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- Corn can be good for you if it's unprocessed – but many types of corn are processed.
- Unprocessed corn contains vital nutrients including fiber, magnesium, phosphorous, and potassium.
- Some forms of processed corn are akin to sugar, not corn, and too much of it can damage your health.
- Visit Insider's Health Reference library for more advice.
In 2019, American farmers planted more corn than any other crop – 69 million football fields' worth, in fact. That's because corn has become one of our most versatile food crops.
There are over 3,500 uses for corn products. In a US supermarket, you'll find corn in 3 out of 4 products from food, to make up, to toothpaste.
Like the corn product in your toothpaste, many food and beverages – like cereal, soda, and cooking oils – contain processed corn that has little to no nutritional value. But that doesn't mean all corn is nutrition-less. Here's what you need to know about corn and its nutritional value.
Unprocessed corn has fiber and vitamins
"Corn can have nutritional value depending on how this vegetable is prepared. It can provide a source of fiber that can help reduce the risk of heart disease and gastrointestinal issues like diverticular disease," says Amber Robins, MD, a family medicine doctor at One Medical, a primary care practice.
A good rule of thumb is the less processing corn goes through, the healthier it is. For example, one cup of corn kernels from the cob contains significant amounts of:
- Fiber: 4.6 grams or about 18% of the recommended daily value (DV) for the average adult.
- Magnesium: 47 milligrams or about 13% of the recommended target for the average adult. Magnesium is important for helping maintain stable blood sugar and blood pressure as well as regulating muscle and nerve function.
- Phosphorous: 124 milligrams or about 17% of the recommended amount for the average adult. Phosphorous works together with calcium to maintain strong bones and teeth.
- Potassium: 414 milligrams or about 8% of DV for the average adult. Potassium works closely with sodium in the body and studies have found that increasing potassium in the diet can help lower blood pressure and reduce the risk of heart disease and stroke.
- Zinc: One milligram or about 10% of the daily quota for the average adult. Zinc helps keep a strong immune system and heals wounds.
Popcorn, which comes from the dry corn seeds and is considered a whole grain, is also a nutritional form of corn. One serving of popcorn contains 14% of your daily fiber needs as well as some iron, vitamin B-6, and magnesium. But if you want to get maximum health benefits from it, then it's best if you skip on the butter and salt.
So corn can have nutritional value. It's just that most corn that Americans eat isn't in the form of corn on the cob or popcorn. It's in a more processed form, such as high fructose corn syrup or oil where many of the nutrients have been stripped away by a process like wet milling. This is when corn "loses its nutritional value," says Robbins.
Processed corn products are less healthy
There are varying levels of processed corn products. For some products, like corn tortillas, corn chips, corn cereals, cornmeal, and cornflour, it's clear they contain processed corn.
But other products are farther removed from their corn origins. You can find these more processed products in the ingredients list as:
- High-fructose corn syrup: Found in soda, ice cream, flavored yogurt, jams, and much more.
- Corn oil: Found in certain margarine brands and fried foods.
- Monosodium glutamate: More commonly called, MSG, it's a flavoring agent that can be made from fermenting corn sugar - though it can also be made from sugarcane, beets, or starch.
- Corn starch: It's often used as a thickener for prepackaged sauces and soups.
- Corn syrup solids: Found in certain packaged nuts and also used in processing certain cured meats.
High fructose corn syrup (HFCS) is one of the more common forms of processed corn because it has preservative properties that can lengthen the shelf life of packaged foods and also help packaged baked goods keep their moist texture for months on end.
So, when you come across that forgotten Twinkie in the back of your cupboard and it still tastes fresh - as only a Twinkie can - that's, in part, thanks to HFCS. But while HFCS and popcorn may initially come from the same product, HFCS is akin to sugar, not corn.
There are two types of HFCS: HFCS 42 and HFCS 55, according to the FDA. The number 42 and 55 refer to the percentage of fructose in the product. So HFCS 42 contains 42% fructose and HFCS 55 contains 55% fructose, with the remaining percent being glucose. Table sugar, by comparison, contains pure sucrose, which is made up of half fructose and half glucose.
Insider's takeaway
Excess sugar, in any form including HFCS, has been linked to adverse health effects including weight gain, obesity, type 2 diabetes, and increased risk of heart disease. So, if you're looking to eat more healthily, you don't have to avoid corn altogether. You just need to focus on whole, unprocessed foods that are rich and nutrients.