GMO Bt corn’s underrated ability to reduce mycotoxins benefits health and economy

Bt crops, the sibling to the herbicide resistant crops often maligned by anti-GMO activists, have not only reduced insecticide use in the U.S. but also have a food safety benefit: The reduction of mycotoxin contamination of crops, which can harm both humans and animals.

Bt seeds are engineered to express the cry genes from Bacillus thuringiensis. These genes code for an insecticidal toxin which makes the crops resistant to certain pests. Farmers, most especially organic farmers, have been spraying the natural form of the bacterium for almost a century to great effect and with no measurable environmental hazards, as the toxin only interacts with targeted insects but not humans.

“The benefit of Bt corn’s reduction of mycotoxin damage has been virtually ignored in policy debates anywhere in the world,” Felicia Wu, a Michigan State University food and nutrition professor, has noted.

There are more than 300 known mycotoxins that have different effects on health. Mycotoxins can be produced by fungi, which absorb best into crops that have been damaged from pests. Contamination can occur either in field or in storage. In short, since Bt maize wards off the corn borer, reduced feeding damage allows less fungus to penetrate.

Two of the most prevalent mycotoxins in agriculture are fumonisins and aflatoxins. Fumonisins are found almost exclusively in corn, while aflatoxins can be found on corn as well as cotton, peanuts, pistachios, almonds and walnuts.

Fumonisins have been connected to high human esophageal cancer rates and neural tube defects in human babies, according to the University of Kentucky Agriculture Extension Service. They can also affect a number of animal species. Animals consume the toxins in animal feed, which can lead to fertility problems or diseases—leukoencephalomalacia in horses and porcine pulmonary edema in pigs.

Increased exposure to aflatoxin can increase risk of liver cancer in humans, modulate human immunity and may contribute to childhood stunting, according to a 2014 paper by Wu.

Bt crops also stand to have greater health impacts in developing nations, where higher rates of malnourishment and high exposure to mycotoxin due to little diet diversity can have more devastating effects, Wu said. But genetically modified crops also face political opposition in some of the countries worst afflicted with aflatoxin exposure. In Africa, only South Africa has adopted Bt corn on a wide scale.

Use of Bt crops could also play a role in reducing contamination and economic and environmental losses. In 2011, 180 bags of maize were destroyed in front of starving farmers in Kenya because the maize had been contaminated with aflatoxin.

Though recent numbers were difficult to find, researchers estimated in 2003 that economic losses in the U.S. due to aflatoxin contamination, ranged $163 to $500 million annually, depending on whether all crops and animal health effects are included. The International Institute of Tropical Agriculture estimates global losses of about $1.2 billion with African economies losing $450 million annually.

Additionally, global trade between wealthy and less developed nations can worsen losses due to contamination when developing nations export their best food and sell contaminated food locally or when intended exports are rejected and wasted due to food safety limits on mycotoxins from other nations, Wu said.

Additionally, Bt crops could be more environmentally sustainable. Numerous studies have shown the benefits of using Bt corn as a part of a strategy to reduce mycotoxin contamination, which would reduce waste.

The University of Kentucky summed up field studies in the U.S. and Europe on furmonisin contamination, saying reductions have ranged from 20 to 90 percent, often bringing the grain below concentrations that pose risks to humans and the most sensitive animals. Aflatoxin reduction typically ranges from 50 to 90 percent when Bt corn is planted.

In Europe, where Bt corn is the only approved GM crop, Andreas Schier of Nürtigen-Geislingen University in Germany is examining mycotoxin levels in maize using different variants, such as soil management, weed management with insecticides and growing Bt maize.

“The levels are lower if the corn borer is controlled with insecticides, and we get the best effects by growing Bt maize,” Schier said. “We can say that the mycotoxin levels are more or less halved in Bt maize compared with conventional maize grown on the same site without measures to control the European corn borer.”

This applies to three classes of mycotoxins: deoxinivalenol, fumonisins and zearalenone.

There are some caveats. Reductions in mycotoxin are not certain. According to the University of Kentucky Extension Service, the Bt toxin must be expressed in the kernel of corn for it to provide reduced mycotoxin contamination. Genetic background of the corn hybrid can also impact the effectiveness, as can the insect pest that is present. For example, lower mycotoxin levels have been shown from feeding damage caused by the European corn borer but not the corn earworm.

