A Remarkable New Technology That Will Diminish A Global Cancer Threat

Maize/Corn

We in the rich societies of the world don’t hear a lot about aflatoxin. It is probably one of the single largest causes of cancer in the developing world – particularly in Africa. Around a half a billion people are at risk from this toxin in their diet. At high doses it can cause acute poisoning and death. It also causes cognitive stunting in children exposed to it. Aflatoxin is a natural chemical that is made by a fungus called Aspergillus that can infect crops like corn, peanuts and tree nuts particularly when there is damage by insects and/or stress from drought. People like Americans are well protected from this threat by farmers who exercise control measures for the insects and disease, by an advanced food system that monitors for the issue in the harvested crops, uses proper storage conditions, and excludes it from what is sold to us. For instance the EU standard for maize is that it must have less than five parts per billion of aflatoxin.  Unfortunately only 20% of the normal maize supply in Kenya meets that standard.

For high value crops like almonds and peanuts, there are not only concerted efforts to prevent this sort of contamination, there are also mechanisms to literally check each individual nut for the presence of the fungus and reject those that are suspect. That kind of detailed scrutiny has never been feasible for a lower value crop like corn (or Maize). But recently, a Swiss, family-owned grain handling equipment company called Bühler has cooperated with Microsoft to develop a system which can process corn at a rate of 15 metric tons per hour and reject any of the kernels that are contaminated with the nasty chemical aflatoxin. That is both amazing and very cool.

The sorting machine in high speed process

This remarkable system relies on very high speed imaging technology using LED lights to look for the florescence that suggests the presence of the fungus. It is applied to every single corn kernel even at that high rate of grain flow. The system uses Microsoft technology to pass all relevant data to the Azure cloud, where visualization of the data, tracking, and reporting are possible in real time. Bühler can also tap into Azure’s massive cloud infrastructure, available in 140 countries, to scale the solution globally.  A puff of air is used to knock the suspect grain out of the main flow and can achieve a 90% or better degree of contamination reduction with something like a 5% level of grain rejection.

In the Buhler applications lab

This technology will have immediate applications in the feed grain industry in the developed world because instead of rejecting entire loads that have some contaminated grain, it will be possible to protect the animals that eat the grain while still using as much of the yield as possible – a food waste reduction success. Also, since aflatoxin can come through to milk, dairy product consumers will also get an even higher level of protection.

Moving this sort of technology into key areas like Africa will require some creative public/private partnership approaches particularly in areas where there are not really any sort of commercial grain handling systems at, say, a village level. The grain equipment company behind this, Bühler has been doing business in Africa for 100 years and runs a milling school in Nairobi, so they are positioned to find creative solutions to the implementation of this advance.

As revolutionary as this technology promises to be, it is a good thing that it isn’t the sole solution. One way to reduce the infection/contamination issue is to intentionally spread a strain of the culprit fungus that does not happen to make aflatoxin. It’s a biological control strategy that was first developed by USDA researchers and commercialized in the U.S., but which has since been re-developed in Africa. Insect resistant, “GMO” maize also significantly reduces the incidence of the problematic infections. There is also a “gene silencing” strategy proven by an Arizona State researchers that would prevent the fungus from making its toxin even if it was able to infect the plant.

There has also been a very creative, to design an enzyme that breaks down aflatoxin into harmless bits that was actually facilitated by an on-line, crowdsourced game effort led by a researcher at UC Davis with support from Mars, Inc. Such an enzyme might be able to turn the rejected, contaminated grain from this new sorting mechanism into more food/feed or feedstock for bio-based materials. The most robust and resilient anti-cancer strategy would be to combine all of these methods and finish off with the high speed sorting technology.

So there is new hope for the mental development status of African children and for a lower incidence of cancer there and elsewhere. I guess I just have to say that technology can achieve some really cool results and I hope that non-profits and governmental entities will join Bühler in extending this to the poorest and most vulnerable populations.

You can comment here and/or write me at savage.sd@gmail.com 

New GM Technology Allows Crops To Just Say No To Dangerous Toxins

Contaminated maize in Africa - Image from International Institute of Tropical Agriculture

(This article originally appeared on Forbes on 3/21/17)

There has been a breakthrough on a way to reduce the risk of a major form of cancer in the developing world. It involves corn genetically modified to "just say no" to the production of a carcinogenic toxin in its grain.

