Everything you need to know about the corn allergy including what it is, what are symptoms of a corn allergy, treatment, what to avoid, and how to stay safe.
The corn allergy is a rare allergy and not included in the top 9 allergies of the world. However, it is a growing allergy among both adults and children.
This article was updated in 2023 with new information, new sources of hidden corn, and a new resource guide.
Corn is one of the most sneaky allergies in that it is so pervasive in our lives. It can be found in sweeteners, foods, candies, soaps, shampoos, and even on meats, cheeses, and in eggs.
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. 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.
Key takeaways
- Corn allergies are very rare, affecting less than 1% of the population. However, a second study found that many people had an undiagnosed corn sensitivity.
- Corn is found in foods, as sweeteners in things like candy and soda, as stabilizers and thickeners in sauces or even soaps.
- While you may have a corn allergy, depending on the severity, you may not need to avoid all forms. For example, you may only need to avoid fresh corn but might be okay with high fructose corn syrup. Make sure to chat with your doctor.
- Common corn allergy symptoms are: Oral reactions (hives, rashes, or tingling sensation in the mouth), Gastrointestinal reactions (nausea, vomiting, diarrhea), or Skin rashes (hives, etc).
Jump to:
- Key takeaways
- What is a corn allergy
- What causes a corn allergy
- Is High Fructose Corn Syrup safe?
- Symptoms
- Anaphylactic reaction
- Diagnosing
- Treatment
- How to manage
- How to read a food label with a corn allergy
- What to avoid
- Corn and Meat / Dairy Industry
- What You Can Eat with a Corn Allergy
- Dining Out with Corn Allergies
- Top corn allergy tip
- More allergy articles to explore
What is a corn allergy
A corn allergy is a response of the body’s own immune system thinking that corn is a threat. This triggers an autoimmune response known as an allergic reaction.
In corn, a protein called “zein” is known to cause the allergic reaction. This protein is naturally found in all corn. The major function of the protein is to store nutrients and energy for the plant. This makes upwards of 50% of the individual corn kernel; so it’s really present in all forms of corn!
The zein protein is extracted and used in many different applications because it is a tough, glossy, waterproof, grease proof, substance that is used on many things (for example fruits and vegetables) to have them last longer in transportation. It also is used to give products a glossy, shiny appearance.
While this is an eco friendly option, it is not so friendly to those with corn allergies!
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.
There is no cure for a corn allergy.
What causes a corn allergy
Corn, like other allergies, can be caused by genetics, the environment, or the way the two interact with each other.
Allergies tend to run in families so if you have an allergy, it is likely that someone else in the family has allergies as well.
The allergies themselves may be different among family members, but there is a genetic component to a tendency to allergies.
Is High Fructose Corn Syrup safe?
For some people, eating highly processed corn derivative foods, such as high fructose corn syrup, is safe.
This is because the zein proteins have been so modified by processing that the body no longer recognizes it as an allergen.
That makes HFCS safe for some people.
However, each person is an individual and you need to know your body and what is safe for you and your unique needs. Talk with your doctor if you are unsure.
Symptoms
If you are allergic to corn you can have one or more of the following reactions. Note that the reactions can occur minutes or hours after exposure.
A list of possible 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 reaction
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 you have an anaphylactic reaction, call 911 or your local emergency number immediately.
Signs and symptoms of an anaphylactic reaction include:
- Swelling and tightening of the throat
- Difficulty breathing
- Chest pain or tightness
- Trouble swallowing
- Dizziness or fainting
- Change of the normal coloring of the skin and in the mucous membranes (inner lips, gums, around the eyes, and the nail beds)
- Light skin, check for signs of a dark blue tint in the mucous membranes
- Medium skin, check for signs of a gray-green tint in the mucous membranes
- Dark skin, check for signs of a gray or white tint in the mucous membranes
If you have had an anaphylactic reaction in the past, talk with your doctor and/or your healthcare provider about receiving an epinephrine auto-injector (Epi Pen).
Diagnosing
A diagnosis begins by sharing your history and suspicions with your doctor or healthcare provider.
An allergist is the most common doctor to diagnose a corn allergy.
There are a few specific allergy diagnostic tests to determine if you have an allergy or not. They may perform one of the following tests to determine your allergies:
- Skin Prick Test: Placing a small sample of the suspected allergen in a purified form into the top layer of the skin with a small poke (not a needle).
