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The BS About Mold and Mycotoxins In Coffee And Why You Shouldn’t Stop Drinking It

Yes, there are mycotoxins in coffee but this is no reason to be scared away from it.

cup of coffee
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“I learned all about toxins in coffee today,” I said to my wife.

“Don’t tell me! I don’t want to hear it!” she wailed. “Coffee is my one enjoyment in life.”

My daily intake of coffee can be measured in liters. I drink giant cup of it after giant cup of it pretty much all day long. When I write, I drink, it’s part of a routine: make a cup of coffee, type, drink it, type, get a little sad that it’s gone, piss, make another cup, on and on throughout the day.

Then around a year ago a friend mentioned to me something that I previously never heard before:

“Something like 90% of coffee has mold on it.”

I initially wrote what he said off as being a transmission from the “fear all foods” sect. I didn’t believe him, I didn’t want to believe him. I didn’t even bother doing an Internet search for more information.

Then over the next year something strange began happening: coffee began making me feel mentally clouded and groggy. It was very incremental and hardly noticeable at first, but then it steadily grew worse. Around five days ago it got really bad — debilitatingly bad — and I realized that there could have been a problem.

To preface this, I had not been drinking very high-quality coffee in China. I’ve resolved to drink Nescafe instant coffee with occasional cups from McDonalds, KFC, and Starbucks. On top of this, I’ve truly been drinking massive amounts of this low-grade stuff. Rationally, I realized that it could be screwing me up, and I began to wonder if there really was really fungi in my coffee and what the potential health impacts could be.

There turned out to be an incredible amount of literature published about the topic online, and, as could be expected, roughly 99.5% of it seemed to be obvious bullshit. The actual scientific studies seemed lacking in both scale, scope, and a proper methodology, hinting that there may be a problem with fungi in coffee but not really going as far as to really prove anything or provide guideposts for the public to go off of. Though they did open a floodgate for a frenzy of data cherry picking, unsubstantiated claims, and counter-claims.

The media whipped the “fear all foods” sect into a frenzy, and where there is the “fear all foods” sect there are the profiteers, like this jerk, right there to offer a “healthy” solution and make a buck. On the other side were the skeptics who seem to believe that saying everything and anything is bullshit is a sign of intelligence. In fact, my search only turned up a single source of decently compiled, thoroughly footnoted, and well presented information on the topic. Surprisingly, it was an original post on a forum.

“The Internet is a cesspool of misinformation.”

This is never more true then when it comes to scientific and medical research being reinterpreted for public consumption. I do not want to add to the cesspool on this matter, but this is what I discerned from wading through the seas of media hype, hysteria, skepticism, and sludge:

