Applying healthy skepticism to Dave Asprey - Are fungal toxins a significant problem in coffee

food safety - Are fungal toxins a significant problem in coffee, and if so, can they be avoided? - Seasoned Advice

Time to apply a bit of healthy skepticism here:

The blog post:

  • Is (so far) the first and only one I've ever seen stating mold to be a practical problem in coffee - in the sense of being present in a high enough quantity to matter (mold grows everywhere).
  • Uses all kinds of weasel words to describe symptoms ("edgy", "cranky", "useless mentally").
  • Describes symptoms that are well in line with plain old caffeine withdrawal.
  • Frequently links to other blog posts on the same site, most of which are "top 10 ways" and "top 5 reasons" fluff pieces.
  • Manages to cite and thoroughly misuse two studies: one from 1995, and another from 2003. Both are about Ochratoxin A (OA), which isn't even the biggest risk; Aflatoxin is. (More on these later).
  • Advertises a fairly expensive product, sold by the same author.

The author:

  • Is, according to his LinkedIn profile (which I refuse to link here), the VP of Cloud Security at Trend Micro - a Silicon Valley tech company. I could not find any evidence that he or his his employer has any experience in human biology or nutrition.
  • Makes all sorts of unusual claims about himself: "He upgraded his brain by >20 IQ points, lowered his biological age, and lost 100 lbs without using calories or exercise."
  • Has an entire page of testimonials, which he frequently cites as "evidence".
  • Has an entire site dedicated to product-peddling, including the ubiquitous six-second abs (yes, that's hyperbole) and a $60 "earthing mat".
  • Has the following disclaimers on the product site (all in tiny print at the bottom):
    The statements made on this website have not been evaluated by the FDA (U.S. Food & Drug Administration). Our products are not intended to diagnose, treat, cure, or prevent any disease.
    The information provided by this website or this company is not a substitute for a face-to-face consultation with your physician, and should not be construed as individual medical advice. The testimonials on this website are individual cases and do not guarantee that you will get the same results.
  • In short, he employs tactics which are commonplace among con artists selling magnetic bracelets. In my opinion, all his claims are technobabble, and I think they are not trustworthy.
The facts and studies:
  • The largest sample tested was just 60 samples of beans, and was tested from only one source (Brazil). This is fine for individual studies, but in the real world there are hundreds (thousands?) of sources from many different countries. It's safe to say that the current studies don't even come close to testing all of the coffee from around the world.
  • Both OA studies found an incidence rate of approximately 50% for the OA-producing mold, at wildly different concentrations (minimum 0.2 ppb in one study, maximum 7.8 ppb in another). If this tells me anything at all, it's that you should probably vary your source if you want to minimize your risk.
  • Neither the FDA nor the EFSA actually have a legal limit for OA, but the EFSA "suggests" a limit of 8 µg/kg, which means that even the worst samples are below the very conservative legal limit.
  • One study actually tested the incidence of OA in brewed coffee, not just the beans, and found a maximum of 7.8 ppb in the brew (that's 7.8 µg per 1 kg of ground coffee).
    • For reference, there's an EFSA directive recommending an intake of no more than 120 ng/kg (body weight) per week, which comes out to 8.4 µg/week for a 150 lb/70 kg individual, or 1.2 µg/day.
    • Based on the worst contamination of brewed coffee (7.8 µg/kg), doing the math, you'd have to consume the brew from 150 g of ground coffee per day. That's about half a standard-sized tin of coffee. Per day. If you drink that much coffee, shame on you.
  • The 3rd study (the one rumtscho linked to, not cited by the blogger/con artist) looked at Aflatoxin, not Ochratoxin, which actually is regulated by the FDA at a maximum of 20 ppb. This study also showed approximately a 50% incidence rate after roasting, with the highest concentration of AT being 16 µg/kg for decaf (less with caffeine). So that means with any random cup of coffee you have up to a 50% chance of consuming an amount of AT that's still well below the FDA limit - that's very nearly zero risk.
  • None of the studies test the rate of mold growth on beans while in storage under various conditions (temperature, humidity, etc.), so we can't comment on what happens in storage. So I guess if you want to really be on the safe side, only buy as much coffee as you think you can use in a week or two.
Don't believe everything that people tell you - especially people with something to sell. Unless you're drinking gallons of coffee a day, brewed coffee is perfectly safe.
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I'm the guy who made this coffee. In my opinion, yes, alfatoxins are dangerous for you, and you should drink coffee which doesn't have them. Most coffee gives me awful symptoms, ones so bad I quit coffee for 5 years before I figured it out. Now I only drink this coffee, because it gives me no symptoms, and I am selling it because I believe it is better for others too. My opinion is that
There are toxins (specifically biogenic amines and mycotoxins) present in coffee at levels high enough to affect how you feel.
Am I saying coffee will kill you? Nope. But bad coffee slows you down - a lot - and low toxin coffee speeds you up - a lot.
To back this opinion, I am currently conducting an IRB-approved study, with Stanford University's assistance, to test the mental performance of people on my Upgraded Coffee vs Starbuck's dark roast. I can also invite you to test the toxin-free coffee for yourself, by purchasing it from me or from other sources (I wrote a blog post "How to find high performance coffee in your city", google it).
My other sources for my opinion are
  • This study. It shows detectable aflatoxin in 85 of 127 samples. Some (many) were below the legal limit, but the problem is that the legal limit is not the safe limit, it's the economically feasible one.
  • This conference talk. It says that coffee can contribute up to 25% of your daily "safe" (not by my standards) dose of the OTA toxin.
  • If you google "coffee mycotoxin" you can find many other studies which have shown the presence of mycotoxin in coffee.
Aaronut's answer suggests that I am not qualified to judge whether coffee with alfatoxins is dangerous. I feel that his "The author section" is an example of "attacking the messenger", which is a poor tactic. Here are my credentials:
  • I'm a very successful Silicon Valley exec with enough money that I don't need to con people at all.
  • I run an anti-aging group that brings world-class experts in every month.
  • My wife is an MD and co-author of my book on nutrition for pregnant women (currently in publishing)
  • I've lectured internationally on human performance
  • 100 000 people a month read my blog
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In short, if you want to keep this answer up here, I suggest you do some substantial clean-up on it. Eliminate the subjective health claims and sales tactics, which unfortunately are almost the entire post. – Aaronut Jun 24 '12 at 11:32

@Aaronut: I think it's safe to delete this answer on grounds that it isn't in fitting with tone for the site (personal attacks, sales tactics), nor is it informative. – BobMcGee Jun 24 '12 at 13:23
I would also be happy to see this question edited to a form more in fitting with the Q&A format and community standards of civility. – BobMcGee Jun 24 '12 at 14:43
Personally, I don't agree with your opinion, and your arguments and list of credentials don't convince me. In my role as a moderator, I tried to be as neutral as possible and edit the post in a way which presents you in a positive light, the way you would have done it. In my role as a community member, I stand by my downvote and will not remove it, because I think your opinion about coffee is wrong, and the arguments you list don't convince me. – rumtscho Jun 24 '12 at 15:02
Likewise, I'm fine with the edited form of this answer and won't delete it; however, it remains an exceptionally poor defense due to the fact that none of the cited sources actually substantiate the claim that "typical" coffee contains dangerous amounts of aflatoxin or ochratoxin, nor do any of the cited credentials lend any credibility to the author as an expert on mycology or even coffee in general. We don't know if your specific claims are supported by these "world-class experts" (or even who they are), and "human performance" is not a scientific field. – Aaronut Jun 24 '12 at 21:16
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