GMO Foods and Your Health: What You Need to Know

Genetically modified organisms (GMOs) were first introduced in the United States in the early 1990s and have remained a hotly debated subject ever since. The question of whether GMO foods should ever have been allowed into the food supply remains the center of the debate. The argument for GMOs is that they are not only safe but necessary to feed the growing world population in the face of climate change and calls for sustainability. In fact, the opposite appears to be true.

The National Academy of Sciences published a report[1] in 2016 after examining the existing research stating that GMOs are safe – but are they? GMO advocates say this report ends the debate on safety. But concerned scientists and consumers remain skeptical arguing that the effect on human health is still unknown.  Polls have shown that 90% of consumers agree with mandatory labeling for GMO food in the grocery store[2].

This article examines GMOs, and what the research says (or doesn’t say) about safety and use in our food supply.

What are GMOs?

Genetically modified organisms (GMOs) are defined by the World Health Organization (WHO) as: “organisms (i.e., plants, animals or microorganisms) in which the genetic material (DNA) has been altered in a way that does not occur naturally by mating and/or natural recombination[3].”

In other words, a GMO is made in a lab by inserting DNA artificially into the genes of a plant or animal.

The process creates a new characteristic (or trait) to the organism that does not occur in nature. The biotech companies who are behind GMOs believe this makes a stronger crop that is more resistant to insects, drought, disease, or tolerance to herbicides[4]. They also argue that using GMO crops will lead to a reduction in food waste, as well as increases in the efficiency of farming practices.

The question is whether the modification of the genetic material in these organisms leads to the expression of unplanned proteins in the crop that can cause unwanted health outcomes in humans.

Who is overseeing GMO safety?

When GMOs were introduced into the food supply, they were accepted as generally recognized as safe (GRAS). The GRAS status, while technically overseen by the FDA, relies on self-regulation by the food company to defend its safety status[5]. This means that research on the safety of the GMO product is conducted by the same company that is attempting to bring the crop into the food supply. The FDA reviews the data provided by the company to decide on the safety of the item and does not require independent testing.

Independent Testing

While many scientists and consumers have requested independent studies for the safety of GMOs, the calls remain unanswered mainly because of a lack of financial support, as well as restricted control of the use of the products by third-party researchers outside of the seed companies[6]. Currently, a small number of biotech companies control the use of all available genetically engineered seeds, with Monsanto being one of the largest.

The seed manufacturers conduct the majority of available peer-reviewed studies published on the safety of GMOs. The editors at Scientific American magazine stated that independent research that was approved by the seed companies was later blocked from publication because the results were not in favor of GMOs[7]. Nearly all the studies examined in the Academy of Sciences paper referenced above were studies conducted or funded by the GMO companies.

There is also evidence that the GMO lobbyists are so powerful that other scientists may be afraid to speak up.

Scientific American reports that scientists who did speak up questioning the safety of GMOs in well-respected medical journals had their reputation attacked – so much so that there is a concern that researchers may not want to publish data against GMOs in fear of consequences[8].

In 2015 a consensus of 300 concerned scientists and researchers published a position paper arguing that there is no scientific evidence that GMOs are safe[9]. In the paper, scientists state that it is not possible to say that all GMOs are safe and that each crop must be assessed individually (a statement echoed by the WHO)[10]. They also argue that the continued claims of safety from the GMO industry are misleading in that it ignores some of the available research. The scientists state they are concerned that by repeating that GMOs are safe without continued testing leads to complacency through lack of proper regulations and oversight, putting human and environmental health at risk.

Concerned scientists also argue that aside from recent third-party voluntary labeling of some foods, the US has no tracking of any kind for GMO products once they enter the food supply. Without monitoring, there can be no long-term epidemiological study to examine long term health effects on human health in the US population[11].

What are the health concerns related to GMO food?

The research on safety is complicated by the fact that third-party testing rarely exists outside of the biotech companies themselves as cited above. For example, a controversial study conducted by Seralini found that rats fed a Monsanto genetically modified maize with small amounts of Roundup (the glyphosate rich herbicide manufactured by Monsanto) over a two-year study period developed tumors, liver and kidney damage, hormone disruption, and in some cases premature death[12].

