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Beginner's Guide to Corn Allergy and Intolerance

By Edited Oct 27, 2016 3 15

Beginner's Guide to Corn Allergy and Intolerance

Photo Credit: Eden, Janine, Jim, flickr.com, CC BY 2.0

If you or a loved one suspect or have been diagnosed with a corn allergy, going corn free is not as simple as giving up obvious sources of corn. Many hidden sources and corn derivatives can be extremely problematic.

Allergies and sensitivities often demand you give up your favorite foods. They interfere with your current lifestyle and require an enormous amount of research, detective work, and phone calls to find safe things to eat. That can feel overwhelming since corn is so prevalent in our food supply. Although the task of removing corn from your diet is huge, don’t give up. This beginner’s guide to corn allergies and intolerance will help you get started.

Begin By Going Corn Light

Going corn free is a difficult task. We live in a corn-saturated world. It’s in our food, medications, cleaning supplies, personal care products, adhesives, scents, plastics, paper, and even cigarettes. For that reason, going corn free is generally done in stages because there’s too much to learn all at once.

Begin by reading labels when shopping and try to eliminate all obvious sources. This won’t be easy because corn is not considered a major allergen. You won’t find a warning on the package that says the item contains it. There are several corn allergen lists available online you can print out to make the process of discovering hidden sources easier. Corn has a variety of different names you'll need to learn, and these lists can help you do that. Initially, watch for words such as starch, modified starch, corn syrup, high-fructose corn syrup, cornmeal and dextrose, which is corn sugar.

Don’t skip a product label just because you don’t think the item contains corn. You will need to become familiar with the ingredients of the products you currently use as well as those you’d like to try. Most brands of baking powder and powdered sugar contain cornstarch. Iodized salt contains up to 50 percent dextrose. You can use plain salt without iodine, but a non-iodized sea salt is better. Many people who avoid corn use Redmond’s Real Salt, which is available locally in many areas. It's also sold at Amazon.

Standard Powdered Sugar Contains Cornstarch

Photo Credit: Salim Virjl, flickr.com, CC BY-SA 2.0

Eliminating obvious sources is called going corn light. This corn reduction will enable your body to begin healing from the damage that corn is causing. While it doesn’t eliminate everything, it does get rid of most of the major offenders. As your body heals, it will regain its ability to detect smaller amounts. At that time, additional foods and products will need to be eliminated from your diet.

It's a good idea to begin researching hidden sources of corn before you start having symptoms again. If you wait until you start reacting, you won't feel like doing the necessary research.

Corn Allergy Difficulties 

While a can of corn, cornstarch, corn syrup and corn meal might be obvious sources of corn, there are many additional sources that go undetected by many consumers. Much of the corn that’s grown in the U.S. is also genetically modified and created to become its own insecticide. That results in wide variations in the way each individual reacts to corn.

Going corn free is further complicated by the fact that it doesn't always behave like a typical allergy. A true allergy occurs when you react to the proteins in a food, but those who have problems with corn often react to its starches and sugars, as well as the protein. Many allergists don’t accept sensitivities that are not true allergies. That makes finding reliable information difficult.

The following areas, tips and suggestions are those I've collected and used over the past few months. They come from various allergy and corn-avoidance forums, blogs, and personal research.

Meat and Eggs

Some individuals react to animals that have been fed a corn-based diet prior to slaughter but not everyone does. To receive USDA certification, meat processors spray the carcass with corn-based antibacterial solutions that contain citric acid or lactic acid. Both of these processing aids are derived from corn. Unfortunately, processing aids or the ingredients used in a food's packaging do not have to be listed on the label. Corn oil, cornstarch, and citric acid are the most popular processing and packaging aids in the U.S. Many plastics and plastic wraps also contain corn.

In addition, the trays that meats sit on can be made from corn. Meat can also sit on a pad soaked in citric acid, or eggs can be washed in a cornstarch solution. Meat cutters may use corny products to clean their machine, or they may use cornstarch on their slicer for deli meats. They might use powered gloves or plastic packaging and wraps coated with cornstarch. Most supermarket meat and dairy products are not safe for the corn intolerant. In fact, what appears to be dairy sensitivity can actually be corn intolerance.

The best way to handle the problem is to find a local farmer who will sell you eggs, chicken, beef, or lamb. If that isn’t possible, whole chickens and game hens don’t have corn-soaked pads, so they will be less contaminated. Another thing to watch out for is repackaging. For example, Laura’s Grass-Fed Ground Beef in the white tray comes straight from the company. They don’t use corn in processing, but grocery stores often open up the packages, treat the ground beef with dye and corny ingredients, and repackage it in different containers. My local Smith's grocery store sells Laura's Ground Beef, but it's in a black tray.

