You’re not crazy: Food allergy reactions can differ day to day

So you’re pretty positive that you have some kind of food allergy, but you just can’t pin it down. It almost seems like your food allergy reactions are always different, and, at this point, you aren’t sure what the trigger actually is. 

If this is your reality, I know it can make your head spin. It’s exhausting and will leave you feeling defeated. But don’t give up yet! You’re not crazy. 

Food allergy reactions can differ day to day. Let’s dig into the research and see if you can relate.

Food Allergy Reactions Depend on Raw v. Cooked Food

When our body reacts to food, it is the result of an immune response. This response is triggered by an initial reaction to the food in which your immune cells produce antibodies to the proteins within that food. What’s pretty wild, though, is that the way a food is prepared affects the shape and form of its proteins. 

In your day-to-day life, this means that different cooking methods can alter your immune response to a food. And what a curveball when you are trying to pinpoint the food that is triggering your symptoms! 

Do you notice problems after eating fried eggs but not soft-boiled? You’re not crazy—your immune system is simply reacting to fried eggs' proteins but tolerating those in soft-boiled eggs.


If this sounds familiar, you are not alone! A case study of 5 patients, all of whom reported an allergy to peas, found that while they had a severe allergic reaction to cooked peas, they could eat fresh raw peas without a problem (1). A skin test confirmed this difference in responses.

This interesting phenomenon goes beyond cooked versus raw. The method of heating also affects the food’s allergenicity. For instance, peanuts are more likely to cause a food allergy reaction if they are dry roasted and less likely if they are boiled or fried (2). This seems to be because boiling and frying significantly reduce peanut proteins called ara h1, ara h 2, and ara h3 (2). These proteins are what commonly trigger a food allergy reaction to peanuts. At least 90% of those with peanut allergies have IgE antibodies to ara h1. 

If you are curious about the temperatures that result in this allergen decrease, boiling and frying occurred at 212 F and 248 F, respectively. Dry roasting was done at temperatures of 302 to 338 F. 

When proteins are heated, they become denatured, meaning that the protein – intricately coiled and folded at the biochemical level – unfolds and loses its signature shape. The ara h1 protein denatures at 194 to 230 degrees F, resulting in reduced IgE binding and an allergic reaction. 

Now, suppose food allergy reactions were rational and straightforward (spoiler alert: they aren’t). In that case, the logical assumption might be that roasting at an even higher temperature would further break down that pesky ara h1 protein.

Although this does happen to an extent, what also happens is that the protein is modified into a kind of jumble, and some important chemical reactions take place. One of these is called the Maillard reaction. This infamous chemical reaction happens when sugars and amino acids are exposed, together, to high heat. And this makes peanut allergen worse (2). 

What’s more, other foods behave differently when heated. The allergic potential of eggs, for instance, is significantly reduced after boiling for 30 minutes, but less so when the egg is fried or boiled for 10 minutes (3). 

Combining foods may also alter food allergy reactions. A fascinating study demonstrated that when egg whites were combined with durum wheat to make pasta, the allergenic and antigenic properties decreased (4). Although these results are impressive, this was a very small study of only five people, and more research is needed in this area. But if you’ve ever wondered why you react to a certain food unless it’s cooked with something else, this may be why.  

Food Allergy Reactions Might be Linked to Toxins


If you are someone who has run the gamut of allergy testing and sought the help of specialist after specialist only to be told that there is “nothing wrong,” you want to read this section. 

Toxicant-induced loss of tolerance (TILT) is a phenomenon that describes multiple intolerances, often occurring out of the blue, and a wide range of symptoms. These intolerances are triggered by an acute toxin exposure or chronic exposure to low levels of toxins over time (5). 

Technically, manufactured toxins are known as “toxicants,” and these substances can be extremely harmful to health. Our body has built-in detoxification processes that break down toxicants and eliminate them. However, many people struggle to detoxify thoroughly. The build-up and storage of toxic metabolites can create a host of symptoms. 

Common sources of toxins include air pollution, fragrances and perfumes, cleaning products, pesticides and herbicides, and plastics. 

Many experts believe that TILT is the cause of chemical sensitivity, aka multiple chemical sensitivity, a condition that affects up to 35% of the US population (5). 

It is also possible that TILT is a factor in new-onset food intolerances and food allergy reactions.


TILT has been observed in events where large populations were exposed to harmful toxins. Documented occurrences include the World Trade Center tragedy, the Gulf war, a remodel of the EPA headquarters, various cases of pesticide, fume, and solvent exposure, and even surgical implants (5) 

There is also a growing body of evidence suggesting that exposure to common environmental toxins increases the development of food sensitivities (6,7). Exposure to household endotoxins, for example, has been associated with moderately increased odds of milk and egg sensitivities (OR 1.7, 95%CI 1.2–2.1 and OR 1.4, 95%CI 1.01–1.9, respectively) (6). 

