The Science Behind GMOs

Note: This webpage is for instructional purposes only and the scenario described below is fictional.

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UW-Madison Task Force Members:
   Janice Cheng, Department of Food Science
   Robyn Klitzman, Department of Dairy Science


Scenario | Abstract | Introduction | Methods | Controversies

          Robyn and Janice have been approached by the National Association of Agricultural Educators (NAAE) for help with teaching their students about genetically modified organisms (GMOs). The teachers in NAAE have noticed that their students have a lot of conflicting opinions about the cultivation and consumption of genetically modified (GM) crops. The teachers would like to teach their students what science really says about GMOs. They've asked Robyn and Janice to determine whether scientific research aligns with arguments that support or disagree with GMOs.


          Organisms that have been altered to be different from their natural form are commonly referred to as GMOs. In modern agriculture a majority of crops grown are GMOs; this results in a majority of foods containing GMOs. The popularity of GMOs has led to contrasting groups with opinions that either support or are against GMOs. The goal of this paper was to determine whether public opinion on GMOs is supported or refuted by scientific evidence. Four common controversies were identified to be examined. The controversies are as follows: GMOs and pesticide/ herbicide use, GMOs and yield, GMOs  and health concerns, and GMOs and potential added benefits. After examining the scientific evidence it was concluded that both the supporting and opposing arguments are partially correct. GMOs can be beneficial but this depends on how the crop is modified. Also there is a lot that still is nfot understood about GMOs and more research needs to be conducted before final conclusions can be made.


Introduction

          A genetically modified organism (GMO) is any organism whose genetic material has been altered to deviate from its natural form. This can be any plant, animal, or microorganism. GMOs are used to produce foods for human or animal consumption; but are also used in areas of scientific research and manufacturing. This paper will focus on genetically modified (GM) crops that have been created using bio engineering techniques. These bio engineering techniques enhance the natural properties of the crop by altering a few specific genes. The altering is done by removing or adding a gene or altering a few base pairs through natural or artificial gene modification systems (Gupta 2017). A common technique for gene editing is detailed below in figure 1. 

Figure 1. Explanation.


Figure 1. Diagram of one from of gene editing,

          The technique for gene modification was developed by Herbert Boyer and Stanley Cohen in 1973. The first crop grown was tobacco in 1983(Gupta 2017). GM foods were approved safe for human consumption in 1994, with the introduction of the Flavr Savr tomato. GM crops have changed a lot in the last 20 years. In present day agriculture 90% of what is being raised are GMOs with common crops being cotton, soybeans, corn and canola. These plants have different modifications; but each modification falls into one of the following categories. A first generation trait adds tolerance to the crop; examples would be plants tolerant to herbicides, pests, and/or resistant to harsh environmental conditions. A second generation trait adds additional value to the crop; and example would be plants with added nutrition such as high lysine corn. A third generation trait adds qualities not usually associated with food; this would be associated with administration of pharmaceuticals or vaccines. Most commonly grown are GMOs with first generation traits. This paper will focus on GM crops with only first or second generation traits. As of 2015 the most prevalent traits of GMOs being grown in the U.S. are herbicide tolerance, agronomic properties, improved product quality, and insect resistance (Wunderlich 2015).

          Today GM crops are grown in 28 countries and account for 181.5 million hectares of the land cultivated in the world (Wunderlich 2015). However the growing usage has caused controversy amongst the scientific community, amongst consumers, and between the two groups. There are many people that are in full support of the use of GMOs in agriculture and many that do not. There is extreme inconsistency in the amount of knowledge and type of information that consumers have regarding this topic. A survey conducted by Rutgers University revealed that 64% of participants knew little to nothing about GMOs. Out of the all the participants only 43% knew that GM foods are sold in supermarkets. The majority of people say they rely on the media and internet for knowledge regarding GMOs (Wunderlich 2015). Gathering information in this manner has led many people to view GMOs as "Frankenfood". Many people associate growing GM crops with unnatural processes and highly industrialized agriculture (Hielscher 2016). Many consumers fear that GM foods have no added benefit and are harmful to the environment and human health. Our effort aims to address four common controversies the consumer has with GM crops. These controversies are: that GM crops increase pesticide, that GM crops do not provide better yields that GM crops cause health issues such as cancer, and that GM crops do NOT have any added nutritional benefits in comparison to non-GMOs. Our effort will look at each controversy and examine scientific research to conclude whether the consumer's argument is supported or refuted by the data.


