Reviewed by Heidi Boudro
If you buy your food at supermarkets or restaurants, you eat genetically engineered food; an estimated 60% to 70% of processed food sold in the United States contains genetically modified ingredients. In the U.S., 89% of soy and 60% of corn is genetically modified. Soy appears in your food as soy flour, oil, protein, and dozens of additives; corn as cornmeal, oil, corn syrup (used almost universally in place of sugar, such as in soda pop), and dozens of additives. U.S. genetically modified (GM) crops are: soy, cotton, canola, corn, papaya, alfalfa, zucchini, yellow squash, and tobacco. The GM foods are unlabeled; the only way to avoid them is to buy organic food.
In no case were the crops engineered for better nutrition, taste, or yield. Most varieties were created to tolerate herbicide--to survive a lethal dose of the seed manufacturer's proprietary herbicide, which the farmer is required to buy along with the seed--and/or to manufacture its own pesticide. (Less than 1% of GM crops--zucchini, squash, and papaya--are modified for virus resistance.)
Are these crops safe to eat?
According to Genetic Roulette: The Documented Health Risks of Genetically Engineered Foods, by Jeffrey M. Smith, "By the beginning of 2007, there were just over 20 peer-reviewed animal feeding safety studies on GM crops. Only a single human feeding trial has been published." As documented in Genetic Roulette, the animal studies unambiguously demonstrate damage--stunting, infant mortality, precancerous changes, asthma--in their subjects.
But perhaps the most frightening aspect of GM food is the potential to spread unwanted genetic material, through genetic exchange, into the human body. Genetic exchange is common in bacteria. (The phenomenon may account in part for the mutations of disease-causing pathogens.) In humans, beneficial, symbiotic gut bacteria help digest food and produce nutrients, and exist naturally in the trillions in the digestive system. Irreversible contamination of human gut bacteria, through genetic exchange or other mechanisms, could have severe consequences, from poisoning and allergic reactions to antibiotic-resistant epidemics.
The only GM feeding study on humans examined the contents of ileostomy bags in seven volunteers. Genes from Monsanto's Roundup Ready soy--an herbicide tolerant (HT) crop widely grown in the United States--were found, by PCR (used for DNA testing), to have transferred into the genes of human gut bacteria in three of the subjects. The genetic material--three different genetic sequences from Roundup Ready soy--that was found in the gut bacteria included the gene for herbicide tolerance (along with a petunia gene and the cauliflower mosaic virus "promoter," which is used in genetic engineering to "switch on genes"). When cultured, the bacteria survived Roundup herbicide. But the researchers were not even able to identify the species of the affected gut bacteria.
In Bayer's Liberty Link crops, also herbicide tolerant, the plant produces an enzyme that converts Liberty herbicide (glufosinate ammonium) into a form called N-acetyl-L-glufosinate (NAG). NAG accumulates within the plant and is eaten when the crops are eaten as food. Yet studies showed that when rats and goats were fed NAG, their gut bacteria converted some of the NAG back into herbicide. The animals displayed the effects of herbicide poisoning, excreted some of the herbicide, and stored the rest of the herbicide in fat, milk, and internal organs.
Genetically modified Bt corn corn that in every cell produces the highly allergenic natural pesticide Bt-toxin, is also grown in the United States. Genetic Roulette quotes biochemist and genetic engineering safety expert Susan Bardocz on the likelihood that Bt-producing genes could transfer into gut bacteria and "convert us and our animals into pesticide factories."
Furthermore, most GM foods, in every cell, contain genes that confer antibiotic resistance--a byproduct of the genetic engineering process. It is known that antibiotic resistance genes can transfer to oral bacteria and to soil microorganisms. It is perhaps only a matter of time for antibiotic resistance genes to spread to gut bacteria or pathogenic bacteria.
Meanwhile, GM crops distribute their genes to non-GM crops at an unknown rate through pollination. In 2000, Aventis's StarLink, a variety of Bt corn unapproved for human consumption, was detected in brand-name supermarket foods and, despite being grown on less than 1% of corn acreage, in 22% of the corn samples tested. An article in Fortune (July 9, 2007) describes how, in 2006, separate strains of unapproved Liberty Link rice were found to contaminate commercial rice in five rice-growing states, U.S. rice exports (refused by Europe and Japan), two major seed stocks (now banned), and supermarket foods (eaten by you). In 2007, in a move that does not inspire confidence, the USDA approved field trials of rice genetically engineered to produce pharmaceuticals.
In a situation created by the FDA, the current human feeding study on genetically engineered food is YOU. You receive no benefits from GM food, but you bear all its risks. For more information see the Institute for Responsible Technology.
Copyright © 2008 by Heidi Boudro