All canned tuna, including salt-free varieties, will be corn light due to the way fish is handled and iced on the boat. Since the ice used can contain corny ingredients, fresh fish at supermarkets may also be further contaminated. Even frozen wild caught salmon isn't safe because the boat might have dipped the fish into a corny glaze before flash freezing it.

Try to work dry beans into your menus more often, and begin investigating alternative sources of protein such as corn-free cheese and quinoa.  

Fruits and Vegetables

Fruits and Vegetables Can Be Contaminated with Corny Ingredients

Photo Credit: Public Domain

While moving to a whole foods diet is always best, produce shipped long distance probably contains some form of corn. Most produce is picked green and then gassed with ethylene to help it ripen at the right time. Bananas, avocados, pineapple, tomatoes, citrus fruits, mangoes, melons, kiwi, papaya, pears, nectarines, peaches, and plums are the most likely to be gassed.

In addition, fruits and vegetables might be washed with a cornstarch-based solution or receive a corn-based wax to help them stay fresh longer. This is particularly true for bagged and pre-cut produce, but is also true for organic products. Tomatoes, apples, peppers, rutabaga, citrus fruits, cucumbers and eggplant are the most likely to be waxed, but anything shiny and slick should be suspect. In addition, the pesticides used on apples, even from organic sources, can also be problematic.

Potatoes can be sprayed or gassed to keep them from sprouting. The safest potatoes are the dirty, loose potatoes found in large bins, not the ones that come bagged. Baby carrots list only carrots on the package, but because they are actually regular-sized carrots trimmed and sanded into their cute little shape, they contain citric acid for freshness. When it comes to produce, the dirtier the better because you don't know how it was washed.

A better choice would be to use your local Farmer’s Market as it reduces the risk for waxed and gassed produce. You can sometimes find corn-free produce at private markets or health food stores that get their stock from local growers.

Despite what some people say, wax doesn’t wash off. It soaks into the pores and contaminates the fruits and vegetables. If you aren’t that sensitive, you can remove some of the wax by using a baking soda and water paste to wash the produce. Washing before peeling reduces the risk of transferring corn residues to the edible portion of the fruit or vegetable.

Finding safe frozen or canned varieties can be just as difficult. Corn contamination can be found in the plastic packaging, how the produce was washed, or the type of salt or sugar used as a preservative. Cornstarch is also used to keep frozen vegetables such as peas from sticking together. This is a common practice among vegetable blends. The packaging used for microwave steamer-bag varieties is definitely made from corn. Canned tomatoes often have citric acid that is not required to be listed on the label. In addition, BPA-free can linings can also contain corn.

Vitamin Enrichment

One of the major practices within the processed foods industry is vitamin fortification and enrichment. Almost all of these vitamin enrichments contain some form of corn. Most brands of wheat flour, white rice, milk, and juice are off limits to those allergic to corn. In the case of enriched white flour, the contamination comes from cornstarch. While there are brands of rice that are not fortified, some use cornstarch in the packaging to keep the rice from sticking.

All Refined Oils Contain Citric Acid (Corn)

Photo Credit: Andre Torrez, flickr.com, CC BY-SA 2.0

Many commercial milks use safflower oil or corn oil to suspend the vitamins in the milk. Vitamin D fortified milk may also contain propylene glycol or polysorbate 80, both derived from corn. All refined oils use corn-based additives such as citric acid as a defoamer. Refined oils are the vegetable oils you generally find on supermarket shelves such as soybean, canola, and safflower oils. Better choices are extra-virgin olive oil, coconut oil, avocado oil, grapeseed oil, and peanut oils.

Additives that are usually corn-derived or contain traces of corn include distilled white vinegar, carageenan, xanthan gum, guar gum, or pectin. Because extracts are generally made from ethanol, vanilla extract can also be a problem. In addition to substances that suspend them, vitamins themselves are often derived from corn. Vitamin C is one example. These additives might not be listed on the label.

Additional Things to Watch Out For

There are several additional things to watch out for when you first go corn free. A common practice among food manufacturers is to use generic terms on the label, so they can take advantage of current prices and vary the ingredients without redoing the label. You’ll often find simple terms such as “starch” or “sugar” on a label without telling you where those starches and sugars came from. While all starch in the U.S. currently comes from cornstarch, imported products may be from wheat.

