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 is typically yellow but comes in a variety of other colors, such as red, orange, purple, blue, white, and black.
This article tells you everything you need to know about corn.
Here are the nutrition facts for 3.5 ounces (100 grams) of boiled yellow corn (1Trusted Source):
Protein: 3.4 grams
Carbs: 21 grams
Sugar: 4.5 grams
Fiber: 2.4 grams
Fat: 1.5 grams
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%) (1Trusted Source, 2).
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 (1Trusted Source).
Despite the sugar in sweet corn, it is not a high-glycemic food, ranking low or medium on the glycemic index (GI) (3).
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 (1Trusted Source, 2, 4Trusted Source).
The predominant fibers in corn are insoluble ones, such as hemicellulose, cellulose, and lignin (2).
Corn is a decent source of protein.
Depending on the variety, the protein content ranges from 10–15% (1Trusted Source, 5).
The most abundant proteins in corn are known as zeins, accounting for 44–79% of the total protein content (6Trusted Source, 7).
Overall, the protein quality of zeins is poor because they lack some essential amino acids (8Trusted Source).
Zeins have many industrial applications, as they’re used in the production of adhesives, inks, and coatings for pills, candy, and nuts (7).
Corn is mainly composed of carbs and fairly high in fiber. It also packs a decent amount of low-quality protein.
The fat content of corn ranges from 5–6%, making it a low-fat food (1Trusted Source, 5).
However, corn germ, an abundant side-product of corn milling, is rich in fat and used to make corn oil, which is a common cooking product.
Refined corn oil is mainly composed of linoleic acid, a polyunsaturated fatty acid, while monounsaturated and saturated fats make up the rest (9Trusted Source).
It also contains significant amounts of vitamin E, ubiquinone (Q10), and phytosterols, increasing its shelf life and making it potentially effective at lowering cholesterol levels (10, 11Trusted Source).
Whole corn is relatively low in fat, though corn oil — a highly refined cooking oil — is sometimes processed from corn germ, a side product of corn milling.
Vitamins and minerals
Corn may contain a fair amount of several vitamins and minerals. Notably, the amount is highly variable depending on the corn type.
In general, popcorn is rich in minerals, whereas sweet corn is higher in many vitamins.
This popular snack boasts several vitamins and minerals, including:
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 (12Trusted Source).
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 (13Trusted Source, 14Trusted Source).
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 (15Trusted Source, 16Trusted Source).
Copper. An antioxidant trace element, copper is generally low in the Western diet. Inadequate intake may have adverse effects on heart health (17Trusted Source, 18Trusted Source).
Sweet corn boasts a number of vitamins, including:
Pantothenic acid. Also called vitamin B5, this acid is found to some extent in nearly all foods. Thus, deficiency is rare.
Folate. Also known as vitamin B9 or folic acid, folate is an essential nutrient, especially important during pregnancy (19Trusted Source).
Vitamin B6. B6 is a class of related vitamins, the most common of which is pyridoxine. It serves various functions in your body.
Niacin. Also called vitamin B3, niacin in corn is not well absorbed. Cooking corn with lime can make this nutrient more available for absorption (2, 20).
Potassium. An essential nutrient, potassium is important for blood pressure control and may improve heart health (21Trusted Source).
Corn is a good source of many vitamins and minerals. Popcorn tends to be higher in minerals, while sweet corn tends to be higher in vitamins.
Other plant compounds
Corn contains a number of bioactive plant compounds, some of which may boost your health.
In fact, corn boasts higher amounts of antioxidants than many other common cereal grains (22Trusted Source):
Ferulic acid. This is one of the main polyphenol antioxidants in corn, which contains higher amounts of it than other cereal grains like wheat, oats, and rice (22Trusted Source, 23).
Anthocyanins. This family of antioxidant pigments is responsible for the color of blue, purple, and red corn (23, 24).
Zeaxanthin. Named after corn’s scientific name (Zea mays), zeaxanthin is one of the most common plant carotenoids. In humans, it has been linked to improved eye health (25Trusted Source, 26Trusted Source).
Lutein. One of the main carotenoids in corn, lutein serves as an antioxidant, protecting your eyes from oxidative damage produced by blue light (25Trusted Source, 26Trusted Source).
Phytic acid. This antioxidant may impair your absorption of dietary minerals, such as zinc and iron (16Trusted Source).
Corn provides higher amounts of antioxidants than many other cereal grains. It’s especially rich in eye-healthy carotenoids.
Popcorn is a special variety of corn that pops when exposed to heat.
This happens when water, trapped in its center, turns to steam, creating internal pressure, which makes the kernels explode.
A highly popular snack, popcorn is one of the most common whole-grain foods in the United States.
In fact, it’s is one of the few whole grains consumed on its own as a snack. More frequently, whole grains are consumed as food ingredients, such as in breads and tortillas (27Trusted Source).
Whole-grain foods may have several health benefits, including reduced risk of heart disease and type 2 diabetes (28Trusted Source, 29Trusted Source).
However, regular popcorn consumption has not been linked to improved heart health (27Trusted Source).
Even though popcorn is healthy on its own, it’s often eaten with sugary soft drinks and frequently loaded with added salt and high-calorie cooking oils, all of which may harm your health over time (30Trusted Source, 31Trusted Source, 32Trusted Source).
