How Food Processing Changes Its Allergenicity

Allergenic protein structures change when processed. Some are more heat labile than others. It all depends on the protein structure.

Higher temperatures for longer times can decrease the allergenicity of the proteins, allowing it to be tolerated by some. Generally the greater the decrease in allergenicity as you heat, cook, and finally bake.

Fermenting is another way protein structures can change enough to make a difference in allergenicity, as they are partially digested into shorter chains (peptides).

Example: gluten content in regular commercial soy sauce. Many test under 20 ppm, low enough to be tolerated depending on one’s sensitivity.

Fermented Soy

Soy decreases allergenicity when fermented, which might be meaningful if you are allergic or intolerant to soy. 

But less well known, some are allergic to fermented soy but okay with soy. 

There is a study on late onset anaphylaxis with natto allergic. Unusual in that it is IgE mediated but triggered only when it reaches the intestines, taking a mean of 8 hours.

I am not okay with soy but my reaction is much worse with raw fermented soy. I suspect it is the difference between soy protein intolerance versus mold (aspergillus) allergy. If I didn’t have the latter I might have tolerated small amounts of fermented soy, such as that of a typical condiment serving size, which would have opened up some more flavor adventures, alas.

Soy Sauce (Free Glutamate) and Hypomania

Before our food journey, sometimes both of us would get horrible migraines at the same time soon after eating out. We thought it must be too much MSG and would avoid the place thereafter. We learned a bit more about ourselves and about MSG when we started a food chemical elimination diet.

The main thing being while MSG (monosodium glutamate) is the artificial form, there are plenty of natural sources of free glutamate, which act identically in the body. This might be why sensitivity to MSG by itself has not been proven.

At the end of the elimination diet we did a free glutamate challenge, actually a soy sauce challenge in our case. We each had a tablespoon with our meal. Mate had a headache for a couple of days. I was expecting migraine as well but instead I felt my whole body was abuzz, pulsing as if I’m running. I didn’t get a wink of sleep that night, wasn’t even tired. Next day still going and barely two hours of sleep, the third day still less than four hours of sleep, finally by the fourth day I came back to somewhat normal. I slept just six hours in three days with no bowel movement either. Suspiciously like hypomania.

I thought about why I didn’t get migraine as I expected. Most of my migraine episodes happen after exercise or watching a movie. And with the elimination diet they mostly disappeared. So it seems the combination of allergen and overstimulation (by exercise etc.) was the main cause for me. So without any allergen I only felt the overly stimulated body and brain. Free glutamate as excitotoxin explains the parallels to exercise induced allergy symptoms.

Non-IgE Mediated Allergies

Non-IgE mediated allergies are a very large and understudied area. And very real. It is possibly the culprit in many long suffering people.

Lots of things are not known well enough especially to the general public, even to practicing doctors.

Makes me wonder how many others suffer from “hidden” allergies and sensitivities.

Especially those prone to gastrointestinal problems, headaches, joint pain, chronic fatigue syndrome, mysterious idiosyncratic inflammations, autoimmunity, and also some mental health issues.

All the underlying mechanisms are not defined well enough that there are no simple medical tests. The skin prick test can detect just a small subset of allergic disorders, doesn’t even detect all the IgE mediated cases.

Trigger and symptom tracking assisted by data might be a viable alternative until better diagnostic methods are developed. A good tracking program can also guide and assist elimination diets.



GI issues, skin problems, headache/ migraine, swelling, mood problems, brain fog, frequent urination, bruxism, body aches, joint pain, sinusitis, glue ear, itchy/ bleeding anus, throat irritation, fatigue, sleep disturbance, muscle cramps, PMS/ menstrual cramps/ infertility, tactile allodynia

Symptoms that May be Caused by Food

Allergies and Food Culture

Common allergies mirror what is frequently eaten in your particular food culture.

The big 8 in the U.S. is actually only true for typical American (SAD?) diets.

Other potent allergens depending on culture: sesame, buckwheat, mustard.

Although it is a tree nut, there was no commercial extract for testing chestnut when I visited an allergist in the US, whereas in Korea, it is a top 3 allergen.