Schier also explained that weather conditions conducive to fungal growth can cause an increase in mycotoxins, as can farm practices, such as straw, soil management and timing of harvest.

“Farmers cannot completely avoid mycotoxin contamination resulting from a serious fungal infection just by growing Bt maize,” Schier said. “All they can do is reduce it to a certain extent.”

In developing countries, other problems exacerbate mycotoxin contamination including low-quality seed, lack of pest control and poor storage, Wu has said.

Nonetheless, growing Bt corn could be a successful part of a strategy to reduce mycotoxin levels.

Rebecca Randall is a journalist focusing on global food and agriculture issues. Follow her @beccawrites

51 thoughts on “GMO Bt corn’s underrated ability to reduce mycotoxins benefits health and economy”

  1. The second paragraph says that the plants are engineered to contain the bacterium bt. I was under the impression that they contain a gene sequence that produces the bt protein. Could you clarify please? Thanks in advance.

  2. If mycotoxins can be considered “toxic chemicals” Then the organic/health advocates should be willing to drop objections to this example of engineering. Especially as it could be a make or break factor for small holder/subsistence folks in any given year. Ye unshockingly we see a lack of logic in this regard.

      • Ha ha, Loren! My own precautionary principle leads me to shun organic corn for that reason. I would love it if there was more Bt sweet corn; most Bt corn is for livestock, I believe. I eat non-organic corn to avoid corn borer infestation, since sprayed organic Bt doesn’t get rid of the corn borer damage as well as Bt inside the corn.

        And adding on to your comments to “Wow,” above: He needs to learn that insect guts and human guts are very different, which is why Bt (I’ll ignore his huge mistake in referring to it as glyphosate, lol) affects insects but not human guts. He also needs to know that sprayed Bt, like organic guys do, also harms non-target insect species that haven’t harmed the corn, and just happen to be hanging around the corn; bad timing for them. With Bt corn, only the insect that eats the corn goes to Insect Heaven In The Sky.

  3. This is an excellent article, and long overdue. The benefits of Bt corn for reducing mycotoxin levels in grain were first published over a decade ago by plant pathologists at Iowa State University, but have largely been overlooked in the debate.

    As to whether mycotoxins can be considered “toxic chemicals”, yes, they are. Three of the types of toxins mentioned in this article (deoxynivalenol, zearalenone, and aflatoxins) are not only proven toxins in mammalian systems, they are internationally regulated substances in corn, wheat, and several other types of stored food and feed commodities. In fact, one of the aflatoxins (aflatoxin B1) is the most potent carcinogen known to science.

    The potential for the mitigation of mycotoxins is not limited to Bt toxin production. There exists authentic potential to bioengineer corn and other stored grain crops to actually prevent the formation of these toxins by the fungi that produce them. The fear-mongering by the anti-GMO faction is what is inhibiting this technology from being developed.

  4. Did you seriously just say that Glyphosate only interacts with insects but not humans? How are you so incredibly stupid? You realize it is a patented chealator which robs nutrients from the food itself and the human body, oh yeah, And it was patented as an antibiotic! But you’re probably too stupid to realize how every single american eating antibiotics multiple times a day is even a bad thing. Like really just kill yourself, don’t write articles. Lol.
    They’re only modifying the plant to take more of their chemical patent so they can sell more of it, duh.. They don’t care about quality. look up the farmer suicides in India because of monsanto seed. God you Americans are ridiculous

    • Did you seriously just confuse glyphosate with Bt?? Before you advise people to stop writing articles and off themselves, do us a favor and learn some science. But to do that, you’ll first have to learn to read. Is everyone where you live as illiterate as you? Be honest.

    • Wow, are you even faintly aware that seeds have been patented since, uh, 1930?
      Are you even faintly aware of the difference between glyphosate (an herbicide) and Bt (an insecticide)?
      If not, then I can only say “Wow.”

      And would you deny antibiotics to people who are sick and need them? Or to an organic dairy cow who needs an antibiotic?
      If so, then to re-quote your name: Wow.