Methods

          Scientific and non-scientific articles were considered in determining some of the most common controversies which are present in the society regarding GMOs and GM foods. The most common issues were selected to be reviewed in this paper. The controversies selected which were brought up were mentioned at least 3 different times in different articles either scientific or non-scientific. To discuss if the controversies were valid or not, we looked up the issues on the library databases with genetically modified crops, pesticide, health and other subtopics as keywords. This is because these crops have the most research conducted on them and it would provide us with the most results to provide higher accuracy in making conclusions. This would also allow us to be as unbiased as possible. Only scientific articles were selected to be discussed and their results to be analyzed. This is to ensure that input from individuals in the field with in-depth knowledge would be discussed to prevent myths and untrue facts to be taken into consideration.


Controversies

GMOs & Pesticide/Herbicide Use

The first issue many people say they have with the growth of GM crops is that growing them increases the use of pesticides and herbicides to control insects and weeds. There are two different types of GM crops that affect pesticide or herbicide use. When it comes to pesticides, plants are genetically engineered to be resistant to pests or secrete a substance that is toxic to pests. As shown in Figure 2a, Bt corn has a gene inserted from a bacterium that causes the plant to be deadly to the corn borer. This gene modification helps reduce the need for pesticides. When it comes to herbicides plants are genetically engineered to be resistant to herbicides so that the weed  killer can be applied without harming the crop. As shown in Figure 2b the active ingredient in herbicides target the EPSPS protein which produces an enzyme that controls amino acid formation. Without this the plant dies. However, herbicide tolerant (Ht) plants have EPSPS from bacteria, and they keep functioning under the presence of herbicides. Therefore the goal is not to affect the amount of herbicide used; but instead how the herbicide effects the the crop. 

Figure 2. Diagram of how GMO pest resistance works Figure 2b. diagram of how herbicider resistant GMOs work

      Figure 2a. diagram of how pest resistant GMOs work (Hall 2006)                                                                Figure 2b. diagram of how herbicide resistant GMOs work                                      

Supporting arguments for this controversy say that GM crops: decrease pesticide/herbicide use, allow farmers to move away from the application of pre-emergent herbicides(application to the soil before plants have sprouted), and helps cut down on crop cultivation (which causes soil erosion and water loss) (Gupta 2017).

Opposing arguments for this controversy say that GM crops: increase pesticide/herbicide usage, cause harm to non-targeted beneficial species such as birds bees and butterflies, lead to creation of ‘superweeds’ (Smith 2011 and Glass 2013).

What does Science say?

Study 1: Genetically Engineered Crops and Pesticide Use in U.S. Maize and Soybeans (Perry 2016)

This study was conducted by an Iowa State University group that aimed to measure pesticide use on corn and soybeans in the US by measuring the total amount of all active ingredient  used on each plot from 1998-2011. A plot was defined as land planted with the same seed trait and tillage method. The data was from AgroTrak, a farm-level data set that is assembled by GFK Kynetec, and included 86,763 soybean and 134,264 corn plots.

Results:

Figure. 3

A) Adoption rates of GT soybeans, GT maize, and Bt maize (embedding one or more genes from Bacillus thuringiensis). (B) Insecticide use in maize (kg/ha and EIQ weights). (C) Herbicide use in soybeans (kg/ha and EIQ weights). (D) Herbicide use in maize (kg/ha and EIQ weights). Adoption rates and active ingredient (a.i.) use (kg/ha) are reported in tables S12 and S13.


