Genetically Engineered Foods May Cause Rising Food Allergies

By Jeffrey M. Smith
Institute for Responsible Technology
June 2007

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.

(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?" It 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.

References available on request

Keeping an Eye on Transgenic Crops

By David Suzuki
Infoshop News
June 14, 2007

Did you know that genetically modified, or "transgenic" crops are now commonplace on North American farms? According to a recent survey in the United States, the majority of Americans have no idea just how pervasive this technology has become. In fact, North Americans have been eating transgenic foods and using products made from their crops for over a decade. So, what kind of effect, for better or for worse, are these crops having on the environment?

One of the major concerns many ecologists had a decade ago was that transgenic organisms could inadvertently disrupt ecosystems by harming other organisms. Some transgenic crops, for example, have been engineered to resist certain types of herbicide. This allows farmers to liberally spray their fields with the herbicide, knowing it won't harm their target crop.

These concerns were apparently warranted, as farm-scale evaluations two years ago in the UK of some transgenic crops found that vigorous application of herbicides was also damaging to the diversity of other life forms around farms. That's because many of the weeds killed by the herbicides were important for butterflies and bees. Populations of these beneficial pollinators on the test farms fell, possibly having other, more wide-ranging implications up the food chain for birds and mammals.

Another common type of transgenic crop has an insecticide "built-in." These crops have been genetically engineered to produce an insecticidal toxin that wards off pests. One of the most well-known has been engineered using a certain kind of bacterium called Bt. The advantage, in theory, is that Bt crops do not need to be sprayed with an insecticide to kill pests, and thus could be potentially cheaper and more environmentally friendly than their contemporary non-transgenic counterparts.

Concerns were raised, however, when lab tests showed that pollen from Bt crops could be potentially harmful to non-target insects, making them grow more slowly or reproduce less often. However a new meta-analysis of the effects of Bt cotton and Bt maize on non-target insects in the field has found that these types of crops appear, at least on the surface, to be less harmful to insects than farming methods that use insecticides.

This report, recently published in the journal Science, looked at 42 field experiments and found that fields of Bt cotton and maize contained more non-pest insects than did those that used insecticides to control pests. Of course, insecticide-free control fields still had the greatest number of insects overall. The authors point out that further studies to examine the impact on specific species of insects, rather than just all invertebrates, are essential to better understand the environmental impact of these crops.

Disturbingly, the researchers had to resort to obtaining much of their information on Bt crops through the U.S. Freedom of Information Act, because the companies that produced them did not publicly disclose it. The researchers also note that the debate around transgenic crops has been a heated and emotional one, "However, in the case of GM crops, scientific analyses have also been deficient. In particular, many experiments used to test the environmental safety of GM crops were poorly replicated, were of short duration, and/or assessed only a few of the possible response variables. Much could be learned and perhaps some debates settled if there were credible quantitative analyses of the numerous experiments that have contrasted the ecological impact if GM crops with those of control treatments involving non-GM varieties."

Transgenic crops are not simple products like widgets, ipods or even automobiles. They are living organisms that can interact with other creatures in the environment in myriad ways. Nature is complicated. When you modify an organism at a genetic level, it shouldn't surprise anyone that the results are also complicated, and often unexpected. Transgenic crops are, in many ways, radically new and should be subject to the greatest of scientific scrutiny, not suppressed by proprietary concerns.

Farm Bill May Ease Modified Crop Ban

By Hank Shaw
Capitol Bureau Chief
June 18, 2007

SACRAMENTO - Buried within the gigantic federal Farm Bill now under debate in Congress lies a seed of discord over the use of genetically modified crops, known by critics as "Frankenfoods."

Section 123 of the federal bill bars state or local governments from banning anything the U.S. Department of Agriculture has already approved. It sounds benign, but the proposal would sweep away existing bans on genetically modified crops in four California counties and block bans proposed in at least 16 other states.

The proposed measure has sparked uproar among the sustainable agriculture community, especially among organic farmers, and the office of House Agriculture Committee member Dennis Cardoza, D-Merced, has received more than 3,000 e-mails protesting the provision.

Cardoza leads the committee's panel on organic agriculture and says he, too, has concerns about Section 123.

"I am slightly troubled by this language, with respect to the fact that it was put in, ... towards the end of the legislative process, without proper debate and consideration," Cardoza said. "I will be monitoring this section closely as the Farm Bill process continues to determine how it might affect laws already on the books in California."

At its core, the conflict is between those who believe it is OK to alter plants and animals by any means necessary to achieve a desired result - making corn more resistant to pests, for example - and those farmers and scientists who find the idea of inserting genes from bacteria or animals into plants abhorrent.

Traditional animal and plant husbandry relies on a slow, progressive progress of selection among similar plants. Genetic engineering can serve as a shortcut that not only can bypass intermediary steps necessary in traditional farming, but can also introduce elements wholly alien to a plant, such as implanting pesticides into corn.

Special effects like this have proved to be genetically unstable; cross-breeding between genetically modified grasses and natural grasses is threatening Oregon's seed industry. Worries over genetically modified rice have caused the California Rice Commission to ban it, largely because export markets in Asia refuse to buy it.

Proponents of the measure argue that modified crops require fewer pesticides and note that a crazy quilt of county and state regulations, especially regarding sale of genetically modified foods, would cripple interstate commerce.

County growers already are raising genetically modified crops such as alfalfa and field corn, both primarily used to feed dairy catt;e.

This sort of "pre-emption" legislation stripping local control has popped up all over the country.

Last year at the Legislature in Sacramento, state Sen. Dean Florez, D-Shafter, sponsored a bill - universally supported by San Joaquin Valley lawmakers - that was effectively a state version of Section 123.

San Joaquin County Supervisor Jack Sieglock was an active supporter of that bill, as were nine agricultural counties as well as nearly every farm group in the state. Nevertheless, the bill died in the waning days of the session.

This year, a state bill allowing farmers to sue if their fields are contaminated by nearby genetically modified crops ran aground in the Assembly Agriculture Committee.

It is unclear who inserted Section 123 into the federal legislation, but staffers working on the bill say they do not expect it to survive intact.

A revised version of the section is expected to be released next week as the Agriculture Committee continues debate on the overall bill.

To read the section of the Farm Bill under debate, go to: agriculture.house.gov/inside/Legislation/110/LDP_Secbysec.pdf.

top of page