Maine Organic Farmers and Gardeners Association

How to Avoid Genetically Engineered Foods

By Jean English

As more crops become genetically engineered, more questions about the safety of those crops arise. Moving genes from species that never before crossed may, for example, hasten the development of resistance to Bacillus thuringiensis, a valuable biological insecticide for organic growers; may have deleterious effects on insect ecology and other aspects of the environment; may result in cross pollination with conventional and/or organic crops, putting growers at risk without their permission; or may affect human health in ways that haven’t even been considered yet. Proceeding with this unnatural type of breeding seems foolhardy, especially when alternative control methods are available.


One of the major concerns of organic growers is that engineering more and more crops to contain the Bacillus thuringinesis toxin will hasten the development of resistance to that pesticide, which is one of the most useful organic pesticides available. When applied only as needed, resistance builds extremely slowly. Companies that have developed corn, cotton, potato and other crops to contain the Bt toxin believe that leaving refuges or refugia – areas where the engineered crop is not planted and where any pests that develop resistance to the Bt toxin will breed with pests that aren’t resistant, thus diluting the resistance gene – will slow the development of resistance. But will refuges really do this? If so, how large should refuges be? Will growers really plant refuges?

Recently, the EPA has conditioned approval of Novartis Bt popcorn and AgrEvo’s Bt field corn on the establishment of large refuges – 40% if the refuge corn was to be sprayed with insecticides; 20 to 30% if the refuge corn was to be unsprayed. The refuges must be within 1500 to 2000 feet for field corn and 1-1/2 mile for popcorn. These requirements are close to those recommended by the Union of Concerned Scientists, which suggests that 50% of a farmer’s corn acreage be planted in non-Bt corn if insecticides are used; 25% if not. (1)

Fears of resistance are real. The diamondback moth already has evolved resistance to Bt in open-field populations. At least two different genetic and biochemical mechanisms were responsible for the resistance, unlike simpler patterns of resistance documented for some synthetic insecticides. (2) In January 1999, Monsanto announced that major producers of genetically engineered corn would require that farmers grow sizable areas of non-engineered corn. As we went to press, the EPA had not yet reviewed details of those agreements. (3)

Who will ensure that refuges are planted? According to author Michael Pollan, “While I was in Idaho and Washington State, I asked potato farmers to show me their refuges. This proved to be a joke. I guess that’s a refuge over there,’ one Washington farmer told me, pointing to a cornfield.” (4)

Effects on Ecosystems

Aggressively killing one pest often results in the proliferation of other pests, causing further imbalance in the ecosystem. Having the Bt toxin present in all parts of a crop throughout the growing season, for example, qualifies as aggressive killing and could affect predators, bees and other insects in agroecosystems.

In laboratory studies, for instance, when green lacewings fed on the Bt-toxin from transgenic organisms, their immature mortality was significantly higher (57%) than in the untreated control group (30%). Previous findings showed almost a doubling of the mortality rate in lacewing larvae that had eaten pests fed with Novartis Bt corn. Lacewing larvae are known for their appetite for aphids and other soft-bodied insects and play an important role in the equilibrium of insect populations. (5) These are not the only studies showing that genetically engineered crops can harm beneficial insects. Nick Birch and colleagues of the Scottish Crop Research Institute in Dundee, for instance, inserted a gene from the snowdrop into potatoes, enabling the tubers to make a lectin that would deter feeding by aphids. When aphids reared on these potatoes were fed to lady bugs, the females lived only half as long and produced more than twice the number of unhatched eggs as lady bugs fed normal aphids. (6)

Will bees be affected by engineered crops? Beekeepers in the United Kingdom say that genetically modified honey is being produced by default in Britain as bees come into contact with nectar and pollen from the 107 field crop trials of oilseed rape planted there. Humans could unwittingly be exposed to the engineered genes by consuming honey. The Advisory Committee on Novel Foods and Processes identified three ways in which transmission of pollen from engineered crops may harm consumers: (1) Bees could transport pollen, leading to contaminated hybrid crops containing toxins or allergens; (2) Toxin residues originating from engineered crops could be contained in honey; (3) Genes could be transferred from pollen (at up to 2% in honey) into the human gut. Many genetically engineered crop strains have an antibiotic marker gene that could lead to extra antibiotic resistance further up the food chain. “Honey bees are under enough stress as it is,” said Richard Jones, director of the International Bee Research Association. “New pressures on them are just not needed.” (7)

