When I first became aware of the notion of modifying food by inserting foreign genetic material, I inclined in favor of it. After all, changing the genes of a plant to cause it to yield more, resist pests, and altogether serve us better sounded like a pretty good idea. How attractive it must be to farmers that a GM seed should increase yields while providing its own internal pesticide. But at the same time, knowing how often well-intentioned quests to mold nature have gone seriously awry, I was hesitant to form an opinion before obtaining more facts.

Today the US seed industry is dominated by two multinational companies, Monsanto and DuPont. Those who buy GM seeds sign contracts establishing how and when the crop can be grown and excluding the right to save seed for the following year (even though many GM seeds are engineered to produce infertile plants).

These are the arguments often espoused in favor of GM foods:
  1. That both locally and world-wide, hunger will be abated by the higher yields of GM crops;
  2. That fewer pesticides are used on them;
  3. That safety assessments on them have been numerous and fair, and that results have been highly positive; and
  4. That seeds from GM crops will not blow into or otherwise accidentally pollinate, and contaminate, neighboring fields.
Let's briefly examine these points.

GM crop yields - After its review of two dozen academic studies of corn and soybeans in the US, the title of a report by the Union of Concerned Scientists was telling - Failure to Yield: Evaluating the Performance of Genetically Engineered Crops - It concluded that herbicide-tolerant soybeans and herbicide-tolerant ("Roundup ready") corn did not show increased yields while insect-resistant corn increased yields only marginally. Although yields in both crops have increased in the 13 years preceding the 2009 report, these scientists attributed the increases mainly to traditional breeding or improved agricultural methods. The report also describes how, in industry assessments of GM crop yields, they manipulate the data by conflating different measures of yield.

Pesticide use - A major component of GM crops is their resistance to herbicides, particularly to glyphosate, the active ingredient in Roundup and other herbicides. Herbicide resistance was intended to decrease the amounts of herbicides applied to fields, but the unintended effect is that farm acreage is being swallowed in an explosion of glyphosate-resistant super-weeds. This is occurring at an "exponential" rate on US farms and is increasingly being reported in countries following our lead. As early as 2003, the first comprehensive study of all major GM crops in the US over the their first eight years of commercial use found that the volume of pesticides applied to corn, soybean, and cotton had increased. A 2008 report confirmed that GM crops on the whole have caused an increase rather than a decrease in use of pesticides and in addition yield no more than conventional crops. In October 2011, a report from the environment editor of the Guardian charged that GM crops promote super-weeds that have become, like GM crops, "Roundup ready".

Safety assessments - Safety research has indeed been done and Monsanto is quick to allay your fears, but if you look beyond industry agitprop a different story emerges. The American Academy of Environmental Medicine cites several animal studies reporting such health risks associated with consumption of GM foods as infertility, immune disregulation, accelerated aging, and disregulation of genes associated with cholesterol, insulin, cell signaling, and protein formation. Also reported here are changes to liver, kidney, spleen, and the gastrointestinal system. Other scientific reports warning of health risks of GM foods are readily available. Keep in mind that the glyphosate in herbicide-resistant plants cannot be washed off; it is systemic to the plant. Also unknown is whether glyphosate accumulates in those who eat it.

Contamination of non-GM crops - Corn is pollinated by wind. If crop A is genetically modified and sits within a breeze's reach of organically certified crop B, crop B will be pollinated by crop A. And since to be labeled "organic" a crop must be free of GM material, that cross-pollination will imperil crop B's organic certification. In 2011, organic corn grown on a 300-acre farm in Iowa by Matthew Kraft tested positive for genetic contamination. Not only wind-pollinated crops are at risk, of course; pollination also occurs through insects, birds, and farmers.

The industry sues for "pollen drift". In 1999 Percy Schmeiser, a farmer in Saskatchewan, was sued by Monsanto for $145,000 because Monsanto's patented gene was found in the farmer's canola plants. Monsanto did not allege that Schmeiser had stolen the seed; it argued simply that plants on Schmeiser's land contained Monsanto's genes. A Canadian judge ruled in favor of Monsanto, writing that "the source of the Roundup-resistant canola . . . is really not significant". Others who have been or are liable to be sued for pollen drift have organized a class-action suit to fight Monsanto.

Thu far the European Union has been less industry-subservient; its regulations on GM foods and crops are the strictest on the planet. Not only is cultivation restricted but foods with GM ingredients must be labeled (unlike in the US). But cracks are developing. In 2010, the EU began permitting farmers to grow GM potatoes not meant for human consumption. European GM-restriction laws also contain a loophole: milk, meat, and eggs from animals fed GM feed need not be labeled. That loophole is being exploited to insert millions of tons of GM crops into the EU food supply without consumer awareness. Although multiple studies have shown that GM feed can affect the health of animals, no one knows how humans who consume milk, meat, and eggs of those animals will be affected. The pressure on EU countries to drop their resistance to GM foods is unrelenting, and Wikileaks has published evidence of US intent to punish their recalcitrance.

