Marks Daily Apple
Serving up health and fitness insights (daily, of course) with a side of irreverence.
30 Dec

Aflatoxins, or Another Reason to Shun Peanuts

We already tend to steer clear of peanuts for some obvious (to our readers) reasons: the fact that they’re legumes, rather than actual nuts; the potentially dangerous, “anti-nutrient” lectins found in them; and their prominent spot in the upper echelons of the “Most Common Food Allergens” list. But there’s another reason to steer clear of peanuts, something we’ve touched on briefly in the past but never expounded upon. Peanuts, along with a couple other crops we tend to avoid, like corn and cereals, are especially susceptible to a mold that produces a mycotoxin called aflatoxin.

Aflatoxin is a carcinogen that has been shown to cause liver cancer in rats (and, presumably, in humans). The amounts given to the rats in the study were highly concentrated, of course, with the express intent to study the effects of acute aflatoxicosis. You won’t be getting a couple grams of aflatoxin with every bag of peanuts or anything, so acute aflatoxicosis isn’t a big issue for people – at least in the US.

That’s not to suggest that correlations between aflatoxin ingestion and cancer rates in humans haven’t been found. In China, for example, a study of five groups of people from different villages found definite positive correlations between the amount of aflatoxin ingested and liver cancer mortality rates. Those villagers who ingested less aflatoxin were less likely to develop liver cancer; those who ingested more were more likely. Unsurprisingly, the three major sources of aflatoxins in this study were peanuts, peanut oil, and corn. Similar reports of aflatoxicosis have been made in India and Kenya.

India, China, Kenya – all developing countries with huge populations to feed. As the recent Chinese pet food contamination debacle attests, health and food standards in developing nations are often lacking. Aflatoxins develop because of these substandard conditions, whether it’s drought afflicted crops weakened and vulnerable to the mold that produces aflatoxin, or insufficient storage facilities letting in the moisture and humidity that creates the mold. Hot, humid climes and improper storage – the real culprits.

The FDA is aware of aflatoxin, and all susceptible foods are tested to ensure they pass muster. Of course, “muster” to the FDA could mean “not so much that acute aflatoxicosis becomes imminent.” What about chronic (a descriptor our nation’s health “experts” seem loathe to address) ingestion of aflatoxins? You know… long term effects? Eating toxic aflatoxin, even in relatively small amounts, over a long period of time (say, slathered on to your morning toast every morning) just doesn’t seem like the best idea.

Well, a link between aflatoxin exposure and stunted growth in West African children has been shown (bolstered by similar laboratory findings in animals), but no specific mechanism has been proposed to explain the relationship. Still, though, the very fact that much of the evidence seems to be pointing towards aflatoxin as a dangerous, development-stunting carcinogen, with a greater propensity to reside in peanuts and cereal grains, only bolsters my resolve to stay off impostor nuts and cereal grains (in or out of the closet alike). If there’s one thing everyone can agree on, it’s that increased liver cancer and stubby limbs are unequivocally devolutions.

I don’t know about you, but the evidence against eating corn and peanuts and cereal grains just seems to be stacking up incredibly high. So high, in fact, that were it not for the remarkably solid foundation of facts, scientific evidence, and personal experience, I would worry it might topple over.

Carol Esther Flickr Photo (CC)

Further Reading:

The Definitive Guide to Grains

Dear Mark: Nuts

10 Ways to “Go Nuts”

You want comments? We got comments:

Imagine you’re George Clooney. Take a moment to admire your grooming and wit. Okay, now imagine someone walks up to you and asks, “What’s your name?” You say, “I’m George Clooney.” Or maybe you say, “I’m the Clooninator!” You don’t say “I’m George of George Clooney Sells Movies Blog” and you certainly don’t say, “I’m Clooney Weight Loss Plan”. So while spam is technically meat, it ain’t anywhere near Primal. Please nickname yourself something your friends would call you.