  • Fungi is present on many types of food and drinks, and is even living on and inside of every human being. We consume fungi every day. Most of it is benign.
  • The problem with fungi on coffee is not the fungi itself, but the mycotoxins they produce. Mycotoxins are non-living substances that fungi produce as ammunition in its natural battle against its arch-enemy, bacteria. As mycotoxins are chemical compounds that are not alive, they cannot be killed.
  • A reasonable percentage of coffee beans have fungi on them. Estimates are in the range from 50-90%, but all available studies up to date on this seem to have major testing flaws.
  • Just because coffee beans have fungi does not necessarily mean they have mycotoxins, but a reasonable percentage of coffee does contain these toxins. 30% has been suggested from one study, but due to the limited testing sample and limited geographic scope this is far from a conclusive estimate. Another study cited that 50% of the coffee they tested had mycotoxins, but they drew their sample from expired stocks that would therefore have contain an elevated amount. As far as I’m concerned, I will take this to mean that a good percentage of coffee contains some amount of mycotoxins.
  • It is widely stated by scaremongers and profiteers that mycotoxins give coffee a particularly bitter taste, but this surely could not ever have been verified, as it’s simply not ethical to knowingly give human test subjects toxic coffee in a taste test.
  • There are two main types of mycotoxins that is typically found on coffee: aflatoxin B1 and ochratoxin A. Aflatoxin is nothing to joke about, it’s is often regarded as the most potent known carcinogen. Less is known about ochratoxin A, but been linked to kidney toxicity, immune suppression, cancer and birth defects in animals. The latter is more common in coffee. Besides their carcinogenic effects, mycotoxins can lead to other diseases of the lungs, nervous system, and kidneys. They have also been known to cause cardiomyopathy, brain damage, and hypertension in animal tests, but this has not yet been proven in humans.
  • Does the level of mycotoxins in coffee have the ability to cause acute or long term injury for drinkers? Who knows?
  • As mycotoxins are a known carcinogen, allowable amounts on foods are regulated by many governmental agencies, including the FDA and the EU health board. The amount of mycotoxins on coffee sold in stores obviously fall within the range of these legal limits, and is officially considered “safe.”
  • The allowable amounts of mycotoxins on food vary greatly per country. In the EU, the limit for aflatoxins is between 4 and 15 μg/kg. In India, it’s 30 μg/kg. In China, it’s 20 μg/kg. The USA is the same as China.
  • Many scientific tests have been done to discover how much mycotoxin is destroyed through roasting coffee beans, but the results have been highly contradictory. Some reports state that only 10% is destroyed while others claim that roasting results in near total elimination. From reading the available material it is my impression that roasting is an effective way to destroy a good percentage of mycotoxins, but there is a good chance that some will remain in the final product.
  • There are ways of producing coffee so that the final product has less mycotoxin, such as through mechanical and wet processing.
  • Arabica coffee tends to have less mycotoxins.
  • The same is true for coffee that is grown at higher elevations, such as in Central America.
  • Decaffeinated coffee is higher in mycotoxins, as caffeine is a natural mycotoxin inhibitor.
  • Instant coffee generally has significantly more mycotoxins than roast beans.
  • Low quality coffee tends to have more mycotoxins than higher quality (price is alone is not a determinant of quality).
  • The fresher the better. The older coffee is the more mycotoxins it tends to have. Of course.
  • Though coffee is occasionally cited as the biggest source for mycotoxins in the American diet, these toxins are also found in many other foods, including but not limited to: peanut butter, nuts, wheat flour, beer, wine, raisins, chocolate, cereals, and hundreds of other things we routinely eat and drink. Basically, fungi and their mycotoxins are just about everywhere.
  • Coffee does not stand alone at the high end of the mycotoxin count when compared with other common foods. In fact, there are many other common foods that tend to have far higher concentrations of mycotoxins than coffee.
  • Chemicals in coffee, such as caffeine, kahweol, and cafestrol, can actually combat mycotoxins in the body or trigger the body to do so. This means that drinking coffee — even that which itself may contain mycotoxins — may provide protection against mycotoxin injury.

This final point is elaborated upon in the CoffeeGeeks forum article, and I feel this is a good statement to sum up my investigation into coffee and mycotoxins as a whole:

Finally, just as coffee is a complex chemical solution, its biochemical effects are just as complex. The answer to why coffee beans use their energy to produce so many compounds, caffeine chief among them, may lie in the conjecture that they, too, are fighting chemical warfare, in this case against bacteria, fungi and mycotoxins and that, by ingesting this marvelous broth, we, too, are enjoying the protective effects of their defenses.

My conclusion

The recent scare over mycotoxin in coffee is little more than media hype derived from the poor interpretation of scientific data, the cherry picking of facts, and not showing the whole picture. Coffee is just as safe/ unsafe as most of the other foods and drinks we consume daily, and should not be singled out for having mycotoxins.

By attacking something that people truly enjoy and have an emotional attachment to unscrupulous journalists can get their articles published, publications can get more pageviews, and profiteering health food vendors can sell more products. Things like peanuts and raisins tend to have far higher concentrations of mycotoxin than coffee, but it would be far less effective trying to cultivate a climate of fear and hysteria over this.

Fear and hysteria spreads and sells.

Few people are going to freak out and Facebook “like” an article about how they can’t eat raisins anymore and then run to the health food store to buy overpriced “Bulletproof Raisins” that are marketed specifically as a clean solution to this latest health threat. Coffee is something that many people highly value. Health, of course, is also something that people highly value. Creating a point of conflict between the two is marketing in its most heinous form.

