The Frightening Uncertainty of Genetically Modified Foods

March 18th, 2010

The genetic modification of food crops may sound like an advantageous use of modern technology, and the biotechnology industry assertively claims that it is, but there are a number of frightening concerns associated with it that aren’t being given the consideration they deserve.

When an organism is genetically modified, a gene from one organism is extracted, modified, and inserted into the DNA of another organism. Generally, the insertion of this gene is intended to provide the recipient organism with a trait that it doesn’t normally possess. For example, the gene in jellyfish that’s responsible for bioluminescence has been used to engineer pigs, mice, and rabbits that glow in the dark. A more relevant use of genetic engineering that’s already in use is the creation of food crops that can produce their own pesticides or be more resistant to other pesticides that are externally applied. The outcome of these genetic alterations can be very unpredictable, and as a result, they present many legitimate concerns relating to our health. They also threaten to disrupt the intricate balance of our ecosystem which can have significant implications as well.

Genetics is a very complex subject that we have yet to fully understand. Considering that it took billions of years for the current gene pool to evolve to be what it is today, is it really a good idea for us to be so casual about altering it?

Genetically Modified Foods May Contain Harmful Proteins

Genes influence an organism’s function and appearance through the production of proteins that act as hormones, enzymes, antibodies, structural support, or transportation molecules. It was originally believed that each gene produced only a single protein which would be extremely convenient for genetic engineering. However, when the Human Genome Project determined in 2003 that humans possess only 20,000 to 25,000 genes1, it became obvious that this was untrue because this would provide for far too few proteins to support the complexity of human function. As such, it was suddenly clear that a single gene can produce multiple proteins. In fact, a particular gene in the fruit fly can produce more than 38,000 different proteins.2 As such, when a gene from one organism is inserted into another, it may cause the recipient organism to produce numerous proteins in addition to the ones desired. This presents a significant concern in regard to the safety and reliability of genetic engineering.

If a genetically modified organism is destined to become food, some of the new proteins that are produced as a result of the genetic alteration may act as toxins or allergens when consumed. Even the nutrient content of the food can be altered. In some cases, a combination of several foreign genes are inserted into the recipient organism which increases the chances of unintended and undesirable proteins being produced. The interactions that may occur between these proteins add even more uncertainty and potential for problems. Despite the fact that the FDA has approved the use of genetically modified foods, albeit hastily, some of their own research has acknowledged the risk of these foods containing increased levels of natural toxins and having reduced nutritional value.16

Once a protein is synthesized, certain molecules such as phosphate, sulfur, sugar, or lipids may be added to alter its function.3 In addition, chaperone proteins can further change the function of a protein molecule by altering how it’s folded.8 It’s possible for the cells of a genetically modified organism to make any of these changes to proteins that are produced by foreign DNA, and when they do, the chances of these proteins being harmful can be even greater. In fact, misfolded proteins can even lead to a number of fatal brain diseases.9

Genetic Engineering is Imprecise and Unpredictable

To say that a foreign gene is inserted into the DNA of an organism implies precision, but to say that genetic engineering is precise is very questionable. A gene is essentially a portion of DNA that contains instructions for the synthesis of specific proteins. As previously mentioned, the production of such proteins is how the characteristics of a particular gene are expressed. Because only a small portion of a gene’s DNA contains the instructions for protein synthesis, scientists once believed that the large amount of remaining DNA was useless and was therefore referred to as “junk DNA.” Although genetic engineers hope for foreign genes to be inserted into these junk sections of DNA, they have little control of where in the recipient organism’s DNA it’s actually incorporated.

As it turns out, junk DNA isn’t the useless junk it was once thought to be and is now believed to influence which proteins a gene produces.3 As such, even if a foreign gene is successfully inserted into the junk DNA of the recipient organism, the outcome is still unpredictable and there’s still a chance for the expression of the native gene to be altered in undesirable ways. If the foreign gene misses the junk DNA and is inserted into a section of the native DNA containing sequences that direct protein synthesis, then there’s even more potential for unpredictable and undesirable effects.

