3.7—High-lysine corn shown to be superior to conventional

High-lysine corn has been shown to be superior to conventional corn in supporting growth and development.

See Genetic Roulette’s False Claims at Bottom of Page

Analysis of Peer-Reviewed Research:

Genetic Roulette claims high-lysine corn is dangerously toxic while animal scientists have demonstrated that it is safe and more nutritious than conventional corn for animals.  Based on bad data analysis, Jeffrey Smith tries to argue that high-lysine corn doesn’t work because animals don’t grow as well.  It sort of defies explanation then that farmers are willing to pay extra for a corn on which their animals don’t grow well.  The corn is not intended for human use but has been approved as a human food—that is to say regulators find it as safe as any other corn.  A key fallacy in Smith’s argument is the highly improbable assumption that 100 percent of the corn supply might be high-lysine corn.  Experts have concluded that even if that were true, no ill effects would be observed—remember that we eat many foods that contain more of the ”toxic” compounds that Smith tries to scare us about.

1.  High-lysine corn has been adopted as an animal feed around the globe but it is not being used as human food. Animals such as chickens require lysine in their diets. A corn-based diet doesn’t provide enough lysine so growers are forced to supplement diets with lysine, and that adds to production costs.  Monsanto developed a high-lysine corn to replace the need for lysine supplementation.  The actual increase in lysine content is very small (about 40 percent) since not much additional lysine is needed to ensure good growth (FDA 2005, Chassy and others 2008).  Conventional varieties of corn are sometimes found to have more lysine than bioengineered corn (Chassy and others 2008, CIMMYT – Future Harvest 2000).  Another way to say this is that the amount of lysine in high-lysine corn is within the range typically observed for lysine in corn (FDA 2005).  The value is that high-lysine corn consistently supplies more lysine than average corn.

2. Extensive animal studies have demonstrated that high-lysine corn supports growth and development of production animals as well as, or better than, conventional corn plus lysine supplement. Genetic Roulette claims that significantly less growth of chickens is observed when fed high-lysine corn.  What Smith doesn’t tell the reader is that Jack Heinemann (representing an anti-GM lobby group called the New Zealand Institute of Gene Ecology) pooled together unrelated data from different experiments to perform an invalid statistical comparison in order to make this claim.  Studies published in the peer-reviewed scientific literature, as well as those supplied to regulators by the developers, consistently show that high-lysine corn is as effective in supporting growth as are lysine supplements (Chassy and others 2008).  Once again, the real-world experience of using high-lysine corn in the production of millions of animals has demonstrated that the product works.

3.  Although it is approved as a human food, high-lysine corn is grown as a specialty crop for animal feed. In the U.S., about 1 percent of all corn is consumed as whole corn or products containing whole corn.  The great majority of corn is fed to animals as whole grain, milled grain, and as corn gluten meal.  Cornstarch and corn oil, products that don’t contain DNA or protein, are the major human food uses of corn.  Let’s put this in perspective, humans consume a tiny amount of whole corn and high-lysine corn is intended for 100-percent animal consumption.  Even if small amounts of high-lysine corn entered the food system, would it be reasonable to conclude as Smith does that this would represent a “huge exposure to an unusual protein?” No.

4.  High lysine corn was approved for human food use because it poses no greater risks than other foods that we routinely consume.  As noted previously, the amount of lysine found in high-lysine corn is within the range normally observed for corn. (The actual amount of lysine is far less than we consume in other foods—in fact, corn is not a major source of lysine for U.S. consumers (FDA 2005, Chassy and others 2008).  Not surprisingly, when a corn plant produces more lysine, it also produces more of the compounds that lysine is synthesized from in the cells, and more of the products that are formed when lysine is broken down.  This is to be expected.  These same metabolites are actually found in much higher concentrations in foods that are more frequently eaten than field corn (Chassy and others 2008).  In spite of the inflammatory claim that “Toxic components could be increased,” regulators in many countries compared the increased levels to those normally found in the diet and concluded that there was no cause for concern (FDA 2005).  Once again, we have millions of animals being produced using high-lysine corn—and farmers haven’t seen any toxic effects.

5.  Genetic Roulette greatly exaggerates the potential consumption of high-lysine corn. In the real world farmers pay more for high-lysine corn seeds than they do for other GM seeds or conventional seeds.  They do this because the supplement saves them money when used as animal feed.  They will want to use all of their more expensive high-lysine corn as animal feed.  Small amounts may find their way into the human food system and it will be as safe as any corn that has similar amounts of lysine—a common occurrence since the levels of lysine in high-lysine corn aren’t elevated by much.  Humans eat very little whole corn, and very, very little of that will be high-lysine corn.  Smith says nothing, or knows nothing, about the fact that we are routinely exposed to much higher levels of what he calls toxic compounds in other foods.  Toxicity is all about dose.  Maybe at very high levels these compounds could be toxic but they are not toxic at the levels at which they are found in the diet.  In fact, animals (and humans for that matter) normally ingest much larger amounts of compounds related to lysine in the diet than would be contributed by high-lysine corn.  Remember, however, that this corn is cultivated for animals, not humans.  Shakespeare would have called this claim “much ado about nothing.”

See also: Food Safety: Focus on Real Risks, Not Fake Ones


Chassy B, Egnin M, Gao Y, Glenn K, Kleter GA, Nestel P, Newell-McGloughlin M, Phipps RH, and Shillito R  (2008). Recent Developments in the Safety and Nutritional Assessment of Nutritionally Improved Foods and Feeds, Comprehensive Reviews in Food Science and Food Safety 7 (1), 50–113 (www.blackwell-synergy.com/doi/abs/10.1111/j.1541-4337.2007.00029_1.x)  See Chapter on Lysine Maize.

CIMMYT – Future Harvest (2000). 35 years in the making, high-protein, high-yielding cprn to prevent malnutrition among millions. www.cimmyt.cgiar.org/research/maize/world_food_prize_qpm/qpm_wfp.htm accessed Jan 10 2009. “The new corn—known as maize outside North America—contains nearly twice as much usable protein as other maize grown in the tropics and yields 10 percent more grain. In recognition of this work…A bumper crop of the maize—called “quality protein maize” or QPM—is expected in the coming months from more than one million hectares (2.5 million acres) currently under cultivation in 11 countries…The varieties produce 70-100 percent more of two essential amino acids—lysine and tryptophan—than the most modern varieties of tropical maize. Amino acids are the building blocks of proteins, which are needed by all cells in the body. But because most maize is deficient in lysine and tryptophan, maize-dependent diets can lead to malnutrition. “

FDA_CFSAN. Biotechnology Consultation Note to the File BNF No. 000087.  Sept 30. 2005.


Genetic Roulette Falsely Claims: High-lysine corn contains increased toxins and may retard growth

  1. Monsanto produced corn with higher levels of lysine.
  2. If consumed in high quantities, the elevated lysine may adversely affect human health in unpredictable ways.
  3. The corn also contains increased amounts of known toxins and other potentially harmful substances.