The Hidden Connection Between Seed Oils and Mycotoxins: What’s Lurking in Your Food?

Oil is a foundational ingredient for nearly every cooked food and cuisine, from appetizers to main dishes and desserts. If you make something with heat, you’re likely using oil. If you eat salad, your dressing will have oil. You use it at home and consume it nearly every time you eat out, even if you aren’t aware of it.

In 2024 alone, 222 million metric tons of vegetable oil were produced. As such a cornerstone of our diets, it’s crucial that the oil we consume is healthy and not adversely affecting our bodies. Unfortunately, many of the most commonly used oils are highly processed and can damage our systems. The number one culprit is seed oil, an umbrella term for any oil that comes from the seed of a plant rather than its fruit. Since they’re both cheap and readily available, seed oils make up the majority of the oils we consume.

While the nutritional properties of seed oils vary, there’s another danger they can harbor: mycotoxins. Let’s look at the connection between mycotoxins and seed oils and the steps to stay safe while eating.

What Are Seed Oils?

Cooking oil (AKA edible oil) is fat derived from plants or animals. These fats are used in cooking because their chemical makeup allows you to cook food at a higher temperature than water, making food more flavorful.

Vegetable oil can be derived from seeds, fruits, nuts, and grains, all processed in different ways. Vegetable oils have been an integral part of culture for as long as we’ve had written history. They are used for cooking, cosmetics, medicine, fuel, lubrication, and more.

While the types of cooking oil all have their unique properties, we’ll be focusing on seed oils.

As mentioned before, seed oil is any oil derived from a plant’s seed. Seed oil examples include:

• Canola/rape seed oil
• Sesame seed oil
• Corn oil
• Grapeseed oil
• Sunflower oil
• Safflower oil
• Peanut oil
• Soybean oil
• ran oil

As you can see, there are many, many types of seed oil that you may or may not have used or consumed before. Of those listed, soybean and canola oils are the most produced and consumed oils worldwide, often lurking in foods you might not suspect, such as packaged baked goods, soups, and crackers. Some seed oils, such as carrot seed oil, aren’t edible and are used topically.

How Are Seed Oils Produced?

There are various ways that seed oils are made, and these can affect their makeup and health properties. The production process generally involves several steps, varying depending on whether the oil is produced through mechanical or chemical methods.

Mechanical extraction

Here’s a quick overview of the mechanical extraction method for seed oils.

• Cleaning and Dehulling: Seeds are first cleaned to remove dirt, debris, and foreign material. Some seeds may also be dehulled, which involves removing the outer shell to access the oil-rich kernel.
• Grinding and Pressing: The cleaned seeds are ground into a paste and pressed using an expeller or hydraulic press. This process applies physical pressure to extract the oil. The first pressing often yields what is known as “cold-pressed” or “virgin” oil, which is considered higher in quality due to minimal processing.
• Filtering: The oil extracted through pressing may contain tiny particles of seed material. It is filtered to remove these impurities, resulting in a clearer product.

Chemical extraction

There are just a few steps involved in chemical extraction for seed oils.

• Solvent Extraction: In large-scale production, a chemical solvent like hexane is often used to extract oil from the seeds. This method is more efficient and can extract a higher percentage of oil compared to mechanical pressing.
• Distillation and Refining: After extraction, the solvent is removed through distillation, leaving behind crude oil. The oil may undergo further refining to remove impurities, improve color, and extend shelf life. Refining can include steps like degumming, neutralizing, bleaching, and deodorizing.

Are Seed Oils Bad for You?

Seed oils have become a topic of debate in recent years, with growing concerns about their potential adverse health effects.

One of the critical concerns regarding seed oils is their high omega-6 fatty acid content, which can contribute to inflammation in the body. Although omega-6 fats are essential for our health, an imbalance between omega-6 and omega-3 fatty acids can result in inflammation and chronic health issues, such as heart disease, obesity, and diabetes.

The modern diet tends to be heavy on omega-6 fats and lacking in omega-3s, exacerbating this imbalance and potentially increasing the risk of these conditions.

Furthermore, the industrial processing of seed oils tends to require high heat and chemical solvents, which can degrade the oil’s quality and produce harmful byproducts like trans fats. These byproducts are well-documented for their negative impact on heart health and overall well-being.

Despite these issues, seed oils aren’t inherently “toxic.” For one thing, if you’re worried about the imbalance in your diet between omega-6s and omega-3s, it can be more beneficial to increase your intake of omega-3s. Eating fish and flaxseed can both help.

Many other issues surrounding seed oils are linked to the fact that they’re often used in low-quality foods. But poor quality seed oils can be a problem unto themselves. One of the more significant issues that isn’t frequently discussed is the problem of mycotoxins in seed oils.

Mycotoxins – A Brief Overview

Mycotoxins are toxic compounds that can contaminate food and crops. These naturally occurring toxins are produced by certain types of mold. Most of the time, they are invisible and odorless, which makes it challenging to detect without proper testing.

Several hundred mycotoxins have been identified, with around a dozen singled out for their harmful effects. Being exposed to mycotoxins poses significant health risks that range from acute to long-term health problems, including imbalanced hormones and allergic reactions.

The severity of these risks depends on the type of mycotoxin, the level of exposure, and the individual’s health status. The more extreme health implications include:

• Immune Suppression: Mycotoxins can suppress the immune system, weakening it to the point that the body has a harder time fighting off infections and diseases.
• Cancer: Certain mycotoxins, particularly aflatoxins, are potent carcinogens. Long-term exposure can lead to liver cancer, especially in populations with preexisting liver conditions or those exposed to high levels of aflatoxins.
• Liver Damage: Many mycotoxins, such as aflatoxins and ochratoxins, are hepatotoxic, meaning they can cause severe liver damage. This can lead to conditions like liver cirrhosis and, in extreme cases, liver failure.

