Corn is a tough crop- on one hand it is considered one of the most common food allergens, while on the other it is a cheap and accessible base for many processed foods and a popular alternative for gluten intolerant individuals. Corn’s wide use in the food and drug industry is thought to be due to the fact that corn is not a highly ”allergenic allergen”, meaning most people can tolerate it well, and intolerant individuals require a significant amount of exposure before eliciting any reaction. However, corn sensitivities seem to be on the rise, individuals with sensitivity to corn are often painfully aware of the seemingly ubiquitous use of corn and corn related products. Corn and corn related products are used in everything from canned goods to toothpaste. Sufferers become experts in inquiring about the source of ingredients to avoid the often uncomfortable,and potentially life threatening consequences of consuming corn. Further, corn is one of the most common genetically modified foods, adding to concerns of its use.
“Corn allergies” can range from immediate type I (IgE) hypersensitivity reactions that can cause anaphylaxis to the more common delayed type, cell-mediated “intolerance's.” Corn intolerance can cause symptoms such as headaches, abdominal pain, fatigue, mood disturbances, joint and muscle pain to name a few. Anaphylactic reactions tend to be rare and most individuals have the latter. Research on the proteins that specifically cause these immune responses is relatively new. A number of proteins have been identified each with different allergenic potential. The primary allergen related to more serious IgE related reactions, is a protein part of the Lipid Transfer Protein (LTP) family. As mentioned earlier this reaction is rare, that being said some of the other proteins in corn can cause cell mediated reactions and the concentration of these proteins (ie. allergenic potential) varies in the different corn based products. For example, unrefined forms such as corn flour and popcorn are more likely to cause the cell mediated response. Other culprits include glucose and fructose syrup, dextrin, maltodextrin. However, ingredients derived from corn are often highly purified, and or hydrolysed during extraction significantly reducing their allergenicity. This is important to note as many ingredients such as the prebiotic fibre xylo-oligosaccharide (XOS), or xylitol, which may be derived from corn but the processing removes most of the allergenic proteins ( confirmed through purity testing), meaning an immune response is not initiated.
As you can see corn can be an excellent alternative or yet another food to avoid, however the form and processing is important when determining its risk potential. As such, we must measure our response to corn- to that of cautious but not fearful. Inquiry into processing methods, GMO status, and individual susceptibility can help alleviate the corn conundrum.