The uncertainty of genetic engineering is clearly shown by a study in which a foreign gene was inserted into petunia plants to give them red flowers. Although the scientists expected all of the plants to have red flowers, the color varied based on where the foreign gene happened to be incorporated into the DNA. In addition, the color of the plant also varied depending on the time of year which indicates that environmental factors can influence the expression of foreign genes as well.7 Likewise, it’s been shown that the same gene inserted into a number of plants of the same species was expressed at different levels and with differing side effects.11,12,13

Given the variety of factors that influence gene expression, the insertion of foreign genes and the alterations to native genes that can result can also influence the expression of other genes. Research relating to the treatment of cystic fibrosis has found that gene insertion can significantly alter overall gene expression by as much as 5%.5 This means that 1 out of every 20 genes can be effected which can mean thousands of genes in some organisms. As unsettling as this may seem, the outcome of genetic engineering can be catastrophic even if the expression of just a single gene is altered. In a study done on mice embryos, the insertion of foreign DNA caused a single native gene to be silenced and resulted in death.6

Many scientists believe that research on genetically modified foods has generated more questions than answers, that the undesirable effects could be immediate or take many years, and because genetically modified foods are already a common part of our food supply, that the general public is being forced to participate in a giant experiment. In fact, one team of researchers concluded that “controversies and knowledge gaps appear to be present at all levels.”24 Given the volatility of genetic engineering, it’s very difficult to be certain of what you’re eating when you consume genetically modified foods and what the risks may be.

The Roundup Ready Soybean and More Uncertainty

The Roundup Ready soybean, created and patented by Monsanto, is one of the most popular genetically modified foods on the market. Monsanto, one of the largest agricultural companies in the world, also happens to be largely responsible for the existence of some of the most infamous toxins such as DDT, Agent Orange, and PCBs. They also manufacture the controversial sweetener aspartame. However, when it comes to Monsanto’s Roundup Ready soybean, which is genetically modified to resist to their own Roundup pesticide, they claim it’s for the good of humanity.

In 2001, years after the Roundup Ready soybean was introduced to the food supply, researchers found it to contain a DNA sequence of 534 base pairs that don’t naturally exist in the soybean and aren’t part of the Roundup gene intended for insertion.22 While it’s possible that this unidentified sequence of DNA could have been a rearrangement of native DNA resulting from the insertion process as opposed to it having been directly inserted, Monsanto has already admitted to unintentionally inserting two other DNA fragments into their Roundup Ready soybeans23. Either way, it’s enough DNA to produce new and potentially harmful proteins and is a legitimate concern.

93 percent of soy in the US is grown from seeds that are genetically modified based on Monsanto’s patents.25. If you eat any soy, there’s a good chance that you’re eating the mysterious DNA fragments that come along with it as well as the byproducts that these fragments may produce.

Altered DNA Can Become Part of Your Intestines

Hundreds of strains of bacteria amounting to as much as 5 pounds reside in the human intestines. Many of these bacteria are critical to our immunity, digestion, and are even a source of nutrients. If the balance or function of these bacteria is altered, it can have a significant impact on human health. As such, it would be of great concern if the foreign DNA in the cells of genetically modified food could be incorporated into the bacteria cells in the intestines. Although it was once believed that the DNA in food wouldn’t survive digestion, research has shown that genetically modified genes can indeed end up in human digestive bacteria which happened to be the case with a gene used in soybeans to improve herbicide resistance.10

Another significant concern regarding genetically modified foods and intestinal bacteria is antibiotic resistance. During the DNA insertion process, the foreign DNA is only incorporated into a small number of target cells. As such, scientists need a way to differentiate the cells with the foreign DNA from those without it. One of the ways this is accomplished is to add something called an Antibiotic Resistant Marker gene to the foreign gene being inserted. This has the effect of making the cell resistant to a specific antibiotic, and when the scientist applies the antibiotic to the targeted cells, it becomes easy to identify which ones the foreign gene was successfully inserted into. However, if the Antibiotic Resistant Marker gene is transferred to intestinal bacteria and eventually other types of bacteria, it can greatly reduce the effectiveness of certain antibiotics.

The Forced Expression of Foreign Genes

A number of factors determine if and when a gene can be expressed. Because these factors may not be satisfied when a foreign gene exists in a genetically modified organism, genetic engineers add to the gene a regulatory element called a promoter to maximize its expression. Unfortunately, this can have the undesirable effect of influencing the expression of native genes in the recipient organism, even if they’re a far distance from the foreign gene or part of a separate chromosome.13 The maximized expression also requires additional energy and resources from the recipient organism which could deprive other important physiological systems.

