Health Benefits Of Corn

Introduction

Corn, also referred to as maize or its scientific name, Zea mays, is one of the most commonly produced cereal crops globally.¹ This ancient grain originates from Central America, but, following its domestication, it quickly spread across the globe, especially throughout Europe and Asia.²

When corn is harvested, the ears of corn are removed from the plant. These include the edible corn cobs, which the corn kernels are attached to, surrounded by protective husks. When you picture corn, you likely think of the small yellow corn kernels, which consist of endosperm, germ and bran structures typical of any whole grain.³ However, corn can come in a variety of different colours including red, purple and even blue.¹ These different colours are the result of varying amounts of pigmented metabolites in the corn such as phenolic acids, flavonoids, which are types of polyphenols and carotenoids.¹

The crop can also be processed to produce a wide variety of other products. For example, wet milling produces corn starch and corn oil, while dry milling is used to make corn meal, corn flour and corn bran.⁴ These corn-based food products are then used to make things like corn tortillas, corn-based snacks and even corn-based breakfast cereals. Corn kernels are even used to make popcorn, so you probably eat more corn-based products than you might think! 

More recently, the health benefits of corn have been questioned due to its carbohydrate and sugar content. However, this article will explore how corn can provide many health benefits and various nutrients and whether there is such thing as too much corn.

About corn

Health benefits of corn

Digestive health 

Corn has been suggested to help support the health of our digestive systems.² This is largely attributed to its high starch content,⁴ which is why you might hear it be referred to as a ‘starchy vegetable’. Most of the starch found in corn is in the form of resistant starch, a type of carbohydrate molecule that ‘resists’ digestion in the small intestine and has beneficial effects in our large intestine.² Specifically, our gut microbiome in the large intestine uses it for fermentation, which helps to support its diversity and contributes to our overall health. 

A study showed that compared to a starch-free diet, diets including corn helped to support and improve digestive health.² Specifically, individuals who ate corn had a greater stool weight and excretion of potentially harmful waste products from the gastrointestinal system.²

Coloured corn, which contains higher levels of anthocyanins has also been suggested to support digestive health through their protective effect against colon cancer.² Anthocyanins are polyphenol compounds found in plants that give them their bright pigments such as blue, red and purple. Polyphenols have been shown to have a variety of health benefits due to their antioxidant and anti-inflammatory properties, including their protective effect against cancers such as colon cancer. 

Anti cancer

Corn, when it is consumed as a whole grain, is thought to be protective against a range of chronic diseases including cancer. Several epidemiological studies have found an association between the consumption of whole grains and both the risk of developing cancers and cancer-based mortality rates.³ This has been found for colorectal, pancreatic and gastric cancers.³

Corn is also a great source of polyphenols and anthocyanins, two types of antioxidants. Polyphenols such as flavonoids, which are abundant in corn, have been shown to have a protective effect against cancer.² Not only do they have an anti-inflammatory effect, but they are also thought to help control cell division, which becomes uncontrolled during the development of tumours.²

There are many vitamers of vitamin E in corn. Vitamers are molecules that are related to the vitamin and have the same effects as the vitamin. Vitamin E helps to support the immune system and protect DNA against damage, both of which help to prevent the formation and development of cancer.²

Metabolic health 

There are many different ways in which corn has been suggested to support our metabolic health in terms of preventing obesity and preventing and managing diabetes. Several epidemiological studies have found that whole grain consumption, in general, is associated with a reduced risk of developing obesity.² In addition, a study found that replacing carbohydrates with the form of the starch found in corn led to changes associated with reduced fat build-up.² This effect of whole grains like corn is thought to occur due to their high fibre content, which slows down gastric emptying and increases your feeling of fullness after you’ve eaten them.³ This increased feeling of fullness has also been found following the consumption of corn bran, a processed corn product rather than the whole grain itself.⁴

