Why Corn Might Be More Harmful Than You Think

by JJ Virgin on April 13, 2023

Corn has a great reputation. You’ll find it in tons of recipes for supposedly healthy salsas and fresh summer side dishes. Brands like SkinnyPop are selling the fantasy that tasty, crunchy popcorn is a nutritious treat. And who doesn’t have a great memory of chomping on some buttery sweet corn at a backyard barbeque or a local fair? 

I’m about to hit you with a hard truth, though: Corn just doesn’t live up to the hype. Along with being inflammatory and often highly processed, it’s what factory farms use to quickly fatten up cows and pigs. Enough said.  

With a greater understanding of the many ways corn can work its way into your diet and have a negative impact on your health, you’ll be better equipped to make smart decisions about how or if you consume it.  

Let’s break down the big reasons I recommend staying away from corn: 

Corn Is Not (Always) a Vegetable 

This one comes as a surprise to a lot of people. Most tend to think of corn as a vegetable, but that’s not always the case. The USDA considers corn a starchy vegetable—only when you eat it in its fresh form (or frozen at peak freshness), like sweet corn on the cob or in a package of frozen veggies. Its nutrient content differs from dry forms of corn. 

In the dry form—like cornmeal used to make corn tortillas and cornbread, or popcorn—corn has been harvested at different levels of maturity than the fresh variety. In these cases, it’s considered a grain. If you’re familiar with my Eat by the Plate principle, you know that I prefer each meal to be heavier in non-starchy vegetables than it is on grains.  

In its vegetable form, corn is starchy. To get the most benefits out of your vegetables, I recommend non-starchy ones like leafy greens, peppers, mushrooms, or peas. They’re typically high in nutrients, and help you feel satisfied without a blood sugar spike. Most importantly, your body will have the fuel it needs to keep kicking until your next meal. 

Corn Can Be Highly Inflammatory 

Ever feel not-so-great after eating corn? Do you have bloating or gas afterwards? You’re not alone. Corn is one of the seven Hi-FI foods, or the foods most likely to cause an inflammatory reaction.  

Inflammation isn’t always bad. Acute inflammation is a necessary part of the healing process—it’s what causes the redness or swelling when your immune system sends healing cells to a cut on your finger or a swollen ankle. That immune response usually clears up within days, or even hours.  

But other times—like when eating inflammatory foods—your immune system can respond to the offender, and that response can linger. So in addition to the immediate uncomfortable reactions like bloating, the chronic inflammation can lead to a larger host of health problems, including type 2 diabetes, chronic pain, and autoimmune issues.  

Corn Is Usually Genetically Modified  

Because corn is in such high demand for so many uses around the world, scientists have been hard at work to find genetic modifications that make it easier (and more lucrative) to grow. Sometimes, the modifications make corn more pest- and climate-resistant. But in many cases, the engineering helps corn tolerate powerful herbicides that kill the plants or insects around corn without harming the corn itself.  

I hate to tell you that the scientists have been super successful in creating herbicide-resistant corn. In some states, as much as 96% of the corn grown there is genetically engineered in some way.1 That means that much of the corn you eat has been sprayed with herbicides powerful enough to kill other plants, insects, or rodents, while the corn you eat has remained standing. Good for their bottom line, but those herbicides stay standing, too. 

The narrative on herbicides can seem conflicting. For example, the World Health Organization has called glyphosate, a common ingredient in herbicides, “probably carcinogenic to humans.”2 Meanwhile, the Environmental Protection Agency has decided it doesn’t pose a significant risk to humans.3 I won’t take my chances. I worry about the research that shows that ingredients like glyphosate can disrupt the gut.4 As our gut flora absorbs those altered genes, it can alter our intestinal flora enough to subsequently become resistant to antibiotics.    

When it comes to corn, that means also being mindful about foods like chickens, cows, and pigs that have been factory farmed. Remember: they’re chowing down on that same corn to fatten up, and you are what you eat, ate.

Corn Is High in Lectin Content  

Lectins, a type of anti-nutrient, are a family of proteins found mainly in legumes and grains—and they have some nasty side effects. 

For one, lectins tend to bind to fibers in your small intestine. As a result, you can’t absorb the nutrients in your food properly. Secondly, lectins also attach to insulin receptors, making you more insulin resistant. In time, insulin resistance can open the door to high blood pressure, type 2 diabetes, and widespread inflammation.  

Depending on how you cook corn (and other foods high in lectins), you may be able to lower the lectin content. But given the rest of corn’s cons, and that there are more nutrient-dense and tasty swaps for corn, you’re better off enjoying a different food. 

Corn Is Processed in Tons of Different Ways 

Why does that matter? Not only can processing strip corn of its nutrients and fiber, it also makes corn and its derivatives incredibly difficult to avoid.  

You might immediately recognize some corn-derived products when you’re shopping. Corn starch and high-fructose corn syrup are mainstays in packaged grocery items, and the word “corn” in the title makes them easy to spot. But there are other ingredients derived or processed with corn that are harder to immediately identify (more on that in a second). It can be tough to get good info about whether a corn product is part of the menu when you’re trying a new restaurant, traveling, or dining at a friend’s house. 

Thankfully, there are a few things you can do to be on the lookout for sneaky corn products, and to counteract its negative effects:   

  • Always check labels: Since corn and its derivatives are present in so many products, you’ll have to keep your eye out for lots of different ingredients as you scan labels. Cornstarch and high-fructose corn syrup are two obvious ones since corn is in their name. If you have a severe corn allergy, you’ll also want to be on the lookout for sorbitol, the vitamins in fortified milk, and dextrose—all can be derived from corn or processed with corn derivatives. They’re typically okay in small amounts, but people with corn allergies might want to be extra cautious. 
  • Be ready to play defense: This is especially important if you’ve noticed you’re one of the many people with a corn intolerance. If you’re heading into a situation where you can’t control the menu, like when you’re eating out or taking a trip, play defense against corn (and other starchy or Hi-FI foods) with DefendZyme. This is my digestive-support formula designed to help protect you from problem foods and minimizes the adverse effects corn and other Hi-FI foods might have on your body.  
  • Try out some delicious corn swaps. There are tons of healthy swaps for corn in its many forms. They have similar textures or flavors, but more nutrients and benefits. Some of my favorites are lentils, roasted nuts, arrowroot powder, grain-free tortillas, and white beans.  

It might take a little detective work and some creative cooking, but if you’re ready to try ditch corn, you can get started with my 21-Day Breakthrough Food Intolerance Cleanse. By carefully eliminating Hi-FI foods and adopting healthy swaps, you can discover the foods that don’t agree with you and fast-track the process of healing your body and reclaiming your health.  


  1. USDA: Adoption of Genetically Engineered Crops in the U.S. 
  2. WHO: IARC Monograph on Glyphosate 
  3. EPA: Glyphosate 
  4. Mesnage R et al (2019). Shotgun metagenomics and metabolomics reveal glyphosate alters the gut microbiome of Sprague-Dawley rats by inhibiting the shikimate pathway. BioRxiv. doi: