Corn makes me think of summer weather, backyard barbecues, and time spent with loved ones. I’ve enjoyed corn on the cob on many a summer night. I’ve also enjoyed my fair share of cornbread, corn tortillas, and more corn chips than I’d care to admit. And I know I’m not the only one.
Corn is a versatile food with a rich history and significant nutritional benefits. From its origins in ancient Mexico to its status as a global dietary staple, corn was and still is an important and valued crop.
This article explores the various types of corn, their nutrition and health benefits, and their potential downsides.
What Is Corn?
Corn is a domesticated crop that originated from teosinte, a wild grass genetically similar to corn, around 10,000 years ago in what is now Mexico. Indigenous peoples in both Central and North America have long practiced a form of companion planting using corn, beans, and squash, which many call “The Three Sisters.”
Both the Olmec and Mayan cultures extensively cultivated corn through ancient agricultural techniques and relied on it for their survival. It even played a role in their spirituality. In the Mayan creation story, humans were created from masa or corn dough.
Corn is also often called maize. While both words refer to the same plant, Zea mays L., their usage depends on whether you’re in the US or Europe and how the corn is being used. In Europe, the word “corn” has traditionally been used to refer to any form of grain. Nowadays, in many parts of the world, corn usually refers to the plant when it’s used for food (corn kernels, corn on the cob, etc.), while maize may refer to crop fields and nonfood uses of the plant (such as ethanol and corn plastics).
And now we come to one of the biggest corn questions of them all: Is corn a grain, a vegetable, or a fruit?
Apparently, that’s a bit of a gray area. Corn on the cob is typically considered a vegetable. But when it comes to the individual kernels, those are whole grains. Kernels are also seeds (you can plant them to grow popcorn!), and technically, that could even make corn a fruit! So, in truth, corn is a grain, a vegetable, a seed, and a fruit all in one! No wonder it’s so versatile!
Types of Corn and Corn Varieties
1. Sweet Corn
This is the yellow corn variety you’re most likely to find on the cob or off the cob — fresh, canned, or frozen. Sweet corn is known for its taste because of its high sugar content. It’s also different from other corn varieties because it’s picked for human consumption before it’s fully mature. This ensures that the kernels stay soft and sweet rather turning hard and starchy. As a result, it also means fresh sweet corn doesn’t keep as well as other types of corn.
Interestingly, sweet corn only makes up 1% of the corn grown in the United States. (More on the other 99% below!)
2. Indian Corn (or Flint Corn)
Often seen in the autumn, Indian corn is a beautiful variety with multicolored kernels. The unique colorings come from the cross-pollination of single-color corn species. Indian corn is also called flint corn (on account of its hard kernels) and is one of the oldest varieties of corn, which Native Americans taught early European immigrant explorers to grow.
Indian corn has hard kernel shells that shrink when cooked, making it less susceptible to spoiling than other varieties. Popcorn is actually a type of Indian corn with hard and slightly translucent kernels that explode from the inside out when heated.
Although it’s often used as table decor during the fall holidays, Indian corn is edible. It works best in dishes like polenta (boiled cornmeal) and hominy (corn cooked by nixtamalization) because it doesn’t taste sweet. Higher in starch than other varieties, Indian corn contains varying degrees of the carotenoids lutein and zeaxanthin, though these appear to be reduced when the corn is boiled.
3. Blue, Purple, or Black Corn
The dark color of blue corn comes from anthocyanins, which are pigments high in antioxidants. Anthocyanins can fight free radicals in the body and stave off disease. The anthocyanins in blue corn have specifically been studied for their anticancer properties and demonstrated an antiproliferative effect on certain cancer cell lines.
Blue corn is also slightly higher in protein, carbohydrates, and minerals than yellow or white sweet corn. Because of their hard texture, blue corn varieties are not usually found in their whole food form. Instead, they’re often ground up and used to make processed foods like tortillas, tortilla chips, and blue corn flour or cornmeal.
4. Field Corn
This corn variety is also called dent corn because of a distinct dent that forms when the kernels dry. Field corn is the most common commercially grown crop in the US, accounting for about 88.2 of the 88.5 million total acres of corn grown. Most field corn grown in the US is also genetically engineered (aka bioengineered) — about 92%. It is primarily used to feed livestock or create ingredients for processed foods such as cornstarch, corn oil, corn cereal, and high-fructose corn syrup. It’s also used for nonedible creations such as corn plastics and biofuels like ethanol. About 45% of total field corn is used for ethanol production, while another 40% is used for animal feed.
5. Baby Corn
You might find baby corn in Chinese food, at a salad bar, or pickled in tiny jars at the grocery store. Many people assume that baby corn comes from a smaller species of corn. Surprise! Baby corn is just regular sweet or field corn picked very prematurely.
Corn Nutrition
Corn’s nutritional value varies depending on its color and variety. Overall, the majority of edible corn is indeed nutritious.