In the broader ecological realm, promoting genetically engineered crops will add to the problem of pest-susceptible monocultures. In Missouri, for example, the state’s worst outbreak ever of Sudden Death Syndrome afflicted soybean crops last summer. Some farm experts linked the problem to extensive plantings of Roundup-resistant soybeans, which comprised 80 to 90% of the soybeans planted in Boone County in 1998. “The handful of modified varieties offered by biotech companies will inevitably be more genetically uniform, hence more susceptible to unforeseen stress, than the plethora of classically bred varieties grown now.” (8) Transgenic soy represents approximately 50% of the soy planted in Argentina and 30% in the United States. (9) Likewise, in 1998, Bt cotton engineered by Monsanto accounted for over 20% of all cotton planted in the United States, while Bt maize developed by several companies grew in over 10% of America’s cornfields. (10)

Some entomologists worry that as more herbicide-resistant crops are planted, such as Roundup Ready corn and soybeans, these could “raise hell with monarchs,” as Dr. Chip Taylor says. Taylor is head of the University of Kansas entomology department and director of Monarch Watch, which is trying to conserve monarch butterflies. He and Dr. Len Wassenaar, an Environment Canada scientist, are afraid that widespread use of Roundup in such crops will drastically reduce populations of milkweed in Midwestern farmers’ fields, where about half of the monarchs that winter in Mexico originate. Taylor also worries that corn containing the Bt toxin could be “a very significant biotoxin for anything that’s within the shadow of that corn.” (11)

Cross Pollination of Adjacent Crops

Can Bt corn cross-pollinate an adjacent field of conventional corn? Evidence from Germany suggests that it can. On Oct. 12, Greenpeace published new evidence showing that a genetically engineered Novartis corn cross-pollinated an adjacent field of conventional corn in Germany. Corn cobs up to 10 meters from the field of engineered corn were taken by the Freiburger Institut fur Umweltchemie e.V. and analyzed by Gene-Scan for the foreign DNA of the Novartis corn. The rate of cross-pollination was around 5% at the field border, 0.2% at 5 meters, and 0.1% at 10 meters distance. This would be a concern for organic growers located near farms that might grow engineered corn. Steve Sprinkel of the Texas Organic Growers Association commented: “When such contamination impacts the organic integrity of the product produced on a certified organic farm, the grower and the provider of the seed that created the contamination should be held legally liable.” After the discovery in Germany, the Ministry of Agriculture in France recalled all of Novartis’ engineered corn. (12)

Last summer, Roundup-resistant engineered canola turned up in a northern Alberta farm where none was recently planted. The resistance appears to have been transferred through pollen movement from engineered canola. Aaron Mitchell, biotechnology manager for Monsanto in Saskatoon, said: “We always expected a level of natural outcross would occur within the species.” He suspected bees carried the pollen. Mitchell said he has promoted the importance of farmers talking to their neighbors about the varieties of canola they grow because of the possibility of cross pollination. (13)

Similarly, plant biologist Allison Snow of Ohio State has shown that engineered rape plants grown in a lab could cross with a weedy relative, Brassica rapa, and that the resulting hybrid weeds were just as strong as wild weeds. The laboratory hybrid has all the aggressiveness of the weed parents with weedkiller-resistance built in. Experiments have shown that oilseed rape pollen can reach weeds more than a mile away. (14) Back in the field, an experimental crop of engineered oilseed rape had to be destroyed in Britain last summer after it pollinated nearby plants. (15) Monsanto and Perryfields Holdings (a seed company) are now being prosecuted in Great Britain for failing to comply with distance requirements established for the experiment by the U.K. Environmental Protection Act. (16)

In another laboratory study, Joy Bergelson, a professor of ecology and evolution at the University of Chicago, studied Arabidopsis thaliana, a species commonly used in genetic research. When Arabidopsis was engineered to resist herbicides, it also developed a greater ability to pollinate other plants and pass the herbicide-resistance trait on, giving credence to the specter of “superweeds” populating ecosystems. (17)

What will happen if engineered crops cross with conventional crops? What are the implications for organic growers, for growers who want to save their own seed, for people with allergies?

