GMO’s in Agriculture: A Brief Review

Genetically modified organisms (GMO’s) have been around for decades. They are organisms which have a gene ‘spliced’ into or out of their DNA. While their prevalence has increased, the information surrounding them has not been on pace. As it stands, over 85% percent of American grown corn and soy are GM plants (1). Transgenic supplementation of genes to organisms has been useful in number of different pathologies and treatments, but only recently it has been utilized in agricultural systems.

The use of genetic alteration for agricultural purposes is generally to increase insect and herbicide resistance. At this point, the gap between GMO ubiquity and knowledge is brought to light. Political dimensions have clouded the debate, but GMO’s have been under or misrepresented in a number of ways. The organismal response, environmental health, and conflicts of interest, when regarded as a whole, paint a much more convoluted picture than the ‘black-and-white’ or ‘science vs. anti-science’ narrative commonly employed. This discussion aims to illuminate and connect the diverse perspectives on a single topic.

Current literature is lacking reproducible science when it comes to individual responses to GMO’s. This may be for a number of reasons. A lack of funding may play a role; agricultural science is aiming to promote and improve crop yields, and toxicological studies can be expensive and unrelated to their goal. GMO’s in many cases have been shown to increase crop yield (2). While on a per-acre basis GMO crops are producing more, scientists have made an effort to find whether or not adverse effects are associated with the produce itself.

A biochemical analysis of sheep fed a diet of insect-resistant GM cotton for 90 days. Following the treatment, no biomarkers of pathology, lipid irregularity, or protein malfunctions were noted in the blood (3).  A similar study was performed on commercially farmed pigs being fed a GMO vs non-GMO diet. The GMO fed pigs were fed a mixture of GM corn and soy that contained genes for both insect and pesticide resistance. The Non-GM fed pigs were given a mixture of corn and soy that was validated by a third party to be substantially and nutritionally equivalent to the GM feed.  In the GMO fed pigs, the males were 4 times as likely to experience severe stomach inflammation, and the females nearly 3 times as likely as their non-GMO counterparts. This was a significant finding, and it was also found that the female pig’s uterine weights had increased significantly (4). This suggested a correlation between genetically modified foods and reproductive toxicology. While it was unclear as to why these adverse effects were happening, the researchers speculated inflammation occurred by the action of the insect-resistant gene product. The protein generated by this gene induces pore formation in the gut of insects, and there is no consensus in the literature as to whether or not mammalian digestive tracts have receptors for this protein. While numerous GM studies point to their safety, a study performed by Seralini that received heavy scrutiny after being published in Food and Chemical Toxicology again found adverse effects. Seralini’s study would have been one of the first long-term, controlled studies of GMOs, but was retracted. A few years later, the study has been repeated and subsequently republished in Environmental Sciences Europe, once again with significant adverse effects in the experimental groups (5).

Individual responses and scientific reproducibility will need to be a fixture in studies to come, but a number of studies have shown that the pesticides that accompany these GMO crops are having adverse effects as well. If the goal of engineering is to make the plants more resistant to pesticides, then more pesticides will be sprayed. Following the precedent set by the organismal responses, pesticides seemed to have an increased effect when it came to reproductive toxicology. No specific method of action was proposed, though the increased pesticide usage accompanying many crops seemed to have an effect. A Danish farmer was alarmed at the high rate of malformation in a group of piglets, and had them tested. Of the 38 piglets, glyphosate residues in all of the tissues tested (lungs, muscles, heart, etc.), were found in every sample. Researchers have said that showed residues on food were crossing placental barriers, but concluded that more research was needed to determine whether or not glyphosate was directly causing the malformations (6). A study performed by Shelton examined the effects on pregnant women and their children in relation to their proximity to certain pesticides. By cross-referencing the pesticide usage with the incidence of Autism Spectrum Disorder and Delayed Development, researchers documented a correlation between them (7). Epidemiological studies are often criticized for their lack of statistical relevance, but Shelton’s study was one of many linking pesticide usage and developmental pathology. A mechanism of action was proposed, and in a study performed by Koureas it was found that pesticides increased DNA oxidation. In the group of subjects who were identified as ‘sprayers’, they were found to have higher levels of a DNA oxidative by-product with a significance (p=0.007) (8).

In addition to direct effects on humans, pesticides are also damaging ecosystems. Bees are one of the best pollinators, and a study published at Harvard University connected their usage with colony collapse disorder (9). Neonicotinoid pesticides are used widely in agriculture, but due to this effect some cities have begun banning their use, most notably Spokane in Washington. The European Food Safety Authority released a statement in 2013 spelling out why these pesticides were harmful (10). The debate on whether or not GMO’s are useful often comes down to crop yields and human health risks, but environmental risks are becoming an integral part of agricultural decision making as well.

