Corn Allergy: What to Eat and What to Avoid

Corn Allergy 101 - everything you need to know to stay safe. Includes a list of common corn allergy symptoms, hidden sources of corn in your life, and what you need to avoid to not have a reaction. 

The corn allergy is not in the top 9 most common allergens in the United States, however, it is a growing allergy among both adults and children. A study performed in 2016 suggested that upwards of 1% of the adult population has an allergy to corn at varying levels of severity. A second study performed on only 50 people found that 6% (3 out of 50 people) of them had an undiagnosed corn allergy. Safe to say, corn allergies are a growing concern. 

Corn is a sneaky allergy in that it is so pervasive in our everyday lives, especially as a sweetener in the form of High Fructose Corn Syrup. 

Corn is often found in baked goods, salad dressings and marinades, sauces, seasoning packets, frying oils, candy, and even on your take-out pizza. In home care and body care, corn can be hidden in make-up, powders, and house cleaning products. 

Those super allergic to corn may find that they can even have a reaction to eating the meat and eggs of animals fed a corn-based diet. 

While living with a corn allergy can seem overwhelming and difficult, it isn’t insurmountable. Pinky promise. And there are many corn substitutions available!

This article walks you through all aspects of what is a corn allergy, symptoms, what to avoid, what you can still enjoy, and how best to manage your corn allergy. 

Jump to:

• What is a corn allergy? 
• Symptoms 
• Anaphylactic corn allergy
• How to manage corn allergies
• Being your own allergy advocate
• Corn allergy safety in school and work
• How to read a food label with a corn allergy
• What to Avoid with a Corn Allergy
• Cross allergic reactions
• What You Can Eat with a Corn Allergy
• Eating Out with Corn Allergies
• Other Hidden Sources of Corn Not In Food

What is a corn allergy? 

Corn is a cereal grain that was first cultivated by the indigenous peoples living in what is now southern Mexico around 10,000 years ago. There are several varieties of corn, including those grown for humans to eat, animals to eat, distilled for alcohols, and even corn that is grown to make biofuels. 

True corn allergies are rare and they are caused by a protein in the structure of the corn kernel itself. Corn contains a lipid protein transfer that survives cooking and this is the protein that causes the allergic reaction. 

Some people who are allergic to corn may still be able to safely enjoy derivatives from corn, such as corn syrup or high fructose corn syrup. However, it is best to consult with your allergist before making any changes to your diet in regards to your allergies. 

Other possible causes of a corn allergy could be related to the minimal amounts of corn pollen found in the corn kernels or in the storage proteins found in corn, similar to the storage proteins found in wheat. 

Symptoms 

Most children and adults will develop an allergic reaction either immediately, a few minutes, or as long as a few hours after coming into contact with corn. Remember, some people are so allergic to foods that even touching the food or smelling the food can cause a reaction. 

A list of probable reactions includes:

• Swelling, itching, or irritation of the mouth, lips, tongue, or throat
• Asthma attacks
• Eczema on the skin
• Hives, itching rash of the skin
• Nasal congestion
• Headaches
• Difficulty breathing
• Cramping and/or pain of the stomach or bowels
• Nausea
• Vomiting
• Diarrhea
• Anaphylactic reaction

Anaphylactic corn allergy

For some people, a life threatening reaction known as an anaphylactic reaction may occur after consuming, touching, or smelling corn or corn by-products. If this happens, please call 911 or your local emergency number immediately. Signs and symptoms of this include:

• Swelling or tightening of the throat
• Difficulty breathing
• Chest pain or tightness
• Trouble swallowing
• Dizziness or fainting
• Change of normal coloring of the skin
  • light skin, check for signs of dark blue tints in the mucous membranes (inner lips, gums, around the eyes, and nail beds)
  • medium skin, check for signs of a gray-green tint in the mucous membranes
  • dark skin, check for signs of gray or white tint in the mucous membranes  

How to manage corn allergies

The best way to manage your corn allergy is to avoid any and all forms of corn or corn by-products.