  1. I have talked to folks at framers markets. I buy raw sprouted peanuts from an organic sprout vendor. They assured me that organic peanuts should be free of aflatoxins because they are organic and not stored like other peanuts and reamain fresher it would be very uncommon to contain any aflotoxins.

    kathleen wrote on January 10th, 2011
  2. Ah it doesn’t measure up to slam peanuts. Peanuts are low in carbs like nuts are low. So all this flack against peanuts is ridiculous. Toxic? Come on! Everyone enjoys peanut butter. I’m sure Grok would have eaten it if he dug em up. BTW Almond butter? It really sucks. Horrible taste.

    Lee wrote on February 14th, 2011
  3. For years I had a huge craving for peanut butter. But, the “health care professionals” always insisted it was okay, nothing’s wrong with you. Even when I was over 200 pounds, and was exercising like a fiend and never losing an ounce, and also getting sick all the time. I stopped eating peanut butter, and you know what? I HATE PEANUT BUTTER NOW. I HATE THE SMELL OF IT. The smell makes me SICK TO MY STOMACH. I will never be convinced again that peanut butter is good eats, when obviously it is not.

    Kim wrote on February 18th, 2011
  4. Ah see peanut butter is one of those things that I can’t give up. I’m paleo, well except for the peanuts, that is. I buy organic peanuts, soak them, dehydrate and roast without the skins. I mostly make my own peanut butter, though sometimes I buy too, not always.

    I’ve had almond butter, even made my own. I’ve made pretty much any other nut into nut butter(soaked and dehydrated first). I don’t really care for almonds or almond butter and frankly, even after soaking and dehydrating, it still bothers me. Other nuts seem to be okay with me aside from almonds. So I’m not sure, anyway, I don’t eat peanut butter everyday.

    Lia wrote on August 1st, 2011
  5. For all those people worried about aflatoxins in corn tortillas: Don’t expect there to be many, mainly due to the process of nixtamalization used in the preparation of said tortillas. The ancient process for the most part kills most of the aflotoxins. So keep on eating corn tortillias and masa by products, as far as freaking over some type of ingredient because its toxic, I would be more worried about things like msg, corn syrup, hydrogented vegetable oils, and weird preservatives causing far more dammage than eating peanuts.
    Rats are slightly different than people remember. Its also like the example sasafrole, native peoples have been eating sassafras for centuries, the fda does a study on rats, and sassafrole and decides its deadly toxic. Turns out rats can’t digest components of sassafrole like humans can but noone is the wiser on that one. Also most almonds grown in the states are irradiated so all those touting almond butter. Honestly the raw nutrient value isn’t there any longer once its under gone irradiation. So I’m not really sure thats a great alternative but hey who really knows anymore?!!!!!!!
    pecan butter sounds yummy to me but thats just me haha

    Justin J wrote on October 8th, 2011
    • +1 pecan butter!

      Michael F wrote on January 12th, 2012
  6. are we saying almond butter is ok?

    mark boyce wrote on January 10th, 2012
  7. I LOVE, LOVE, LOVE Peanut Butter. I buy the organic kind from Earth Fare. I really hate to hear it might be bad for you:( Almond Butter really doesn’t agree with my ummmm hmmm, digestion. Anyone else have that problem???

    Krissa wrote on January 18th, 2012
  8. I just ate some organic cashews, most of which were delicious, except the last one I ate, which was a bad one. I spit most of it out, but couldn’t get the taste out of my mouth for a minute or two. I could tell immediately there was something toxic in it, and think it was probably aflatoxin or else the toxic portion of the cashew shell that I was tasting. It seemed a lot stronger than the random bad peanut you get.

    Michael G. Fons wrote on February 27th, 2012
  9. I definitely had some stomach problems after eating almonds and other nuts daily. I only eat raw nuts and I try to get them organic. Whoever it was that was saying they had problems from eating nuts… I eliminated nuts from my diet for a while and now I can eat them again. Another weird thing. Apparently I’m allergic to peanuts according to a blood test taken, but I have absolutely no symptoms whenever I eat it. I wonder if my body has grown tolerant of it since I’ve eaten it throughout my life. Anyway, I’m enjoying being able to eat nuts again, but I’m going to be careful not to over do it! I’ve known about the mold thing in peanuts for a while. And after reading the comments, I’m curious about the Trader Joe’s Organic Valencia peanuts. If that’s true, then I’ll be buying that kind from now on because I do like to have a little from time to time. Especially in my green smoothies!