Diabetes is a metabolic disorder that occurs when your body is unable to make sufficient insulin in response to your blood sugar levels. A meta-analysis found that consuming whole grains was associated with a reduced incidence of type 2 diabetes.³ The high fibre content of corn helps to slow down digestion and reduce the rate of glucose absorption and blood sugar level changes. This helps to control your body’s insulin response and prevents diabetes.³ It has also been suggested that other nutrients in corn, such as magnesium, chromium and its antioxidants help to prevent diabetes.³

Eye health 

Age-related macular degeneration is one of the main causes of blindness in older adults worldwide, with approximately 8 million people affected globally.⁵ Corn is an important source of carotenoids lutein and zeaxanthin, both of which have been shown to help slow down the progression and reduce the incidence of age-related macular degeneration.⁶ Research has also suggested that consuming these carotenoids as part of your diet can help improve your macular pigment optical density, which also helps support eye health.⁶ While most vegetables only contain one of these carotenoids, corn contains both. 

Corn also provides nutrients such as vitamin C, vitamin E, vitamin A, beta-carotene, zinc, selenium, B vitamins and folate, which also help to support eye health.⁶

Heart health 

Corn and other whole grains are also thought to help support your heart health and reduce the risk of developing cardiovascular disease.² Consuming whole grains has been shown to help lower blood pressure, LDL cholesterol and total blood cholesterol levels, all of which are determinants of your risk of developing heart disease.² This protective effect has been shown from the consumption of 3 servings of whole grains each day.²  

Nutrients we can get from corn

The nutrients we can get from 100g of yellow sweetcorn (the most commonly consumed type of corn in America and Europe) are listed below.²

Corn also contains:²

• Anthocyanins (primarily in the coloured varieties such as blue, red and purple corn)
• Vitamin A
• Vitamin B
• Vitamin C
• Vitamin E
• Vitamin K 
• Magnesium 
• Potassium 
• Phosphorus
• Folate

Ways to use and include corn in your health

There are many different ways to include corn into your diet, and it’s likely you already consume some of these foods.

Corn is generally purchased on the cob, but you can also buy it canned or frozen. All of these corn products provide the health benefits associated with consuming corn in its whole-grain form. You can prepare it in a number of different ways: boiled, steamed, roasted or even grilled. Corn can be an excellent addition to a variety of different meals and recipes.

Popcorn is also a great snack and contains lots of fibre to help support your health as explored above. And consuming corn-based products such as corn tortillas (made from corn flour) or corn bran products is also thought to have beneficial effects.⁴

How much is enough?

Side effects and how much to consume and other information

In general, it is recommended that starchy foods make up approximately a third of your diet, and corn can also help to meet the recommended intake of 5 servings of vegetables and 30 grams of fibre a day.⁷ One serving of corn is equivalent to approximately three heaped tablespoons.⁸ However, if you consume too much corn you may experience side effects from eating too much fibre. These include bloating, stomach pains, flatulence and constipation. These symptoms should go away within a few days but can be managed by reducing your fibre intake, drinking lots of water and participating in light-to-moderate exercise. 

Some research has also shown that corn can cause issues for individuals with celiac disease. Corn contains a protein that resembles gluten, called zein. In some individuals who suffer from celiac disease, zein protein causes an immune response similar to that of gluten and should be avoided if this is the case for you.⁹

While corn is a great source of nutrients, it also contains phytic acid or phytate. This compound can reduce the bioavailability of nutrients such as zinc, iron, magnesium, calcium and potassium.¹⁰ However, this is not a cause for concern if you are consuming a varied diet that consists of other sources of these nutrients. 

Summary

This article has looked at the health benefits of corn, highlighting just how beneficial the whole grain and its products can be. The specific macro and micronutrients in corn provide us with fibre, starch, vitamins, minerals and antioxidants. These help to support our digestive health, protect against cancers, prevent obesity and diabetes, support eye health and even reduce the risk of heart disease. Corn can be consumed in a variety of ways, helping you to reach your daily recommended intake of vegetables and fibre. While there are some things to keep in mind with regards to adding corn to your diet, such as consuming too much fibre or if you suffer from celiac disease, in general, it is a safe and delicious vegetable to add to your diet.