Okay, thus far the industry has not quite lived up to its promises. So what?

Don M. Huber is Professor Emeritus of Plant Pathology at Purdue University. With a background on soil-borne disease, microbial ecology, and host-parasite associations, he warns that damage from genetically engineered crops is expanding beyond what anyone knew.

Agriculture is a system that comprises plants, soil, soil microorganisms, and pests and diseases that, in a well-functioning system, are held in check. The quality of food is greatly dependent on the quality of the soil that nourishes it. Micronutrients in the soil enable roots to absorb nutrients. Dr. Huber reports that glyphosate is having a major effect on microbes in the soil.

Glyphosate leaches from herbicide-tolerant plants. Herbicides such as glyphosate are chelators. In chemistry, chelators are substances that bind with metals, preventing their interaction with surroundings; chelation is a way to remove heavy metals from the bloodstream. Herbicides and pesticides are specific chelators of copper, zinc, iron, and manganese. These metals are essential micronutrients for plants (as well as animals). Once chelated they are immobilized and no longer available to plants. Even herbicide-resistant plants are affected - the inserted gene stunts the plant's ability to absorb nutrients. According to Dr. Huber, the nutritional efficiency of GM plants is "profoundly compromised". In GM plants, iron, manganese, and zinc can be depleted by as much as 90 percent. When glyphosate is applied externally, the effect is compounded.

Bacteria in the intestines of animals and man are quite sensitive to glyphosate. When the balance of the "intestinal milieu" is disturbed, unhealthy organisms normally held in check will blossom. Botulism in dairy cows was once rare but is now becoming a common cause of death. Beneficial gut organisms are no longer capable of holding Clostridium botulinum in check. Ecology and physiology function best in balance; when balance is disturbed there are consequences. In the 15 or so years since GM foods were introduced and the floodgates opened (already GM is 86 percent of corn, 93 percent of soy, canola, and cottonseed oil, and 95 percent of sugar beets), food allergies have risen substantially. Correlation may not be causation, but then again it could be and is being investigated.

Now an alarming new aspect of GM has emerged. An unknown and unclassified micro-fungal organism inhabits GE feed. The organism, which is not fungus, bacteria, mycoplasma, or virus, was first identified by veterinarians around 1998 - two years after soybeans, one of the staple livestock feeds, were introduced as "Roundup ready". The veterinarians had been investigating in livestock a sudden high rate of infertility and spontaneous abortion. The organism is also associated with a condition in soy called Sudden Death Syndrome. They detected this organism, which in size is similar to a small virus. When cultured alone it does not survive well, but in combination with yeast, bacteria, or fungus it grows heartily. What this organism is and what it does still remain largely a mystery.

Dr. Huber wrote to USDA Secretary Tom Vilsack, urging him to postpone approval of genetically engineered alfalfa until more research is done, but GE alfalfa was approved early in 2011.

As severe droughts become more common on the warming planet, pressure to believe the industry on another point, that GM crops can be engineered to use less water, will increase. The first drought-resistant GM crop that Monsanto wants approved is another variety of patented corn. Monsanto is pressuring for approval with the cooperation of the Obama administration, but the USDA has denied that this new variety of corn works as well to resist drought as many natural corn varieties already available. Despite its own objection the USDA does deem the crop safe for the environment and for humans, although it has never been tested on humans.

An oft-cited example of GM benefit is the case of the European corn borer, a persistent pest that is thwarted by GM corn. When females lay their eggs there, emerging larvae feed and in short order die. This is an attractive result. However, in just three months animals fed on GM maize show signs of liver and kidney damage. This information came from Monsanto itself when opposition groups forced it to release raw data on its tests of three strains of GM corn, two of which contain the genes that kill corn-borer larvae.

I will end with an interesting fact. Monsanto employees will not have GM foods served in their cafeterias. The company confirms that it is following their wishes, as it "believes in choice". It is interesting that Monsanto is open to choice with its employees while striving to abolish choice, and maybe much more, in its customers.

About the author

Dr. Dial is a psychologist and medical illustrator who for well over a decade has worked as a freelance medical writer and editor. She has recently made contributions to encyclopedias of medicine (Magill's Medical Guide, 6th edition), genetics (Genetics and Inherited Disorders, revised edition, Salem Press), and forensic sculpture and handwriting analysis (Salem Encyclopedia of Forensic Science). She has published articles on such subjects as the interaction of cocaine and alcohol, how cancer interacts with its host, and creativity, and written a book (For the Health of It: Preventive Breast Care). Her wide-ranging interests unfortunately cannot exclude alarmed observations of current political and environmental calamities.