Science Review Letters

Letter # 157

The Full Catastrophe Of Agrobiotechnology, Genetically Modified (GM) Foods, Genetically Modified Organisms (GMOs) - Part II

Abstract: Bt cotton triggers allergic reactions - Bt corn pollen may cause allergies - Studies show immune responses to GM crops

More scientific research on Genetically Engineered Corn show that it triggers allergic reactions and may cause allergies. Studies show immune responses to GM crops.

„The biotech industry is fond of saying that they offer genetically modified (GM) crops that resist pests. This might conjure up the image of insects staying away from GM crop fields. But "resisting pests" is just a euphemism for contains its own built-in pesticide. When bugs take a bite of the GM plant, the toxin splits open their stomach and kills them. The idea that we consume that same toxic pesticide in every bite is hardly appetizing. But the biotech companies and the Environmental Protection Agency—which regulates plant produced pesticides—tell us not to worry. They contend that the pesticide called Bt (Bacillus thuringiensis) is produced naturally from a soil bacterium and has a history of safe use. Organic farmers, for example, have used solutions containing the natural bacteria for years as a method of insect control. Genetic engineers simply remove the gene that produces the Bt in bacteria and then insert it into the DNA of corn and cotton plants, so that the plant does the work, not the farmer. Moreover, they say that Bt-toxin is quickly destroyed in our stomach; and even if it survived, since humans and other mammals have no receptors for the toxin, it would not interact with us in any case. These arguments, however, are just that—unsupported assumptions. Research tells a different story. Bt spray is dangerous to humans When natural Bt was sprayed over areas around Vancouver and Washington State to fight gypsy moths, about 500 people reported reactions—mostly allergy or flu-like symptoms. Six people had to go to the emergency room for allergies or asthma.[1],[2] Workers who applied Bt sprays reported eye, nose, throat, and respiratory irritation,[3] and some showed an antibody immune response in linked to Bt.[4] Farmers exposed to liquid Bt formulations had reactions including infection, an ulcer on the cornea,[5] skin irritation, burning, swelling, and redness.[6] One woman who was accidentally sprayed with Bt also developed fever, altered consciousness, and seizures.[7] In fact, authorities have long acknowledged that "People with compromised immune systems or preexisting allergies may be particularly susceptible to the effects of Bt."[8] The Oregon Health Division advises that  "individuals with . . . physician-diagnosed causes of severe immune disorders may consider leaving the area during the actual spraying."[9] A spray manufacturer warns, "Repeated exposure via inhalation can result in sensitization and allergic response in hypersensitive individuals."[10] So much for the contention that Bt does not interact with humans. As for being thoroughly destroyed in the digestive system, mouse studies disproved this as well. Mice fed Bt-toxin showed significant immune responses—as potent as cholera toxin. In addition, the Bt caused their immune system to become sensitive to formerly harmless compounds This suggests that exposure might make a person allergic to a wide range of substances.[11],[12] The EPA’s own expert advisors said that the mouse and farm worker studies above "suggest that Bt proteins could act as antigenic and allergenic sources."[13]The toxin in GM plants is more dangerous than natural sprays. The Bt-toxin produced in GM crops is "vastly different  from the bacterial [Bt-toxins] used in organic and traditional farming and forestry."[14] First of all, GM plants produce about 3,000-5,000 times the amount of toxin as the sprays. And the spray form is broken down within a few days to two weeks by sunlight,[15] high temperatures, or substances on the leaves of plants; and it can be "washed from leaves into the soil by rainfall,"[16] or rinsed by consumers. A Bt producing GM plant, on the other hand, continuously produces the toxin in every cell where it does not dissipate by weather and cannot be washed off. The natural toxic produced in bacteria is inactive until it gets inside the alkaline digestive tract of an insect. Once inside, a "safety catch" is removed and the Bt becomes toxic. But scientists change the sequence the Bt gene before inserting it into GM plants. The Bt toxin it produces usually comes without the safety catch. The plant-produced Bt toxin is always active and more likely to trigger an immune response than the natural variety.[17] Bt-toxin fails safety studies but is used nonetheless. Tests cannot verify that a GM protein introduced into the food supply for the first time will not cause allergies in some people. The World Health Organization (WHO) and UN Food and Agriculture Organization (FAO) offer criteria designed to reduce the likelihood that allergenic GM crops are approved.[18] They suggest examining a protein for 1) similarity of its amino acid sequence to known allergens, 2) digestive stability and 3) heat stability. These properties aren’t predictive of allergenicity, but their presence, according to experts, should be sufficient to reject the GM crop or at least require more testing. The Bt-toxin produced in GM corn fails all three criteria. For example, the specific Bt-toxin found in Monsanto’s Yield Guard and Syngenta’s Bt 11 corn varieties is called Cry1AB. In 1998, an FDA researcher discovered that Cry1Ab shared a sequence of 9-12 amino acids with vitellogenin, an egg yolk allergen. The study concluded that "the similarity . . . might be sufficient to warrant additional evaluation."[19] No additional evaluation took place.[20] Cry1Ab is also very resistant to digestion and heat.[21] It is nearly as stable as the type of Bt-toxin produced by StarLink corn. StarLink was a GM variety not approved for human consumption because experts believed that its highly stable protein might trigger allergies.[22] Although it was grown for use in animal feed, it contaminated the US food supply in 2000. Thousands of consumers complained to food manufacturers about possible reactions and over 300 items were subject to recall. After the StarLink incident, expert advisors to the EPA had called for "surveillance and clinical assessment of exposed individuals" to "confirm the allergenicity of Bt products."[23] Again, no such  monitoring has taken place.

