clinically evaluated for their allergenic potential."
Even the Corn Refiner's Association admits: "Though allergens in other food systems have been well characterized, very little work has been devoted to identifying allergens in corn or corn ingredients."
So for starters, the tests are not accurate measures of IgE responses to corn, probably because the allergens in corn have not been fully identified to even make an accurate test for corn. Clearly for diagnosing a corn allergy, testing alone is not going to be an accurate measure of an IgE mediated food allergy reaction. (Despite what your allergist may tell you)
How can you tell if its a Corn Allergy or a Corn Intolerance? What is the difference?
One difference between a food allergy and a food intolerance is portions. A person with a food allergy usually cannot tolerate any amount of that allergen; however a person with a food intolerance can usually tolerate a small portion of an offending food but a larger portion will cause problems. Tolerances on this will differ from person to person whether they have a food allergy or intolerance.
The main difference however is the involvement of the immune system. Despite some sites claims to the contrary, there are a few symptoms which signify the immune system is getting involved. If you have any of the following, you most likely have a food allergy and should see your doctor immediately (you will want to get a script so you can have an Epipen handy).
Hives, urticaria, skin rash, eczema, - Skin may become red or flushed, raised bumps, itching, or fluid filled blisters.
Itching/burning around the mouth (or other contact area) usually accompanied with swelling.
Labored breathing, tightness of the chest, wheezing, asthma, shortness of breath.
Skin Contact reactions.
This is not an all inclusive list of food allergy reactions but these generally are not present with food intolerances and only present when the immune system is getting involved. (however there are always exceptions)
I should probably clarify here that when I say "immune system is involved" or maybe I should state that when 99% of the medical field states the "immune system is involved" they are referring only to the IgE immune response.
The immune system has many little warriors out there battling diseases and bacteria on our behalf. Some are IgA, IgG, IgM, IgD, and of course IgE. However, IgE is about the only one that has been even close to thoroughly researched and is the only immune response considered when declaring a food allergy.
IgG has also been proven to have reactions to foods; however these reactions are considered minor and temporary. Thus in medical circles, IgG mediated food allergies are considered intolerances despite the immune systems involvement. It is believed that if you avoid an IgG allergen long enough that the body will stop reacting to it. This is not true of an IgE allergy.
Genova Diagnostics explains the differences between IgE and IgG pretty simply:
IgE Mediated Allergies
Immediate onset (within minutes)
Circulating half life of 1-2 days
Stimulates histamine release
Includes foods, inhalants & molds
IgG Mediated Allergies
Delayed onset (4-72 hours)
Circulating half life of 21 days
Stimulates histamine release
Includes foods, herbs & spices
This is generally considered the differences between IgE and IgG allergies. Yet, an article by the University of South Carolina School of Medicine gives more time for IgE mediated responses:
"Type I hypersensitivity is also known as immediate or anaphylactic hypersensitivity. The reaction may involve skin (urticaria and eczema), eyes (conjunctivitis), nasopharynx (rhinorrhea, rhinitis), bronchopulmonary tissues (asthma) and gastrointestinal tract (gastroenteritis). The reaction may cause a range of symptoms from minor inconvenience to death. The reaction usually takes 15 - 30 minutes from the time of exposure to the antigen, although sometimes it may have a delayed onset (10 - 12 hours). Immediate hypersensitivity is mediated by IgE." - U of South Carolina, School of Medicine
So if your reactions to foods are more than minutes but less than hours, your chances are pretty good that its IgE mediated and would be considered an actual food allergy. Keep in mind, that though IgG mediated food allergies involve the immune system, the medical community still considers them “intolerances”.
What is a Food Intolerance (Corn Intolerance)?
Food Reactions.org and WebMD both give pretty clear cut and accurate definitions of real food intolerance.
Food Reactions.org states: "Food Intolerance is the inability to completely break down food into absorbable components due to lack or insufficient amounts of digestive enzymes. The unabsorbed food which remain in the digestive system causes the classic symptoms of bloating and cramps and others."
WebMD states: "Food intolerance is a digestive system response rather than an immune system response. It occurs when something in a food irritates a person's digestive system or when a person is unable to properly digest or breakdown, the food. Intolerance to lactose, which is found in milk and other dairy products, is the most common food intolerance."
Rules about food intolerance seem to be breaking down in recent years. These two definitions are more conservative than what some sites will tell you, as the discovery of IgG mediated food allergies (intolerances) has made some alter their definitions of food intolerance which I believe is misleading. (one such definition can be found at Australian Disability Online which lists asthma and other histamine type responses as a symptom of food intolerance.)
Food Intolerance symptoms should be mostly harmless, though when you're suffering through it you might wish it wasn't as these can be quite painful and debilitating. These symptoms include: (be aware these can also be present if it’s a food allergy)
These symptoms may start about a half hour after eating or drinking the problematic food, but they may also be delayed.
Rules of Thumb on differences between Corn Allergy and Corn Intolerance:
1. Immediate (minutes - Corn Allergy) vs. delayed reactions (hours - Corn Intolerance).
2. Immune system involvement: Hives (skin irritation), stuffy nose, chest congestion, swelling, anaphylaxis. (Food intolerance is mainly digestion issues.)