Sugar can be from beets, sugar cane, or corn. According to John H. Boyles, Jr. in his journal article, "Allergy Problems From 'Hidden' Corn," the most common form of sugar used commerically is corn sugar. Since manufacturers are only required to list "sugar" on the label, he advises those with corn allergies to be careful when using such products because manufacturers commonly vary the type of sugar they use throughout the year.

Soy lecithin also contains corn as well as all artificial flavorings. Caramel coloring can be from cane sugar or dextrose. Ground spices may have cornstarch or wheat added to prevent clumping without it being listed on the label. Quaker Oats in the cardboard cylinder uses cornstarch on the film that’s attached to the safety seal, but oats also come with their own set of problems. Just as oats can be contaminated with wheat due to adjacent fields, transportation, or manufacturing processes, they can also be contaminated with corn. In addition, the plastic bottles that filtered water and juices come in are often made from corn as well.

Scented Products

Food is not the only place you’ll find corn. Almost all scents, perfumes, and colognes come from ethanol. That means fabric softener, air freshener, lotion, deodorant, shampoo and conditioner. Anything that has a scent such as kitchen trash bags or cleaning supplies contain corn. Washing soaps, chlorine bleach, dishwasher soaps, shower gels, and hand soap also need to be scrutinized. So does toothpaste, makeup, toilet paper, paper towels, paper plates, and cups. If you’re partial to essential oils, they have to be steam distilled. In essence, you have to change almost everything you now use to something fragrance free.

Smells result from particulates in the product being suspended in the air. When you inhale these particles, it’s the same as if you ate them. Since flour dust can stay in the air for up to three days, you can accidentally ingest corn by simply going to a party or bakery even if you don’t eat anything. These air-borne particles can also be absorbed through the skin.

Going Corn Free is a Major Lifestyle Change

With corn so prevalent in American society, going corn free will be a major lifestyle change. Corn-free food is expensive, and withdrawing from the products and foods you’re used to eating and using won’t be easy. Most people discover they are addicted to the foods and products that contain a lot of corn. Corny foods can also make you hungry. This can make pinpointing corn sources easier. It can also take a while for your taste buds to adjust after giving it up because most processed foods contain additives that alter our sense of taste.

Many people go through different states where they believe they are corn free only to discover they are not. Just the act of removing major sources of wheat and corn, will make you more sensitive to their presence. The more gluten and corn you remove from your diet, the more sensitive you will become. Things you previously thought were safe, will now cause you to react.

Food Journal Keeps You Aware of Your Corn Allergy

Photo Credit: o5com, flickr.com, CC BY 2.0

One of the best ways to keep on top of your allergy or sensitivity is to keep a food journal or notebook handy to record the foods you experiment with and your reaction to them. Allergens can take up to four days to leave the body, so a record can be handy when watching for patterns and reactions you didn’t realize you were having. You will also need to know which foods are always safe for you. Although our current corn-saturated society makes going totally corn free almost impossible, the goal is always to get rid of as much of it as you can.



Aug 24, 2012 12:55pm
Hi--Everytime I read an article on alergies I am thankful that I am one of those persons who has no known alergies except for work and yellow lines. That's good because I am an absolute corn lover...Anyway, 2 big thumbs up for U--the article is written well and quite informative
Aug 27, 2012 4:59am
I'm a corn lover too, which makes this particular problem especially depressing. My life keeps evolving...but smaller! First gluten, then cow's dairy, and now corn. At the moment, I've been able to get away with corn light, but I don't know how long that will last. I do miss my corn on the cob though.
Jan 18, 2013 5:31pm
Hey there! This article is a really excellent 101/Cliff Notes introduction. It strikes a perfect balance between thorough and succinct. In fact, this is such a great summary that it has made big waves on the Facebook Corn Allergy & Intolerance group. A number of us would love to see you on the group if you'd care to join: https://www.facebook.com/groups/cornallergy
Jan 19, 2013 3:34am
Thanks for your comment. I've been working on the emotional and mental aspects of this particular allergy lately, but I still have a long way to go. I'll definitely check out your corn allergy facebook group. Thanks again.

Jun 24, 2013 1:34pm
Hey, I've been handing out this link to newbies left and right, and just now noticed that the article mentions specific brands of items that are NOT safe for even medium-sensitive corn allergies. Starkist Tuna and Quaker Oats come to mind first. The issue with these guys are cross contamination so the more corn-lite would not react perhaps, but many, many corn allergics can't do these at all.