- Blood Test: Drawing a small sample of blood to be sent to a lab where they will check the blood’s reactivity to various suspected allergens.
- Food Elimination: This is the gold standard for diagnosing a food allergy. The suspected food is removed in all forms from the diet for 2 to 3 weeks and then reintroduced under the supervision of your doctor. If a reaction occurs, it is likely to be an allergy.
It is only safe to do food challenge testing under the supervision of a doctor. Do not eat food you know you are allergic to.
Treatment
The only treatment for a corn allergy is to avoid the corn as much as you can.
If you do have a reaction, talk with your doctor about what to do in your unique circumstances. Things like over the counter antihistamines, Epi Pens, or going to the urgent care or ER center are all possible outcomes of having a corn allergy reaction.
How to manage
The best way to manage your corn allergy is to avoid any and all forms of corn and corn related products to the best of your abilities.
As with most allergies, the more frequently you are exposed to the allergy, the worse your reaction will be over time.
If you are having symptoms and are unsure of the cause, it can be helpful to keep a food and life journal to mark down what you eat and what you encounter to track if any patterns emerge.
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.
Want to take this list on the go? Make sure to get my free printable of the hidden names of corn!
What to avoid
Products will not always be labeled if they contain corn ingredients. Always read labels carefully.
If you are unsure about a product, contact the manufacturer. Even if you have used a product before, ingredients are always changing.
- Corn (fresh, canned, creamed, frozen, corn oil, popped corn, caramel, etc.)
- Alcohol (grain alcohol, alcohol in extracts)
- 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, erythritol, Dyno, Cerelose, Puretose, Sweetose, glucose, sorbitol, xylitol, inositol, sodium erythorbate
- Food Starch
- Fructose
- Grits
- Hard Liquors (vodka, moonshine, whisky, gin, brandy)
- Hominy
- Maize
- Mannitol
- Margarine
- Nutritional Yeast (yeast is grown on corn)
- Rubbing Alcohol (isopropyl alcohol is sometimes distilled from corn)
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
- 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
- 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)
Non Food Corn Products
- Medications
- make sure you talk to your doctor before stopping medications and ask about switching to a different medication!
- The corn is found in the bindings and coatings of the medications and is often labeled as “food starch”.
- Adhesives on envelopes, stickers, stamps, etc
- Biodegradable bags
- Glues and other adhesives like in tape
- Hand Sanitizer (alcohol derived from corn)
- House cleaners (anti-bacterial sprays, wipes, window cleaner, etc)
- Inks (both things printed at home, and eco-friendly inks on products like cards, newspapers, packaging, etc.)
- Inks and materials used in 3D printing
- Paper containers
- Food wrappers
- Disposable straws
- Toothpaste
- Laundry starch
- Surgical gloves
- Pet food
- Crayons
- Dish washer soap
- Shampoo
- Paint
- Dextrose intravenous solutions
Possible Sources of Zein Proteins
- Fibers, Textiles
- Adhesives (glues)
- Coatings (fruits and vegetable waxes, other products with a non-stick coating)
- Ceramics
- Inks
- Cosmetics
- Chewing gum
- Biodegradable plastics (single use plastics)
Corn and Meat / Dairy Industry
The majority of corn grown in the US is grown to feed to animals - beef cattle, dairy cows, chicken, pork, lamb, and goat.
This makes it possible for you to have a reaction to consuming any animal product (meat, milk, cheese, or eggs) that is produced from an animal fed corn.
Additionally, corn is a hidden ingredient in the industry standard disinfectant washes used in the processing of meats. All meats are washed in this solution to make it safer for handling.
If you are severely allergic to corn, you need to source meat, dairy, and eggs from suppliers who do not use corn in their feed, corn in their washes, or corn in their packaging.
To date, I have found that Northstar Bison and White Oak Pastures are safe suppliers for corn free meats. They have a good allergen safety protocol on their site and I encourage you to check them out.
What You Can Eat with a Corn Allergy
Tip! Check out my shop page for corn free solutions to powdered sugar, baking powder, vanilla extract, and more.
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.
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.
As always, if you want to try a new food that could be a concern, make sure you do a food challenge under the supervision of your doctor.
- Brown rice syrup can be used in place of corn syrup to make sweets and candies.
- Arrowroot starch, tapioca flour, potato flour, potato starch, and white rice flour can all be used as a thickener in sauces and gravies. They can also be combined with wheat flour to make a safe cake flour. Simply remove 1 tablespoon of wheat flour and add 1 tablespoon of one of these other starches.