Have you heard of Aflatoxin? It is a major risk factor for cancer in the developing world.  Aflatoxin is a natural chemical produced by a fungus. It is a highly toxic and is a very potent carcinogen in animal studies. Those of us in the developed world are fortunate in that a number of safeguards keep aflatoxin out of our animal feed and human food supplies. Unfortunately, in the developing world, people are not so well protected. In those regions aflatoxin contaminated foods are responsible for many poisonings, and high cancer rates. Researchers in Arizona have recently published a paper about a biotech crop breakthrough that could dramatically improve that situation.

Aflatoxins are chemicals produced by certain fungi that infect food crops (Aspergillus flavus, Aspergillus parasiticus). The biggest developing world risks are with maize (corn), and groundnuts (peanuts) - staple, subsistence crops in parts of Africa and Asia. When insect feeding damages crops and/or through drought stress, they are most susceptible to infection by these fungi. The infections can continue to develop after harvest, particularly under less than ideal storage conditions.

Maize (corn) in Africa (Image by Kate Holt/AusAID)

In an article published in the prestigious journal, Science Advances, five scientists from public institutions in Arizona described how they genetically engineered corn to prevent its contamination by aflatoxin. For this article I spoke with Dr. Monica Schmidt of the University of Arizona. Schmidt’s team engineered the corn to make three small RNA molecules designed to specifically bind to parts of a particular RNA produced by the fungus. These small RNAs made in the kernel cells are able to move from the corn into the invading fungus. Once there, they trigger a mechanism in the fungus cells that blocks the production of a key enzyme required by Aspergillus to make aflatoxins. Because this approach involves three separate bits of targeting RNA, it is extremely unlikely that the fungus could mutate in a way to get around this blockage. The corn plants modified this way are effectively protected from contamination with aflatoxin. This kind of corn could give developing world consumers a much safer food supply.

This work was funded by the Gates Foundation, which also funds work to develop corn that is resistant to insect damage and drought. In combination with the aflatoxin protection this constitutes an ideal integrated solution for that critical crop. This is also a proof of concept for taking a similar approach with peanuts. The intention is to make this technology freely available for breeding into the local crop varieties that are best adapted to the regions in question.

What about the developed world? It would actually make a lot of sense to add this technology to the diverse toolset that we already use to keep aflatoxin out of our corn and peanuts. There are also other crops that could benefit from another protection strategy from aflatoxin – notably tree nuts like almonds, pistachios, walnuts and pecans. Aflatoxin can also be an issue in cottonseed that is used as an animal feed. The same biotech strategy may well work with other fungal toxins that can be an issue in other crops.

The world’s consumers can derive great health benefits from the further development of this technology.  This is definitely one to track and to encourage.

You are welcome to comment here and/or to email me at savage.sd@gmail.com

A Curious Silence: The Environmental Working Group and Mycotoxins

The Environmental Working Group (EWG) tells us:

"The mission of the Environmental Working Group is to use the power of public information to protect public health and the environment."  

If you look at their website, a great deal of what they do involves warning people about various "toxic risks."  They publish an annual "dirty dozen" list ranking crops by pesticide residues.  They have a major effort to identify purported risks from chemicals in cosmetics and sunscreens.  They look at toxic things in drinking water and in pet food.  They have an extensive "Chemical Index" with toxicity ratings.  But there are some very important toxins about which EWG is completely silent.

The Missing Toxins

The extremely important class of toxic chemicals that is completely absent from the EWG website is Mycotoxins.  You can go to the search engine on the site and enter words like: mycotoxin, aflatoxin, fumonisin, ochratoxin, vomitoxin... and find absolutely nothing.  What makes this silence so strange is that mycotoxins are known to be some of the most dangerous substances to which people can be exposed, particularly in food.  If one of EWG's primary purposes is to "protect public health" it seems odd that they would not say one thing on their web site about this extremely well-documented risk.

Beth Hoffman, an information technology writer, raised an interesting issue today in an article in Forbes.  She was discussing the huge disparity between what government and academic scientists say about pesticide safety and what the Environmental Working Group says with its "Dirty Dozen" list.  She says, "But at its core, the argument for and against lists like the Dirty Dozen is a question of trust."

