ADHD and Food Allergies by Anthony Kane, MD
Introduction
There are a number of controversial areas in medicine when it comes to ADHD. Food allergy is certainly one of them.
The classic allergic reaction, which is classified as
type-1 hypersensitivity reaction, can be elicited by food, but this is fairly uncommon. When we discuss food sensitivities in ADHD we are discussing a different, not well-defined, mechanism.
One of main progenitors of food allergy/ADHD connection is Dr. Doris Rapp. Dr. Rapp was a pediatric allergist who noticed that many children in her practice had significant physical and behavioral changes when exposed to certain foods. They may have red ear lobes, dark circles under their eyes, or glazed eyes after eating certain foods. These children could have tremendous swings in behavior. They can be calm one minute and wildly hyperactive a few minutes later.
To make it more interesting, children with food allergies usually crave food that affects them negatively. That means a child who is allergic to peanuts will demand peanut butter and jelly for lunch everyday, and for rest of afternoon you have to peel him off of ceiling.
What is Food Allergy?
The classic allergic reaction operates through a very specific mechanism. The reaction is caused when a specific type of antibody, called IgE, reacts with a specific provoking substance called an allergen. The result of this interaction is an allergic response and person is deemed allergic to that allergen.
The specific type of antibody involved in classic allergy is called IgE. The proposed antibody mechanism for this type of food allergy does not involve IgE, but a different antibody called IgG. This is significant because standard allergy testing tests only for IgE antibodies. If your child has IgG mediated sensitivity, his allergy test is going to miss it. That means that your child may have a severe allergy to a specific food, but your allergist will tell you he is not allergic to it.
Why Controversy?
Reason 1: Diagnosis
I said this was a very controversial area of medicine and here is one of reasons why. Food allergies are very difficult to diagnose. One reason is that symptoms wax and wane. When a child has a classic allergy, for example to bee stings, then every time a bee stings him, he will have a reaction. Food allergies don’t work that way. There seems to be a threshold that must be exceeded before there are any symptoms. In addition, this threshold seems to vary from day to day. On some days a food will affect child, and on other days it won’t. Dr. Rapp explains this phenomenon using analogy of a barrel.
We can view each allergic child as if he has a barrel. As long as barrel is empty or only partially full, your child will have no problems. Your child won’t become hyperactive until his barrel is overflowing.
Various things will fill your child’s barrel. Let’s say your child is sensitive to chocolate, cats, and peanut butter. Each of these things all can partially fill his barrel. As long as he only has peanut butter or only plays with cat, his barrel is only partially full. That means that there are no symptoms and that his behavior is fine. Then, one day he has a peanut butter and jelly sandwich, has chocolate ice cream for dessert and plays with cat all afternoon. These things in combination make his barrel overflow, and by evening he is out of control. Your child has food allergies, but sometimes they affect him and sometimes they don’t.
The barrel can change sizes. If your child has a cold or is upset his barrel gets smaller. It takes less to make it overflow. If he is happy his barrel is bigger. It takes more to make it overflow. If he isn’t eating well and that day he is low on certain nutrients his barrel gets smaller.
Many traditional allergists find this barrel concept ludicrous. It doesn’t fit into pattern of how other allergies work.
Reason 2: Method of Diagnosis
The next problem is way in which you test for food allergies. Dr. Rapp describes a technique called provocation-neutralization testing. This method works as follows: Say that a child frequently has headaches after eating eggs. The practitioner will give an intradermal injection of egg extract. If this elicits child’s headache, then child tests positive for egg allergy. Other signs of a positive test include an increase in pulse rate of 20 points, a large skin reaction (this indicates a classic IgE reaction), a change in child’s handwriting, or some other physical or emotional complaint. This last criterion “some other physical or emotional complaint” is problematic. It is too vague. The result is that when studies compared how several physicians evaluated same group of patients, their results didn’t agree. For each patient if there were twenty different doctors with twenty different sets of findings. None of their diagnoses matched.
Reason 3: The Mechanism
As I mentioned before, proposed mechanism is an IgG mediated response. Some food allergists diagnose specific food allergies by measuring IgG levels. This runs counter to all of modern allergy practice.
Allergists give allergy shots to treat allergy. The way this works is they give a low level of allergen, which is not enough to elicit an IgE reaction. The dose is slowly increased until eventually patient can tolerate a significant exposure to allergen.
This is how it works. The repeated low-level exposure to allergen induces body to make a different antibody to substance. This antibody attaches to allergen and deactivates it before IgE can cause allergy reaction. What is this antibody that allergists try to induce to cure their patients of their allergies? You guessed it, IgG. So very antibody traditional allergists have been inducing for decades to successfully treat allergies, food allergy people claim is antibody guilty of causing allergies.
For a traditional allergist this is nothing short of heresy. IgG has been used for decades to treat allergies successfully. Comes along Rapp and her friends and they claim that IgG causes allergy? This is a little hard for some people to accept.
Just how strongly do allergists reject this idea? I once tried to contact an Israeli physician who was a food allergy specialist to discuss with him provocation-neutralization testing. I called hospital where he is on staff and asked to speak with him. For some reason operator instead put me through to head of Department of Allergy.
I began discussing with him theory of food allergies, provocation-neutralization testing and IgG testing. He told me that he was head of a committee of allergists who were in process of testifying before Israeli Knesset to get legislation passed to make IgG testing illegal in Israel.