  5. So if organic farmers have been spraying their crops with Bt bacterium successfully for almost a century, Id like to see a study of the cost difference between patented, GMO seed crops (which are VERY expensive seeds), and the cost of heirloom crops that are sprayed with the bacterium. The article is clear in the fact that GMO crops are not the end-all magic pill to eliminating mycotoxin contamination, so what is the REAL benefit of one over the other?

    • As the article stated, and as previous comments have stated as well, the REAL benefit is the reduction in mycotoxins (natural toxins produced by fungi) from deployment of genetically modified corn, and potentially other crops. They are not “magic pills” as you suggest, but there exists an authentic possibility to eliminate, not just reduce, known mycotoxins if only the anti-GMO screamers would halt their diatribe for just a moment and let the technology be deployed. As for “heirloom” crops, they are simply that…heirlooms. They don’t feed the vast majority of people.

    • Krystal, it’s a lot more than the cost of the seeds. Farmers buy GMO seeds because they get better yields with less disruption of the soil, and using less pesticides.
      I’d rather eat Bt corn anyday, over corn borer-infested organic corn.

      • You have no point. It’s like saying the amount of milk you drink with your breakfast is more than the amount of milk that you consume for the rest of the day in the other foods you eat. Either way, you digest the milk. It’s a non-issue.

          • You have cited an article in an organic restaurant magazine. It’s not science. More like a comic book. Any bumbling idiot can publish an article such as that….and they frequently do. I’ll bet you are a marketeer’s dream.

          • No I cited articles, from The Journal of American Science that showed that Bt corn is toxic, that were mentioned in an organic restaurant magazine. See the difference? Nice try at obscuring the truth though. Monsanto has trained you well.

          • No, you cited an article from the restaurant magazine, which is simply an advertisement to induce you to pay a lot of money for “organic” slop. It’s not the original article, which you never read, and have no ability to understand anyway. Go back to school and learn something about biotechnology. Better yet, go farm your own food. You will learn pretty fast what works and what does not work.

          • I’ve been growing my own ORGANIC vegetables for over 40 years so I think I know a wee bit more about biotechnology than you do. I’ve read everything I could lay my hands on regarding conventionally and organically grown food. I’ll stick to organic. Oh and organic is not necessarily more expensive if you know where to shop. Now go eat your GM corn. Good luck.

          • Uh so you grow food and that makes you an expert in biotechnology? I drive cars. Does that make me an expert in engine design?

            I’ve read everything I could lay my hands on regarding conventionally and organically grown food.

            …and probably disregarded anything that didn’t fit with your pre-chosen conclusion.

          • Says Pasty who never studied toxicology but yet says the poisons in vaccines are perfectly

          • Says Pasty who never studied toxicology

            Well if I use the Ron Roy definition of “studied” then I’m a PhD in toxicology.

            the poisons in vaccines are perfectly safe

            I’ve never said that anything is perfectly safe. So that’s typical lying on your part. The doses of most things in vaccines that you whine and whine about are sufficiently small as to be lost in the background exposure. Which doesn’t require a background of toxicology to determine so much as one in statistics…and hey…I have that. :-)

          • No I cited articles, from The Journal of American Science

            Nope. You cited an article in an organic food magazine which summarizes several studies and links to them. See the difference?

            Further more the “Journal of American Science” is from Marsland Press a known predatory publisher[1] so it’s not exactly high quality information. As evidenced by the creationist nonsense it publishes. Also those two studies don’t even say that corn is toxic. It says that there are changes in body wieght in one and specific histopathological changes …and if you read the study which everyone who has even met you for ten seconds knows you didn’t – it uses a ridiculously small sample of ten rats per arm. Even the the second paper it barely makes significance and in some cases only in male rats.

            As usual you haven’t even read the bonkers web page you are citing carefully the studies they claim actually cite organ damage are from two other entirely different journals.


    • There is an anecdote which you may find
      on French websites: the Moroccans are said to have preferred a maize
      shipment from Spain rather than France. The reason : GMO, less
      mycotoxins, less problems in the stable.

