Institute of Science in Society (ISIS)

Dr Mae-Wan Ho

A comparison of US Midwest non-GM with GM corn shows shockingly high levels of glyphosate as well as formaldehyde, and severely depleted of mineral nutrients in the GM corn.

The results of a comparison of GM and non-GM corn from adjacent Midwest fields in the US that first appeared on the Moms Across America March website [1] are reproduced in Table 1.

Table 1

*The GM corn was grown in a field that has been no-till, continuous GM corn (Roundup Ready) for 5-10 years and with a glyphosate herbicide weed control regime for all of the 10 years. The Non-GM corn has not had glyphosate (or Roundup) applied to the field for at least five years. The GM corn test weight was 57.5 lb; and non-GMCorn test weight 61.5 lb.

As Zen Honeycutt, who posted the report commented, glyphosate, shown to be toxic at 1 ppm, is present at 13 ppm in the GM corn. Similarly, formaldehyde at 200 ppm is 200 times the level known to be toxic in animals.

The GM corn was also severely depleted in essential minerals: 14 ppm vs 6 130 ppm calcium; 2 ppm vs 113 ppm of magnesium; 2 ppm vs 14 ppm of manganese 3 ppm vs 44 ppm of phosphate, 3 ppm vs 42 ppm of sulphur, and so on.

It is not surprising that this analysis has been carried out independently; i.e., not by biotech companies. It was done by farmers themselves. The high level of glyphosate is bad enough. Scientific evidence on glyphosate accumulated over three decades documents miscarriages, birth defects, carcinogenesis, endocrine disruption, DNA damage, neurotoxicity, and toxicity to liver and kidney at levels well below recommended agricultural use (see our recent review [2] Why Glyphosate Should Be Banned, SiS 56). The presence of formaldehyde – a genotoxic and neurotoxic poison at such enormous concentration – is totally unexpected.

Analysis obtained by Midwest farmers

Howard Vlieger, a crop nutrition advisor working with family farmers in 10 states across the US, who has been involved in the study and research of GMOs since 1996, explained in an interview [3] that people want “a side by side comparison” of the corn in the same soil conditions with the only difference being the application of glyphosate based herbicide on the GM Roundup Ready (RR) corn and a conventional herbicide on the non-GM corn. “This has not been done and cannot be done according to the technology agreement signed by a farmer planting GM seed without being at risk of being sued by the patent holder of the GM RR corn,” he said.

In this case, however, ears of corn from two adjacent corn fields in the Midwest, separated only by a fence, were sampled two weeks before harvest. The corn fields were selected by a third party and the samples collected in exactly the same manner. The separately bagged ears of corn were shelled from the cob and the grain samples sent to the lab for glyphosate testing. The non-GM corn field has not been sprayed with glyphosate for at least five years (see Table 1).

The samples were sent to a certified laboratory where it was prepared for testing on gas chromatography-mass spectrometry, an analytical method in which chemical compounds are first separated on a chromatographic column according to their size and charge and other chemical properties, and then ionized and identified based on mass to charge ratios. The RR corn tested contained 13 ppm glyphosate – coincidentally the EPA’s newly set legal limit of glyphosate in corn – while the other non-GM corn sample tested free of any glyphosate. The RR corn sample that tested positive for the glyphosate residue also tested positive for formaldehyde at a level of 200 ppm.

Where does the highly toxic formaldehyde come from?

Plant pathologist and retired Purdue University professor Don Huber, who has been sounding dire warnings on glyphosate poisoning crops, soil, livestock, and people (see [4] USDA Scientist Reveals All – Glyphosate Hazards to Crops, Soils, Animals, and Consumers, SiS 53), commented that formaldehyde can come from degradation of glyphosate [5]. But it can also come from normal plant 1-C metabolism, as for example, de-methylation of serine to glycine plus formaldehyde.

Formaldehyde does not exist in the free-state in a healthy normal plant. It is toxic compound that reacts with proteins, nucleic acids and lipids, and has been classified as a mutagen and suspected carcinogen [6]. Formaldehyde is also neurotoxic, and at ~100 ppm induced amyloid-like misfolding of tau protein, leading to the formation of protein aggregates similar to those found in Alzheimer’s disease; followed by programmed cell death of the neurons [7]. In normal cells and organisms, formaldehyde is detoxified by glutathione-dependent formaldehyde dehydrogenase (GDFDase) to formic acid [8]. GDFDase is dependent on zinc [9], and it is likely that the chelating action of glyphosate [4] may be responsible for inhibiting the enzyme’s activity by depriving it of zinc.