The EWG clearly distrusts the scientific/regulatory consensus.  But should consumers trust the EWG?

Should we trust an organization that either ignores or fails to recognize a real and present risk when they are telling us that there is significant risk where science says there is not?  EWG says it "provides practical information you can use to protect your family and community."  How can we trust that statement if EWG provides zero information about chemicals which are not in the "you just never know" category, but in the "clearly documented as toxic and carcinogenic" category?

What Are Mycotoxins?

Mycotoxins are potent, natural chemicals which are produced by certain fungi.  These fungi can, under various circumstances, grow on food and feed crops either while they are growing in the field, or later during the storage and/or drying of certain commodities.  The most important example is a toxin called aflatoxin which is produced by some strains of the fungi Aspergillus flavus and Aspergillus parasiticus.  These organisms can grow on things like peanuts, tree nuts, and corn.  It can also grow on hot chili's or figs while they are drying if that is done improperly.  It can occur in imported spices like nutmeg.  It has been found in imported chocolate.  It is thousands of times more toxic than most pesticides, and it is one of the most potent carcinogens known.  It is estimated that aflatoxin is the a major  cause of cancer deaths world wide.  Unfortunately, this mainly occurs in the third world, and even places like China are just now beginning  to address the issue.

Why Haven't Most People Heard of Aflatoxin or Other Mycotoxins

In the developed world, extraordinary efforts are made to keep food mycotoxin levels in general, and aflatoxin levels in particular, low enough to make our food safe.  The system works well enough that it does not come to the public attention very often.  This success is based on the same sort of science-based regulation and testing that are designed to insure that pesticide usage is safe.  The system of mycotoxin exclusion generally does a great job, but occasionally something slips through - mostly incidents involving pet foods or imported products from regions of the world that don't have adequate safety practices in place.

Just as an example, nut crops like peanuts and almonds can potentially become contaminated with aflatoxin, usually because of insect damage.  In our food system, the individual, shelled nuts that go into something like peanut butter or roasted almonds are put one-by-one through a light-based screening process to reject any individual nut with even the possibility of contamination.  Peanuts and other nuts sold in-the-shell cannot be screened to that degree.  EWG could instruct consumers to avoid in-the-shell nuts to protect their family. It has also been shown that eating green plants like spinach gives us chlorophyll which can bind aflatoxin in the gut so that it never gets into our blood stream.  EWG could recommend that one eats a salad with peanut butter sandwiches just to be safe.  EWG could talk about which imported foods might be most likely to have aflatoxin.  These examples would be practical guidance about real risks.  On such issues, the EWG has long been silent.   Contrast this with the proactive efforts by the Bill and Melinda Gates Foundation to address mycotoxin issues in the third world.  Yet this major oversight is not the only reason to distrust EWG.

A Serious Issues With the Way That EWG Does Its Analysis

An analogy might be helpful here.  Domesticated dogs come in a huge range of sizes from tiny Chihuahuas to huge Mastiffs.   They also come in a huge variety of personalities, from breeds which you could easily trust with a baby to those which have been bred for aggressiveness and which have been known to maim and kill people.  If anti-dog activists were to propose that any dog should be avoided and that people should move to towns that exclude all dogs, most people would dismiss the idea as ridiculous.  This is; however, directly analogous to what EWG does with pesticide residue data and their "solution" of buying organic.  The amounts of pesticides that the USDA finds on foods in its residue testing program can vary by 1000-fold or more - actually much more than the range of dog sizes.  The intrinsic properties of the different chemicals that are detected also differ even more than the differences between aggressiveness in breeds of dogs.  Yet what EWG does when it makes its dirty dozen list is to treat every residue detection the same.  This is just like our fictitious anti-dog activist who says that all dogs represent a equivalent risk, or that you just never know about any dog.  Why should anyone trust this method to analyze risk?

Beth, the Forbes writer, gives indications that she tends to distrust the scientific/regulatory consensus.  I wonder if she has thought about whether she should trust the EWG? Do you trust an organization uses a seriously over-simplified analysis of one category of chemicals while ignoring toxins of far greater concern?  Or might it make more sense to trust science backed up by government and academic scrutiny?

You can comment here and/or you are welcome to email me as savage.sd@gmail.com.

Aflatoxin contaminated groundnut image from IITA Image Library