Did you always have these brands mentioned and I didn't notice or did you perhaps add them later?
Jun 24, 2013 1:36pm
Ahem, I see that these items are on the "corn free food and products list" blog as being safe. So I guess some people may still be using them. I wouldn't, for myself.
Jun 25, 2013 9:20am
I haven't changed the article. It has always had those two brands and types mentioned. For Starkist Tuna, my understanding is that only the very-low sodium albacore in the gold can is safe (because it contains no salt or broth). All of the other types of Starkist Tuna are not safe. I've also been told by those extra sensitive to corn that Quaker Oats in the Large CostCo type boxes, where the oats are packaged with 2 super-sized bags inside are safe. But the cylinders you purchase at the grocery store are not safe due to the glue they use in the lid.

Is that wrong?
Jun 26, 2013 6:10pm
Ah crap, I flagged your post when I was trying to reply because I wasn't logged in and the button wasn't there. Sorry!

I don't know how to answer "wrong" or not. The thing is is that there is no one list of what is safe and as someone who is very very sensitive and steeped in the craziness of talking with other very very sensitive people, I forget what it's like for "normal" people who can still eat things with labels. As you probably realize by now it's only a matter of avoiding corn as much as possible, as you can't completely avoid it, at least not in the USA or really most of the Western world. I do my best not to be a shut in even at my level of sensitivity but honestly I do have to make significant preparations every time I set foot outside of my front door. Anyway.

Any canned tuna is necessarily going to be corn lite and not corn free due to how commercial fish are processed. Quaker Oats or really any oats are also going to be corn lite because the oats will be grown near corn, stored in facilities with corn, threshed on equipment that also threshes corn, milled on equipment near corn or that also mills corn, etc, etc, etc. For more details check the Hidden Corn entry under the heading "CANNED FISH"- http://cornallergygirl.com/2013/06/03/wheres-the-corn-in-foods/

Anyway, I try not to come from the perspective that everyone will have to worry about certain things just because I do, however on the Facebook group I told you about above it seems that even medium-sensitive people seem to start react to just about every brand of canned fish at least intermittently, and I haven't seen a brand of oats that was okay for the more sensitive.

Anyway sorry to be a nitpicker here! I should have private messaged you probably rather than leaving these comments here forever and ever. This article is still AWESOME and a really good overview, I just hadn't realized previously that specific brands were mentioned as being safe. If I were writing the article, i probably wouldn't mention brands, because even if they were at one point that could change at any time.

If you have admin access to delete this comment thread, please do- you can always ask me via private message. BTW Corn Allergy Girl is my blog and you can always contact me that way.
Jun 27, 2013 2:06pm
That's okay. Flags send me a private email with a carbon copy to admin, but I never got the flag, so something wacky was probably going on. Don't worry about it. Spam buttons and flag buttons get accidentally punched every now and then. It's okay.

I don't mind nitpicking, because my purpose with this article was to try and get some exposure for the problem, as well as help those who can't figure out what's wrong with them get started. Your comments are extremely valid. Brands do change, so now that you mention it, the article would be better without brand names for that reason.

If medium people are reacting to all brands of tuna, then the article needs to be updated to reflect that. The same goes for oatmeal. I appreciate your taking the time to comment. It's perfectly okay to do that here, in the comments. That way others who need to see what you have to say can read it. But it's also okay to private message back and forth too.

I also appreciate the point that corn allergy is an evolving issue. I realize now that I can't just write the article and not keep up with what's going in the corn-avoidance world. Thanks for that reminder too.

I will work on updating the article tomorrow. Thanks again for your time and comments.
Nov 3, 2013 11:51pm
I too love corn. Ona gluten free diet many people get into trouble with corn for 3 reasons:
Blood type incompatibility - I research this a lot, and only blood type A and AB (80% of them) tolerate corn.
Other problems are the GMO effects. In some cases, even if OK for the blood type, there are problems.
Lastly - some people are allergic to the grass family and can only tolerate rice. I know somebody like this. She, like you, stresses that gluten free is not the endo f the story.
Well done and a top rating!
Nov 5, 2013 1:11pm
Thanks for your insights. I totally agree that since celiac disease is autoimmune, there are often a lot of other problems in addition to gluten.
Nov 11, 2013 2:23am
I have discovered a way to test for the presence of starch (if you suspect corn in say, tuna or a cosmetic). Take a sample and add a drop of iodine. Iodine turns black of dark blue in the presence of starch. I will link this article to my "corny" contribution. Thanks for your thorough survey of the market place.
Feb 10, 2014 4:44pm
Wow. Thanks Yindee. That's extremely helpful.
Aug 31, 2014 2:39am
Excellent and informative read - thanks. (as an aside, I can't help but wonder how much GMOs are impacting allergies and other issues as well)
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