Yes, coffee has mycotoxins; yes, mycotoxins are bad for your health; no, coffee should not be put on a pedestal separate from all the hundreds of other foods that also contain mycotoxins; yes, governments, health organizations, and food producers should work towards limiting and eliminating the amount of mycotoxins in the food supply. This issue is far more wide reaching than just mold on coffee, and I see little point in vilifying and circumventing a single substance when the same toxins are on just about everything else we eat and drink.

Now back to me

As far as I’m concerned if my condition was coffee based, and it seemed to be — though I have to admit that it very well could have been caused by something else — there is no way that I can tell if it was a direct result of mycotoxins or an allergic reaction or intolerance to mycotoxins, caffeine, or other chemicals present in the coffee.

The fact of the matter is that I consumed coffee to excess, and this was more than likely the problem. Abuse just about any food or drink to that extent that I did coffee is a recipe for adverse health effects. I was also primarily drinking instant NesCafe or cheap-o McDonalds and Starbucks coffee, all of which more than likely contain more toxins than good cup of delicious, quality brewed coffee.

If I were to consume high quality coffee — preferably Arabica bean, wet processed, Central American grown, and roasted — in reccomended proportions and kept in a sealed container and refrigerated, the amount of mycotoxins that I would intake from it would probably be negligible.


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Filed under: Coffee, Food, Health

About the Author:

I am the founder and editor of Vagabond Journey. I’ve been traveling the world since 1999, through 91 countries. I am the author of the book, Ghost Cities of China and have written for The Guardian, Forbes, Bloomberg, The Diplomat, the South China Morning Post, and other publications. has written 3717 posts on Vagabond Journey. Contact the author.

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VBJ is currently in: New York City

8 comments… add one

Leave a Comment

  • Tristanbul September 18, 2013, 6:26 am

    I had to giggle a little bit, after reading this long and detailed article about health and mold in coffee, the next “related article” listed is:

    “Homemade Coffee Filter Tip: Use a Sock”

    Link Reply
    • Wade Shepard October 14, 2013, 1:23 am

      Haha yes, that’s strange. Well, at least I use a clean sock.

      Link Reply
  • Jack September 21, 2013, 1:37 pm

    Coffee is a zero calorie stimulant. With that kind of coffee consumption, no wonder you are so thin. 🙂

    One thing you didn’t mention in the article, or I didn’t see it, have you dropped instant coffee altogether?

    Link Reply
    • Wade Shepard October 14, 2013, 1:25 am

      Yes, I cut out instant coffee and did not take in any coffee for a while. I now try to drink “normal” amounts of better quality coffee. It seems to be fine. I think my problem may have been more related to mold in the apartment I was staying in than the coffee I was drinking — though the two ways of ingesting mycotoxins do exacerbate each other.

      Link Reply
  • Paul French October 23, 2013, 11:50 am

    Coming from someone who has the exact same coffee drinking habits as yourself, I want to thank you for doing some research on this. I hear this stuff all the time, and it’s sort of hard to take it all seriously. Did cutting back on your consumption help?

    Link Reply
    • Wade Shepard October 23, 2013, 10:32 pm

      Hello Paul,

      Yes, cutting back did help, but my problem, as it turned out, was more related to a more extreme barrage of mycotoxin poisoning/ allergy/ overexposure that came to a head from living in an dank dark apartment that was essentially a mold farm. So while the coffee aggravated my symptoms it was probably not the cause. So I did cut out coffee for a while and moved to a new apartment. I’m now trying to gradually build previous my habit back up 🙂

      I really need to drink something while writing. It’s just this little routine of knocking out a paragraph or two then sitting back and rereading it/ acting it out while taking a drink. Without the drink it feels like something is missing. So I exchanged coffee for rum for a while, and while this did the job it really just left me drunk by the end of the day with all of my prospective earnings already consumed. So to save my budget and maybe my liver I’m trying to reintroduce coffee again. Hopefully it will work haha.

      Link Reply
  • JJ Thompson June 3, 2014, 7:58 pm

    Dead on analysis. And I agree, “The Internet is a cesspool of misinformation.” Btw, Bulletproof coffee has been debunked by Joe Rogan – http://youtu.be/rwY4H3cNTH0

    Link Reply
    • VagabondJourney June 3, 2014, 8:27 pm

      Excellent. Thanks for sharing that. Glad the deeper story is coming out about this.

      Link Reply