What are mycotoxins?

Here is a guide to some of the most common mycotoxins found in foods. For a deeper dive into the science of mycotoxins that can contaminate our food, visit our resources section, where new information will be posted monthly.

What are mycotoxins?

Mycotoxins are toxic compounds made by molds that grow on crops and foods. They're invisible — you can't see, taste, or smell them — and they can survive baking, cooking, and processing. Mycotoxins can contaminate crops such as corn, wheat, oats, and nuts, as well as other foods, particularly processed foods. When consumed in high enough amounts, many mycotoxins can disrupt your gut, liver, kidneys, immune system, and brain and nervous system. Because of their high prevalence in the processed food supply, the European Union has established regulatory limits and Tolerable Daily Intake (TDI) standards for many mycotoxins. Infants and children are particularly at risk for harmful effects due to immature body systems and a smaller body size relative to toxin load.

Types of Mycotoxins

Aflatoxins

Aflatoxins B1, B2, G1, G2, and M1 are among the most toxic and carcinogenic compounds ever discovered, and are produced by Aspergillus molds. They have the potential to cause DNA damage, which can lead to the development of liver cancer, cancers in other organs, underscoring the serious health risks associated with aflatoxin exposure. Aflatoxins B1, B2, G1, and G2 are often found in corn, peanuts, grains, and M1 can be found in dairy products from animals that were fed a contaminated diet.

Beauvericin and Enniatins

Beauvericin and Enniatins (e.g., A, A1, B, and B1) are emerging mycotoxins produced by molds like Beauveria bassiana and Fusarium species. Beauvericin has antibiotic, insecticidal, anticancer, and cholesterol-lowering properties, but it can also harm beneficial gut bacteria and may disrupt calcium metabolism. It is commonly found in grains such as wheat, rye, oats, barley, and rice, with 40-90% contamination rates in some foods. Enniatins, which can adversely affect certain healthful gut bacteria and potassium metabolism, are also found in grains, with prevalence varying from 12% to 100%. Both may have immunosuppressive effects and may damage human and animal mitochondria, possibly leading to poor health.

Cyclopiazonic Acid (CPA)

Cyclopiazonic acid is another emerging mycotoxin discovered in 1968, produced by Aspergillus and Penicillium molds. Initially thought to be non-toxic, it is now known to harm animals such as rats, pigs, poultry, and dogs, causing severe gastrointestinal and neurological issues. It has been almost exclusively studied in animals, so its effects on humans are still not well understood. However, Cyclopiazonic acid has been found to cause liver and kidney inflammation and impair immune function in human cell lines and has been implicated in Kodua poisoning in humans. This toxin can occasionally be found in foods such as seed oils, nuts and seeds, corn, cereal grains, dried figs, milk, cheese, and processed meats.

Generate a picture of combining grains, milk, cheese and processed meats

Vomitoxin (Deoxynivalenol/DON)

Common in wheat, corn, and other cereal grains, but can also be found in a wide array of foods, including coffee. Vomitoxin is named after its emetic effects on the gastrointestinal tract. Vomitoxin has been shown to cause immune system disruption, nausea, vomiting, abdominal pain, headache, diarrhea, fever, gastroenteritis, the malabsorption of vital nutrients, and inhibit protein synthesis (making new proteins), potentially leading to growth failure in infants and children. Because of these adverse effects, some scientists have theorized that chronic exposure could contribute to the symptoms experienced by those with inflammatory diseases of the gastrointestinal tract, such as IBD, celiac disease, and IBS.

Fumonisins

Fumonisins are a group of mycotoxins primarily produced by Fusarium species of molds. These molds often infect corn (i.e., Maize) grown in temperate regions. They have been linked to neural tube defects in infants, immune disruption, and esophageal cancer in humans.

Ochratoxin A and Citrinin

Ochratoxins and Citrinin. Ochratoxins are another group of mycotoxins that Aspergillus and Penicillium molds can produce. Three notable types of Ochratoxins impact the human food supply: A, B, and C. Ochratoxin A is one of the most common and important contaminants in foods. Chronic exposure to it can damage kidney cells and impair kidney function. It has been detected in coffee, dried fruit, and cereal grains and may have harmful effects on the kidneys and brain. Citrinin has also been implicated in causing kidney damage in animals. Various Penicillium, Aspergillus, and Monascus species of mold can produce it. Citrinin has been found in wheat, oats, rye, corn, barley, rice, certain cheeses (e.g., Camembert), food colorings, soy sauce, and naturally fermented sausages from Italy.

Zearalenone

Zearalenone, produced by Fusarium species molds that commonly infect grains, was once studied for its potential use in medicine and is still used in some areas of the world today. It is an estrogen-mimicking toxin found in grains. It is a potent hormonal disruptor that has been used as a birth control medication in humans and is linked to polycystic ovarian syndrome (PCOS) in animals.

Patulin

Often in Apple and other processed fruit-based products. Linked to gut irritation, nausea, gastritis, and gastrointestinal bleeding in humans and toxicity in children.

T-2/HT-2 Toxins

These are trichothecene mycotoxins, similar to Vomitoxin, which can cause nausea, vomiting, diarrhea, and other unpleasant GI symptoms, immune system disregulation, and may be toxic to the nervous system. While they can cause symptoms similar to those caused by vomitoxin, they are even more potent.