If after some time you feel you would like to test and see if you are still allergic to corn, consult your doctor and ask about doing a RAST, SPA, or food challenge test to gauge your reaction under the supervision of your doctor. 

It is super important that you only do the challenge testing with a doctor present as food allergies can change in severity at any time. 

Being your own allergy advocate

If you are certain something is wrong, don’t give up! In my late 20s, my primary care physician was unconvinced I had developed new allergies. He was ready to prescribe an anti-acid medication, assuming I was eating too much fast food. However, I was adamant in my knowing that something was wrong and went to an allergy specialist. I had my blood checked and my IgE levels were off the charts! We did an elimination diet of wheat and saw immediate improvements in my health. Be your own advocate at the doctor’s office, and make sure you take someone with you to help navigate if you need. 

Corn allergy safety in school and work

If your child has a corn allergy, make sure to let both the school and their individual teachers know of their allergy. Any medication you or your child might need, including an EpiPen if the reaction is severe, needs to be kept at the school in case of emergencies.

In elementary school, when they have assigned seating, it is easier to maintain a clean workspace for your child. As they go through middle and high school and beyond, make sure to have them wipe down the desk before they use it as there could be oils or protein on the desk after someone ate a granola bar, for example.

The most dangerous moments for your child will be during school parties when parents bring in sweet treats to celebrate. You must teach your child that they can’t participate in these events no matter how good the cupcake (or whatever the treat is) looks because we don’t know if it’s safe.

Another dangerous moment is at the lunch table. While you might pack a safe lunch for your kid, there is no guarantee that they don’t swap foods to share with friends at the table. This is another thing you need to teach your kids not to do.

In a work environment, you should inform your coworkers of your allergy and ask them to not eat around you or your workspace, especially if your allergy is severe and anaphylactic. Making sure to wipe down surfaces is again important.

How to read a food label with a corn allergy

Learning how to read food labels is one of the most important things you can do after developing a corn allergy. Always make sure that you read the entire label and not just quickly scan for corn as ingredients can hide under different names.

Sometimes companies will place advisory statements on their label to say things such as, “May Contain” or “Produced in the same facility as…”. These are not required by law but are placed there at the discretion of the company. Talk with your doctor about whether you should avoid these food labels as well.

In general, I tend to avoid any and all food products that list my own allergies on these advisory statements. You never know if one day cleaning the machines, an allergen was totally washed away or not. I err on the side of caution with my health and suggest you do the same.

What to Avoid with a Corn Allergy

When looking at a food label, make sure that the ingredient list does not contain any of the following items. The list of foods to avoid is long. I’ve done my best to include them all here, I am sure there are more being made and discovered each day. If you know of an allergy name that I’ve missed, write it in the comments below and I’ll be sure to add it to the list!

• Corn (fresh, canned, creamed, frozen, corn oil, popped corn, caramel, etc.)
• Baking powder
• Breakfasts cereals such as Corn Flakes
• Confectioners’ Sugar (also known as powdered sugar and 10X sugar)
• Cornmeal
• Corn starch
• Corn syrup
• Corn Sugars including: dextrose, dextrin, maltodextrin, fructose, Dyno, Cerelose, Puretose, Sweetose, glucose, sorbitol, sylitol, inositol, sodium erythorbate)
• Food Starch
• Fructose
• Grits
• Hominy
• Maize
• Mannitol
• Margarine