As previously mentioned, the foreign DNA in genetically modified organisms can be transferred to other organisms. This is the case with promoters as well. Research done by the Norwegian Institute for Gene Ecology found that the CaMV promoter, which is commonly used in genetically modified foods, transferred to the tissue of the rats it was fed to. They also found the promoter to be active in rat, fish, and human cells inside test tubes.33 More recent research has confirmed this promoter to be active in human cells.38 The transfer of this promoter is believed to have the ability to reactivate dormant viruses, cause new viruses, and is also believed to be a legitimate cancer risk.15

Allergic Reactions to Genetically Modified Foods

Food allergies and sensitivities typically involve adverse reactions to proteins. Because genetically modified foods can contain new varieties of proteins, the risk of adverse reactions is increased. Not only is it possible for new and unpredictable allergies to develop, but also for known allergens to appear in unsuspecting foods. This is exactly what happened when a seed company now owned by DuPont used a gene from the Brazil nut to improve the protein quality of soybeans. Fortunately, these genetically modified soybeans were tested before being introduced to the market, which hasn’t always been the case, and were found to contain what the researchers considered very likely to be a major allergen from the Brazil nut.17

Another alarming case of a genetically modified food being allergenic is StarLink corn. This corn was genetically modified with a gene from the soil bacteria Bacillus thuringiensis, often abbreviated Bt, to produce its own pesticide. Because the approval of pesticides is handled by the EPA, they oversaw the approval of StarLink corn instead of the FDA and decided to not approve it because of its potential to be allergenic. However, the EPA did approve StarLink corn as feed for pigs, cows, and other livestock, but relied on the farmers who grew the corn to keep it segregated from any corn grown for human consumption. Unfortunately, StarLink corn eventually made its way into the food supply and caused a massive recall which is estimated to have involved tens of millions of products.18 StarLink corn ended up in tacos, tortillas, and other corn products and caused reactions in some people that ranged from abdominal pain, diarrhea, and skin rashes to life threatening anaphylactic shock. Even inhaling the pollen of StarLink and other Bt crops has been shown to be a likely cause of allergic reaction.19

Aventis, the maker of StarLink, was faced with numerous lawsuits and the difficult task of preventing any further contamination of the human food supply. However, after admitting that it would be impossible to completely irradiate StarLink and that it would be part of the food supply forever, Aventis petitioned the EPA to deem the existing level of contamination as acceptable.20 Although the allergenic response to StarLink has been downplayed by the FDA, Keith Finger, an optometrist from Florida who suffered anaphylactic shock after eating tortillas containing StarLink corn, was able to reproduce his severe reaction by consuming a verified sample of StarLink.21 This is despite the FDA testing that concluded Finger isn’t allergic to StarLink.

Animals Avoid Genetically Modified Feed

According to a report written by the Soil Association on genetically modified crops, a number of farmers have noticed their livestock having an aversion towards eating them.26 There have been numerous instances of cattle, pigs, elk, and rodents being able to naturally identify genetically modified crops and choosing to avoid them. One farmer even reported on his cattle breaking through a fence to eat regular corn crops despite genetically modified corn crops being readily accessible to them. We seem to have lost this innate ability of animals to choose healthful food, probably as a result of our intelligence. However, in the case of genetically modified food, perhaps we’re too smart for our own good.

According to one of the scientists involved in testing the Flavr Savr tomato, one of the first genetically modified foods to be tested, they had difficulty getting the rats used in the research to eat them.27 A Dutch undergraduate student found similar results after giving mice a choice between regular food and its genetically modified equivalent. The mice ate 61% regular food and 39% genetically modified food.28. A report published by Acres U.S.A. includes additional accounts of animals avoiding genetically modified foods. This includes deer devouring regular soy crops and raccoons eating regular corn crops with both animals completely avoiding adjacent genetically modified crops of the same foods .29 Although this doesn’t prove anything about the safety of genetically modified foods, it’s certainly raises some questions.

A Dangerous Genetically Modified Supplement

A number of supplements are produced by various strains of bacteria, some of which are genetically modified to yield greater quantities of the desired substance. This was the case for a tryptophan supplement produced by a Japanese company named Showa Denko. Tryptophan is an amino acid required for the synthesis of the neurotransmitter serotonin, and in turn, the production of the hormone melatonin. Based on the actions of serotonin and melatonin, tryptophan is often used as a natural method of alleviating depression and improving sleep. However, in 1990, it was estimated that between 5,000 and 10,000 people had contracted a debilitating neurological disorder called eosinophillia-myalgia syndrome from the use of a tainted tryptophan supplement which was later isolated to Showa Denko30 and confirmed to be genetically engineered.31

As previously stated, it’s difficult to predict what type of proteins a genetically modified organism will produce, and in some cases, this may lead to the direct or indirect production of toxic substances. Although the impurities that caused the eosinophillia-myalgia outbreak aren’t proven to be the result of genetic engineering, the indications are pretty strong. As such, it would be in your best interest to verify that any supplements you use are not manufactured with genetically modified bacteria.