After publication, the publishing journal received pro-GMO letters to the editor attacking the author’s study design and accusing him of fraud. The study was eventually retracted for being “inconclusive,” with mixed reactions from scientists who either condemned the retraction or applauded the decision[13].

The following are several examples of GMO health concerns or areas in need of further study found in the research.

All studies have been conducted in animals as there has been no long-term data available on human consumption of GMOs:

Increased pesticide exposure: Genetically modified (GM) crops are associated with the increased use of chemicals like glyphosate because they are resistant to an herbicide so farmers are able to spray heavily[14]. Because the crops are designed to withstand chemicals, it is not only the exposure to the GMO that may be a health issue, but the pesticide residue left on the plant as a result of the increase in tolerance. As herbicides such as glyphosate have their own significant health concerns, this increases the potential risk of GMOs, both for humans and the environment. The WHO has determined that glyphosate is “probably carcinogenic to humans.” GMOs are also associated with resistant “superweeds” that have become resistant to herbicides, creating a vicious cycle requiring more pesticide use[15].

Allergenicity: Several studies have suggested GMO foods cause increased immune dysregulation, inflammation, and increased the risk of asthma. A study on rats found that those who ingested or inhaled genetically modified proteins had upregulation of cytokines (inflammatory markers)[16]. Another study found that pigs fed GM maize had an upregulated immune response with an increase in cytokine production[17].

Studies on Mice

Mice who were fed genetically modified peas developed antibodies and experienced an inflammatory response against the genetically modified protein but not to the non-modified peas[18]. The mice who ate the GM peas also became more sensitized to egg whites, suggesting that through the ingestion of the GM peas, the immune system was primed to be more sensitive to developing immune reactions.

As a result of findings like these, some believe GMOs may play a role in the increase in food allergies in the US, but again there have been no human studies to support this theory, and more research is needed[19].

• Reproductive and hormone disruption: A study published in 2008 suggested that mice fed GM corn had a significant decrease in offspring as well as lower litter weight[20].

Another study examining the effect of the intake of pesticide residue in women trying to conceive with fertility treatment found that women with the highest consumption of pesticide residue had the lowest probability of live birth[21]. Since GMO plants are designed to be herbicide-resistant and therefore are often sprayed more heavily, the conclusion of this article suggests that women who are trying to conceive should be avoiding GM herbicide-resistant plants.

Reproductive Concerns

Reproductive concerns were also seen in male rats fed GM corn[22]. These rats not only displayed disruption in male fertility, but also experienced blood chemistry changes (including alterations in blood lipids), fatty liver, and damage to the kidneys and liver.

GI disorders and disruptions to the microbiome

A study examining “vulnerable” (weaning and older) mice who were fed GM maize found increased inflammatory immune activity in the gut suggesting “the importance of the gut and peripheral immune response to GM crop ingestion as well as the age of the consumer in the GMO safety evaluation.”[23]

Another study that fed mice GM potatoes showed defects in the cells of the small intestines as compared to the control group, causing damage to the intestine[24].  This also suggests that while GMO scientists state that the toxins added to the GM plants are broken down as part of digestion, they actually survive and may cause damage to the intestines.

A recent paper also found that exposure to glyphosate caused microbiome disruptions in rats[25]. As the majority of our immune cells reside in our gut, and the health of our gut is intimately connected with a wide-variety of chronic-health conditions, the exposure to these heavily sprayed GM crops can lead to increased risk of disease through the disruption of healthy gut bacteria.

Where are GMOs found in the grocery store?

GMO foods are pervasive in our food supply. The USDA estimates that 94% of soybeans grown in the US are GMO, while cotton reached 98% in 2019[26]. 90% of corn in the US is produced with herbicide-tolerant GMO seed. Animals are also fed genetically modified grain.

Current GMO foods include:

• Canola oil
• Soy
• Corn/High Fructose Corn Syrup
• Sugar beets
• Papaya
• Potato
• Cotton
• Summer squash
• Apples

How can you avoid GMOs?

While the US and Canada have not had strict GMO labeling laws, Europe, Australia, and Japan all require GMO labeling. The US has been slowly making positive changes towards the labeling of GMO foods. However, the process is still not 100% transparent. Starting in 2022, mandatory labeling of some GMO foods is required[27]. There are loopholes, however, so this is still not a clear path to avoiding GMOs.

