Corn (also known as maize) is among the oldest of cultivated grains, dating back 10,000 years to pre-Mayan times in South America. But corn didn’t make it onto European menus until 1493 when Christopher Columbus brought seeds to Spain. Corn was rapidly embraced, largely replacing barley and millet due to its spectacular yield per acre.

Widespread, habitual consumption of cornbread and polenta resulted in deficiencies of niacin (vitamin B3) and the amino acids lysine and tryptophan, causing epidemics of pellagra, evidenced as what physicians of the age called “The Four Ds”: dermatitis, diarrhea, dementia, and death. Even today, pellagra is a significant public health issue in rural South America, Africa, and China. Meanwhile, in coastal Peru, Ecuador, Mexico, and the Andes mountain highlands, increased corn consumption led to increased tooth decay, tooth loss, anemia, and iron deficiency, as well as loss of height in children and adults.

Today, farmers fatten livestock by feeding them intact corn kernels. But much of the corn consumed by humans is in the form of cornmeal or cornstarch, or derivatives of corn such as high-fructose corn syrup. This concentrated source of fructose is a form of sugar that fails to signal satiety— you don’t know when to stop. Corn and wheat jockey for inclusion in just about every processed food, many of which contain both. Corn in some form is therefore found in obvious sources, such as corn chips, cornbread, breakfast cereals, soft drinks with high-fructose corn syrup, tacos, tortillas, and corn dogs, but also in some not-so-obvious foods, including hamburger meat, ketchup, salad dressings, yogurt, soup mixes, candy, seasoning mixes, mayonnaise, marinara sauce, fruit drinks, and peanut butter.

Corn strains with the highest proportion of rapidly digested amylopectin, rather than the less efficiently digested amylose, are chosen to grind into cornstarch. Given the exponential increase in surface area that results when corn is reduced to granules or powder, these products are responsible for extravagant rises in blood sugar. With a glycemic index of 90 to 100, the highest of any food, they are perfectly crafted to contribute to diabetes. (Research Study.)

Corn allergies are on the rise, likely due to changes in alpha-amylase inhibitor proteins, lipid transfer proteins, and others. Because the various grasses that we call “grains” are genetically related, there can be overlapping grain allergies in humans exposed to them.  Repeated and prolonged exposure to corn proteins, as in people who work in agriculture, food production, or the pharmaceutical industry (cornstarch is found in pills and capsules), can lead to as many as 90 percent of workers developing a corn allergy. (Research Study) Such extravagant levels of allergy development do not occur in people working with apples, beef, kale, or olives— only grains.

The zein protein of corn triggers antibodies reactive to wheat gliadin, which can lead to gastrointestinal distress, diarrhea, bloating, bowel urgency, and acid reflux after corn consumption. (Research Study) The immune response responsible for the destruction of the small intestine that occurs in people with celiac disease can also be triggered, though less severely, by the zein protein of corn.

Nevertheless, cornstarch is— wrongly— used in gluten-free foods. Though they look quite different and the modern processed products that emerge from them look, smell, and taste quite different, wheat and corn are too closely related for comfort.

Yours in grainless health,

Dr. William Davis