With individual responses understudied and pesticide risks elucidated, it’s unclear as to how GMOs have become such a fixture in our food system. Removing ourselves from food production is one aspect, but that puts blame on individual consumers. Corruption is commonplace, and while Congress continues to generate lobbyists in all sectors of the economy, the agricultural industry has joined in. A list shown on the “organic consumer’s” website provides names of all the politician-lobbyists who have at one point worked for the government and Monsanto. This list is free of bias, and is simply a compilation of names and job titles that can be found on a number of websites. Most notably, Michael Taylor, a former Monsanto Vice President of Public Policy, has been appointed by President Obama to be the current Deputy Commissioner for foods at the FDA (11). Additionally, the United States is one of the last countries to have not outlawed GMOs. France, Germany, Russia, Spain, and a host of other countries have partially or completely banned them (12).

A list of individuals who have worked for both Monsanto and the United States Government
A list of individuals who have worked for both Monsanto and the United States Government

This fall, Colorado and Oregon had ballot measures to require these genetically modified foods to be labeled. Both measures failed by close margins. Agrochemical companies have spent millions in lobbying and made a concerted effort to stop these foods from being labeled (13). Not only have GMO foods been slowly removed, alternatives have already been proposed. The UN released a document spelling out the impacts of food production, and ultimately concluded that small-scale organic farming was the best way to feed the world (14).

From the very limited amount of non-industry funded research that has been done, it is safe to say that GMO science is still inconclusive. Preliminary toxicological studies have shown that GMO’s engineered for insect resistance and pesticide tolerance correlate with increased inflammation of the stomach as well as increased uterine weights and supposed reproductive effects. These negative correlations are still being developed and reinforced, and I would expect them to continue as more studies are pursued. Pesticide exposure has also become a problem. The main aim is to increase crop yields. Engineering plants to survive heavier doses of pesticides defeats the purpose if everything is being poisoned. Unsurprisingly, the same company that stands to gain from the sales of these pesticides and crops is also the one vehemently denying any adverse effects. Also, UN endorsed alternatives have proven to be effective, and a decentralization of agricultural is the only feasible option for growing demand.

GMO

This debate is monumental. Food runs our lives, and we should control our food. Monsanto is to agribusiness what BP is to oil; companies with shareholders value a bottom line, which often places profit over people. On that same note, these bottom lines are established by us; without reprioritizing cultural values around environmental health and ethical practices nothing will change. If they believed in their product, why spend millions to stop it from being labeled? How did GMO foods become so prevalent with so few relevant long-term toxicological studies? A number of questions can be asked when it comes to this topic, and as research moves forward, it will need to address them. To start, long-term studies can be done with larger sample sizes on an individual level. Also, continued epidemiological data accumulation will further cement the link between industrial farming and environmental health risks. Moving beyond the research, scientists and voters will need to consider conflicts of interest when perspectives on GMOs are offered.

References:

  • Dupont, “GMO corn, soybeans dominate US Market” Org Biotechnology, Published 2013, Accessed 2014.
  • Qaim, “Yield Effects of Genetically Modified Crops in Developing Countries”, Science, 2003
  • Anilkumar, “Sero-biochemical studies in sheep fed with Bt cotton plants” Toxicology International, 2010
  • Carman, “A long-term toxicology study on pigs fed a combined genetically modified (GM) soy and GM maize diet.” Journal of Organic Systems, 2013.
  • (5)    Seralini, “Long-term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maize” Environmental Sciences Europe, 2014
  • (6)    Kruger, “Detection of Glyphosate in Malformed Piglets” Journal of Environmental and Analytical Toxicology, 2012.
  • Shelton, “Neurodevelopmental Disorders and Prenatal Residential Proximity to Agricultural Pesticides: The CHARGE Study.” Environmental Health Perspectives, 2014
  • Koureas, “Increased Levels of DNA damage in pesticide sprayers”, Science of the Total Environment, 2014
  • Chenseng, “Sub-lethal exposure to neonicotinoids impaired honey bees winterization”, Bulletin of Insectology, 2014
  • “EFSA Identifies Risks to Bees from Neonicotinoids.” European Food Safety Authority, 2013.
  • “Organic Consumers Association · Campaigning for Health, Justice, Sustainability, Peace, and Democracy.” Organic Consumers Association,
  • Bello, “Twenty-Six Countries Ban GMOs-Why Won’t the US?” The Nation, Published Oct. 2013, Accessed Nov. 2014.
  • Jargon, “Dough Rolls out to Fight ‘Engineered’ Label on Food.” The Wall Street Journal, 2014.
  • Lilliston, Ben. “New UN Report Calls for Transformation in Agriculture.” Institute for Agriculture and Trade Policy, 2014.

-Harley Fredriksen

harley.fredriksen@gmail.com

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