If you want to avoid GMOs in your food, there are several things to look for on the food label.

The first is the non-GMO project label[28]. The non-GMO project provides voluntary third-party testing and labeling for companies to show that they are GMO-free. The other way is to purchase organic. If a food is labeled organic in theory, it cannot contain a GMO product/ingredient, although this is not tested/verified.

The Bottom Line

As a consumer, you deserve to be informed about your food choices.  Until more data is published by non-GMO supported companies, the debate on safety will continue.  The fact that GMO foods are still not labeled to help your family is unacceptable. Financial interests and corporate power should not outweigh the rights of consumers.

In the meantime, purchasing organic and non-GMO project verified products help to ensure that the food you are consuming is safe. Purchasing organic also sends a message to the food manufacturing companies that you care about transparency.

 

References:

[1] “Genetically-Engineered Crops Past Experience and Future Prospects | National Academies.” Accessed May 5, 2020. https://www.nationalacademies.org/our-work/genetically-engineered-crops-past-experience-and-future-prospects.

[2] “Consumers Want Mandatory Labeling for GMO Foods – Consumer Reports.” Accessed May 5, 2020. https://www.consumerreports.org/food-safety/consumers-want-mandatory-labeling-for-gmo-foods/.

[3] WHO. “WHO | Frequently Asked Questions on Genetically Modified Foods.” World Health Organization. Accessed May 5, 2020. http://www.who.int/foodsafety/areas_work/food-technology/faq-genetically-modified-food/en/.

[4] GMO Answers. “GMO Basics.” Accessed May 5, 2020. https://gmoanswers.com/gmo-basics.

[5] Nutrition, Center for Food Safety and Applied. “Generally Recognized as Safe (GRAS).” FDA. FDA, September 6, 2019. https://www.fda.gov/food/food-ingredients-packaging/generally-recognized-safe-gras.

[6] “Do Seed Companies Control GM Crop Research? – Scientific American.” Accessed May 5, 2020. https://www.scientificamerican.com/article/do-seed-companies-control-gm-crop-research/.

[7] IBID

[8] “The Truth about Genetically Modified Food – Scientific American.” Accessed May 5, 2020. https://www.scientificamerican.com/article/the-truth-about-genetically-modified-food/.

[9] “No Scientific Consensus on GMO Safety | Environmental Sciences Europe | Full Text.” Accessed May 5, 2020. https://enveurope.springeropen.com/articles/10.1186/s12302-014-0034-1.

[10] “WHO | Frequently Asked Questions on Genetically Modified Foods.” Accessed May 5, 2020. https://www.who.int/foodsafety/areas_work/food-technology/faq-genetically-modified-food/en/.

[11] “No Scientific Consensus on GMO Safety | Environmental Sciences Europe | Full Text.” Accessed May 5, 2020. https://enveurope.springeropen.com/articles/10.1186/s12302-014-0034-1.

[12][12] Ge, Séralini, Clair E, Mesnage R, Gress S, Defarge N, Malatesta M, Hennequin D, and de Vendômois Js. “Long Term Toxicity of a Roundup Herbicide and a Roundup-Tolerant Genetically Modified Maize.” Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association. Food Chem Toxicol, November 2012. https://doi.org/10.1016/j.fct.2012.08.005.

[13] “Retraction Notice to ‘Long Term Toxicity of a Roundup Herbicide and a Roundup-Tolerant Genetically Modified Maize’ [Food Chem. Toxicol. 50 (2012) 4221-4231].” Food and Chemical Toxicology: An International Journal Published for the British Industrial Biological Research Association 63 (January 2014): 244. https://doi.org/10.1016/j.fct.2013.11.047.

[14] “Genetically Engineered Crops and Pesticide Use in U.S. Maize and Soybeans | Science Advances.” Accessed May 5, 2020. https://advances.sciencemag.org/content/2/8/e1600850.

[15] “GM Crops Created Superweed, Say Scientists | Food | The Guardian.” Accessed May 5, 2020. https://www.theguardian.com/science/2005/jul/25/gm.food.

