Mycotoxins in Coffee & Mycotoxin Free Coffee Brands

As a doctor I think it's very important that we do as much as we can to help prevent diseases before they start, and one way to help do this is to limit our exposure to potentially harmful chemicals in our day to day lives.

Unfortunately many of the products that we use on a daily basis including our skincare products, cookware, cleaning products, mattresses, and food and drinks can contain ingredients that are harmful to health, and it is my goal to help you choose the healthiest options to help keep you and your family safe. So with that in mind, today we are going to discuss the issue of mycotoxins in coffee, and what you can do to help limit your exposure to these potentially harmful ingredients.

The mycotoxins found in coffee:

Like other crops, coffee beans can become contaminated by microorganisms and mold during the various stages of growing, harvesting, processing, transport, and storage. Many studies have shown that toxigenic fungi (Aspergillus and Penicillium in particular) are natural coffee contaminants and certain conditions such as high temperatures and humidity favour mold growth in coffee beans.

Additionally, removing the outer layer of coffee beans, the mucilage, can require large amounts of water (referred to as washed processing), and if not dried properly, the coffee beans provide a moist environment for mold to grow. Even using natural processing or dry processing where the beans are not washed and are left to dry naturally can lead to mold growth because the beans spend more time wrapped around the pulpy, humid outer layer of the beans.

Mold can also grow on green coffee during transportation because coffee beans are often transported in burlap sacks, and can sometimes sit in these sacks for weeks. The issue with this is that burlap is made of jute or other vegetable fibers, and mold tends to grow really well on natural fibers like jute.

And mold doesn't just grow on green coffee beans. It can also grow on coffee beans during roasting. There are multiple steps involved in roasting coffee beans and each step gives mold the opportunity to grow and multiply in the warm roasting environment.

The frequency of mycotoxins in coffee:

The two most common mycotoxins found in coffee are Ochratoxin A and Aflatoxin B1, and unfortunately, these mycotoxins are actually quite common in coffee.

52% of green coffee beans have been found to have Ochratoxin A, 32% of green coffee beans had Aflatoxin B1, and 45% of brewed coffee had Ochratoxin A.

Instant coffee is often even higher in mycotoxins with one study showing that 62% of instant coffee samples were contaminated Ochratoxin A.

Roasting coffee may help reduce the levels of mycotoxins, but when tested, 27% of roasted coffee still contained Ochratoxin A and another study has shown that roasting coffee didn't reduce the amount of Ochratoxin A at all.

One interesting thing to note is that studies have shown that Ochratoxin A levels are typically higher in non-trademark coffees which may indicate less strict growing and processing methods in non-trademarked coffee compared to trademarked coffee.

The health risks of mycotoxins in coffee:

Different mycotoxins can have different health risks, and the risks can depend on the amount of the mycotoxin present (with higher levels typically being more harmful). When looking at the mycotoxins found in coffee they can have various health risks:

• Ochratoxin A has been shown to exhibit hepatotoxic, nephrotoxic, teratogenic, and carcinogenic properties. In other words it can cause liver problems, kidney problems, be harmful in pregnancy, and can increase the risk of cancer. The International Agency for Research on Cancer (IARC) has classified Ochratoxin A as a presumed human carcinogen. According to the European Commission Regulation, in order to be considered safe, the maximum levels for Ochratoxin A are 3 μg/kg for roasted coffee beans and ground roasted coffee, and 5 μg/kg for soluble coffee (ie. instant coffee).
• Aflatoxin B1 is a known carcinogen and studies have shown that it can have other harmful effects. The International Agency for Research on Cancer (IARC) classifies aflatoxin B1 as a group 1 carcinogen meaning it is carcinogenic to humans. Aflatoxin toxicity can lead to nausea, vomiting, abdominal pain, convulsions and liver injury. Long-term exposure can cause a number of health complications including stunting growth, problems with the immune system, liver damage and cirrhosis, as well as liver cancer (reference). US food safety regulations have set a maximum limit of 20 μg/kg for aflatoxin B₁ in coffee and most other foods.