Endotoxins are a component of the outer cell wall of gram-negative bacteria. Endotoxins are composed of lipopolysaccharides (LPS) and are often simply referred to as LPS. Endotoxins are also found within the gut microbiota, and a higher level of endotoxin circulating in the body is a well-known marker of inflammation.

Predictors of higher endotoxin in household dust include mold, mildew, cigarette smoke, dogs in the home, children in the home, food debris, rodents, and cockroaches (7). 

What’s sprayed on your food could also worsen your food allergy reactions. Exposure to common pesticides that use dichlorophenol, a chlorinated compound also used as a disinfectant, has been linked to increased food allergies (8). 

Yep, Stress Plays a Role


Ugh, I’m sure you are probably tired of hearing about how bad stress is for your health. So am I. But knowledge is power, y’all! When it comes to food allergy reactions, stress needs to be acknowledged because it can lead to intestinal permeability. 

Also called “leaky gut,” intestinal permeability is thought to be a critical factor in the development of food sensitivities and allergies (9). A healthy gut is semi-permeable, which means that certain things are allowed to cross the gut wall into the bloodstream. This includes digested food and nutrients. It also means that viruses, bacteria, and undigested food stay in the small intestine and do not enter the bloodstream.

When the gut wall becomes “leaky,” this allows all of those unwanted things to slip into the bloodstream, creates inflammation, and triggers an immune response. And remember, when your body has an immune reaction to food, this can result in food allergy or sensitivity. 

During times of increased stress, food allergy reactions may worsen due to increased inflammation. The upside is that having a healthy gut microbiome can protect against a leaky gut, even during periods of stress. To learn more about how to strengthen your gut and immune system, be sure to check out my group coaching program, The Good Poopers Club!

Menstrual Cycle Phase and Food Allergy Reactions


Have you ever noticed that your food allergy reactions seem to pop up at the same time every month? Well, it’s more than your imagination—certain stages of the menstrual cycle can heighten food allergy reactions!

An interesting experimental study discovered that allergic reactivity was greatest during the middle of the menstrual cycle, around day 14 or 15 (10). There was also a positive correlation between estradiol and luteinizing hormone and allergic reaction. When these hormones were elevated, mast cell degranulation increased. Mast cells are responsible for classic symptoms of allergic reactions. Degranulation means they release chemicals like histamine, which increases blood flow and swelling. 

Other Influences on Food Allergy Reactions


There are a few lesser-known and lesser-studied influencers of food allergy reactions. 

One is called food-dependent exercise-induced anaphylaxis (FDEIA). FDEIA is a serious condition where an IgE-mediation reaction to food only occurs when the food is eaten either four hours before physical activity or one hour afterward. If the food is eaten and there is no physical activity, there is no reaction (11). 

This could look like having scrambled eggs for breakfast, then going on a hike a few hours later, and then experiencing a reaction such as hives, swelling, or GI symptoms (11). But the next day, if you ate eggs and sat on the couch afterward, you would be fine!

Various foods may contribute to FDEIA, including tomatoes, wheat, mushrooms, eggs, peaches, apples, hazelnuts, milk, meat, fish, and even alcohol. 

To further complicate things, some people may only react when two foods are combined or when a non-food trigger is added into the mix. These non-food triggers include pollen and dust, NSAIDs, extreme temperatures, and the menstrual cycle. 

Sensitivity to a variety of food chemicals may manifest as a food allergy reaction (8). One of these is histamine intolerance/sensitivity. Histamine is a natural chemical present in many foods, especially fermented foods like kefir, aged cheese, sauerkraut, kimchi, vinegar, pickles, and alcohol. Histamine intolerance can lead to bloating, abdominal pain, diarrhea, constipation, and feeling overly full after meals (12). (We review histamine intolerance in The Good Poopers Club as well!)

Sensitivity to food additives can also look like a food allergy. Sulfites, a common additive in  wine and dried fruits, and monosodium glutamine (MSG), an additive in tons of packaged foods, can lead to symptoms that look similar to a food allergy reaction (11). 

What does this all mean?


Food allergy reactions are tricky! Many things can affect how and when they manifest. And remember: food allergy and food hypersensitivity are different, even though they can share symptoms. Learn about those differences here.

Gut health plays a foundational role in the development of food allergies, sensitivities, and symptom severity. If you feel like your gut needs some love, you are in the right place. The Good Poopers Club™ contains everything you need to turn your gut health around and give your immune system a break, so that it can stop reacting to so many foods!