Is Corn Bad for You? Here’s Everything You Need to Know

Eaten on the cob or off, snacked on popped or consumed in syrup form, corn is everywhere—seriously. According to the U.S. Grains Council, in 2016 and 2017, the United States grew more than 14.6 billion bushels of corn. That’s about 385 million metric tons. For anyone who’s agriculturally clueless (guilty), that translates to…a lot.

But for as omnipresent as it is, corn sometimes gets a bad rap for being unhealthy, as far as vegetables go. That’s why we set out to examine whether or not munching on an ear here and there is negatively affecting our health. Read on to find out whether these kernels are doing more harm than good.

Here’s what you can expect to find in one medium-sized ear of corn:

• 88 calories
• 4g total fat
• 15mg sodium
• 275mg potassium
• 19g carbohydrates
• 2g dietary fiber
• 4g sugar
• 3g protein

1. It’s a Good Source of Vitamins and Minerals

Specifically, vitamin C, B vitamins and magnesium. Vitamin C is important in cell repair, boosting immunity and has anti-aging properties, whereas B vitamins are important in energy metabolism. Magnesium is important for nerve conduction and muscle contraction.

2. It Could Aid in Digestion

The insoluble fiber in corn feeds good bacteria in your gut, which aids in digestion and helps keep you regular. But warding off constipation isn’t the only benefit of dietary fiber. In addition to protecting against gut issues, an increase in dietary fiber has been linked to a lower risk of several diseases, including heart disease and some cancers, per this study from Kansas State University’s Department of Human Nutrition. Unlike many other grains, corn is a naturally gluten-free food, making it a good option for people who avoid gluten but want to consume grains.

3. It Could Improve Eye Health

Corn is also high in the carotenoids zeaxanthin and lutein, which have been proven to promote macular health. According to a study in published in Nutrients, lutein and zeaxanthin can prevent and reduce cataracts and age-related macular degeneration. Vitamin C can also help lower your risk of getting cataracts, says the American Optometric Association (AOA). Other foods that are high in these carotenoids are carrots, leafy greens and sweet potatoes.

1. It Could Spike Blood Sugar

Corn and other starchy foods have relatively high glycemic loads, which can product blood sugar spikes after they are eaten. This could ultimately make you want to consume even more. Because of its high starch content, people with diabetes should limit their intake of corn, because studies—like this one published in the American Journal of Clinical Nutrition—have shown that low-carb diets are more effective at managing diabetes.

2. It Could Contribute to Weight Gain

In a 2015 study at Harvard’s T.H. Chan, researchers found that while eating more fruit and vegetables overall can promote weight loss. However, study participants who ate more starchy vegetables (like corn, potatoes and peas) tended to gain weight, while those who ate more non-starchy vegetables and fruits—such as string beans, green leafy vegetables, apples, or pears, which are higher in fiber and lower in carbohydrates—lost weight. Why? Compared to starchy vegetables, these non-starchy foods have lower glycemic loads, producing smaller and fewer blood sugar spikes after they are consumed, which may reduce hunger.

A lot of corn’s unhealthy reputation stems from its relationship to corn syrup, a food syrup made from the starch of corn that’s used to soften texture, add volume, prevent crystallization of sugar and enhance flavor. It’s important to keep in mind that regular corn syrup isn’t the same as the much-maligned high fructose corn syrup (HFCS). Both are made from corn starch, but regular corn syrup’s sugar contents are 100 percent glucose, while some of the sugars in HFCS are converted from glucose to its more dangerous cousin fructose. A UCLA study found that countries that mix high-fructose corn syrup into processed foods and soft drinks have higher rates of diabetes than countries that don’t use the sweetener.

Corn syrup—high fructose or not—should be treated like other refined sugars. A little bit every once in a while probably won’t kill you, but it should be consumed very sparingly. “It is known, however, that too much added sugar of all kinds—not just high-fructose corn syrup—can contribute unwanted calories that are linked to health problems, such as weight gain, type 2 diabetes, metabolic syndrome and high triglyceride levels,” says Katherine Zeratsky, R.D., L.D. “All of these boost your risk of heart disease.”

According to the Center for Food Safety, up to 92 percent of U.S. corn is genetically engineered (GE). Why? Per the FDA, "Developers genetically engineer plants for many of the same reasons that traditional breeding is used. They may want to create plants with better flavor, higher crop yield (output), greater resistance to insect damage, and immunity to plant diseases." But does that make it less healthy? According to a meta-analysis of 21 years of field data published in the journal Scientific Reports, GE corn is actually safer than non-GE corn, since it contains lower levels of naturally-occurring mycotoxins, which are dangerously poisonous and potentially carcinogenic. 

Like many foods, corn can be good for you, as long as you consume it in moderation—and in its most minimally-processed form (read: not corn syrup). Corn is a good source of fiber and antioxidants that promote eye health. Consumed in excess, it can spike blood sugar and contribute to weight gain, but eaten in reasonable quantities, it’s a versatile and affordable addition to a healthy, balanced diet.