The data from this study revealed that pesticide use decreased over time for both soybeans and corn and herbicide use on corn plants decreased but increased on soybeans. Graph B of Figure 3 shows the decreasing trend of pesticides used on corn plants. Overall the rate of insecticides applied to corn saw a 75% decrease. Also farmers growing GM corn used 11.2% or 0.013kg/ha less pesticide than their non-GM corn counterparts. Graph D of Figure 3 depicts the trend of lower herbicide use on GM corn, with GM corn growers using 1.2% or 0.03kg/ha less herbicide than the non-GMO users. The increasing trend of graph C showed that, over the course of the study, there was an increase in total usage of herbicide on soybeans. Also growers of GM soybeans used 28% or 0.3kg/ha more herbicide than growers of non-GMOs. However when looking at specific ingredients it is found that there has been an increase in glyphosate, a broad spectrum herbicide, since 1998; which can be seen as in the red bars on Graphs C and D in Figure 3. The data showed that glyphosate is the most common herbicide used, contributing to 80% of the herbicide applied to soybeans and 40% of the herbicide applied to corn. All of these trends correlated with the increased growth of GM crops, shown in Graph A of Figure 3.

Study 2: Environmental Impacts of Genetically Modified (GM) Crop Use 1996–2014: Impacts on Pesticide Use and Carbon Emissions (Brookes 2016)

This study explores environmental impacts of GMOs and pesticide and herbicide use from 1996-2014. It uses previous studies and literature to make its conclusion. The data on usage of pesticides and herbicides relies on national surveys conducted by the USDA. They also analyzed greenhouse gas (GHG) emissions for cultivation of these types of GM crops.  The paper relies on review of literature relating to changes in fuel systems, tillage systems, and the typical emissions associated with herbicide and pesticide application.

Results:

Figure 4. Herbicide use on GM soybeans

Figure 4. Herbicide use on GM soybeans



Figure 5. Pesticide use on GM corn

Figure 5. Pesticide Use on GM corn

The two figures above indicate the opposing changes in use of pesticides and herbicides. Figure 4 shows an increase in herbicide usage over the course of the study, while Figure 5 shows a decrease in pesticide use. Use of GMO crops reduced pesticide spraying by 581.4 million kg, an 8.2% decrease from 1996-2014. The study reports a 71% decrease in pesticide usage for all crops. The increase in herbicide use is on GM soybeans, with a total 3.3% increase in usage. Brookes also states that the reduced pesticide/herbicide usage in combination with reduced tillage or no tillage farming greatly affected GHG emissions. The paper states 2396 million kg of CO2 were saved from being released in the air due to this, the equivalent to taking more than one million cars off of the road for one year.

Discussion

These two studies do not completely support or deny the issues raised by the consumer. While there is a consensus that the use of GMO crops reduces the use of pesticides there is inconclusive evidence surrounding herbicide use. It appears that herbicide use depends on the type of GMO being grown. Also it is important to note that in both studies the increased herbicide use was attributed to the development of glyphosate resistant weeds. This shows that consumers and scientists are valid in fearing the development of resistance in plants. Therefore the agricultural community needs to look further into its herbicide use, to develop strategies to reduce use and prevent further issues of resistance. Also none of these studies looked into the long term effects of the GM crops or their herbicide/pesticide use on the larger ecosystem. Therefore more long term studies need to be conducted on this controversy and people still need to question the true effect of GMOs on the environment in regards to their resistance to and usage of herbicides and pesticides.

GMOs & Yield

          The second controversy covered in our effort is the claim that growing GMOs does not increase the yield per amount of land used.

Those in support of GM crops say that the qualities such as herbicide resistance, pesticide resistance, disease resistance, and harsh condition tolerance allow farmers to get more crops out of their land. It is argued that this can help farmers in developing countries grow more food which will benefit their family and community both nutritionally and economically. Many argue that better yields benefit farmers and consumers worldwide. (Gupta 2017)

The opposing side argues that using GMOs does not increase yield and that while some farmers can see increases the results are highly variable so they cannot be trusted. (Smith 2011)


What does Science say?

Study 1: Yield Effects of Genetically Modified Crops in Developing Countries (Qaim 2003)

This study was conducted on farm in India. It used Bt cotton, a GM cotton that is resistant to bollworms, a common insect pest in India. These field trials were conducted in 2001 on 395 farms in India. The sites were managed by the farmers themselves, not by the professionals conducting the study. On the sites three plots were set up; one containing the Bt cotton, one containing non-Bt cotton, and one containing another hybrid common for growth in each geological location.