You can avoid added oils by making your popcorn in an air popper.
Popcorn is a type of corn that pops when heated. It’s a popular snack food that’s categorized as a whole-grain cereal. To maximize its benefits, make homemade popcorn without oils or additives.
Regular whole-grain intake may have a number of health benefits.
Macular degeneration and cataracts are among the world’s most common visual impairments and major causes of blindness (33Trusted Source).
Infections and old age are among the main causes of these diseases, but nutrition may also play a significant role.
Dietary intake of antioxidants, most notably carotenoids like zeaxanthin and lutein, may boost eye health (25Trusted Source, 34Trusted Source, 35Trusted Source).
Lutein and zeaxanthin are the predominant carotenoids in corn, accounting for approximately 70% of the total carotenoid content. However, their levels are generally low in white corn (26Trusted Source, 36Trusted Source, 37Trusted Source).
Commonly known as macular pigments, these compounds exist in your retina, the light-sensitive inner surface of your eye, where they protect against oxidative damage caused by blue light (38Trusted Source, 39Trusted Source, 40Trusted Source).
High levels of these carotenoids in your blood are strongly linked to a reduced risk of both macular degeneration and cataracts (41Trusted Source, 42Trusted Source, 43Trusted Source).
Observational studies likewise suggest that high dietary intake of lutein and zeaxanthin may be protective, but not all studies support this (44Trusted Source, 45Trusted Source, 46Trusted Source).
One study in 356 middle-aged and older adults found a 43% reduction in the risk of macular degeneration in those with the highest intake of carotenoids, especially lutein and zeaxanthin, compared to those with the lowest intake (45Trusted Source).
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 (47Trusted Source).
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 (48Trusted Source).
As a good source of lutein and zeaxanthin, corn may help maintain your eye health. What’s more, it doesn’t promote diverticular disease, as previously thought. On the contrary, it seems to be protective.
Corn is generally considered safe. However, some concerns exist.
Antinutrients in corn
Like all cereal grains, whole grain corn contains phytic acid (phytate).
Phytic acid impairs your absorption of dietary minerals, such as iron and zinc, from the same meal (16Trusted Source).
While usually not a problem for people who follow a well-balanced diet, it may be a serious concern in developing countries where cereal grains and legumes are staple foods.
Soaking, sprouting, and fermenting corn can reduce phytic acid levels substantially (16Trusted Source, 49Trusted Source, 50Trusted Source).
Some cereal grains and legumes are susceptible to contamination by fungi.
Fungi produce various toxins, known as mycotoxins, that are considered a significant health concern (51Trusted Source, 52Trusted Source).
The main classes of mycotoxins in corn are fumonisins, aflatoxins, and trichothecenes. Fumonisins are particularly noteworthy.
They occur in stored cereals worldwide, but adverse health effects have mostly been linked to the consumption of corn and corn products — especially among people who depend on corn as their main dietary staple (53).
High consumption of contaminated corn is a suspected risk factor for cancer and neural tube defects, which are common birth defects that may result in disability or death (54Trusted Source, 55Trusted Source, 56Trusted Source, 57Trusted Source).
One observational study in South Africa indicates that regular consumption of cornmeal may increase the risk of cancer of the esophagus, the tube that carries food from the mouth to the stomach (58Trusted Source).
Other mycotoxins in corn may also have adverse effects. In April 2004, 125 people died in Kenya from aflatoxin poisoning after eating homegrown corn that had been improperly stored (59Trusted Source).
Effective preventive strategies may include fungicides and proper drying techniques.
In most developed countries, food safety authorities monitor the levels of mycotoxins in foods on the market, with food production and storage strictly regulated.
Gluten intolerance or celiac disease is a common condition caused by an auto-immune response to gluten in wheat, rye, and barley.
The symptoms of gluten intolerance include fatigue, bloating, diarrhea, and weight loss (60Trusted Source).
For most people with celiac disease, the symptoms disappear on a strict gluten-free diet. However, in some people, the symptoms seem to persist.
In many cases, celiac disease may persist because of undeclared gluten in processed food. In other cases, a related food intolerance may be to blame.
Corn contains proteins known as zein that are related to gluten.
One study showed that corn zein caused an inflammatory reaction in a subgroup of people with celiac disease. Nevertheless, the reaction to zein was much smaller than that of gluten (61Trusted Source).
For this reason, scientists have hypothesized that corn intake may, in rare cases, be the cause of persistent symptoms in some people with celiac disease (62Trusted Source).
Corn has also been reported to be a symptom trigger in people with irritable bowel syndrome (IBS) or FODMAP intolerance (63Trusted Source).
FODMAPs are a category of soluble fiber that are poorly absorbed. High intake can cause digestive upset, such as bloating, gas, and diarrhea, in some people.
Corn contains phytic acid, which may reduce mineral absorption. Mycotoxin contamination may also be a concern in developing countries. Finally, corn’s soluble fiber (FODMAPs) may cause symptoms for some people.
The bottom line
Corn is one of the most widely consumed cereal grains.
As a good source of antioxidant carotenoids, such as lutein and zeaxanthin, yellow corn may promote eye health. It’s also a rich source of many vitamins and minerals.
For this reason, moderate consumption of whole-grain corn, such as popcorn or sweet corn, can be an excellent addition to a healthy diet.