Bt Cotton Triggers Allergic Reactions

A 2005 report by medical investigators in India describes an ominous finding. Hundreds of agricultural workers are developing moderate or severe allergic reactions when exposed to Bt cotton. This includes those picking cotton, loading it, cleaning it, or even leaning against it. Some at a ginning factory must take antihistamines daily, in order to go to work. Reactions are only triggered with the Bt varieties.[24] Furthermore, the symptoms are virtually identical to those described by the 500 people in Vancouver and Washington who were sprayed with Bt. Only "exacerbations of asthma" were in one list and not the other (see table).
                              Upper respiratoryEyesSkinOverall
                              Bt SpraySneezing,
                              runny nose,
                              exacerbations of asthmaWatery,
                              redItching, burning, inflammation, red,
                              some in hospital
                              Bt cottonSneezing,
                              runny noseWatery,
                              redItching, burning, eruptions,
                              red, swellingFever,
                              some in hospital

(We are unaware of similar reports in the US, where 83% of the cotton is Bt. But in the US, cotton is harvested by machine, not by hand.) The experience of the Indian workers begs the question, "How long does the Bt-toxin stay active in the cotton?"  Is there any risk using cotton diapers, tampons, or bandages? In the latter case, if the Bt-toxin interfered with healing it could be a disaster. With diabetics, for example, unhealed wounds may be cause for amputation. Cottonseed is also used for cottonseed oil—used in many processed foods in the US. The normal methods used to extract oil likely destroy the toxin, although cold pressed oil may still retain some of it. Other parts of the cotton plant, however, are routinely used as animal feed. The next part of this series—focused on toxicity—presents evidence of disease and deaths associated with animals consuming Bt cotton plants.

Bt Corn Pollen May Cause Allergies

Bt-toxin is produced in GM corn and can be eaten intact. It is also in pollen, which can be breathed in. In 2003, during the time when an adjacent Bt cornfield was pollinating, virtually an entire Filipino village of about 100 people were stricken by a disease. The symptoms included headaches, dizziness, extreme stomach pain, vomiting, chest pains, fever and allergies, as well as respiratory, intestinal, and skin reactions. The symptoms appeared first in those living closest to the field, and then progressed to others by proximity. Blood samples from 39 individuals showed antibodies in response to Bt-toxin; this supports, but does not prove a link to the symptoms. When the same corn was planted in four other villages the following year, however, the symptoms returned in all four areas—only during the time of pollination. The potential dangers of breathing GM pollen had been identified in a letter to the US FDA in 1998 by the UK Joint Food Safety and Standards Group. They had even warned that genes from inhaled pollen might transfer into the DNA of bacteria in the respiratory system.[25] Although no studies were done to verify this risk, years later UK scientists confirmed that after consuming GM soybeans, the foreign inserted genes can transfer into the DNA of gut bacteria. If this also happens with Bt genes, than years after we decide to stop eating GM corn chips, our own gut bacteria may continue to produce Bt-toxin within our intestines.