The higher the amount of these mycotoxins in coffee (and other foods), the higher the risk of adverse health effects from them are. Different studies have found differing concentrations of mycotoxins in various coffee ranging anywhere from 0.35 to 90 μg/kg for Ochratoxin A and from 1.51 to 1.93 μg/kg for aflatoxins.

As you can see, the amount of aflatoxins typically found in coffee are well below the cut off set by the FDA, but the amount of Ochratoxin A in many coffees exceeds the limit set by the European Commission Regulation.

The other thing to consider is that coffee is not the only source of exposure to mycotoxins. Many other foods can contain mycotoxins and Ochratoxin A has been found in many foods including cereals and cereal products, cacao products, nuts, spices, beer, grape juice, dried fruits, and wine, so your cumulative exposure to these potentially harmful toxins will depend on the other foods and beverages you are consuming.

One piece of good news is that there have been no reports of acute toxicity resulting from mycotoxin exposure from coffee. The main concern is whether the mycotoxins in coffee can increase the risk of chronic health issues. Not surprisingly there have been no studies specifically looking at the potential adverse health effects in humans from mycotoxins in coffee, but given that many coffees have been shown to contain higher levels of Ochratoxin A than the safety limits set by the European Commission Regulation, this is concerning.

How to reduce mycotoxins in coffee:

Coffee manufacturers can take steps to try and reduce or eliminate the amount of mycotoxins in their coffee. A few of these steps include:

• Keep the moisture in green coffee below 12.5% to reduce the likelihood of mold growth.
• Get rid of any coffee beans that have defects or that have an earthy, musty, or moldy smell.
• Grow coffee beans at higher altitudes because the high altitudes help reduce the amount of mold that can grow on the coffee plants.
• Use wet processing, which helps reduce most of the molds and mycotoxins on coffee.

Can you get mycotoxin free coffee?

If you are like me, and would feel more comfortable avoiding excess mycotoxin exposure if possible (it's impossible for us to completely avoid exposure to mycotoxins given how common they are), the good news is that there are a number of brands who do produce mycotoxin free coffee. The only way to know for certain that a coffee is mycotoxin free is if the brand sends the coffee for third party testing for mycotoxins to certify that it is mycotoxin free.

Here is a list of tested and certified mycotoxin free coffee brands:

• Kion coffee - This is the coffee I drink most days. I love how it tastes! Besides being mycotoxin free it is also organic and tested for pesticides. I personally buy the medium roast coffee beans. They have also been kind enough to give me a discount code for you. To get the deal, shop through this link and use the code DRERIN at checkout to get 10-20% off your order!
• Bulletproof coffee - they test every batch of their coffee for toxins and this coffee is sustainably sourced from small farms, where the coffee is all hand picked.
• Spirit Animal coffee - this coffee is grown and produced in Honduras and is a very popular mycotoxin free coffee. Their coffee is third party tested for mold and mycotoxins and additional independent testing confirms it is also pesticide free and yeast free.
• Death Wish Coffee Co - This brand uses USDA Organic and Fair Trade Certified coffee beans from India, Peru, and other countries throughout South and Central America to produce their coffee and the Death Wish coffee was recently independently tested and found to be free of mycotoxins, mold, yeast, and pesticides.
• Danger coffee - besides being mycotoxin free this coffee is unique because they add trace minerals and electrolytes to their coffee which can have additional nutritional benefits.
• Equal Exchange coffee - This organic coffee is grown on small farms and is also Kosher. Recent independent testing also confirms it is free of mycotoxins, yeast, mold and pesticides.
• Lifeboost coffee - This coffee is organic, low-acid, and they use single origin coffee beans. They also third party test their coffee for mycotoxins, molds, heavy metals, pesticides and 400 other toxins to ensure its safety.

Note that I have not included Purity coffee as a recommended brand because it recently tested positive for evidence of PFAS contamination in independent testing, so while it is mycotoxin free, since PFAS chemicals are very harmful to health I would not recommend this brand as you do not want to be ingesting these chemicals (you can learn about the health risks of PFAS chemicals in this post).

Our expertise:

Dr. Erin Carter, MD, FRCPC, is a physician with board certifications in internal medicine and rheumatology. She is passionate about preventative healthcare including nutrition, environmental health and low toxicity living.