      • Michel Naud investigated this anecdote and it proved to be false. I suppose you have an access to the AFIS forum so you can check the rationale and explanaiton here :)

  6. This is perhaps a bit off topic. Many fungi produce toxins and some produce very dangerous toxins.

    I bake my own bread, and can keep it for only a few days before it begins to grow mold. But the bread I buy at the supermarkets stays mold-free for several weeks. The commercial bread stays fresh because it contains preservatives.

    But mold starts as a tiny inconspicuous growth, easy to miss. What level of fungal toxins am I likely to be ingesting by eating bread that has just barely begun to grow mold?

    I don’t know the answer but my guess is that all the food products that self-label as containing no preservatives may be exposing people to fungal toxins that are much more dangerous than anything that can possibly be in the preservatives.

    • Your observations & question are cogent to the discussion about GMOs (transgenics), which technology could be used to significantly reduce mycotoxin exposure in human and livestock diets. The fungal toxins with known high hazard x exposure quotients, i.e. high quantitative risk, are of several chemical types, such as trichothecenes, fumonisins, aflatoxins, and zearalenone. These are the substances for which action levels (MRLs or tolerances) have been set by the various regulatory agencies around the world. There are hundreds, perhaps thousands of other natural toxins in food crops, some of which are produced by the plants themselves in response to invasion by pathogens and insects, and some of which are constitutive, i.e. they are just a normal part of plant physiology. The toxicological load that they place on humans and livestock that consume them has for the most part not been studied. My position, and my continued advocacy, is that the regulatory framework which governs food safety should focus more intently on natural toxins. Today, the system is lopsidedly, irrationally preoccupied with synthetic substances as if there were some legitimate rationale for that. As you are well aware, Bruce Ames and his team published long ago there is no such basis for presumption against synthetic materials, and that the probable risks of chronic disease (including genotoxically induced cancers) are about equal from natural vs. synthetic substances.

      Incidentally, I bake bread too, and have done so for several decades. The most common bread mold fungi that I’ve encountered are Penicillium spp., which are known to produce antibiotic substances [recall the origin of the methicillin antibiotics such as penicillin]. Penicillium italicum, which is not as common bread as on rotting fruit, is well known in human pathology for producing toxic substances. There are many others.

    • If you look at the labeling initiatives that have failed, you will see that they resulted in 1) no pertinent info about allergenicity or ingredients/calories; 2) misled by requiring some foods (like sugar) to be falsely labeled as gmo; 3) misled by not requiring cheese (genetically modified) to be labeled); and 4) giving a “pass” to 2/3 of the food we eat.
      Some truthiness.
      If you want to avoid gmos, eat organic or “non-gmo.” Some of us prefer to eat gmo foods to avoid stuff like fuminosins, so leave us alone please and go hang out with the anti-vaxxers.

  7. This is the content of a “poster” presentation I gave at the 5th Italian Conference of Agriculturale Economists “The changing role of regulation in the bio-based economy” 16-17 June 2016, Bologna, Italy. The full paper is under review for publication in a journal.
    “GMO” maize and public health: A little case of Schumpeterian policy in the EU
    * The current double standard that EU lawmakers apply to agricultural “GMOs” is simple: cultivation is generally forbidden; importation (as feed) is necessary.
    * The only “GMO” currently approved for cultivation is a variety of Bt maize: for many years, most EU politicians successfully fought against the actual use of that cultivar, while the various attempts to block it – mostly resorting to the “safeguard clause” – were considered inacceptable by the EFSA, the EU Court of Justice, and the Commission itself.
    * In particular seasons, the level of noxious fungi (fumonisins) contained in “non-GMO” maize varieties harvested in some European countries exceeded the legal limits; rather than liberalizing the use of “GMO” maize, which is safer than traditional ones, EU decision-makers chose to raise the threshold for the poison.
    * This may be considered a minor but not insignificant case of “Schumpeterian” policy, where public choices are not inspired by a science-based mind-set, but are substantially dictated by a calculus of consent: most probably, EU politicians reckoned that an adjustment of the legal level of contaminants would have cost them less than the possible outrage deriving from encouraging “GMO” cultivation.

