Corn is a starchy vegetable and cereal grain that has been eaten all over the world for centuries.
However, the health benefits of corn are controversial — while it contains beneficial nutrients, it can also spike blood sugar levels. In addition, the crop is often genetically modified.
It’s rich in fiber, vitamins and minerals. Corn is a staple in cuisines all around the world. In the United States, nothing says summertime quite like corn on the cob. While plenty of people enjoy corn, many don’t realize that it’s actually a very nutritious crop. Depending on how it’s prepared, corn can provide the best of both worlds: delicious food that’s good for your health.
Consistent with recommendations from leading cancer and heart disease authorities, my recommended Daily Dozen includes at least three daily servings of whole grains. One serving can be considered a half cup of hot cereal such as oatmeal, cooked grain such as rice (including the “pseudograins” amaranth, buckwheat, and quinoa), cooked pasta, or corn kernels; a cup of ready-to-eat (cold) cereal; one tortilla or slice of bread; half a bagel or english muffin; or three cups of popped popcorn.
Harvard’s Nurses’ Health Study and the Health Professionals Follow-Up Study have found that people who eat more whole grains, including corn, tend to live significantly longer lives independent of other measured dietary and lifestyle factors. Indeed, eating whole grains appears to reduce the risk of heart disease, type 2 diabetes, obesity, and stroke. Take note of the whole, however. While whole grains, such as corn, oats, whole wheat, and brown rice, have been shown to reduce our risk of developing chronic disease, refined grains may actually increase risk.
People who ate the most whole grains had significantly slower narrowing of two of the most important arteries in our body: the coronary arteries that feed the heart and the carotid arteries that feed our brain. Since atherosclerotic plaque in the arteries is our leading killer, we should not just slow down the process but actually stop or even reverse it altogether, and eating more whole grains, whole vegetables, whole fruits, whole beans, and other whole plant foods can help with that.
About 10,000 years ago, corn was first cultivated in parts of Mexico and Central America. Corn is usually considered a vegetable but it is actually a grain, rich in fiber, vitamins, minerals and antioxidants. Although the yellow color corn/maize is very common around the world, did you know that corn varieties come in many other colors too such as red, orange, purple, blue, white and even black. Corn or maize is a grain plant, which originated in southern Mexico.
The kernels of the seeds of corn hold the majority of nutrients and are the most consumed parts. If you love munching these little golden kernels then here are more reasons to add them to your diet. Corn may be high in sugar (sucrose), but there are several other properties of this grain that must not be overlooked.
In this article, we explore the nutritional content and potential health benefits of corn. We also discuss risks, health myths, and some tips for eating and preparing corn.
What Is Corn?
Also known as maize (Zea mays), corn is one of the world’s most popular cereal grains. It’s the seed of a plant in the grass family, native to Central America but grown in countless varieties worldwide.
Popcorn and sweet corn are popular varieties, but refined corn products are also widely consumed, frequently as ingredients in processed food.
These include tortillas, tortilla chips, polenta, cornmeal, corn flour, corn syrup, and corn oil.
Whole-grain corn is as healthy as any cereal grain, as it’s rich in fiber and many vitamins, minerals, and antioxidants.
Corn, also known as maize, is a starchy vegetable that comes as kernels on a cob, covered by a husk. Corn is one of the most popular vegetables in the U.S. that sometimes gets a bad rap because it has a lot of natural sugar and carbs. But don’t overlook the health benefits of this versatile veggie.
Corn is a favorite of summertime cookouts. Popped, it makes the perfect snack for movie nights or parties. Dried and ground into flour, its seeds become cornmeal for tortillas, chips, and crackers. In this form, it’s a grain, not a vegetable.
Farmers in southern Mexico first cultivated corn about 10,000 years ago from a wild grass called teosinte. Teosinte kernels were much smaller than modern corn kernels. As farmers carefully chose which corn seeds they replanted, corn evolved into the version you know today.
Natives of North and South America grew corn, which they called maize. Europeans who came to New England learned about it and brought it back to their home countries. The pilgrims of Plymouth Colony and members of the Wampanoag Tribe probably ate corn at the first Thanksgiving dinner in 1621.