Effects on Human Health

Will engineered crops result in the uptake of foreign DNA into our bodies when we eat them? If so, what are the effects of that DNA on our bodies? Experiments have shown that foreign DNA ingested with food survives the digestive process in mice and can reach their white blood cells, spleen, liver, brain cells and can cross the placenta and get into fetuses. (18, 19) Since the Bt toxin and other engineered chemicals have never been common ingredients in the human diet, we should find out how they affect our bodies before they hit the grocery shelves, not after. Commenting on the health effects of the Bt toxin present in the NewLeaf potato, Margaret Mellon of the Union of Concerned Scientists told Michael Pollan, “That research simply hasn’t been done.” (4)

Alternatives are Available

Many alternatives are available, not just to synthetic chemical pesticides, but to genetically engineered crops as well. Consider corn, for instance. At MOFGA’s Farmer to Farmer Conference in November 1998, Cooperative Extension Small Fruits and Vegetables Specialist David Handley outlined many environmentally sound methods for controlling corn pests. He told how to scout for borer damage on corn and when to spray Bt according to economic threshold levels. He told how to use trap counts to see if spraying is necessary for a second generation of borers. It is much more ecological and economical to scout and to use Bt only when – and if – it is needed, rather than have it present continuously. Handley also said that in New Hampshire, Dr. Otho Wells does not have to spray early corn if it’s protected by row covers. Although these row covers will cost growers $1500 per acre, they can be used on other crops later, reducing the cost, and they have the added benefit of pushing corn growth so that an earlier crop is produced that can capture more of the early-market, higher prices.

Regarding the corn earworm, Handley pointed out that this insect does not overwinter in Maine, that the pest generally comes with weather fronts from the south, but that when most of our weather comes from the northwest, it is not much of a problem. He talked about methods for monitoring to see if treatment is needed, and if it is, how a new type of backpack sprayer/applicator can be used to apply mineral or vegetable oil to the silks. He also said that after Hurricane Bob, which increased the population of earworms in Maine, some growers cut the top 2 inches off of their corn to eliminate the earworm damage, and the corn sold with no problem. In many cases, non-engineered crops are the crops of choice – of consumers’ choice – and are filling a market demand. In January 1999, for instance, the New South Wales Grains Board shipped the largest crop of canola ever to leave Australia. The crop went to oilseed crushing plants in Europe, which has become a major buyer of Australian canola because Australia is the only country to guarantee that its crop has not been genetically engineered. (20)

Bans and Labels

As consumers learn more about engineered crops, they are increasingly reacting against them – especially in Europe. For example, the British government has put a three-year moratorium on trials of plants modified to produce insecticides, as it fears that these crops could pose a threat to species that are not pests. (21)

Greece has banned the import and marketing of a genetically altered strain of rapeseed, and it voted against plans to give European Union-wide approval to genetically modified maize. “Our country voted against this product (maize) because of reservations about possible effects on the environment and public health,” Environment Minister Theodoros Koliopanos said. He added that developments in genetic engineering should be subject to exhaustive scientific research focused “with the greatest care on the possible negative effects on the environment and public health.” (22)

In August, the French government announced a partial moratorium on the introduction of genetically engineered crops for the next two years. No approvals would be given for the commercial-scale growth of oilseed rape or any other modified crop that poses the risk of gene transfer to related species. (23) Austria has also temporarily banned the growth of genetically engineered crops until more is known about their effects on the environment (24), and Luxembourg has a ban on genetically engineered plants. (25)

