Is Corn Oil Bad for You?

author avatar Dr. Eric Berg 09/06/2024

Corn oil is a common ingredient found in many households and restaurant kitchens as it’s affordable, has a neutral taste, and can withstand high cooking temperatures. 

However, while cooking with corn oil may be convenient, consuming it regularly can negatively impact your health and well-being.

Here’s why you should avoid corn oil and explore healthier alternatives without the health risks of highly refined cooking oils.


Pitcher of corn oil

What is corn oil?

Corn oil is a type of seed oil extracted from the germ of corn kernels. It’s used for cooking and frying and is a key ingredient in many processed foods.

Corn oil is made using a combination of mechanical and chemical processes, including pressing, hexane extraction, degumming, bleaching, and deodorization.

The result is a highly refined cooking oil with a crystal clear appearance, neutral flavor and scent, and a smoke point of 450° F (235° C). 


These attributes, combined with its low production cost and long shelf life, have made corn oil a favored choice in the food industry. Additionally, it’s utilized in various industrial applications such as cosmetics, biodiesel production, and animal feed.

According to a report published by Global Market Insights, the corn oil industry is expected to be valued at $10.33 billion by 2032.

Nutrition facts

According to data provided by the U.S. Department of Agriculture (USDA), a serving size of one tablespoon of corn oil contains:

  • 122 calories

  • 0 grams protein

  • 13.6 grams fat

  • 0 grams carbohydrates

While corn oil contains a small amount of vitamin E, it’s generally considered to have little to no nutritional value as heavy processing leaves behind mostly empty calories and unhealthy fats.

 

Watch the video below to learn why seed oils may be worse than sugar.

Is Seed Oil Worse than Sugar?

Is corn oil bad for you?

Despite claims from brands like Mazola corn oil and Golden corn oil that their products are heart-healthy choices, increasing evidence indicates that regular consumption may carry notable health risks.

One concern is its high linoleic acid content, a pro-inflammatory omega-6 polyunsaturated fatty acid. 

While omega-6 fats are essential in moderation, research published in NPJ Science of Food found that excessive intake of polyunsaturated fatty acids, such as linoleic acid, is related to:

  • Headaches

  • Inflammation

  • Neurological issues, including ataxia

  • Abnormal neurodevelopment

  • Reduced cognitive skills 

  • Higher mortality rates linked to neurodegenerative diseases

The detrimental role of these lipids is well understood, and maintaining a balanced intake of omega-6 to omega-3 fatty acids is critical for optimal health. 

“The ideal ratio of omega-6 to omega-3 should be 1:1. Unfortunately, the average American consumes closer to 20:1,” explains Dr. Berg, “This is largely due to the high consumption of processed and fast food, which can push ratios as high as 70:1.”

Research published in Biomed Pharmacotherapy shows that a high omega-6 to omega-3 ratio can contribute to serious health issues, including cardiovascular disease and cancer, as well as inflammatory and autoimmune disorders.

These findings underscore the importance of avoiding unhealthy cooking oils to maintain a healthy body and help prevent disease. 


Doctor cardiovascular check-up

4 reasons to avoid corn oil

While corn oil may be a convenient and cost-effective product in the short term, its long-term health effects significantly outweigh its benefits.

Here are four reasons you should avoid using corn oil.

1. Increased risk of metabolic disorders 

Corn oil is exceptionally high in omega-6 fatty acids and contains very little omega-3, resulting in a dangerously imbalanced omega-6 to omega-3 fat ratio of around 46:1. 

Prolonged omega-6 fat intake at this level can lead to significant metabolic disturbances, including chronic inflammation, insulin resistance, and obesity, all of which contribute to cardiometabolic disease and diabetes. 

Furthermore, research published in The Journal of Lipid Research reveals that a diet high in omega-6 fatty acids can have lasting, generational effects by altering gene expression and increasing the risk of obesity in offspring.


Free radical oxidation word cloud

2. Linked to cellular damage

The chemical composition of refined corn oil makes it especially susceptible to oxidation. When exposed to heat, light, or air, these fats quickly degrade, which can generate harmful free radicals and advanced lipoxidation end-products (ALEs).

Free radicals and ALEs are highly unstable and pro-inflammatory compounds that can damage cell membranes, cellular organelles, proteins, and DNA, potentially leading to chronic diseases and accelerating aging.

3. Long-term health risks

Unlike other nutrients that can be quickly metabolized and eliminated from the body, omega-6 fatty acids from corn oil can accumulate and reside in fat cells for up to three years. 

As these fatty acids accumulate, they can influence the body's inflammatory responses and cellular functions, leading to various adverse effects, including increased inflammation, oxidative stress, and an elevated risk of chronic diseases.


Mass-produced vegetable oil

4. Increases the risk of neurotoxicity

After mechanical pressing, crude corn oil undergoes intensive processing, which includes using chemical solvents, such as hexane, to extract oil from kernels. 

Although hexane is typically removed after processing, residues can remain in the refined oil products.

Evidence published in Foods has identified concerns about hexane, linking it to neurotoxicity and potential health risks, including connections to Parkinson’s disease and endocrine disruption.

In addition, other refining methods, such as bleaching and deodorizing, are used to remove free fatty acids, increase shelf life, neutralize odors, and enhance the final product's appearance. 

While these processes improve the oil's aesthetics, they also alter its fatty acid composition and can generate potential carcinogenic contaminants, including 3-monochloropropane-1,2-diol (3-MCPD) and glycidyl esters.