    • I am in full agreement with the substance of your post. I am a bit curious, however, about your use of “Schumpeterianism”. I am a devotee of his theory of creative destruction and entreneurship but was trying to interpret the basis of your reference. Sorry a bit off point. Thx

      • Just 2 quotations from my paper which is under peer review:
        EU lawmakers have long refused the cultivation of “Genetically Modified Organisms”. An example of this struggle is the revision of the accepted level of contaminants in maize: rather than admitting that Bt maize is safer than “non-GMO” varieties, and therefore European farmers should be allowed not only to import it, but also to produce it, politicians have raised the threshold of the poisonous fumonisins that may be legally present in food and feed.
        This decision is an example of a “Schumpeterian” approach to policy, where public choices are not inspired by a science-based mindset, but are substantially dictated by a calculus of consent; economic/commercial protectionism has also been considered as a motivation.
        While scholars must continue to explain that every policy decision should have a basis in sound science, no way out of the “GMO” imbroglio seems to be foreseeable, as long as politicians stick to the Schumpeterian iron law.
        [From the text]
        Politicians always proclaim their approach to be inspired by the search for common good, but a much less idealistic reading was proposed decades ago by Joseph Schumpeter, when he argued that, in a democracy, any political or administrative action is a mere corollary of the opportunistic estimates which every law-maker adopts. “The democratic method produces legislation and administration as by-products of the struggle for political office” (Schumpeter 1942, Capitalism, Socialism and Democracy, p. 286). It is impossible to escape the clear impression that such a disposition is applicable in our case, and maybe most “normal” politics falls into the narrow definition highlighted by the great economic-political thinker.
        Another quotation may reinforce understanding of the mindset which leads to such apparently illogical policy decisions: “Politically speaking, the man is still in the nursery who has not absorbed, so as never to forget, the saying attributed to one of the most successful politicians that ever lived: “What businessmen do not understand is that exactly as they are dealing in oil so I am dealing in votes”.” (Schumpeter 1942, p. 286) Crude but truthful realism, which explains policy outcomes substantially dictated by a calculus of consent: most probably, in our case EU politicians reckoned that an adjustment of the admitted threshold of maize contaminants would have cost them less than the possible outrage deriving from encouraging “GMO” cultivation. An exquisite example of political expediency.

        • This is the first I have heard that the EU raised the tolerance for mycotoxins as a cynical rationale for not approving Bt corn. Whether or not that is Schumpeterian or not it certainly is detestable.

  8. Are you suggesting that the worldwide regulatory agencies, who established toxicity and toxicology testing protocols for these products, don’t know how to interpret the data?

    Are you a devotee of exogenous semiotic entropy as well?

        • The Genetic Literacy project is of utmost importance for mankind’s better future. Gene sequencing and establishing correlations for agricultural and medical solutions is the purest and most intelligent research for now and all future generations. Please google Peter Diamandis, former CEO of International Micro Space, and founder of Human Longevity Project Inc., the “largest gene sequencing project on the planet.” Quantum mechanics specifies with virtually infinite mathematical precision the electron wave probability functions which create the Periodic Table used for all computational molecular biology.

  9. Quantum physics has nothing to do with molecular biology, quantum mechanics deals with the very small, hence the name.

    Thus in order to establish the safety of human laboratory genetic engineering technologies to be as reliable as mother nature’s genetic engineering, we need more rigorous safety protocols approach certainty

    The exact opposite is true. Mother nature’s genetic engineering is totally random and has no concern for the health or safety of humans. Human controlled genetic engineering is tested for health and safety. What the heck is a glycosylated protein? There is no such thing.

    This is just a crazy word salad.

    PS we don’t breed crops so they can survive in the wild, we breed them to eat. This goes for all breeding methods. Most crops cannot even survive in the wild for more than a season or 2.

    • Randomly occurring subtle molecular changes to trans-gene expressed proteins, such as micro-small glycosylated proteins (with sugars added), obey the superordinate quantum probability principle, “Mother nature’s genetic engineering is totally random and has no concern for the health or safety of humans.”

Leave a Comment

News on human & agricultural genetics and biotechnology delivered to your inbox.
Optional. Mail on special occasions.

Send this to a friend