Results:

Figure 6. Change in Yield

Figure 6. Difference in yield from Bt and non-Bt crop

The results of the Qaim study saw more yield from the GM Bt cotton than from the non-Bt cotton and the hybrid crop grown on the third plot. The Bt cotton had 80% more yield than the non-Bt cotton and 87% more yield that the non-cotton hybrid. (Qaim 2003)

Study 2: Impact of genetically engineered maize on agronomic, environmental and toxicological traits: a meta-analysis of 21 years of field data (Pellegrino 2018)

This is a meta- analysis of GMO corn. The analysis looks at 40 different studies conducted from November 1996 - September 2016. These 40 different studies included only experiments conducted in field conditions and only experiments where a non-GMO crop, grown in the same conditions, was used as a control.

Results:

                  Figure 7

Figure 7. Change in Yield


The results of the meta-analysis concluded a higher grain yield from GM corn than from non-GM corn. The data showed a range of increase from 5.6-24.5%. This variation is due to the stacking of traits, meaning how many GM traits each variety has. The single, double, and triple stacked traits saw yield increases ranging from 5.6-11.7%. Quadruple stacked traits, however, say as 24.5% increase in yield. The yield increase can be seen from the orange bars in Figure 7. The blue bars show a decrease in the amount of damaged ears.

Discussion:

The data from these two studies do refute the controversies made against GMOs. The research concluded that GM crops can have higher yield than non-GM crops. However this an effect of traits the gene modification. Increased yield is NOT a trait plants are edited to have. Also not all traits will consequently increase the yield of a crop. For example the Bt cotton has a higher yield because its genetically modified trait helps to fight against crop loss from pests. Yet a crop modification affecting the nutrient profile would have no bearings on the yield of the crop. However the yield of crops is highly variable and can be affected by more than just the gene modifications a plant has. While the increased yields can be a benefit to the farmer there is no guarantee that this is the solution to a world hunger problem as the pro-GMO argument states. Therefore it can be concluded that certain GM crops can offer higher yields as a correlation to the gene edited property;  but consumers and the agriculture and scientific communities need to be cautious as to the price that needs to be paid to get more by using GMOs. This can only be fully understood by conducting more long term research of the effect of GMOs.


GMOs & Health

          In the book "Public Engagement on Genetically Modified Organisms: When Science and Citizens Connect", the authors list some of the common opinions of the public on GMOs. The issues addressed in the book were a summary of issues presented at a workshop with journalists and professors in the field as speakers. Based on opinion polls carried out between June 2012 and January 2013, it was found that two thirds of what concerns consumers most in the United States about GMOs is if they were safe for consumption of not. The same group of consumers was unsure if there were any risks related to health upon consumption of GMOs, particularly if GMOs cause cancer. Dominique Brossard of the University of Wisconsin-Madison, who was one of the speakers at the workshop, believes that consumers fears of health issue are not only caused by how much they know about GMOs but also GMOs' potential to disrupt the daily lives of consumers. This controversy analyzes if GMOs cause health issues such as cancer (Council, National Research 2015).

What does Science say?

Study 1: Debate on GMOs Health Risks after Statistical Findings in Regulatory Tests (De Vendômois, et al. 2010)

Results:

Studies on rats showed that genetically modified feed can cause short term effects such as hepatorenal toxicity and long term effects such as reproductive disorders, carcinogenesis, immune, nervous and genetic or metabolic defects.

Figure x1. Studies on rats showed that genetically modified feed can cause short term effects such as hepatorenal toxicity and long term effects such as reproductive disorders, carcinogenesis, immune, nervous and genetic or metabolic defects.

