In an article on Medline, the authors suggest that
widespread and uncontrolled use of elimination diets for atopic dermatitis may have played a role in the increase of allergy and anaphylaxis.
They are talking especially about children with allergy problems.
The treatment has been avoidance of the foods responsible, once they're identified.
But the authors think food avoidance may be part of the reason why so many people these days have allergies! They call elimination diets the "factory of anaphylaxis".
When someone stops eating a food they're allergic to, they become more sensitive to the food. There are ways the body tries to combat a food allergy, when someone is eating the food. Those methods don't work perfectly, but they work somewhat.
Food allergies are maladaptive, because people need food to survive. They can be life-threatening. So people's bodies have evolved to try to correct a food allergy. But those ways require that the body is exposed to the allergenic food.
So that raises the question, do the body's attempts to correct a food allergy, tend to suppress allergic reactions in general - inhalant allergies, allergies to other foods?
When food antigens get past the intestinal epithelial barrier, cytokines IL-10 and TGF-beta are generated that downregulate immune reactions. Having a "leaky gut" - i.e. a leaky intestinal epithelial barrier - actually may enhance the immune downregulation.
This process can go wrong so that eating an allergenic food actually increases the immune reaction - causing a vicious circle so a new food allergy develops.
You may have heard of "masked food allergies". The idea is that people can be profoundly affected, emotionally and physically, by food allergies that "hidden", so that they don't have obvious symptoms after eating the food.
The way one finds the "masked food allergies" is to eliminate the food and other allergenic foods for a week or so. Then one tries the foods that have been eliminated one by one, to see if a reaction happens. During the elimination diet, the body stops doing whatever it was doing to suppress the food reaction - so food reactions are much stronger and more noticeable.
This tells one about food allergies that have started that the body is trying to combat.
Even though the body tries to combat these food allergies, they can have severe bad effects. And when one stops eating the food, it can be extremely helpful. I experienced that in a huge way after I quit gluten and various other foods.
But I have been asking myself recently, did completely quitting those foods that made me sick after doing an elimination diet, actually leave my immune system in an up-regulated state?
I live mostly on an exotic-foods diet. I'm not allergic to only four foods that I ate at all often before I went gluten-free: lettuce, radishes, vanilla and mint! So I did this quitting-foods process to an extreme extent.
The papers I've cited seem to suggest that it's a bad idea to totally exclude a huge number of foods as I did.
And perhaps, excluding foods at all is a bad idea. Oral immunotherapy - eating small amounts of foods one is allergic to - has been found to be helpful even for dangerous food allergies that can cause anaphylaxis.
Oral immunotherapy isn't yet a part of allergists' repertoires.
But I've been trying a kind of oral immunotherapy for myself. This isn't a good idea for people who have dangerous symptoms, but allergists have never thought my kind of food reactions were dangerous. The allergist I see in NYC, actually suggested that with oral cromolyn, I might be able to reintroduce the foods I have these allergies to, into my diet.
Using oral cromolyn, plus the allergy meds Singulair and loratadine, I found I can eat about 10 mg of foods I'm allergic to. I still have a reaction, but so far, the reaction has faded away after a month or so.
I eat any given food only once every 4 days, because in the past I've found this helped me to avoid developing new food allergies. In the past, eating even a small amount of a food every day has sometimes created a new allergy to that food. It activated that vicious circle I mentioned above.
Patients tend to be more paranoid about food allergies than doctors are. Avoiding foods, labeling them "bad", doing elaborate precautions to avoid even traces of the food, is similar to a paranoid or obsessive-compulsive disorder. It engages negative parts of the mind. I don't say it IS a mental disorder, because there's a real physical reason for it - but it means behaving as if one had a mental disorder.
So encouraging tolerance of foods seems psychologically healthy as well as hopefully good for my immune system.
I have been trying this for some of my inhalant allergies, too. I've been eating tiny amounts of dog allergen. I asked a friend to rub a piece of towel that I sent him on his dog, and mail it back to me. I've been eating about 1/8" of thread from this towel, with only a microgram or so of dog allergen (!) once every 4 days. I've been doing this for a month. At first, it made me sick for about 2 days, but recently the reaction has gotten less intense, and I'm optimistic that this will help me a lot with my dog allergy!
This may not work for people with less severe inhalant allergies, because the allergen gets digested by stomach acid. But since I do have reactions, I think it will work for me.