But mainstream medicine didn't think that delayed food allergies even existed until very recently! Except for celiac disease (gluten intolerance). Alternative medicine has tried to take up the slack; for example, naturopaths commonly recommend that people try avoiding wheat and dairy for a while to see if they feel better.
Alternative practitioners have helped many people with their food sensitivities. I think delayed food allergies are a major reason that alternative medicine exists: the elephant under the rug that creates the bump that we call alternative medicine. But they have also harmed people, for example by giving people who have celiac disease the impression that they only need to avoid wheat and that rye and barley are OK, as long as they don't cause symptoms.
So, I am glad that medical researchers are investigating non-IgE food allergies, and validating some of what people with food sensitivities have been saying. Non-IgE allergies might involve Th1-mediated inflammation or immune complexes.
There's been a lot of recent research on gluten sensitivity, which affects about 10% of people and apparently involves the innate immune system. The only kind of gluten sensitivity that is classically known is celiac disease, an autoimmune disease that affects about 1% of people. Gluten may increase intestinal permeability somewhat even in people who don't have celiac disease. Gluten may cause an inflammatory response in everyone, mediated by innate immunity. Gluten sensitivity may cause or aggravate many conditions.
Gluten is linked with psychiatric conditions. Schizophrenia and autism sometimes involve the immune system . Some schizophrenics and people with bipolar disorder are gluten-sensitive and may be helped by a gluten-free diet. 23% of schizophrenics had elevated IgA antibodies to gliadin vs. 3% of controls, in one study. (Gliadin is the peptide in gluten that causes the trouble in celiac disease.) People with autism and their relatives are more likely to have high intestinal permeability than normals, although the intestinal permeability of the autistic people who were on a gluten/casein free diet was lower than for normals. A single-blind study found that the gluten/casein free diet helped children with autism spectrum disorders. A gluten-free diet reduces anxiety in people who have celiac disease. I certainly found that to be true!
Gluten sensitivity also may be involved in a wide range of neurological problems such as ataxia (difficulty with balance or coordination), peripheral neuropathy, epilepsy, dementia, migraine, encephalopathy, chorea (an involuntary movement disorder), brain stem dysfunction, myelopathy (spinal cord pathology).
Celiac disease is likely to occur with other autoimmune diseases, such as autoimmune thyroid disease, type 1 diabetes, lupus, rheumatoid arthritis, Sjogren's and scleroderma. Gluten sensitivity may be more common in people who have multiple sclerosis. A gluten-free diet helps prevent type 1 diabetes. Since many autoimmune diseases are associated with increased intestinal permeability, a gluten-free diet may help prevent many autoimmune diseases. A diet free of gluten and other foods one is allergic to is anti-inflammatory, so it might ameliorate the symptoms of many autoimmune diseases.
Many medical authorities say things like "25% of people think they have a food allergy. Only 2% actually do." This is horribly arrogant! It assumes that food allergies can only have the symptoms that are produced by IgE food allergies; that people can't have delayed food reactions; and it ignores the fact that before doing an elimination diet, people are unlikely to have obvious reactions to eating a food. It assumes that medical knowledge about the immune system is complete, which is incredibly far from the truth and unscientific. No wonder many people with delayed food allergies are scornful of "allopathic medicine".
I get sick from a huge number of different foods, not just gluten and dairy. I get sick from traces of many of these foods. Some of these foods, I've tried several times and I got sick each time, for up to 6 days. Other people describe similar symptoms.
I probably have celiac disease, and that may be the reason why I have so many food allergies. Celiacs often have delayed allergies to other foods besides gluten grains. I got a test from Enterolab that showed I had high levels of antibodies that are characteristic of celiac disease, and I have Hashimoto's, an autoimmune thyroid disease that is associated with celiac disease.
I got IgE RAST testing for some of the foods I can't eat, and it was almost entirely negative. I used to have an IgE yeast allergy, but my symptoms from that were different.
There are, to be sure, plenty of people who decide with no solid evidence that they have a food allergy, building up a personal secular religion. Leaving their real problem untreated. People who try to heal themselves need to be more careful about their self-diagnosis, not less.
Probably many people are severely affected by food allergies without knowing it, because the body tries to compensate for delayed reactions, so nothing noticeable happens after they eat the food. For years I ate spaghetti and cheese like anyone else and I never noticed anything special happening. It took several elimination diets to find my food allergies. No doctors, no therapists and almost no regular people ever mentioned delayed food allergies to me. And, the foods that people have delayed allergies to are often their favorite foods. Sometimes the allergic reaction to a food and the body's effort to suppress it causes pleasure, and people interpret that as "I like that food". That makes them reluctant to explore hidden food allergies. And people are notoriously reluctant to change their diet for ANY reason, even if it's making them deathly ill.
Celiacs don't necessarily have intestinal symptoms after eating gluten. Celiac disease can even be silent.
What to do about it, once you've found you have delayed food allergies.