In the study performed by the scientists from France, as shown in Figure x, it was found that the laboratory test subjects had hepatorenal toxicities, in which the kidneys and/or liver loses its function due to introduction of substances toxic to the rats. While the study was carried out for 3 months, the scientists hypothesized that long term consumption of GM foods can cause chronic pathologies. Among the long term effects which were predicted by scientists were reproductive disorders (lack in production of relevant hormones for sexual and reproductive behaviors), carcinogenesis (the initiation of cancer formation), immune defects (weakened immune system in the body), nervous (decreased responsiveness of the nervous system) and genetic or metabolic defects. However, the scientists concluded that insufficient tests were performed to determine if the toxicity was chronic or not. They also highlighted that the number of experimental rats was too low, the duration of study was too short and the number of times the experiment has been repeated is too low to make a conclusive and generalized conclusion.


Study 2: Survey Reports Improved Health After Avoiding Genetically Modified Foods (Smith 2017)
In an article written by Jeffrey Smith, who researches biotechnology and its effect on human health, he analyzes the results of a survey conducted on 3,256 individuals. The survey was completed by consumers in the United States where their data were validated by their physicians. In addition, Smith also explained the results of his research from meta-analysis of published articles in terms of how the consumption of a non-GMO and organic diet could possibly result in the conclusion of the survey mentioned before. His studies considered any sort of crop or organism which has been modified in any way at all but he notes that most genetic modification are done in response to making crops “Roundup Ready”, where Roundup is a commonly use herbicide on crops.

Results:

  The survey which Smith analyzed revealed that more than 80% of the respondents whose health improved were initially having digestive issues while more than 50% of the respondents whose health improved were initially having food allergies, clouding of consciousness, obesity and fatigue. Smith reasons that these improvements in health are possibly due to changes in protein where GMOs consumed modify amino acid sequence, properties of binding of sugar in body and change in shape of proteins, unanticipated change in RNA function upon change in structure and gene transfer of GMOs. He argues that these factors are the causes of growth of cancer cells in humans. Figure x2 illustrates one of the studies Smith analyzed to explain the symptoms of the respondents in his study.

The digestive tract of rats fed GM potatoes engineered to produce GNA lectin showed excessive cell growth compared to rats fed non-GMO potatoes. Another group of rats fed non-GMO potatoes plus the GNA lectin did not exhibit the cell growth. This suggests that the process of genetically engineering the potato, and not the lectin, was the cause.

Figure x2. The digestive tract of rats fed GM potatoes engineered to produce GNA lectin showed excessive cell growth compared to rats fed non-GMO potatoes. Another group of rats fed non-GMO potatoes plus the GNA lectin did not exhibit the cell growth. This suggests that the process of genetically engineering the potato, and not the lectin, was the cause.

Study 3: Variation of Anthocyanin and Carotenoid Contents and Associated Antioxidant Values in Potato Breeding Lines (Brown et al. 2005)

In 2005, another group of scientists studied the effects of genetically modified potatoes on human health. Various potato clones were selected for this study where the cultivar and breeding lines had varying colors of flesh. The genetically modified cultivars had their composition of starch altered. The effect of an increased amount of amylose on human health was observed and analyzed.

Results:

  The study of GM potatoes on human health revealed different results. This study found that if the contents of starch in potatoes is modified to be more than 20%, it will alter the digestion properties of human in a positive manner. Starch with higher amylose content was found to contain more nutritional fibre and prebiotic effects which leads to improved gastrointestinal health in humans (Leeman 2006). Similarly, potatoes can be modified in terms of antioxidant contents, vitamin content and more. In a similar study where the content of anthocyanin and carotenoid were modified to change the antioxidant content, it was found that the consumption of the genetically modified potatoes had correlation with decrease in frequency of certain cancers as well as a decrease in heart disease.

Discussion:

The results from the studies differ from one another. The first study related to Bt corn and genetic modification of maize plant resulted in cancer when being tested on rats and the second study concludes that consumption of genetically modified foods result in growth of cancer cells. However, the other study related to the genetic modification of potato showed positive effects on human health. All 3 studies stated that more in depth as well as long term studies need to be conducted in order to determine the real extent of the damage the genetically modified crop can cause or the full extent of the advantage the crop can provide. The variability of these results could be due to the plant in which its genetic material is modified as well as what aspect of the genetic material is modified. Even so, modifying genetic material in relation to pesticide or herbicide use on maize might cause growths of tumors whereas it might not be the same for other plants if genetically modified in the same way. On the other hand, if modifying plants for clear intent to improve human health such as increasing vitamin and antioxidant content in potatoes, the result in which it has on human health is clearly different from modifying it to resist herbicides and pesticides.