Limiting Dietary Mycotoxin Exposure

The increasing threat of mycotoxin contamination in processed foods sheds light on why eating fresh, locally grown foods is essential to maintaining good health. These foods are also packed with vital nutrients and antioxidants that protect your body by helping it to filter out toxins. The following are some suggestions for improving your health and limiting dietary mycotoxin exposures.

Food Choices

Processed foods

Limit or eliminate your intake of processed and ultra-processed foods. Foods with many ingredients often go through multiple processing and packaging steps, increasing the risk of harmful mold and mycotoxin contamination. Be your own food processor by preparing meals from fresh farm ingredients and freezing leftovers. This reduces exposure to mold and other toxic exposures from additives, preservatives, plastics, food colorings, and other processing chemicals.

Water

Use filtered water for cooking and drinking. Many health-compromising toxins, including mycotoxins, can find their way into drinking water.

Cereal Grains

Gluten-containing grains often contain mycotoxins like DON, causing gastrointestinal issues. Fusarium infections have spread, leading to contamination in gluten-free grains like corn, oats, and rice. Consider removing grains such as wheat, corn, barley, oats, rye, sorghum, triticale, and rice, including cereals and pasta, for several weeks. Reintroduce less contaminated options like white rice, which loses some mycotoxins during processing but also loses prebiotic fiber.

If you are missing grain-based foods, non-grain flours like tapioca, arrowroot, coconut, and almond flour may be less contaminated, particularly with fewer gut-disrupting trichothecene mycotoxins, when good manufacturing processes are used, and can be used to make bread and similar foods.

Fruits and Vegetables

Choose in-season, local fruits and vegetables for freshness. Select blemish-free produce, avoiding discolored ones with soft spots. Opt for fresh or frozen options over dried varieties, which are prone to mold. Berries like blueberries, blackberries, and raspberries boost phytochemicals and prebiotic fiber, helping prevent mycotoxin exposure. When possible, select organic produce for probiotic and prebiotic benefits. Incorporate cruciferous and leafy greens rich in toxin-eliminating compounds. Instead of commercial juices, make your own from fresh fruits and vegetables.

Starchy and Root Vegetables

Fresh, organic carrots, potatoes, sweet potatoes, and turnips provide energy and nutrients for a healthy lifestyle. They are rich in antioxidants and polyphenols that may protect against mycotoxin exposure, but are also prone to mold-related diseases. Green-tinged skin, like on some potatoes, may indicate the presence of aflatoxin. Dark spots may indicate a Fusarium infection, which produces trichothecene mycotoxins such as DON. Always select fresh, healthy-looking produce.

Nuts and Nut Butter

Buy whole fresh nuts, not pieces, as they are less prone to mycotoxin contamination. Avoid discolored nuts. Choose trusted brands of commercial nut butters that monitor for mycotoxins, or make your own with fresh, cleaned nuts.

Dairy Products

Even pasture-fed animal milk can contain mycotoxins from silage, hay, and moldy cheese, which harbor toxins. Consider limiting dairy and cheese for a few weeks, and when reintroducing, make homemade yogurt with probiotic cultures to reduce mycotoxin effects like Aflatoxin M1 and Zearalenone. Non-dairy milks like oat milk are also at risk for contamination. More testing and awareness for public safety.

Meats

Eat pasture-raised meat, fowl, and wild-caught fish whenever possible. Pasture-raised meats may contain fewer toxins. Avoid processed meats completely, as even the spices used during processing can be moldy.

Herbs and Spices

Use fresh spices and herbs instead of dried ones whenever possible. Dried herbs and spices can be contaminated with multiple mycotoxins. Cinnamon, oregano, garlic, turmeric, and a few other dried spices have some antifungal properties and may be okay to use instead of fresh. Once a container of dried herbs or spices is opened, store it in a dehumidified refrigerator or freezer to keep it fresh.

Cooking Oils

Avoid pro-inflammatory seed oils like canola, corn, and soybean because they can contain mycotoxins and other toxins. Instead, choose anti-inflammatory oils high in monounsaturated fats and polyphenols, such as extra virgin olive oil and extra virgin avocado oil, for cooking and baking.

Coffee, Tea, and Cocoa

Tea and coffee are both moldy crops. Stick to brands that test for mycotoxins and take steps to prevent their occurrence, like Purity Coffee. Cocoa can be contaminated with ochratoxin A and aflatoxin. Addictive Wellness Chocolate tests their cacao powder for mycotoxins.

Alcoholic Beverages

There is no way to prevent mycotoxin exposure from alcoholic beverages, and the distillation process does not completely remove them. Grain-based drinks are susceptible to contamination with DON, zearalenone, and ochratoxin A, among others. Some wine companies test for other contaminants, but to our knowledge, none test for mycotoxins.

Sweeteners

Replace refined commercial sugars that support fungal growth with honey or pure maple syrup. Honey and pure maple syrup serve as excellent sweeteners for cooking and baking. Both can help improve your microbiome and gut health and possess healing properties.

The Power of the Microbiome

Mycotoxins are external threats that may be mitigated by maintaining a healthy microbiome, which is populated by trillions of beneficial microbes. Including fermented foods such as sauerkraut, kimchi, or coconut/almond milk yogurt in your daily diet and taking a high-quality probiotic can help foster a healthier gut.

References