Corn Nutrition Facts
The following nutrition information is provided by the USDA for 1 medium (6 3/4″ to 7 1/2″ long) ear of sweet yellow corn (yields 102g).
- Calories: 88
- Fat: 1.4g
- Sodium: 15mg
- Carbohydrates: 19g
- Fiber: 2g
- Sugars: 6.4g
- Protein: 3.3g
There are 19 grams of carbohydrate in one ear of corn. Of those carbohydrates, fiber makes up 2 grams and natural sugars make up 6.4 grams. Corn is considered moderate on the glycemic index scale with a rating that falls between 56–69.
Like all cereal grains, corn is primarily composed of carbs.
Starch is its main carb, comprising 28–80% of its dry weight. Corn also provides small amounts of sugar (1–3%).
Sweet corn, or sugar corn, is a special, low-starch variety with higher sugar content, at 18% of the dry weight. Most of the sugar is sucrose.
Despite the sugar in sweet corn, it is not a high-glycemic food, ranking low or medium on the glycemic index (GI).
The GI is a measure of how quickly carbs are digested. Foods that rank high on this index may cause an unhealthy spike in blood sugar.
Corn contains a fair amount of fiber.
One medium bag (112 grams) of cinema popcorn boasts approximately 16 grams of fiber.
This is 42% and 64% of the Daily Value (DV) for men and women, respectively. While the fiber content of different types of corn varies, it’s generally around 9–15% of the dry weight.
The predominant fibers in corn are insoluble ones, such as hemicellulose, cellulose, and lignin
Corn is naturally pretty low in fat, with 1.4 grams per medium-sized ear. The majority of fat in corn is from heart-healthy monounsaturated or polyunsaturated fats.
Corn has just over 3 grams of protein per ear. Compared to most vegetables, corn is pretty high in protein. That’s because corn is technically not a vegetable at all, but rather a whole grain.
Depending on the variety, the protein content ranges from 10–15%.
The most abundant proteins in corn are known as zeins, accounting for 44–79% of the total protein content.
Overall, the protein quality of zeins is poor because they lack some essential amino acids.
Zeins have many industrial applications, as they’re used in the production of adhesives, inks, and coatings for pills, candy, and nuts
Vitamins and Minerals
Corn contains the nutrients potassium, iron, zinc, magnesium, phosphorus, and selenium.3 It also provides folate, vitamins C and E, and vitamin A in the form of beta carotene.
- Manganese. An essential trace element, manganese occurs in high amounts in whole grains, legumes, fruits, and vegetables. It’s poorly absorbed from corn due to this vegetable’s phytic acid content.
- Phosphorus. Found in decent amounts in both popcorn and sweet corn, phosphorus is a mineral that plays an important role in the growth and maintenance of body tissues.
- Magnesium. Poor levels of this important mineral may increase your risk of many chronic illnesses, such as heart disease.
- Zinc. This trace element has many essential functions in your body. Due to the presence of phytic acid in corn, its absorption may be poor).
- Copper. An antioxidant trace element, copper is generally low in the Western diet. Inadequate intake may have adverse effects on heart health.
Kinds of Corn
The sweet corn that you eat at cookouts comes in yellow, white, or a combination of the two colors, and it has a mildly sugary taste.
Popcorn, before you prepare it, has a soft, starchy center surrounded by a hard gold-colored shell. Inside is a tiny drop of water. When you heat popcorn in a pan or in your microwave, the moisture inside gives off steam. Pressure from the steam builds to the point where the kernel explodes, and the center opens into a fluffy white nugget.
Flint or Indian corn is harder than sweet corn. It comes in red, white, blue, black, and gold. Flint corn grows in Central and South America. In the U.S., we use it mainly for fall decorations.
Dent corn, which comes in white and yellow, has a dent in the top of each kernel. Its main uses are animal feed and manufactured foods, like tortilla chips and grits.
Health Benefits of Corn
It provides many health benefits due to the presence of quality nutrients within. Besides being a delicious addition to any meal, it’s richness in phytochemicals protects some chronic diseases. The well-researched and widespread health benefits are listed below.