“Of course the scariest part of this is that any RR plant (corn, soybean, canola, cotton, sugar beet or alfalfa) that is sprayed with glyphosate could potentially produce formaldehyde … and then the formaldehyde would unknowingly end up in the feed and food supply.” Vlieger said [3].  The accumulation of formaldehyde was not due to any unusual environmental stress experienced by the GM corn.  “This corn was not raised in an area that was affected by the extreme drought conditions of 2012.”

He also told UK group GMWatch [10] that the glyphosate and formaldehyde could “explain the continuing problems we are witnessing in livestock operations with poor animal health when GMO feed stuffs are in the diet.”

Obviously, the analysis should be repeated on more samples of GM and non-GM corn grown side by side to see if these remarkable differences could be replicated. If so, we can only conclude that previous data submitted by and for the companies that found GM corn “substantially equivalent” to non-GM corn must have been fraudulent, and the perpetrators need to be brought to justice.


1. “Stunning corn comparison: GMO versus non GMO”, Zen Honeycutt, 15 March 2013, Moms  Across America March,

2. Sirinathsinghji E and Ho MW. Why glyphosate should be banned. Science in Society 56, 21-32, 2012.

3. “More info on 2012 corn comparison report 12 April 2013, Zen Honeycutt, Mom Across America March 4 July,

4. Sirinathsinghji E. USDA scientist reveals all, glyphosate hazards to crops, soils, animals and consumers. Science in Society 53, 36-39, 2012.

5. Huber D. Formaldehyde and glyphosate in corn. Powerpoint presentation, 2012.

6. IARC Monographs on the Evaluation of Carcinogenic Risk for Humans  62, Wood Dust and Formaldehyde, IARC, Lyon, 1995.

7. Nie CL, Wang XS, Liu Y, Perrett S and He RQ. Amyloid-like aggregates induced by formaldehyde promote apoptosis of neuronal cells BMC Neurosci 2007, 8, 9.

8. Achkor H, Diaz M, Fernandez MR, Biosca JA, Pares X and Martinez MC. Enhanced formaldehyde detoxification by overexpression of glutathione-dependent formaldehyde dehydrogenase from Arabidopsis. Plant Physiol 2003, 132, 2248-55.

9. Barber RD, Ott MA and Donohue TJ. Characterization of a glutathione-dependent formaldehyde dehydrogenase from Rhodobacter sphaeroides. J Bacteriol 1996, 178, 1386-93.

10. GMWatch Comment on 2012 corn comparison report. 19 April 2013,

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3 Responses to ““Stunning” Difference of GM from non-GM Corn”

  1. nedlud says:


    I grow open-pollinated corn. We have farmed ‘natural’ (no chemicals, using traditional methods of animal husbandry and field and farm care) for plus 30 years. Our dairy farm was ransacked and our family brutalized by Organic Valley/USDA executives and bureaucrats and we now live in deeper despair and poverty than we ever imagined possible 30+ years ago when we started. We thought people would wake up and would care. They do not. Assuredly, they do not. They chase the money ’round and ’round and ’round and drive their cars incessantly. The freeway and highways near here just hum in the background constantly and fill the air with pollution. And there is very little neighborliness left in this area, only a tiny vestige of what was once, beautiful and thriving.

    Anyway: I can report that wildlife KNOW the difference between natural corn and the gm exotic synthetic artificial. Wildlife species go after our corn with great gusto and leave the giant fields of gmo corn in the vicinity with little interest. A few birds will peck at the outer rows. That is about it. I have witnessed this now, for many years.


  2. Abe says:

    Barb Stunning doesn’t quite describe the truth. It’s more like getting hit in the back of the head with a spitball or a howitzer.
    But on the other side of the coin, the sleeping giant is waking up in the last week since Boston. Now it’s becoming mainstream that it was Craft International that blasted them poor souls in Boston. And guess what. They’re the same rats that did Sandyhook, Milwaukee, and Aurora! Oh yeah gunrunner, fast & furious, and wide receiver. The dots are so big they connect themselves. Why? Money & power. I think some one took to big of a bite and has just had there muzzle duct tape shut! People are finally starting to get it! Them rats incharge are murdering “We The People!” 237 years later it starts in Boston again! God Bless America and them 2 Chechin kids! al-CIA-duh, mossad, MI-5, and the rest of the alphabit groups are starting to unravel!!
    Finally the sleeping giant has waken up, and filled him with terrible resolve! No more eating, drinking, breathing, and being injected with poison!! Time for them worthless politicians to either jump on board and save there ass or get consumed by the worthless eaters!
    Barb You’ve been steadfast and true! Bless You!

  3. Karin says:

    Just gets worse all the time.

    So sick of this poison and no “federal” insight other than paid off agencies and politicians on both side of the aisle.

    Thanks Barb ( huge hug )