The European Commission Scientific Committee on Plants rejected authorization for an engineered potato because the possibility of the crop passing its genetically altered qualities – specifically its antibiotic resistance gene – to other species – including bacteria – had not been examined sufficiently. “Without an adequate risk assessment of the potential consequences of horizontal gene transfer from the genetically modified plants to humans, animals and the environment, the safety of the transgenic potato line cannot be fully assessed,” the scientists said. (26) Likewise, the European Parliament’s Environment Committee has called for a moratorium on new authorizations of genetically modified organisms for commercial purposes while the scientific issues are being clarified. (27)

The British government has banned genetically engineered foods from Palace of Westminster restaurants, and on September 16, 1998, education chiefs in Gloucestershire County (UK) banned genetically modified foods from school dinners in 200 schools so that children could stop being “human guinea pigs.” A similar ban was enacted by County Councilors in Warwickshire, England. Also, 19 of the top-rated 23 restaurants in Britain have joined the Friends of the Earth campaign by calling on the British government to impose a five-year ban on the use of genetically modified foods while those foods are tested for safety and while the public decides whether it wants the new technology.

Recombinant bovine growth hormone has been banned in the European Union until the end of 1999, and the Canadian government is expected to ban the product this June. India’s agriculture minister, Som Pal, has banned the import of seeds containing the terminator gene (a gene that prevents crops from producing seed, thus preventing farmers from saving and growing their own seed) because of potential harm to Indian agriculture. (28)

The US EPA is reconsidering its regulations for Bt plants over the next three years, according to Janet Andersen, director of the agency’s biopesticides division. (29)

Regarding labeling, health ministers in Australia ruled in December 1998 that all food containing genetically modified material must be labeled, where the manufacturer knows that the food contains such material. The law is to take effect this year (30), although the governments of Australia and New Zealand must decide first whether to accept the decision of the Australia New Zealand Food Standards Council and, if so, how to implement it (31). In the United States, Hain’s Foods has started labeling some of its products as free of genetically engineered organisms by putting a “Pure Food” insignia on its packages; the company is also putting out its message: “Just Say No to GEOs [Genetically Engineered Organisms]." (32)

Can You Trust Corporations’ Data?

In applying for registration for engineered products, companies submit data that they have generated themselves and that they think are pertinent to the application. These data can be incomplete, and Monsanto, one of the leading, so-called “life sciences” corporations, has a notorious history of suppressing evidence about its products’ problems. See, for instance, Brian Tokar’s expose of Monsanto in the latest issue of The Ecologist (which nearly didn’t reach the newsstands as the magazine’s printer was afraid of reprisal by Monsanto) (33) and stories about Canadian health officials receiving gag orders regarding their concerns about the safety of rBGH (34). In the United States, two investigative reports have accused Fox Television of succumbing to pressures from Monsanto after it lobbied to pull or heavily edit a story about recombinant bovine growth hormone. The reporters refused hush money and were fired last December. (35) Recent revelations that Monsanto may have concealed troubling rBGH safety tests on rats (rats fed high levels of rBGH showed damage to thyroid and prostate tissues – potential danger signals for cancer) from government regulators in the United States and Canada have led to renewed calls to have rBGH pulled from the market (36).

We already have more than enough pollution to clean up, much of it resulting from Monsanto’s “science,” which has given us Agent Orange, PCBs and other deadly chemicals. We already are leaving this overwhelming burden of chemical pollution to the next generations. Lets not add genetic pollution to that load.


1 The Gene Exchange, UCC; See also Now or Never: Serious New Plans to Save a Natural Pest Control, $14.95 plus $3 shipping/handling to UCS Pubs., 2 Brattle Sq., Cambridge MA 02238-9105; Tel. 617-547-5552.

2 "Global variation in the genetic and biochemical basis of diamondback moth resistance to Bacillus thuringiensis." Tabashnik, B.E., Liu, Y.B., Malvar, T., Heckel, D.G., Masson, L., Ballester, V., Granero, F., Mensura, J.L., and Ferre, J., Proc. Natl. Acad. Sci. USA, 94(24): 12780-5, Nov. 25, 1997. Dept. of Entomology, Univ. of Arizona, Tucson 85721;

3 Washington Post, Jan. 12, 1999

4 “Playing God in the Garden,” Michael Pollan, The New York Times Sunday Magazine, Oct. 25, 1998.