Lutein and Zeaxanthin Content May Benefit Eye Health
Corn is particularly high in lutein and zeaxanthin, two carotenoids that may prevent cataracts and age-related macular degeneration (AMD).
This is likely because lutein and zeaxanthin make up a large part of the macular region of your eyes.
One study in 365 adults found that those who had the highest intake of carotenoids — especially lutein and zeaxanthin — had a 43% lower chance of developing AMD compared to those with the lowest intake).
Therefore, regularly eating corn may promote eye health — especially for those who are at risk of AMD.
Prevention of Diverticular Disease
Diverticular disease (diverticulosis) is a condition characterized by pouches in the walls of your colon. The main symptoms are cramps, flatulence, bloating, and — less often — bleeding and infection.
Popcorn and other high-fiber foods were once believed to trigger this condition.
However, one 18-year study in 47,228 men suggests that popcorn may, in fact, protect against diverticular disease. Men who ate the most popcorn were 28% less likely to develop diverticular disease than those with the lowest intake.
Reduces Risk of Type 2 Diabetes
Polyphenols are beneficial plant compounds that are found in whole grains, fruits, vegetables, and nuts. Purple corn owes its color to a type of polyphenol, called anthocyanin, which has been shown to improve the regulation of insulin and glucose.5
Including a variety of colorful, plant-based foods in your meal plan like purple corn, is a proactive way to prevent the onset of type 2 diabetes. If you have diabetes and want to incorporate purple corn into your diet, consider the carbohydrate count. In addition, purple corn should not replace any current medical regimen that is currently being followed.
The fiber content in one cup of corn amounts to 18.4% of the daily recommended amount. This aids in alleviating digestive problems such as constipation and hemorrhoids, due to maize being a whole-grain. One study found that corn barn was significantly better than wheat barn in relieving constipation.
Dietary fiber can help bulk and soften stools, promoting regular elimination, and decreasing straining. This process is done by stimulating the peristaltic motion and the production of gastric juice and bile. By adding bulk to loose stools, the chances for irritable bowel syndrome (IBS) and diarrhea can be greatly reduced.
Some corn varieties are rich in antioxidantsTrusted Source, specifically in a group of antioxidants called carotenoids.
Antioxidants combat the effects of harmful free radicals in the body. Research suggests that free radicals may play a role in the aging process and the development of a number of chronic diseases.
Many fruits and vegetables, including dark leafy greens, carrots, and sweet potatoes, are also rich in carotenoids.
Can Spike Blood Sugar and May Prevent Weight Loss
Since corn is high in starch, it can spike your blood sugar and may not be suitable for some populations.
People who have diabetes may need to limit their starchy carb intake, including corn.
Research specifically focusing on corn intake and diabetes is limited, but studies suggest that low-carb diets are more effective at managing diabetes.
A study in 115 adults with obesity and type 2 diabetes found that eating a diet with only 14% of calories coming from carbs resulted in more stable blood sugars and a reduced medication need compared to getting 53% of the daily calories from carbs.
Eating less of other corn products, especially high-fructose corn syrup, may help prevent diabetes.
One study found that the prevalence of diabetes was 20% higher in countries with easier access to high-fructose corn syrup, compared to areas where the syrup was not readily available.
Finally, people who are trying to lose weight may want to limit their intake of starchy carbs from corn.
A 24-year Harvard study in 133,468 adults found that each additional daily serving of corn was associated with a 2-pound (0.9-kg) weight gain per 4-year interval. Potatoes, peas and other starchy vegetables did not contribute to as much weight gain.
May Help Prevent Colon Cancer
Corn is a good source of fiber that promotes the growth of “good bacteria” in the gut. These bacteria produce short-chain fatty acids to help prevent colon cancer.6 Eating fresh corn, popcorn, and checking food labels to ensure that you a buying a “whole grain” corn product will ensure that you get the most fiber out of your corn consumption.