According to research published by the Food & Drug Association (FDA), “In studies of rodents, 3-MCPD caused adverse effects on kidneys and male reproductive organs, and both 3-MCPD and glycidol caused cancer.”


Extra virgin olive oil

Healthy alternatives to corn oil

Given the potential risks associated with corn oil consumption, a shift towards healthier alternatives is critical to maintaining a healthy body and mind. Fortunately, there are many nutritious options to choose from.

Organic, cold-pressed avocado oil is an excellent alternative to corn oil. Similarly to corn oil, avocado has a neutral flavor and a high smoke point, making it an excellent oil for frying and a highly versatile option for hot and cold dishes. 


Additionally, avocado oil provides essential nutrients, including vitamins, minerals, and phytonutrients, that offer several health advantages, such as supporting cardiovascular health and reducing inflammation.

If you prefer to cook with fats that offer more flavor, consider using grass-fed butter, ghee, or beef tallow.

These fats are rich in omega-3 fatty acids, vitamin K2, and conjugated linoleic acid, which support heart health, promote bone strength, and may aid in weight management by improving fat metabolism.

Coconut oil is an excellent choice for baking or adding healthy fats to your morning coffee. Rich in medium-chain triglycerides (MCTs), a health-promoting saturated fat, coconut oil provides a quick burst of energy and supports brain function.

Extra virgin olive oil (EVOO) is a delicious option for salads, condiments, and other cold dishes. 

EVOO is a rich source of heart-healthy monounsaturated fats such as oleic acid and offers impressive concentrations of antioxidants, which can help reduce free radical damage and promote cardiovascular functions.

 

In addition to choosing healthy cooking oils, you can increase your intake of healthy fat through cod liver oil supplementation. 

Cod liver oil contains the essential omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), as well as vitamins A, D, and E, which support brain health, vision, and immune function and protect against oxidative damage.


Ultra-processed food

Learn more about ultra-processed oil

With the prevalence of ultra-processed seed and vegetable oils in foods, it's more important than ever to be aware of their potential risks to health and wellness. 

Download the The Truth About Ultra-Processed Foods booklet to learn more about the harmful impacts of highly refined ingredients.


Pouring out vegetable oil

Key takeaways

Corn oil is a highly refined product widely used in ultra-processed foods due to its low production costs and neutral flavor profile. 


However, corn oil consumption is associated with serious risks, including increased inflammation, poor metabolic health, and long-term adverse effects on overall health.


To mitigate these risks, it’s recommended to replace corn oil with healthier alternatives, such as cold-pressed EVOO, avocado oil, coconut oil, grass-fed tallow, and ghee.

FAQ

1. Is corn oil good or bad for you?

Corn oil isn’t good for you and should be avoided. It’s high in pro-inflammatory omega-6 fats and undergoes intensive processing, which makes corn oil prone to oxidation. 

Lipid oxidation can lead to the formation of harmful compounds that can contribute to inflammation and increase the risk of chronic diseases, including cancer.

2. Is corn oil better than olive oil?

Extra virgin olive oil is much healthier than corn oil as it offers an excellent balance of fatty acids and antioxidants that support cardiovascular and brain health.

To maximize the health benefits of olive oil, choose products labeled as certified organic and cold-pressed. These olive oils offer the most nutritional value and minimize exposure to potential contaminants used during chemical oil extraction. 

3. Can I have corn oil on keto?

No, you should avoid corn oil on a keto diet due to its high concentrations of linoleic acid, which can trigger inflammation and interfere with ketosis. Instead, use keto-friendly fats, such as coconut, avocado, or extra virgin olive oil.

4. Is corn oil healthier than canola oil?

Corn and canola oils have similar health concerns. However, corn oil can contain more than twice the amount of linoleic acid than canola oil, making it a slightly worse option for your health.

If your goal is to promote a healthy body, you should avoid these oils and instead choose nutritious options, such as grass-fed butter, ghee, tallow, organic extra virgin olive oil, or avocado oil.

5. Which is healthier, corn oil or peanut oil?

Both corn and peanut oil contain excessive amounts of omega-6 fatty acids and are highly processed. For better health, choose oils such as extra virgin olive oil or avocado oil instead.

6. What are the healthiest oils to use?

The best oils are organic, non-genetically modified, cold-pressed extra virgin olive oil and pure avocado oil. These options offer various health benefits, including heart support, anti-inflammatory properties, and essential nutrients that promote overall well-being.  

7. Why is olive oil healthier than corn oil?

Healthy oils, such as olive oil, contain monounsaturated fats and antioxidants that support overall health. In contrast, corn oil is rich in omega-6 fatty acids, which can contribute to inflammation and increase the risk of chronic diseases when consumed in excess.

8. Is it safe to consume corn oil daily?

No, excessive intake of high omega-6 sources, such as corn oil, can contribute to chronic inflammation and an increased risk of developing inflammation-related chronic diseases.

9. How does corn oil compare to rice bran oil?

Corn and rice bran oil are high in omega-6 fatty acids and highly processed, making them less healthy choices than cold-pressed extra virgin olive or avocado oil.


Sources

  1. /corn-oil-market#:~:text=Corn%20Oil%20Market%20size%

  2. https://fdc.nal.usda.gov/fdc-app.html#/food-details/171029/nutrients 

  3. https://www.nature.com/articles/s41538-019-0061-9 

  4. https://pubmed.ncbi.nlm.nih.gov/12442909/

  5. https://www.jlr.org/article/S0022-2275(20)37071-1/fulltext 

  6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9655691/ 

  7. https://www.fda.gov/food/process-contaminants-food/3-monochloropropane-12-diol

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