Be careful in using the following items as they are often made using corn

• Breaded or fried foods (cross contamination or corn oil)
• Baking mixes
• Baking vanilla extract (use this brand for a corn free vanilla)
• Baby formulas
• Biodegradable bags
• Cheese and cheese spreads
• Chop Suey and Chow Mein
• Caramel color (made with corn syrup)
• Carbonated drinks such as pop and soda
• Citric Acid (a mold grown in corn sugar)
• Fish sticks
• Fried items (if corn oil is used)
• Fruits like apples and citrus (sprayed with a vegetable wax derived from corn)
• Frozen Mixed Vegetables
• Gravy (thickened with cornstarch)
• Graham crackers
• Glues and other adhesives like in tape
• Hand Sanitizer (alcohol derived from corn)
• House cleaners (anti-bacterial sprays, wipes, window cleaner, etc)
• Ice creams, sherbets
• Instant coffee
• Jams and jellies
• Malt syrup
• Modified food starch
• Marshmallows
• Medications are often made with corn starch
• Milkshakes
• Monosodium glutamate
• Ketchup and mustard
• Pancake Syrup
• Pet foods (search for corn free)
• Pork and beans
• Polenta
• Supermarket meats (sprayed with lactic acid fermented in corn sugars)
• Table Salt (made with dextrose)
• Vanilla extract (can be made with corn syrup)

Want to take this list on the go? Make sure to get my free printable of the hidden names of corn!

Cross allergic reactions

It is possible that you may experience a cross-reactivity to other foods when allergic to corn. Here are the possible foods you may also experience reactions to:

• Rice
• Barley
• Peaches

What You Can Eat with a Corn Allergy

After developing a new allergy, how you eat both at home and out and about is very likely going to change. Cooking at home is going to be the safest option for you and your family as you can ensure no allergens come into contact with the food and no cross contamination can occur. Make sure your diet is filled with simple whole foods, such as meats, grains, vegetables, fruits, beans, and lentils.

Living with allergies has gotten so much better in the past few years thanks to the requirements of labeling all food in grocery stores, as well as the sheer quantity of allergy free alternatives available in most stores.

The main challenge when being allergic to corn is where it is used as a sweetener and a thickening agent. Look for products and foods that do not contain these items.

It is possible that you are allergic to corn, but are still able to eat things with high fructose corn syrup. This is because after manufacturing the corn syrup the zein, the protein that causes the majority of corn allergies, is removed. If you are allergic to corn, you may not be allergic to high fructose corn syrup. As always, if you want to try a food allergy, make sure that you do a food challenge under the supervision of your doctor.

Some of the best swaps for soy allergies are other grains.

Brown rice syrup can be used in place of corn syrup to make sweets and candies.

Arrowroot starch, tapioca flour, and white rice flour can all be used as a thickener in sauces and gravies. They can also be used when combined with wheat flour to make a safe cake flour. Simply remove 1 tablespoon of wheat flour and add 1 tablespoon of tapioca flour.

Eating Out with Corn Allergies

Perhaps the biggest change to your life with a corn allergy will come from the options available to you when dining out. No longer can you just go grab a quick bite to eat, nor will you be able to freely eat at a friend’s house.

The best way to avoid (or at least try to avoid) getting sick at restaurants is to research ahead of time. Most restaurants post their menus online, which gives me a chance to figure out if this restaurant would be a safe option. Even if the menu says “allergy friendly” you still should research, because it is really difficult to ensure that a chef or kitchen will wipe off any surfaces, open new bags of ingredients, or even use a different set of gloves when preparing food.

For corn allergies in particular it is important to ask the restaurant what oil they use to fry their food. Often places will use soy or vegetable oil which includes corn in the blend. You also need to ask if there are any items that go into the fryer that contain corn as you don’t want to have the risk of cross contamination via the oil.

Other Hidden Sources of Corn Not In Food

Beyond food, there are places that corn can hide, making you sick even though you don’t eat corn anymore! While you won’t be eating these things, you should be aware that a reaction can occur from touching or smelling corn. These hidden corn places include:

• Medications (make sure you talk to your doctor before stopping medications and ask about switching to a different medication!)
• Adhesives on envelopes, stickers, stamps, etc
• Paper containers
• Food wrappers
• Disposable straws
• Toothpaste
• Laundry starch
• Surgical gloves
• Pet food
• Crayons
• Dish washer soap
• Shampoo
• Paint
• Dextrose intravenous solution

Make sure you check these places and use the list above to make sure that you and your family are safe from these hidden corn sources!

Have other allergies? Check out these articles to learn more

Coconut Allergy 101

Wheat Allergy: What to Eat and What to Avoid

Dairy Allergy: What to Eat and What to Avoid

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