5 Hilbeck, A., Moar, W.J., Pusztai-Carey, M., Filippini, A., and Bigler, F., 1998, "Toxicity of Bacillus thuringiensis CrylAb Toxin to the Predator Chrysoperla cornea (Neuroptera: Chrysopidae)." Environmental Entomology, Vol. 27, no. 4, August. Hilbeck, A., Baumgartner, M., Fried, P.m. and Bigler, F., 1998, "Effects of transgenic Bacillus thuringiensis corn-fed prey on mortality and development time of immature Chrysoperla cornea (Neuroptera: Chrysopiae)." Environmental Entomology, Vol. 27, no. 2, p. 480-487.

6 New Scientist, Oct. 31, 1998.

7 Source: “Bees make honey from genetically altered crops,” by Alison Craig, The Independent (UK), Aug. 9, 1998.

8 New Scientist, Oct. 31, 1998

9 Journal Gazeta Mercantil (Brazil) Oct. 13, 1998

10 New Scientist, Oct. 31, 1998.

11 “Science Could Spell End of the Monarch: Genetically Altered Crops Could Eliminate Their Main Food Source,” by Margaret Munro, National Post (Canada), Dec. 22, 1998.

12 Genetic Engineering News, Richard Wolfson, Oct. 14, 1998. For more information, contact Charles Margulis, Greenpeace USA, Tel. 212-865-5645.

13 Source: “Canola Crossbreeds Create Tough Weed Problem,” by Mary MacArthur, Western Producer, Oct. 15, 1998.

14 “Genetic crops can aid superweeds, claim scientists,” Tim Radford, Science Editor, Guardian (London), Aug. 7, 1998, reporting on Snow’s presentation to the Ecological Society of America.

15 The Mail on Sunday, Oct 25, 1998 (UK)

16 The Independent (U.K.), Dec. 18, 1998.

17 Nature, Aug. 27, 1998

18 Doerfler, W., & Schubbert, R., “Uptake of foreign DNA from the environment: the gastrointestinal tract and the placenta as portals of entry,” Wien Klin Wochenschr, 110(2):40-4, Jan 30, 1998; Institut fur Genetik, Universitat zu Koln, Federal Republic of Germany.

19 Journal of molecular genetics and genetics, Vol. 242:495-504, 1994

20 Asia Pulse, Jan. 8, 1999

21 New Scientist, Oct. 31, 1998.

22 Reuters, Athens, Oct. 1998

23 Paris, Aug. 3, 1998, ENS

24 The Independent on Sunday, London, Sept. 6, 1998

25 New Scientist, Oct. 31, 1998

26 Reuters, Brussels, Oct. 8, 1998

27 Genetic Engineering News, Nov. 14, 1998, Richard Wolfson,

28 Genetic Engineering News, Oct. 1, 1998

29 New Scientist, Oct. 31, 1998

30 Australian Financial Review, Dec. 18, 1998

31 The Royal Society of New Zealand Science and Technology Alert, Dec. 23, 1998.

32 Biotech News, Jan. 9, 1999

33 The Ecologist, Vol. 28, No. 5, Sept./Oct. 1998. This special issue of The Ecologist was a response to Monsanto’s large-scale, Europe-wide advertising campaign, in which Monsanto tried to convince the European public that genetic engineering was safe and good for the world – especially for the poor, starving nations. The campaign essentially backfired. The Ecologist highlighted Monsanto’s track record of social and ecological irresponsibility and asked, “Should we allow such corporations to gamble with the very future of life on Earth?” For more information, visit The Ecologist’s website ( or call 510-527-3873.