Dining Out with Corn Allergies
The biggest change to your life with a corn allergy comes from the options available to you when dining out.
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.
Top corn allergy tip
This article is a good overview of a corn allergy, but it is not everything. For a blogger who devotes her whole blog to a corn allergy, I highly recommend that you check out Corn Allergy Girl.
More allergy articles to explore
If you try these out, please leave a comment below! This provides helpful feedback to both me and other readers. And if you want more delicious, dietary friendly recipes you can subscribe to my newsletter and follow along on Instagram, Twitter, and Facebook!
MaryD says
Thank you so much for this article. My sister-in-law has corn allergy and I'm starting to suspect my infant does, too, due to the issues we've had and how hard it's been to get her comfortable and tolerating what she's consuming, breastmilk then hypoallergenic formula. I'm wondering if you have any information on infants and corn allergies: how early you can test for the allergy, could they be sensitive to corn derivatives in mothers milk, or a good resource to check out for more information on corn allergies and infants.
Laura says
Hi Mary!
Thanks for reaching out. I’m so glad that you found this helpful and I hope I can help you and your daughter out.
First, if you don’t have an allergy specialist, I really recommend that you make an appointment as soon as you can.
Yes, babies can react to things in mother’s milk just as they can react to things in formula.
This article breaks down how and why corn is often used in American formulas. It also has a list of different formulas for you to purchase from Europe that specialize in dairy, soy, corn free formulations. This would be my place to start. It’s from a Swiss company that specializes in allergy friendly baby formula for all life stages. More and more families across America and Australia are ordering online for allergy friendly baby products, so you are not alone in your search!
https://organiclifestart.com/blogs/guides/baby-formula-without-corn-syrup-without-sugar
Another company that you can look into is one based in Ohio, Nature’s One. It has a pea formula that also states that they are corn free.
https://www.naturesone.com/organic-plant-based-pea-protein-formula/
Technically, you can test for allergies at any age, but most doctors won’t do any skin tests before 6 months old. Also, skin testing isn’t the best method for finding out allergies. Food avoidance and then challenge testing is the best and most reliable method for food allergy testing, something that should be done with an allergist.
Here are some more corn free references that you can look into.
Corn Allergy Girl - She has the best blog on corn allergies around. She lives with a severe corn allergy and has put together this guide on misconceptions on corn allergies.
https://cornallergygirl.com/2019/01/10/clearing-up-some-misconceptions-about-corn-allergy/
She also has a list that was just updated in March 2023 of her current list of safe products. Corn can hide in almost anything! So it may not be the formula she is reacting to, but maybe something else in her environment.
https://cornallergygirl.com/2013/07/14/safe-for-me-products-the-list-of-what-i-use/
Hope this is helpful and please send me an email anytime with more questions or other concerns!
Avid host says
Hey, I’m plant based and am intending to host someone who can’t have nuts, milk, gluten, soy or corn (and a bunch other things but those were the biggies), I want to make sure she has food and is safe while eating it. I have recipes that are do gf sf but I am currently checking for corn replacements as well. so I have been going through searching. I’m curious as to why powedered sugar and baking powder are on the no list. I noticed you listed some sugar alcohols but not Erythritol. Is erythritol safe? I will obviously go through the recipes with her beforehand but want to make sure I put out my best options and choices first.
Laura says
First, thank you for taking the time to make sure that food allergies are taken seriously. You are a rock star of a host for that!
Yes, corn is kinda a sneaky ingredient that works into a lot of foods you may not think of, like powdered sugar. In the sugar they use cornstarch to keep the sugar from clumping. So far, I've found that Wholesome makes a good corn free powdered sugar - they use tapioca flour to keep it from clumping. Similar to the powdered sugar, baking powder uses cornstarch to keep it from clumping. Vanilla extract is often suspended in a corn derived alcohol. I have corn free options for all of these on my shop page if you want to take a look at some safe brands.
For erythritol, I would avoid it. It is often made from corn and while it is processed, it still might contain traces of corn for those super sensitive for it.
If you need a sugar substitute that is safe, I would recommend asking her about xylitol, coconut sugar, date sugar, or monk fruit sugar. Those might be better, but as I don't know all her allergies, I can't say for certain.
Thank you for being such an awesome host! If you have any other questions, please don't hesitate to send me an email.