Studies Show Immune Responses To GM Crops

Studies confirm that several GM crops engineered to produce built-in pesticides provoke immune responses in animals. A Monsanto rat study on Bt corn (Mon 863), that was made public due to a lawsuit, showed a significant increase in three types of blood cells related to the immune system: basophils, lymphocytes, and total white cell counts.[26]  Australian scientists took an insecticide producing gene (not Bt) from a kidney bean and put it into a pea, in hopes of killing the pea weevil. The peas had passed the tests normally used to approve GM crops and were on the way to being commercialized. But the developers decided to employ a mouse study that had never before been used on other GM food crops. When they tested the pesticide in its natural state, i.e. the version produced within kidney beans, the protein was not harmful to mice. But that "same" protein, when produced by the kidney bean gene that was inserted into pea DNA, triggered inflammatory responses in the mice, suggesting that it would cause allergies in humans. Somehow, the protein had been changed from harmless to potentially deadly, just by being created in a different plant. Scientists believe that subtle, unpredicted changes in the pattern of sugar molecules that were attached to the protein were the cause of the problem. These types of subtle changes are not routinely analyzed in GM crops on the market. Experimental potatoes engineered with a third type of insecticide caused immune damage to rats.[27] Blood tests showed that their immune responses were more sluggish, and organs associated with immune function also appeared to be damaged. As with the peas, the insecticide in its natural state was harmless to the rats. The cause of the health problems was therefore due to some unpredicted change brought about by the genetic engineering process. And like the peas, if the potatoes had been subjected to only the type of tests that are  typically used by biotech companies to get their foods on the market, the potatoes would have been approved. Allergic reactions are a defensive, often harmful immune system response to an external irritant. The body interprets something as foreign, different and offensive, and reacts accordingly. All GM foods, by definition, have something foreign and different. According to GM food safety expert Arpad Pusztai, "A consistent feature of all the studies done, published or unpublished, . . . indicates major problems with changes in the immune status of animals fed on various GM crops/foods." [28] In addition to immune responses, several studies and reports from the field provide evidence that GM foods are toxic. In the next article in this series, we look at thousands of sick, sterile and dead animals, linked to consumption of GM crops". (NL Spilling the Beans, June 2007)