34 Alive: Canadian Journal of Health and Nutrition, Oct. 1998 issue; 7436 Fraser Park Drive, Burnaby, BC, V5J 5B9

35 Lancet, Vol. 352, #9125, Aug. 1, 1998, p. 380

36 Food Bytes #13, Oct. 31, 1998, Ronnie Cummins,;

Much of the information for this article was taken from Genetic Engineering News, in which Richard Wolfson, Ph.D., compiles information from worldwide publications. Wolfson’s on-line Genetic Engineering News is available for $35 per year; contact him at Consumer Right to Know Campaign, for Mandatory Labelling and Long-term Testing of all Genetically Engineered Foods, 500 Wilbrod St., Ottawa, ON Canada KIN 6N2; Tel. 613-565-8517; fax 613-565-1596; email:; website:


How to Avoid Genetically Engineered Foods

The simplest ways to avoid genetically engineered foods are to buy certified organic foods and to grow your own crops from seeds that are known not to be engineered (or, in the future, contaminated by engineered crops). The following list of common foods that are engineered and are on the market shows why it is easier to take this positive approach than to avoid specific crops or ingredients.

Additives and enzymes – amylase, catalase and lactase may be genetically engineered. Engineered additives are in many processed foods, beer, “dough conditioner,” baby foods and other foods.

Aspartame – This artificial sweetener, aka Equal and NutraSweet, contains a genetically engineered enzyme. In addition, one of its breakdown products is the carcinogenic chemical, formaldehyde.

Baking powder – may contain genetically engineered additives or enzymes.

Corn – engineered to resist the herbicide Roundup; to contain a virus gene; and/or with bacterial DNA from Bacillus thuringiensis. Note that engineered corn can be used to make: corn syrup (found in many drinks and processed foods; fructose and fructose corn syrup may come from engineered corn);

corn chips;

corn starch, (which is even in some yogurts

and aspirin);

corn meal (in many processed products, cereals and chips);

corn oil

vitamin C

baking powder



soy sauce

powdered sugar

enriched flours and pastas

Cotton – engineered with bacteria and virus genes; engineered to tolerate the pesticide bromoxynil. Cotton seed oil is a common ingredient in processed foods, including some peanut butters, chips, etc.

Meat – unless certified organic, meat may come from animals that have been raised on genetically engineered grains.

Milk and dairy products, unless organically produced or from farms that have committed themselves to not injecting their cows with recombinant Bovine Growth Hormone, may come from such cows. (In Maine, Oakhurst, Grants and Houlton Farms Dairy are not selling milk from cows that have been treated with rBGH; and Kate’s butter and State of Maine cheese are from untreated cows.) Dairy cows may be fed genetically engineered grains. In addition, most non-organic cheese is made with chymosin, a genetically engineered rennet.

Potatoes – some are engineered with wax moth DNA or the DNA of Bacillus thuringiensis bacteria.

Rapeseed (Canola) – engineered with California bay turnip, virus and bacteria genes; engineered to resist herbicides. Canola oil is widely used in such processed foods as some chips, salad dressings, baked goods, margarine and soy cheese – and others.

Soybeans – engineered varieties may contain bacterial genes or genes altered to tolerate Roundup herbicide. Note that engineered soy can be widely used in:

soy burgers



infant formula and baby foods

many baked and processed foods;

tofu and tofu hot dogs;

soy milk;

ice cream;

pet food;

salad dressings;

snack chips;

soy sauce;

lecithin and soy lecithin;

soy oil

vitamin E

soy cheese

and thousands of other products. Between 60 and 70 percent of processed food contains soy.

Tomatoes – engineered varieties may contain genes from bacteria, viruses, flounder, and/or antibiotic marker genes; engineered tomatoes could be in canned tomatoes, catsup and tomato sauces.

Yellow crookneck squash – engineered varieties may contain virus genes; this squash is used in some baby foods.

Sources: Genetic Engineering News; “Shop to Avoid Biotech Foods,” by Richard Wolfson, Ph.D., Alive: Canadian Journal of Health and Nutrition, March 1997; “Biotech Food – What’s On Our Shelves,” by Richard Wolfson, Ph.D., Alive: Canadian Journal of Health and Nutrition, Nov. 1996; “What to Eat, How to Shop,” Mothers for Natural Law, website:; P.O. Box 1117, Fairfield IA 52556; Tel. 515-472-2809. (The sole focus of Mothers is genetic engineering; it has a petition that you can sign mandating labeling of engineered foods.) Patricia Dines, personal communication.


MOF&G Cover Spring 1999