The Path from Seed to Oil – Where Mycotoxins Come In

The molds that produce mycotoxins thrive in warm, humid environments, making certain regions and agricultural practices particularly susceptible to contamination.

Crops such as grains, nuts, dried fruits, and spices are common sources of mycotoxins, as well as what we’re focusing on today: seeds.

Seeds used for oil extraction, such as sunflower, soybean, and corn seeds, can become contaminated with mycotoxins during various stages of their production cycle. Contamination can occur:

• During Harvest: If the crops are harvested during wet weather or are not promptly dried, the moisture can promote mold growth, leading to mycotoxin production.
• In Storage: Improper storage conditions, such as high humidity or inadequate ventilation, can also encourage mold growth on seeds. If the storage facilities are not kept dry and cool, the risk of mycotoxin contamination increases significantly.

The biggest issue is that fungal spores are extremely difficult to remove fully. Once seeds are contaminated, the mycotoxins can be persistent, resisting traditional cleaning methods and making their way into the oil extraction process.

Impact of refining process on mycotoxins

One of the biggest problems is that most mycotoxins are heat resistant, so they aren’t removed from food by standard cooking methods. That means the oil refining process will most impact mycotoxin’s presence.

The refining process for seed oils involves multiple steps designed to remove impurities and improve the oil’s quality. However, these processes each affect mycotoxins differently.

Some mycotoxins, such as aflatoxins, can be partially removed during the refining process, particularly during bleaching and deodorization. These steps can reduce the levels of mycotoxins, but they may not eliminate them entirely.

Mycotoxins are known for their thermal stability, meaning they can withstand the high temperatures used during oil refining. For example, ochratoxin A is relatively heat-resistant and may survive the refining process, potentially ending up in the final product.

While refining can reduce mycotoxin levels, it is not always effective at removing all traces. This is particularly concerning for oils intended for direct human consumption, as even small amounts of mycotoxins can pose health risks.

Mycotoxin’s presence in the final product

Currently, about 50 percent of the fat humans consume comes from vegetable oil. And much of this oil, as we noted, comes from seed oils that are at risk of contamination from mycotoxins.

In one study, 416 edible oils were checked for contamination by 51 different mycotoxins. Twenty-four of these mycotoxins were found in the oils, and nearly half of the samples were contaminated with 6-9 types of mycotoxin.

The worst offenders were found to be peanut and sesame oils, which had unacceptable levels of aflatoxins, which can lead to cancer.

Mycotoxin presence varies depending on the kind of oil, where they were harvested, and the way the seeds were stored.

What Can You Do About Mycotoxins?

Despite the health risks, there is a significant lack of consumer awareness regarding mycotoxins in seed oils and their potential impact on health. Many people are unaware that seed oils, commonly perceived as healthy or neutral, can carry these hidden toxins. Food labels typically do not indicate the presence of mycotoxins, and the focus on other aspects of food safety, such as preservatives and additives, often overshadows the issue of mycotoxin contamination.

This gap in consumer knowledge makes it challenging for individuals to make informed dietary choices.

Regulatory bodies in many countries have set limits on the allowable levels of mycotoxins in food products, including oils. However, the effectiveness of these regulations depends on strict monitoring and testing throughout the production and refining process.

As a consumer, you have a few options to lower your exposure to mycotoxins. First—and most importantly—you can limit processed foods in your diet. With processed foods, you have the least control over the quality of ingredients. Many processed foods contain poor-quality seed oils that are more likely to contain some form of mycotoxin.

When you do buy packaged or processed foods, opt for ones that use higher-quality oils. While not free of mycotoxins across the board, extra virgin olive oil is generally of higher quality with higher production standards than many seed oils. Try to avoid peanut and sesame seed oil since those were the worst offenders.

In general, pick higher quality oils at the grocery store since those likely have higher production standards. Most of the risk of mycotoxins comes from poor production and storage practices.

If you’re concerned about the overall healthiness of your oil choice, switch from seed oils to alternative oils. Olive oil is rich in monounsaturated fats and antioxidants and is a heart-healthy alternative to seed oils. It’s less prone to oxidation and is often less contaminated with mycotoxins. Avocado oil is another excellent alternative, offering a good balance of monounsaturated fats and a mild flavor. It also has a high smoke point, making it suitable for high-heat cooking.

These alternatives provide healthier fat profiles and reduce the likelihood of ingesting mycotoxins commonly associated with seed oils.

Knowledge Is Power: Be a Conscientious Consumer

To be a conscientious consumer, you must be aware of many hazards that companies don’t advertise, especially regarding food. Mycotoxins aren’t a danger most people know to be aware of. As seed oils remain a staple in our diets, their potential contamination with mycotoxins raises significant health risks that you shouldn’t ignore. By understanding how these toxins infiltrate our food supply and persist through processing, you can make more informed choices about the oils you use and consume.

Opting for higher-quality oils, limiting processed foods, and considering alternative oils like olive or avocado can significantly reduce exposure to harmful mycotoxins.

If you’re concerned about whether you’ve been exposed to mycotoxins, you can gain peace of mind with the MycoTox Mold Profile. This test screens you for eleven different mycotoxins. Learn more and order your test today.

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