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