Corn is in the Poaceae family of plants, this family includes other cereal plants including barley, durum wheat, oat, wheat, rice and rye.

The terms maize and corn are often used interchangeably- maize is the name of the plant that grows corn, which is the product we eat.

There are 5 key allergens associated with maize, 3 of them are classified as airway allergens and 2 food allergens.

Zea m 8 is a chitinase protein. This is a plant derived enzyme made by plants naturally to act as a defence against fungal attacks.

Zea m 14 is a Lipid Transfer Protein. This is considered to be a panallergen, causing allergic reactions over lots of different groups of foods.

Zea m 1 is a beta expansin protein. Expansins are proteins involved in cell wall expansion and modification. .

Zea m 12 is a profilin protein. This is another panallergen, found in both foods and pollens.

Zea m 25 is a thioredoxin protein which is in part responsible for cell growth of the maize plant.

Corn is a low FODMAP food. FODMAP stands for Fermentable oligosaccharides, disaccharides, monosaccharides and polyols. Foods high in FODMAPs can cause symptoms of food intolerance, affecting the gastro intestinal system and this can be mistaken for a true IgE food allergy. Corn syrup however is high fructose and is considered a high FODMAP food.

Corn, like other grains contains a moderate amount of lectins, another cause of food intolerance. Cooking foods with lectins makes them more digestible and can reduce the symptoms of food intolerance.

Fresh corn is low in salicylates and canned sweetcorn has a moderate amount of salicylates. Salicylates have the potential to cause worsening of asthma, swelling, itching and hives as well as food intolerance symptoms in people who are sensitive to salicylates.

Corn derivatives like corn starch and corn syrup (and those processed foods containing them) contain a low to moderate amount of sulphites. Fresh or cooked corn is low in sulphites. Sulphites are inorganic salts used in preservations and have the potential to cause symptoms of food intolerance to those sensitive to sulphites, this food intolerance is more common in asthmatics. An improvement in symptoms can be made with a change to a low sulphite diet.

You can read more about Food Intolerances on the dedicated Food Intolerance Page.

Corn/maize allergy has been seen in conjunction with allergies to other foods presenting as Latex Food Syndrome. This is due to the chitinase allergen. The body confusing the proteins it encounters in food to that of latex proteins to which it is already sensitised.

LTP's are a group of proteins which can cause more serious allergic reactions in patients, you may suffer from LTP Syndrome if you suffer IgE type allergy symptoms to foods mentioned in the cross reactivity section below.

Those with a sensitivity to chitinase may have linked allergies to foods which contain high levels of chitinase like chestnuts, banana, avocados, papaya, pomegranate, kiwi and tomatoes.

Common foods involved in LTP allergy include kiwi, strawberries, sunflower seeds, walnut, apple, mulberry, banana, pea, apricot, cherry, plum, almond, peach pomegranate, raspberry, tomato, grape, celery, peanut, asparagus, cabbage, broccoli, chestnut, lemon, tangerine, orange, hazelnut, lettuce, lentils, lupin, green bean, pear, mustard, wheat and maize.

Many different species of grasses contain the beta-expansin allergen, including rye, rice and maize.

Other plants containing profilin inhalant allergens are ragweed, wormwood, birch, sunflower, olive, plantain, poplar and oak. Profilins are also found as food allergens in kiwi, celery, peanut, chilli, watermelon, orange, hazelnut, melon, carrot, strawberry, soya, walnut, lychee, lupin, apple, cherry, almond, peach, pear, mustard, tomato and aubergine.

Thioredoxin is also common in moulds and wheat.

Read more about Grain Allergens and Pseudocereals.

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