Sammy says
I have suffered from air borne allergies most of my life. I have also had severe GERD and constantly struggled with abdominal discomfort. I didn't get hives or rashes. Not one doctor ever suggested I get tested for food allergies. In my early 50's, I decided to get tested for food allergies. I found out I am allergic to corn, seafood, soy bean and a couple of others. I eliminated those things from my diet. Suddenly my acid reflux and GERD disappeared. After suffering for 25 years, my stomach and intestines healed. I still take Nexium or Prevacid but only once every 2-3 days. But corn was the main culprit, especially corn starch. Corn Starch just about kills me. The allergist tested for IgE for corn but said it was really low. She said I couldn't be allergic to the starch because when you have food allergies, she stated your only allergic to the protein. Allergists and doctors in general are taught a certain methodolgy and are just wrong. After doing some research, I found out this horse with blinders attitude by doctors is just bullshit. They really don't know anything about this stuff. All they want to do is put you on precription antihistamine, prescribe inhalers, Breo, etc. and get allergy shots. They just mask the symptoms. Not one ever discussed foods and what to stay away from. Most of the info I have learned over time came from other people with food allergies, especially corn. Also you can be allergic to many things besides the protein in food. Like I said corn starch kills me. I can eat corn tortillas but I don't get that much discomfort. Basically you have to do your own research and determine what you need to do to make yourself better. There are many alternatives to meds. Chinese medicine works well. Look into Perilla Seed Oil, etc. to tamp down your allergy sensitivity.
Laura says
Thank you for sharing your story! Yes, it's so true how allergies can go undiagnosed for so long. I'm glad to hear that you are feeling better with changing your diet and other alternatives. I find that doctors who have never had a food allergy are like so many other people - they just don't know how far down this rabbit hole goes! Food, cosmetics, even glue on envelopes can trigger some people! Like you said, learning to listen to your body and trust it is one of the most important things. Glad you are getting better and so happy you are here!
Dana Crowder says
You reference a mildly allergic/sensitivy to corn - what does that equate to? My numbers from the bloodwork done show .26 which seems to be "in control" range. The Moderate Range is .35 - 3.49 so I am clearly below that. Can these mean that the corn has a cumulative effect? In other words, even though I have a "in control" range - should I avoid anything with corn or just watch how much I consume. It is in a lot of the supplements I take. I am wondering if I must avoid it completely even though my #'s are so low? I have a call into the docs office but I don't know if she can answer this? I am scheduled to see an allergist but not until March/April of 2022. Ugh. Any help is appreciated. Thank you!
Laura says
Hi there! So without knowing what specific tests you were doing, I can't speak directly to the numbers for your allergic level. Different tests and doctors have different values.
That said, yes, you can totally watch how much corn you eat and see how you feel. If you don't food journal, I really recommend that you do so, especially on days/times that you eat corn. Monitor how you feel, how you react, how your digestion is, all of it. All are clues to helping understand what is going on. I think that there is no harm in avoiding corn in your diet and seeing how you feel. I would not stop any medications or supplements that have been prescribed by your doctor. If you feel better avoiding eating things with corn or corn derived ingredients, I would say to just avoid it. At a later point, if you don't have an allergy, you can see about adding it back in.
Also, remember that having an allergy and having an intolerance are two separate things. For example, I'm not allergic to dairy but do find that I've developed a bit of lactose intolerance. So it is possible that you are not allergic to corn, but have an intolerance of it. You mention. cumulative effect, and for sure. I can tolerate a small amount of dairy but can't do a lot or I get a bad stomach ache!
I know the struggle of waiting to get in to see doctors so that we can make the right changes. It can seem like forever!
So, long story short. I think that as long as you take any medications or supplements your doctor has prescribed, there is nothing wrong with removing obvious corn from your diet. Keep a food journal and see how you feel over the next few weeks. Then you can take that info to your doctor appointment and chat with them about if you have an allergy, intolerance, or something else.
Remember, I'm not a medical professional, just someone who has been living with allergies my whole life! Hope this helps and let me know if you have any other questions.
Pat says
Ok so where are the corn free meats? All grass fed meat are fed a vegetarian diet (which are grain diet I.e corn)
Laura says
That's a really good point. I've started researching it and plan on having a deep dive article on this topic up soon. In the meantime, I would say that if you are only mildly allergic/sensitive to corn, the research shows it isn't an issue. If you are very allergic/sensitive, the research shows to avoid meats that have been fed corn. A good place to purchase is North Star Bison farms. I'll more info available soon!