[1] Washington State Department of Health, "Report of health surveillance activities: Asian gypsy moth control program," (Olympia, WA: Washington State Dept. of Health, 1993).
[2] M. Green, et al., "Public health implications of the microbial pesticide Bacillus thuringiensis: An epidemiological study, Oregon, 1985-86," Amer. J. Public    Health 80, no. 7(1990): 848–852.
[3] M.A. Noble, P.D. Riben, and G. J. Cook,  "Microbiological and epidemiological surveillance program to monitor the health effects of Foray 48B BTK spray" (Vancouver, B.C.: Ministry of Forests, Province of British Columbi, Sep. 30, 1992).
[4] A. Edamura, MD, "Affidavit of the Federal Court of Canada, Trial Division. Dale Edwards and Citizens Against Aerial Spraying vs. Her Majesty the Queen, Represented by the Minister of Agriculture," (May 6, 1993); as reported in Carrie Swadener, "Bacillus thuringiensis (B.t.)," Journal of Pesticide Reform, 14,  no, 3 (Fall 1994).
[5] J. R. Samples, and H. Buettner, "Ocular infection caused by a biological insecticide," J. Infectious Dis. 148, no. 3 (1983): 614; as reported in Carrie Swadener,   "Bacillus thuringiensis (B.t.)", Journal of Pesticide Reform 14, no. 3 (Fall 1994)
[6] M. Green, et al., "Public health implications of the microbial pesticide Bacillus thuringiensis: An epidemiological study, Oregon, 1985-86," Amer. J. Public  Health, 80, no. 7 (1990): 848–852.
[7] A. Edamura, MD, "Affidavit of the Federal Court of Canada, Trial Division. Dale Edwards and Citizens Against Aerial Spraying vs. Her Majesty the Queen,    Represented by the Minister of Agriculture," (May 6, 1993); as reported in Carrie Swadener, "Bacillus thuringiensis (B.t.)," Journal of Pesticide Reform, 14, no, 3 (Fall 1994).
[8] Carrie Swadener, "Bacillus thuringiensis (B.t.),"  Journal of Pesticide Reform 14, no. 3 (Fall 1994).
[9] Health effects of B.t.: Report of surveillance in Oregon, 1985-87. Precautions to minimize your exposure (Salem, OR: Oregon Departmentof Human Resources, Health Division, April 18, 1991).
[10] Material Safety Data Sheet for Foray 48B Flowable Concentrate (Danbury, CT: Novo Nordisk, February, 1991).
[11] Vazquez et al, "Intragastric and intraperitoneal administration of Cry1Ac protoxin from Bacillus  thuringiensis induces systemic and mucosal antibody     responses in mice," Life Sciences, 64, no. 21 (1999): 1897–1912; Vazquez et al, "Characterization of the  mucosal and systemic immune response induced by Cry1Ac protein from Bacillus thuringiensis HD 73 in mice," Brazilian Journal of Medical and Biological Research 33  (2000): 147–155.
[12] Vazquez et al, "Bacillus thuringiensis Cry1Ac protoxin is a potent systemic and mucosal adjuvant," Scandanavian Journal of Immunology 49 (1999): 578–584. See also Vazquez-Padron et al., 147 (2000b).
[13] EPA Scientific Advisory Panel, "Bt Plant-Pesticides Risk and Benefits Assessments," March 12, 2001: 76.  Available
[14] Terje Traavik and Jack Heinemann, "Genetic Engineering and Omitted Health Research: Still No  Answers to Ageing Questions, 2006. Cited in their quote    was: G. Stotzky, "Release, persistence, and biological  activity in soil of insecticidal proteins from Bacillus thuringiensis," found in Deborah K. Letourneau and Beth  E. Burrows, Genetically Engineered Organisms. Assessing Environmental and Human Health Effects (cBoca Raton, FL:  CRC Press LLC, 2002), 187–222.
[15] C. M. Ignoffo, and C. Garcial,  "UV-photoinactivation of cells and spores of Bacillus thuringiensis and effects of peroxidase on inactivation," Environmental Entomology 7 (1978): 270–272.
[16] BT: An Alternative to Chemical Pesticides, Environmental Protection Division, Ministry of Environment, Government of British Columbia, Canada,  
[17] See for example, A. Dutton, H. Klein, J. Romeis, and F. Bigler, "Uptake of Bt-toxin by herbivores feeding  on transgenic maize and consequences for the predator Chrysoperia carnea," Ecological Entomology 27 (2002): 441–7; and J. Romeis, A. Dutton, and F. Bigler,  "Bacillus thuringiensis toxin (Cry1Ab) has no direct effect on larvae of the green lacewing Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae)," Journal of Insect Physiology 50, no. 2–3 (2004): 175–183.
[18] FAO-WHO, "Evaluation of Allergenicity of Genetically Modified Foods. Report of a Joint FAO/WHO  Expert Consultation on Allergenicity of Foods Derived    from Biotechnology," Jan. 22–25, 2001;
[19] Gendel, "The use of amino acid sequence alignments to assess potential allergenicity of proteins used in genetically modified foods," Advances in Food and  Nutrition Research 42 (1998), 45–62.
[20] US EPA, "Biopesticides Registration Action Document  (BRAD)—Bacillus thuringiensis Plant-Incorporated Protectants: Product Characterization & Human Health Assessment," EPA BRAD (2001b) (October 15, 2001): IIB4,
[21] ibd.
[22] "Assessment of Additional Scientific Information Concerning StarLink Corn," FIFRA Scientific Advisory Panel Report No. 2001-09, July 2001.
[23] EPA Scientific Advisory Panel, "Bt Plant-Pesticides Risk and Benefits Assessments," March 12, 2001: 76. Available at:
[24] Ashish Gupta et. al., "Impact of Bt Cotton on  Farmers’ Health (in Barwani and Dhar District of Madhya Pradesh)," Investigation Report, Oct–Dec 2005.
[25] N. Tomlinson of UK MAFF's Joint Food Safety and Standards Group 4, December 1998 letter to the U.S. FDA, commenting on its draft document, "Guidance for Industry: Use of Antibiotic Resistance Marker Genes in Transgenic Plants,";  (see pages 64–68).
[26] John M. Burns, "13-Week Dietary Subchronic Comparison Study with MON 863 Corn in Rats Preceded by a 1-Week Baseline Food Consumption Determination with PMI Certified Rodent Diet #5002," December 17, 2002, see also Stéphane Foucart, "Controversy Surrounds a GMO," Le Monde, 14 December 2004; and Jeffrey M. Smith, "Genetically Modified Corn Study Reveals Health Damage and Cover-up," Spilling the Beans, June 2005,
[27] A. Pusztai, et al, "Genetically Modified Foods: Potential Human Health Effects," in: Food Safety: Contaminants and Toxins (ed. JPF D’Mello) (Wallingford    Oxon, UK: CAB International), 347–372, also additional communication with Arpad Pusztai.
[28] October 24, 2005 correspondence between Arpad Pusztai and Brian John

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