The Politics of Genetically Modified Foods

As with most health related controversies, there’s plenty of political and corporate influence behind the approval genetically modified foods, their introduction into the food supply, and the claim that they’re just as safe as their natural counterparts. Much of this has been driven by Monsanto, the producer of the Roundup Ready Soybean discussed earlier. The U.S. government’s support of the biotechnology industry, mostly based on its potential for economical growth, has been a significant factor as well. Monsanto has been accused on numerous occasions of influencing the FDA to gain approval of their genetically modified products and bullying the media to gain public acceptance of the supposed safety of genetically modified foods. The extent of this warrants a separate article which will be coming soon.

The misfortune of Arpad Pusztai, a very highly regarded researcher and one of the first to truly assess the safety of genetically modified foods, shows how destructive the political influence of a major industry can be. Pusztai and his colleagues conducted a study on potatoes that were genetically modified to produce their own pesticide.32 Despite being an advocate of genetically engineered foods and expecting not to find any issues, Pusztai was alarmed to discover that the rats fed the genetically modified potatoes suffered from impaired immunity, damage to the thymus and spleen, underdevelopment of the brain, liver, and testicles, and enlargement of the pancreas and intestines. When he realized that similar foods were already approved and introduced into the food supply, he was disgusted and felt obligated to make the general public aware of his findings. In exchange for his honest intentions, he was suspended from his job, put under a gag order, and harshly criticized by the biotechnology industry and its supporters.33

The Supposed Benefits of Genetically Modified Foods

Many proponents of genetically modified foods, particularly the biotechnology companies that produce them, claim that they deliver higher crop yields, require less use of pesticides, and increase profit for farmers. However, the opposite has proven to be true in many cases. After switching to genetically modified seeds, many farmers observed a decrease in crop yield, became more reliant on pesticides, and made less money. It has also been claimed that genetically modified crops would improve the nation’s economy, but because other nations have refused to import them, it’s estimated that the transition to these crops has caused a loss of more than $12 billion between 1999 and 2001.26

Biotechnology proponents even go as far as saying that genetically modified foods are the answer to alleviating world hunger, and this was even a major objective for President Bush in 2003. However, considering that genetically modified foods have been shown to incur added costs and potentially decrease crop yield, this seems like more of a marketing ploy than anything else. This especially seems to be the case with “golden rice” which was genetically modified to produce vitamin A. The supposed motivation behind this rice was to reduce the prevalence of vitamin A deficiency in African and Asian children which often results in blindness. However, according to Greenpeace, an adult would need to consume nearly 20 pounds of cooked golden rice to obtain their daily vitamin A requirement. Despite this obvious obstacle, one of the companies owning patents on golden rice claimed that delaying its approval by just a month would cause 50,000 children to go blind.34 At the time, more than $100 million had been invested in the development of golden rice with another $50 million slated for advertising.35 In contrast, UNICEF has found that two annual doses of a high potency vitamin A supplement, at the cost of just 4 cents per child, can cure and prevent vitamin A deficiency.36

Most of the supposed benefits of genetically engineered foods have been proven on multiple occasions to not be true, but even if this weren’t the case, would the benefits be worth the potential health risks? Or how about the irreversible and unpredictable alterations to our food supply? Once a genetically modified crop is introduced to the food supply, it can cross pollinate with other crops and become a permanent fixture in the gene pool. This has already happened on a number of occasions. In 2002, Mexico admitted to a major contamination of their corn crops with 95% of the sites analyzed having contaminated seeds.37 How far will we go in allowing the biotechnology industry to endanger our health, our environment, and our future?

How to Minimize Your Risk

As previously stated, at least 93% of soy and 80% of corn in the United States is genetically modified.25 To make matters worse, soy and corn exist in most processed foods which is something that many people don’t realize. As such, many people are unknowingly eating foods that contain genetically modified ingredients. A large majority of canola is also frequently genetically modified as is about half of the papaya that comes from Hawaii. Because the derivatives of these genetically modified crops can sometimes be very difficult to identify in ingredients lists, the best way to avoid them is to choose products that are certified organic, or even better, to follow a diet based mostly on natural whole foods obtained from reputable farms.

For more information on the risks and politics associated with genetically modified foods, I highly recommend reading Seeds of Deception by Jeffrey M. Smith.

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