Sweet corn nutritional facts:
According to the USDA, one medium-sized sweet corn ear has approximately 88 calories, 3 g protein, 19 g carbohydrates (including 2 g fiber and 6 g sugar), 2 mg calcium, and 275 mg potassium. Corn also contains folate, vitamin A, and choline.
As mentioned previously, when talking about the different types of corn, depending on the kernel colors, many corn varieties also contain a number of important antioxidants. The majority of phytochemicals in corn can be found in the bran and germ. That’s why whole corn and whole grain corn products are more nutritious than more refined foods, which may only be made from the endosperm.
The Health Benefits of Corn
In addition to health-promoting antioxidants, edible corn offers some other health benefits, too:
1. Corn may help keep your eyes healthy.
Corn is high in lutein and zeaxanthin, which are carotenoid compounds naturally found in the macula of your eyes. Lutein and zeaxanthin in foods have been studied for their impact on preventing age-related macular degeneration (AMD). A study in JAMA found that of 365 adult men and women, those who consumed the highest amounts of these compounds had a 43% reduced risk of AMD compared to those who ate the lowest amounts. A more recent study in the International Journal of Molecular Sciences also showed that sweet corn extract had anti-inflammatory activity capable of preventing AMD.
2. Corn may be good for your gut.
The high fiber content of corn is probably good for your gut. Fiber is essential for digestive health. It’s been shown to reduce the risk of digestive diseases like colorectal cancer and diverticulitis.
People with diverticulitis have traditionally been told to avoid eating popcorn. But a 2008 study published in JAMA followed over 47,000 men between the ages of 40 and 75 with no history of diverticulitis for 18 years. Researchers found that men who ate popcorn at least two times per week had a significantly lower risk of developing diverticulitis than men who ate no popcorn. As a result of this and other studies, official recommendations for diverticulitis have been updated.
3. Corn may have anticancer properties.
Corn has anticancer activity due to the presence of bioactive peptides, which are small protein fragments that can influence biological processes in the body. They work by promoting apoptosis, which is the programmed death of cancer cells, and by inhibiting the growth and spread of tumors. Corn-derived nanoparticles have also been studied as a possible adjuvant to cancer therapy. The particles have been found to shrink tumors without damaging organs, unlike chemotherapy which can be harsh on organs.
Additionally, corn (especially darker varieties like blue and Indian corn) has strong antioxidant properties that can help protect cells from oxidative stress. By reducing oxidative damage in the body and supporting the immune system, the peptides and antioxidants in corn can play a significant role in cancer prevention.
4. Corn is a hydrating food and provides essential electrolytes.
Sweet corn, in particular, is an excellent source of hydration and is composed of about 76% water when fresh. It also provides essential electrolytes such as potassium and magnesium. Potassium helps regulate fluid balance, nerve signals, and muscle contractions, while magnesium is crucial for muscle and nerve function, blood sugar control, and bone health, among other things. These electrolytes are essential for maintaining proper hydration levels and overall health, especially in hot climates where dehydration risks are higher.
Eating corn for hydration is particularly beneficial in lower-income regions where access to clean water and balanced nutrition may be limited. Glucose polymers from corn and other starchy grains have been used to create oral rehydration solutions for cholera and other diarrheal illnesses in developing nations.
What About Popcorn?
Popcorn is a whole grain with many of the same nutrients as sweet corn or field corn, including a significant amount of fiber and polyphenols. Although there are many delicious ways to prepare this popular snack, the mode of preparation is key. That’s where an originally healthy snack can transform into an unhealthy one.
For instance, many microwave popcorn bags contain perfluorooctanoic acid (PFOA), which has been linked to thyroid problems and ADHD. Many packaged popcorn brands also contain hydrogenated or partially hydrogenated oils, which can contain trans fats that are harmful to your heart health. And what about if it has fake butter on it, like what’s used on movie theater popcorn? “Buttery flavor,” as it’s called, often contains a host of nasty ingredients. One of the worst is a chemical called diacetyl, which has been linked to a condition called “popcorn lung” — a type of constrictive bronchiolitis. Yikes.
If you like the taste of popcorn, it’s best to enjoy it air-popped. That way, you can avoid the oils and chemicals used in processing most commercially available popcorn. And instead of mounds of melted butter and salt, try popcorn with healthier toppings. Sprinkle some nutritional yeast, lemon juice, herbal seasoning, hot sauce, curry powder, garlic powder, onion powder, a dash of sea salt, and/or other herbs and spices on top. Some people even like it with cinnamon. The possibilities are endless!
Health Downsides to Corn
Corn Allergy
A corn allergy is considered rare but can cause a range of symptoms, from mild to severe. Individuals with corn allergies may experience hives, itching, swelling, gastrointestinal issues, respiratory problems, or even anaphylaxis after consuming corn or corn-derived products.
Corn is not one of the “Big 9” allergens, but a severe allergy can still be extremely prohibitive since corn derivatives are in almost everything you can think of. Corn is also found in many processed foods, making it challenging to avoid in food from the grocery store.