[16] Kroghsbo, Stine, Charlotte Madsen, Morten Poulsen, Malene Schrøder, Peter H. Kvist, Mark Taylor, Angharad Gatehouse, Qingyao Shu, and Ib Knudsen. “Immunotoxicological Studies of Genetically Modified Rice Expressing PHA-E Lectin or Bt Toxin in Wistar Rats.” Toxicology 245, no. 1–2 (March 12, 2008): 24–34. https://doi.org/10.1016/j.tox.2007.12.005.

[17] Walsh, Maria C., Stefan G. Buzoianu, Gillian E. Gardiner, Mary C. Rea, Eva Gelencsér, Anna Jánosi, Michelle M. Epstein, R. Paul Ross, and Peadar G. Lawlor. “Fate of Transgenic DNA from Orally Administered Bt MON810 Maize and Effects on Immune Response and Growth in Pigs.” PLoS ONE 6, no. 11 (November 23, 2011). https://doi.org/10.1371/journal.pone.0027177.

[18] “Transgenic Expression of Bean Alpha-Amylase Inhibitor in Peas Results in Altered Structure and Immunogenicity – PubMed.” Accessed May 5, 2020. https://pubmed.ncbi.nlm.nih.gov/16277398/.

[19] Science, G. M. O. “Are GMOs Contributing to the Rise in Chronic Health Conditions in Our Children?” GMO Science (blog), December 23, 2015. https://www.gmoscience.org/777-2/.

[20] “Biological Effects of Transgenic Maize NK603xMON810 Fed in Long Term Reproduction Studies in Mice | MADGE Inc.” Accessed May 5, 2020. https://www.madge.org.au/biological-effects-transgenic-maize-nk603xmon810-fed-long-term-reproduction-studies-mice.

[21] Chiu, Yu-Han, Paige L. Williams, Matthew W. Gillman, Audrey J. Gaskins, Lidia Mínguez-Alarcón, Irene Souter, Thomas L. Toth, Jennifer B. Ford, Russ Hauser, and Jorge E. Chavarro. “Association Between Pesticide Residue Intake From Consumption of Fruits and Vegetables and Pregnancy Outcomes Among Women Undergoing Infertility Treatment With Assisted Reproductive Technology.” JAMA Internal Medicine 178, no. 1 (January 2018): 17–26. https://doi.org/10.1001/jamainternmed.2017.5038.

[22] Science, G. M. O. “GM Bt Corn Caused Organ Damage and Altered Blood Biochemistry, and Threatened Male Fertility.” GMO Science (blog), March 18, 2019. https://www.gmoscience.org/gm-bt-corn-caused-organ-damage-and-altered-blood-biochemistry-and-threatened-male-fertility/.

[23] Finamore, Alberto, Marianna Roselli, Serena Britti, Giovanni Monastra, Roberto Ambra, Aida Turrini, and Elena Mengheri. “Intestinal and Peripheral Immune Response to MON810 Maize Ingestion in Weaning and Old Mice.” Journal of Agricultural and Food Chemistry 56, no. 23 (December 10, 2008): 11533–39. https://doi.org/10.1021/jf802059w.

[24] Fares, N. H., and A. K. El-Sayed. “Fine Structural Changes in the Ileum of Mice Fed on Delta-Endotoxin-Treated Potatoes and Transgenic Potatoes.” Natural Toxins 6, no. 6 (1998): 219–33. https://doi.org/10.1002/(sici)1522-7189(199811/12)6:6<219::aid-nt30>3.0.co;2-k.

[25] the Guardian. “Glyphosate Shown to Disrupt Microbiome ‘at Safe Levels’, Study Claims,” May 16, 2018. http://www.theguardian.com/environment/2018/may/16/glyphosate-shown-to-disrupt-microbiome-at-safe-levels-study-claims.

[26] “USDA ERS – Recent Trends in GE Adoption.” Accessed May 5, 2020. https://www.ers.usda.gov/data-products/adoption-of-genetically-engineered-crops-in-the-us/recent-trends-in-ge-adoption.aspx.

[27] “Here’s a First Look at the Label That Must Appear on All GMO Foods by 2022.” Accessed May 5, 2020. https://thecounter.org/gmo-label-rule-usda-bioengineered/.

[28][28] “About | Living Non-GMO : The Non-GMO Project.” Accessed May 5, 2020. https://livingnongmo.org/learn/about/.