A genetically modified red-fleshed apple vs a non-GM Royal-Gala apple

Changes which occur to the fruit upon genetic modification


          In the paper analyzing genetically modified apples, the authors found that an over expression of the gene MYB TF allowed for a highly-pigmented red fleshed fruit. The genetic modification may result the flesh to resemble the color of the flesh of tomato on certain over expression occasions. The increase in flavonoids among other nutrient and antioxidants as a result of this modification was said to associated with increase in polyphenol, among other substances. Figure x5 shows the increase in gene expression of flavanol synthase (FLS) and levels of quercetin glycosides in MYB10 and ‘Royal Gala’ apple. This has positive implications cardiovascular health and the flavonoid-rich diet could incur positive health benefit on its consumers. However, it was said that there was more browning in the apple but it was limited to the cortex of the apple. Overall, the study reasoned that this attribute would incur benefits to its consumers on top of increasing consumer appeal.

Increase in gene expression of flavanol synthase (FLS) and levels of quercetin glycosides in MYB10 and ‘Royal Gala’ apple

Study 2: Nutritionally Enhanced Food Crops; Progress and Perspectives. (Hefferon 2015)

          In a paper written by a professor from Cornell University who performed a meta-analysis on the benefit of GMOs in thers of nutrition, she studied what sort of benefits can come out of the genetic modification of crops. Among the crops she studied were rice, wheat, maize and cassava, just to name a few. She determined if the crops provided nutritionally-enhanced benefits from regular crops by identifying specific micronutrients such as iron and vitamin A. She notes that these crops also have the ability to be disease resistant, which allows the crop to be able to yield.

Results:

          The paper written by a professor from Cornell University concluded that genetically modified crops allow for nutritionally enhanced crops. She notes that when nutritionally enhanced feed crops were modified to have free lysine content. This transgenic maize was found to benefit animals by increasing their body weight in a healthy manner as compared to when they were fed lysine in the form of supplements. On top of that, it was found that this transgenic waste has an increased yield of at least 145.3%. However, she also notes that the insertion of β-carotene, the precursor molecule to synthesize vitamin A, into rice decreases the yield of this crop. This genetic modification, therefore has not been implemented widespread as of yet.

Discussion:

          Both papers conclude that GMOs do provide additional benefits to the consumers in terms of nutritions while maintaining economic benefits to farmers and businessmen. However, this is again a case-to-case basis scenario where the interaction between the modified gene in crops would be affected by many factors such as what crop it is inserted into and what gene is being inserted. It is possible that genetically modified crops which are being circulated only have economic benefits but do not benefit consumers. The opposite scenario, however, will not be likely as farmers would not plant crops with decreased yield to provide consumers with additional health benefits.


Conclusion

          Conclusively, the evidence regarding increased use of herbicide and pesticide in genetically modified crops are still inconclusive. The results from the studies this paper looked at depended on what crops the research was studying. However, evidence is present that GM crops increase the resistance of plants toward herbicide and pesticide use. In terms of yield, studies show that genetically modifying crops enables the amount of yield per unit land to increase. This, however, has to be intentional modification of a certain gene to ensure that yield is increased. This is a given as the relevant parties would only plant GM crops if there were economic benefit. The controversy that arose with GMOs causing cancer cannot be validated either as it requires a case-to-case basis analysis. This, too, relies on the type of crop modified and the gene which will be modified among many other factors. Lastly, GMOs might or might not provide additional benefit to consumers, making the controversy partially valid. While most plants circulated and promoted to the public would have additional benefits, some do not. This controversy cannot be explained with a one word answer as this, too,  needs to be analyzed on a case-to-case basis. All in all, there are many elements surrounding GMOs which has not been fully understood. This would call for more research to be conducted before making any conclusive statements. Sufficient studies have to be performed based on each modification on a crop and not as a general study.