    Amber Carr wrote on March 12th, 2012
  10. I have been eating organic valencia peanut butter for a long time with no ill effects….from time to time, i do cleanses, including liver cleanses, just to stay overall detoxed…

    Selene wrote on March 19th, 2012
  11. What are the chances that Grok would have eaten peanuts?

    dulst wrote on March 31st, 2012
  12. Why, when one buys in-the-shell peanuts by the bag, is there no certification on the bag that the contents were inspected? Even p-butter should show whether it is inspected, yes?.
    Also, what can a whole-peanut consumer watch for when opening peanuts? Some shells are a dark color inside — does that matter? If a kernel tastes weird, should it be carefully and completely expelled? Does or does not roasting, or re-roasting increase safety? Questions, questions…

    Pete wrote on April 29th, 2012
  13. Paranoid crap

    Really ? wrote on August 2nd, 2012
  14. Hey, after a bit of research, I found a very informative article regarding U.S. standards regarding aflotoxins:

    It cites an FDA maximum limit of 20 parts per billion for this toxin in human food. I’ve seen from the UN FAO that those European countries that have legal limits have set them at 5 to 10 to 15 parts per billion for coffees:

    Last, I saw a pie chart from the UN FAO showing the breakdown of foods that are responsible for aflotoxin exposure:

    I did not see a category for oil nuts (like peanuts) except “Other”.

    Tom wrote on September 5th, 2012
  15. I thought I would chime in since my mom worked for the USDA in the lab that examined almonds. I am pregnant and was mentioning my plans to add almond flour and almond butter to recipes when she warned me not to use store-bought varieties because of the aflatoxin.

    Her explanation was that these products are made from the broken pieces of nuts that remain after all the higher grade nuts have been sorted out. They have the highest allowance for “serious damage” meaning nuts unfit for human consumption (3% for Grades U.S. No. 1 Whole and Broken and US No. 1 Pieces). Additionally, some portion of samples from each manufacturer is allowed to be above the USDA maximum. When her colleague assessed various almond products for aflatoxin those made purely from the lowest grade nuts had the highest concentrations. Organic can actually be worse because the pesticides prevent much of the mold responsible for aflatoxin.

    Her recommendation was to buy whole almonds (or whole peanuts, she didn’t comment on Valencia) and grind them into your own butter or flour. The US #1 whole almonds have allowances of 1 1/2% or lower, and you can remove shriveled or damaged nuts as you find them.

    She did comment that peanut butter is even worse, so the same recommendations would apply. Overall, she said it’s fine to have processed nut products once in a while since everything has risks, but if you eat them often or are pregnant or feeding little ones, make your own from higher grade nuts.

    Christine wrote on December 7th, 2012
  16. Who cares if peanuts are a “real nut” or not? What matters is its nutritional profile. In many ways this is more similar to nuts than to legumes and what’s so bad about legumes anyway?

    Sean wrote on February 10th, 2013
  17. High dosed vitamin C neutralizes aflatoxins just like it neutralizes innumerable other poisons. Everyone should be taking at least 10grams/day.

    snfkd wrote on May 10th, 2013
  18. Read this whole post and all the comments while eating a bag of salted peanuts- shells included. I have no regrets.

    blindoctor wrote on September 6th, 2013
  19. I live in Thailand. I’ve been eating about 2 lbs per week of pistachios – air cooked, in a recloseable bag, for the last couple months. I don’t have ANY faith in the Thai food standards, and I’ll be stopping all peanut consumption over here. One of the problems of living in a 4th rate country.

    Vern L wrote on September 10th, 2013

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