3. Skin contact problems - skin contact reactions have nothing to do with digestion and are only mediated by the immune system (except harmful chemicals which harm anyone’s skin). If you break out (eczema and acne included), have difficulty breathing, swelling, nausea, etc. by skin contact with a food item, you are most likely allergic to it (or something in it).
Important to note: The body can mask allergy symptoms as a way of survival. So some of these symptoms may not be noticeably present at first, or may not seem to be linked to a particular food. Masked allergies to foods are often present in persons with other skin (eczema and acne) conditions, airborne allergies, mood & behavioral issues, dark under eyes, sleep problems, and other miscellaneous conditions. (See Women to Women: Food Allergy Symptoms for more clues as to conditions which may be caused by hidden food allergies)
Telling the difference between an allergy and intolerance isn't always easy, but your family history will help. According to statistics on Australian Disability Online "Children who have one family member with asthma or eczema have a 20-40 per cent higher risk of developing allergy; if there are two or more family members with allergies then the risk increases to 50-80 per cent." Since asthma and eczema are often symptoms of allergic reactions themselves, its possible that the genetic allergy risk may be even higher than stated.
A full list of food allergy symptoms would be very long and there will be a separate article hopefully fully encompassing any and all symptoms you may experience. However in the meantime, Women to Women has an article which gives the most comprehensive list of systems. Keep in mind, that a food allergy can have all the same symptoms of a food intolerance (digestion issues), but a food intolerance will not have the symptoms of a food allergy (aka immune system response symptoms as explained earlier).
Where to start looking for Food Allergies?
If you just read through the last several paragraphs and you think you might have a food allergy but you don't know where to start, here are a few clues.
There are often two ways people react to allergy foods. They either love them (food allergy addiction) or they hate them. If there is a food you dislike (or strongly disliked as a small child), its possible that a food allergy may be the culprit. Keep in mind that this is not always accurate as the older you get the more memories you have about food, and you may stop liking foods based on non-food related memories. Aka you don't like orange jello because you associate it with the time you had that violent flu.
For parents of young children: Despite what some doctors and parenting advisors might say, young children (babies included) often refuse a food that they know is bad for them or has previously caused them problems. This can also include breast milk if the mother is eating a food to which the child is allergic. Children as they grow older may get finicky and like or dislike foods for other reasons, but pay attention to foods your child is refusing. Keep a list, including brand names as some brands may have added ingredients that others do not. This will help you narrow down possible food allergies. FYI: Enriched products (milks, flours) often have added corn and soy as carriers for the added vitamins.
According to FAAN, common food allergens are: Milk, Eggs, Peanut/Soy, Wheat (other related grains), Tree Nuts, Fish, Shellfish. The FDA only recognizes these 8 allergens to be serious enough to require labeling. FAAN does not recognize corn (nor does most of the USA) and you'll find many doctors will actually discourage a corn allergy even if the test results are positive. Corn Allergy and Intolerance is on the rise. If you do test positive to corn at all (in any even slight amount) you should investigate it through diet. Avoidance and retrial, is the only accurate way to know if it’s going to be a real issue.
Food Allergy Addiction is also something for which to watch out. It sounds funny or like a "fat persons" disease, but it isn't necessarily. Physiologically, the body becomes dependant (addicted) to the allergens presence and starts a craving for it. There are several theories for this (see below links) which center more on the chemical reaction that happens in the body when an allergen is introduced. When those chemicals start to wane, the body craves another dose of the allergen to increase the levels of those chemicals again. These foods are usually eaten within a 3 day cycle, or less depending on the level of addiction. Some may be eaten daily, or every meal/snack/drink.
Why do I crave foods to which I'm sensitive?
Allergy Addiction Cycle
With corn, these cravings can manifest as a craving for any number (or multiple) of foods as corn is everywhere and it can be very hard to detect. One days craving may lead to ice cream, another day to Spaghetti-O's, baked beans, cookies, crackers, canned fruits, juices, salami, hotdogs, candy, chocolate, beer, etc.
My (Von) allergy to corn was based in a food allergy addiction cycle. It wasn't until I removed 80% of the corn from my diet (corn starch, corn syrup, etc) that I realized that corn was getting me high. My body was addicted, even though it was also making me sick. I would crave anything and everything in my cupboards. I actually started figuring out certain corn derivatives because I would crave the foods they were in - when you're starving for canned beets (corn vinegar), and will eat them straight out of the can (can't get them fast enough), you start wondering if maybe you might have a problem. After avoiding corn for two years, my body is finally starting to reprogram its addiction and is starting to react to corn as an aversion to it. It’s much easier to stop your body from eating something it doesn't like, rather than something it insanely wants. I have other food allergies as well, but none are instigators of the addiction cycle, only corn.
WebMD - Allergy or Intolerance
Food Reactions.Org - Food Allergy & Intolerance
SAGA - Intolerance and Allergies
Women to Women: Allergy Symptoms
Allergy, Intolerance, & Sensitivity explained
Why do I crave foods to which I'm sensitive?
Allergy Addiction Cycle