Citations

Brookes, Graham, and Peter Barfoot. “Environmental Impacts of Genetically Modified (GM) Crop Use 1996–2014: Impacts on Pesticide Use and Carbon Emissions.” GM Crops & Food 7.2 (2016): 84–116. PMC. Web.


Brown, C, et al. “Variation of Anthocyanin and Carotenoid Contents and Associated Antioxidant Values in Potato Breeding Lines.” Journal of the American Society for Horticultural Science, vol. 130, no. 2, 2005, pp. 174–180.


Council, National Research. Public Engagement on Genetically Modified Organisms: When Science and Citizens Connect: Workshop Summary. Washington (DC): National Academies Press (US); 2015 Jul 7. 


De Vendômois, Joël Spiroux S, et al. “Debate on GMOs Health Risks after Statistical Findings in Regulatory Tests.” International Journal of Biological Sciences, vol. 6, no. 6, 2010, pp. 590–598.


Espley, R.V., et al. “Analysis of Genetically Modified Red-Fleshed Apples Reveals Effects on Growth and Consumer Attributes.Plant Biotechnology Journal, vol. 11, no. 4, 2013, pp. 408–419.


Glass, Emily. “The Environmental Impact of GMOs”. One Green Planet. (2013) Web.

Gupta, R., Singh R.L. In: Singh R. (eds) Principles and Applications of Environmental Biotechnology for a Sustainable Future. Applied Environmental Science and Engineering for a Sustainable Future. (2017) Web.

Hielscher, S., et al. "Rationalizing the Gmo Debate: The Ordonomic Approach to Addressing Agricultural Myths." International Journal of Environmental Research and Public Health 13.5 (2016). Web.


Hall, Hardy. (2006) "Bt Corn: Is it Worth the Risk?The Science Creative Quarterly. Web. 


Hefferon, K. L. (2015). Nutritionally Enhanced Food Crops; Progress and Perspectives. International Journal of Molecular Sciences, 16(2), 3895–3914. http://doi.org/10.3390/ijms16023895


Leeman M. 2006. Means to optimize the nutritional properties of starch in potato products. PhD Thesis, Lund University, Sweden.


Pellegrino, E., Bedini, S., Nuti, M., & Ercoli, L. "Impact of genetically engineered maize on agronomic, environmental and toxicological traits: a meta-analysis of 21 years of field data." Scientific Reports, 8(1). (2018) Web.


Perry, Edward D. et al.  2016. Genetically Engineered Crops and Pesticide U.S. Maize and Soybeans. Science Advances 2.8 e1600850 PMC. Web


Qaim, Matin, and David Zilberman. "Yield Effects of Genetically Modified Crops in Developing Countries." Science 299.5608 (2003): 900-2. ProQuest. Web. Smith, J. “10 Reasons to Avoid GMOs.”  Institute For Responsible Technology. (2011) Web.


Smith, J. M. (2017). Survey Reports Improved Health After Avoiding Genetically Modified Foods. International Journal of Human Nutrition and Functional Medicine®. Retrieved April 17, 2018.


Wunderlich, Shahla, and Kelsey A Gatto. “Consumer Perception of Genetically Modified Organisms and Sources of Information.” Advances in Nutrition 6.6 (2015): 842–851. PMC. Web.


Acknowledgements

This project would not have been successful without the contributions of the outstanding students in our Food Systems, Sustainability, and Climate Change class.  We would particularly like to acknowledge the wonderful and challenging questions, and the specific knowledge that students with different areas of expertise provided.


About the Authors


robyn.jpg

Robyn is a senior at UW-Madison studying dairy science. She grew up on a small dairy farm in Rock County, WI. Outside of class Robyn works at ABS Global in Deforest, WI and at Frito Lay in Beloit, WI. If not at school or work she enjoys spending time with her three dogs: Oakley, Dega, and Nova.

 

janice.jpg

Janice is a junior at UW-Madison studying food science. She grew up in a tropical country, Malaysia which is hot all year round. She works at the Babcock Dairy Plant as a research and development intern. She enjoys watching tv shows and and reading blogs in her free time.




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