Individuals who suspect they have a corn allergy should read food labels carefully and consult with an allergist for proper diagnosis and management. Corn allergies and sensitivities are usually diagnosed through an elimination diet or allergy testing by a health care professional.
Corn in Processed Foods
As mentioned previously, corn is a common ingredient in many processed foods. From high-fructose corn syrup to cornstarch to the additive maltodextrin, corn derivatives are often used as sweeteners, thickeners, and fillers in various products.
Using corn in processed foods is economical for the US food industry because it’s a commodity crop, meaning the government subsidizes it, which in effect drives down the price.
But corn-derived ingredients in processed foods are often unhealthy because they may have been largely or completely stripped of the fiber, vitamins, minerals, protein, and antioxidants originally in the corn. What’s worse, high-fructose corn syrup is made from corn starch and is linked to an increased risk of obesity, cancer, type 2 diabetes, and metabolic syndrome. These ingredients may be high in calories but are low in essential vitamins, minerals, and fiber, leading to poor dietary quality. They’re also often combined with added sugars, unhealthy fats, and a variety of chemicals. And as if that wasn’t bad enough, the convenience and palatability of processed foods make them easy to overconsume, exacerbating the health risks.
Environmental Concerns about Corn
Pesticides and Bioengineering (BE)
Most corn, especially field corn, is grown in enormous monocultures with little to no rotation of crops. Partly as a result of this, corn is highly susceptible to pests. So it’s often sprayed with pesticides and herbicides, most of which the thick corn husk prevents from infiltrating the edible corn itself. But that doesn’t stop these chemicals from being incredibly harmful to the environment and to species that come in contact with these poisons, like bees.
Genetic modification, or bioengineering (BE), is another strategy employed by agribusiness in its war against the pests that pose a particular threat to monocultures. As of 2023, at least 90% of corn grown in the United States was genetically modified.
One goal of BE corn is to make it resistant to herbicides (like Bayer’s RoundUp). What’s more, most genetically modified corn can produce a protein that’s naturally made by Bacillus thuringiensis (Bt) bacteria, which kills pests like the southwestern corn borer that can threaten corn crops. When the corn borer eats this kind of BE corn, the bug’s intestines explode, causing rapid death.
Historically, Bt was sometimes sprayed on the outside of plants, as a pesticide — and it could even be washed off. But with BE crops, it’s built in and found in literally every cell of the plant — with the result that humans are now eating it in unprecedented quantities.
And there’s more bad news. Bt corn worked to repel pests for a while, but now the pests appear to be building a resistance to the corn’s toxin. How do farmers protect the crops when that starts to happen? By spraying with more pesticides, of course.
The good news is that there is no BE popcorn (although it may still be treated with pesticides). And the majority of sweet corn (the kind people eat the most frequently) is not genetically modified. Sweet corn is on the Environmental Working Group’s Clean Fifteen list of crops that contain the least pesticide residues. However, Bayer isn’t standing idly by when there’s money to be made. Now, between 10 and 25% of sweet corn sold in stores may be bioengineered.
If you want to avoid BE corn, there are a couple of actions you can take. First, you can ask your local farmers if they’re planting genetically modified seeds. This is, of course, easiest to do if you’re buying directly from them at a local farmers market or through a CSA. You can also look for USDA Organic corn or Non-GMO Project certified corn. Neither of these certifications allows for the use of GMO (BE) crops. (For more on the difference between organic and non-GMO / non-BE, click here.)
Corn as Feed Rather Than Food
Over half of the grain grown in the US, and a strong majority of the corn, is fed to livestock, not humans. It takes about 2.5 pounds of corn to produce one pound of feedlot beef, or around 2,800 pounds of corn per animal. This isn’t exactly the peak of efficiency. In fact, modern meat production is something of a protein factory in reverse.
And feed corn (almost all of which is field corn) uses an immense amount of natural resources. In fact, it uses more water for irrigation than most other feedlot grains and requires more fertilizer than any other crop (due to total acreage). Fertilizers are rich in nitrogen and phosphate, which are linked to the development of ocean dead zones as agricultural runoff reaches our waterways. Corn production is responsible for approximately 40% of the nitrogen pollution in agricultural runoff.
In the United States, corn also uses more land than any other crop — about 92 million acres. Meanwhile, there are nearly one billion people hungry or starving around the world. If we stopped cycling so much corn and other crops through livestock and cars, we’d free up vast amounts of land and water, which could be used to grow food directly for humans.
The counterintuitive reality is that a typical factory-farmed steak contains significantly more corn and soy than a dinner of corn on the cob and tofu.
Kernels of Truth: Should You Eat Corn?
If you have a corn allergy, as some people do, then, of course, it goes without saying (but should be said anyway): Don’t eat corn. But is corn good for you? For most people, unprocessed, non-BE corn is a nutritious food that can be a healthy addition to your diet. You can experiment with different ways to enjoy corn, knowing you’re enjoying a long-standing and nourishing staple food that’s tasty and has some intriguing health benefits.
Tell us in the comments:
- Do you eat corn? Why or why not?
Featured Image: iStock.com/AllNikArt
