Corn derivatives can be found almost everywhere: high-fructose corn syrup, maltodextrin, and cornstarch are commonly used fillers and flavor enhancers. They’re all over the place in sweets, processed snacks, and ready-to-eat meals that promise dinner in five minutes. That’s why it’s so important to carefully analyze the ingredients of the products you choose.
Which proteins are responsible for corn allergies?
The main allergens found in corn are LTP proteins, which are responsible for transporting fats. These proteins are resistant to heat treatment, meaning they can trigger allergic reactions even after being cooked at high temperatures, such as boiling or roasting. At the same time, they often cause cross-reactions with other foods, so it’s important to pay attention to what we eat [1].
Zejins located in the endosperm can also be problematic, as they may cause cross-reactions, e.g., with pollen [2]. Interestingly, it is in the endosperm that starch is produced, which is used on a massive scale as a thickening agent in food, pharmaceutical, and cosmetic products [3].
Another allergen is thioredoxin-h1—an enzyme that protects corn from the adverse effects of oxidative stress. This component shares up to 74% similarity with wheat thioredoxin-hB (Tri a Bd 36 K). Therefore, individuals working in the baking industry who are in constant contact with wheat may experience a cross-reaction after consuming corn [4].
What are the symptoms of a corn allergy?
Corn can cause a range of symptoms typical of food and inhalant allergies:
- hives on the skin,
- redness of the skin around the mouth,
- wheezing and symptoms typical of asthma,
- a runny nose and/or a stuffy nose,
- diarrhea,
- nausea and/or vomiting,
- abdominal pain.
In some cases, symptoms of anaphylaxis may occur—a severe allergic reaction that poses an immediate threat to life:
- swelling of the face, throat, and neck,
- difficulty breathing,
- rapid heart rate,
- confusion, drowsiness,
- disorientation,
- loss of consciousness [5].
What should you avoid eating if you have a corn allergy?
We associate corn with breakfast cereals, corn chips, and corn porridge. Meanwhile, corn derivatives are an integral part of nearly every store-bought product. So what should you avoid if you have a corn allergy?
We should pay particular attention to ingredients such as:
- cornstarch,
- corn flour,
- dextrose and maltodextrin,
- corn oil,
- high-fructose corn syrup—which are added to many dishes, snacks, and beverages [6].
Both high-fructose corn syrup and sorbitol, which are most commonly derived from cornstarch, are used as substitutes for white sugar. So when reaching for diet cookies or gummy candies, we should take a look at the label to check for hidden allergens.
The same applies to alcohol: beer, bourbon, gin, and some vodkas are made from corn mash or malt, which retain their allergenic properties even after distillation. These beverages often also contain barley or wheat malt, which can cause cross-reactions [8].