Some are not potent but eaten frequently enough may cause cases: rice as reported in Japan.

My allergies mirror my upbringing, representing both East and West.

East: buckwheat, chestnut, soy, fermented soy, shrimp
West: milk, wheat (barley, rye), pecan

Buckwheat Allergy

Buckwheat is actually a highly allergenic food (potentially dangerous reactions), especially in the East Asian food culture, that I didn’t suspect.

But after allergy tests showed a positive result I looked back at my food and symptoms diary. Immediately after each time I had buckwheat, which I occasionally had since going gluten free, I had noted scratchy sore throat. I’m also highly suspicious it caused GI issues but 1) all these symptoms were on the milder side and 2) I had been eating other problem foods.

Again a case that shows our subjective expectations can cause blindspots. Also, testing and tracking used together are a pretty powerful combination that can help confirm suspicions.

Other similar pseudo grains (seeds) such as quinoa, and amaranth are suspected of causing diarrhea as well. Are they cross reactive to buckwheat?

Shrimp Allergy Trial and Errors

Anchovy products

“Why in the world would you have to be careful with anchovy products? It’s a fish! Not shellfish/ crustacean!” is an all too common sentiment. BUT, as is the case with many things in this world, it’s a little more complicated than that.Shrimp is a common bycatch with anchovy. I first realized this when I bought dried anchovies. And this was more common the smaller they are. The package always says 100% anchovy but if you look closely you can see small shrimp mixed in among them. It becomes more obvious when you start cooking it as the shrimp would turn red. This I’ve experienced myself.

I have also heard people saying for larger anchovy, if you try gutting them yourself, you sometimes find undigested shrimp in their bellies! if this is true it’s an even bigger problem. Anchovies are pretty much out of the picture unless they are big enough to be gutted or you gut them yourself.

Still from personal experience, I seem to be okay with fish sauce (fermented anchovy), and dried anchovy (roughly inch long and larger without unintended shrimp mixed in).

Seaweed products

Most are fine. But there was one case where kelp bought at the source had lots of tiny crustaceans attached to it. Other than that I haven’t had any problems with commercial seaweed products.

The minefield of eating out and other randomness

Fermented shrimp paste or broths made with dried shrimp hides in many Asian foods.

An entirely unexpected case where sweet potato starch noodles (supposedly an upgraded version) had chitosan (from crab) in it. All other clear noodles I’ve tried have been fine as they were 100% sweet potato starch.

Food Challenge Trial and Errors

Even if you are “sure” you don’t have any food issues, even if your skin-prick test is negative, don’t just scarf down a whole serving when you reintroduce a food. I thought I would die when I tried it with milk, and shrimp. You might still react and you might literally risk your life.

At least it made me never want to touch milk again despite my lifelong love for all things dairy.

Subjective Symptoms

When people ask me why I am eating gluten free I sometimes find myself leaving out the seemingly “subjective” symptoms and focus on the more physical “objective” ones. Yet it was my “subjective” symptoms following a gluten challenge that were severe enough to convince me that I never want to eat it again, in spite of my former love of pastries, breads, pastas, and the occasional cookie.

So what were these subjective symptoms?


The smallest things would get me to snap. And there seems to be no brakes. No room for reason to step in. Just escalation.

Brain… just… would. not…….work.

I would feel extremely slow, like my brain ground to a halt. I might find myself trying to decide whether to get groceries today or not and an hour would go by getting super frustrated at my inability to make simple decisions.

Less obvious to myself, but maybe easier to measure, slower reaction times when playing sports or driving.

Now I suspect that these are not truly subjective, just because it’s “in the head”. There could certainly be ways to measure such things.

For example, cognitive functioning tests, reaction speed tests, physical measurements of stress levels, etc.

Even the most seemingly subjective mood can be tracked by various means these days. Especially with smartphone apps/ wearables through activity levels, sleep patterns, and even the tone and speed of one’s speech.

On a side note, I wonder if the sensation of hunger can be objectively measured as well. Perhaps through blood sugar levels?