Provides Essential Minerals
Corn contains several essential minerals that can help in ensuring proper growth and fighting diseases. According to a 2017 study, published in the Journal of Food Science and Technology, it is an important source for Fe, Zn, Cu, Mn, Mg, and P. The nutritional composition can, however, vary according to the way it is harvested and processed. The nutritional content is best preserved when it is eaten whole or as popcorn. Steaming, boiling, or roasting lowers the nutritional content.
It also contains trace minerals like selenium, which are difficult to find in most diets. Phosphorus is essential for regulating normal growth, bone health, and optimal kidney functioning. Magnesium is necessary for maintaining a normal heart rate and for increasing bone mineral density.
Protects Your Heart
According to research, corn oil has been shown to have an anti-atherogenic effect on cholesterol levels, thus reducing the risk of various cardiovascular diseases. Corn oil, in particular, is the best way to improve heart health and this is derived from the fact that corn is close to an optimal fatty acid combination. This allows omega-3 fatty acids to strip away the damaging LDL or bad cholesterol and replace them at the binding sites. This can reduce the chances of arteries becoming clogged, lower blood pressure, and minimize the risk of heart attack and stroke.
According to another study, consumption of corn husk oil lowers plasma LDL or bad cholesterol by reducing cholesterol absorption in the body. As mentioned earlier, this reduction in LDL cholesterol does not mean a reduction in HDL or good cholesterol, which can have beneficial effects on the body. They include the reduction of heart diseases, prevention of atherosclerosis, and general scavenging of free radicals throughout the body. The Australian government recommends corn oil as one of the foods that can help in preventing heart diseases.
In recent decades, the world has seemed to suffer from an epidemic of diabetes. Although the exact mechanism for this cannot be pinpointed, it is generally related to nutrition.
According to a study published in the journal Food Science and Human Wellness in 2018 have shown that consumption of whole-grain corn is related to a decreased risk in the development of type 2 diabetes. According to the Journal of Medicinal Food, consumption of its kernels assists in the management of non-insulin-dependent diabetes mellitus (NIDDM) and is effective against hypertension due to the presence of phenolic phytochemicals in whole corn. Phytochemicals can regulate the absorption and release of insulin in the body, which can reduce the chance of spikes and drops for people with diabetes and help them maintain a healthy lifestyle, as per the British Journal of Nutrition.
Although corn is technically a grain, it is also gluten-free. This makes corn a safe option for people with celiac disease or gluten intolerance who want to add grains to their diet.
High in Protein
Corn is higher in protein than many other vegetables, making it a good choice for vegetarians and vegans, or for people hoping to eat more protein from nonanimal sources.
Some studies also suggest that a diet rich in protein may support healthful weight loss by either reducing hunger or helping the body burn extra calories.
The primary health concern that nutrition advocates have with corn is that it may act as a filler, which may cause people to eat too many carbohydrates and too few of more nutrient-dense foods.
According the Tufts University Health & Nutrition Letter, more than a third of corn people eat in the U.S. is in the shape of high fructose corn syrup, or HFCS. This sugar, which is a derivative of cornstarch, has triggered numerous debates about manufacturers adding sweeteners to consumables.
Corn is a starchy vegetable, like potatoes and peas. That means it has sugar and carbohydrates that can raise your blood sugar levels. It can still be a healthy part of your diet if you don’t overdo it. If you have diabetes, you don’t necessarily need to avoid corn, but watch your portion sizes.
Corn also has antinutrients, which are compounds that keep your body from absorbing nutrients as well as it should. Soaking your corn can help remove many of them.
Often, corn gets contaminated by fungi that put off toxins called mycotoxins. If you eat a lot of corn with these toxins, you’re at a higher risk for certain cancers, liver problems, lung issues, and slowing of your immune system.
Some people who have celiac disease — a disorder that causes an autoimmune response when you eat any kind of gluten — find that corn causes issues for them. Corn may also cause a symptom flare if you have irritable bowel syndrome (IBS).
Some people have raised concerns about genetically modified (GM) corn. Scientists can change the DNA in corn to make it more resistant to drought or insects, or to give it more nutrients. Farmers sometimes use this type of corn in their crops.
There’s no evidence that genetically modified corn poses any risk to human health.