FAQs on GMOs: What the Science Says

Tuesday, November 6, 2012

Do you know what GMO even means, or have good understanding of the potential risks and benefits of this technology? Get the facts, and separate science from anti-science here.

(And for far more evidence-based information on all things food and nutrition, from farm to fork, GMOS and beyond, buy my new book Food & Nutrition: What Everyone Needs to Know here.)

Got ScienceDo you know someone with diabetes who needs insulin? Chances are it was synthesized using genetic engineering, like many other life-saving medicines. Love cheese? Rennet is a collection of enzymes produced by mammals needed in cheese-making but the majority is now synthesized animal-free using genetic engineering. This is the same technology that is used to create genetically modified foods.

Still think GMOs (genetically modified organisms) are just about politics and (cons)piracy?

Think again.

I challenge you not to dismiss this powerful technology out of hand whether due to distaste for corporate ethics or fear of the unfamiliar. Ever heard of golden rice? Amazing how few mentions I’ve seen of this crop whenever the subject of GMOs arises. The rice, which is biofortified with beta-carotene using genetic engineering, could potentially save hundreds of millions of children from needless suffering from blindness and death due to vitamin A deficiency.

Because of the prominence of GMOs in the news due to California’s Prop 37,  which would require labeling of foods containing GE ingredients, I’ve been writing about this technology at the behest of my Farm to Fork: Why What You Eat Matters students. The first post of the series is a hip hop music video that summarizes the salient questions in a clear and balanced fashion; it’s worth watching. In the second, I encourage readers and voters to look to the science by providing links to a few solid sources of information on the technology. Today I address eight issues I recently discussed in a television interview: as I’m not sure what I said will get on air, or how it will be presented, this piece also provides greater context for my answers. It’s far longer than my average article, but I’ve used bolding to help you along. Stick with it, if you can: this is an important issue that’s worth understanding, no matter where you live or how you vote.


  • What are GMOs?
  • How long have they been around?
  • Why were they developed?
  • How prevalent are they today?
  • What are the potential benefits?
  • What are the potential risks?
  • Are genetically engineered foods safe?
  • What would you say to people who are adamant they are dangerous?


Genetic engineering, applied to food. GMOs are created using the modern tools of molecular biology and genetics using recombinant DNA (rDNA) or transgenic techniques to switch genes on or off within the same plant or to transfer genes between species, often unrelated. The objective is to create a specific, desired trait. Organisms created through this genetic engineering (GE) process are also commonly referred to as genetically modified organisms (GMOs). Note that molecular techniques for the production of new varieties of plants is a new methodology applied to a very old human activity, which is genetic recombination through traditional seed selection and cross breeding.


From the discovery of DNA to genetic engineering. The development of this technology logically followed the scientific discovery of DNA by Watson and Crick in 1953. As the scientific understanding of how genes worked evolved, genetic engineering was first described in the early 1970s as a way to create desired traits using recombinant DNA technology, thus avoiding sexual reproduction.

Genetic engineering of crops: decades in the making. Research and development of GMOs have been going on for more than 30 years, with the first wide scale planting of GE crops in 1996. The first genetically modified food designed and approved for human consumption that came to market in 1994 was the FlavrSavr tomato.


The “why” depends on the “what”. Simply speaking, GMOs were created to have some perceived advantage to producers and/or consumers. More importantly, the “why” really depends on the “what,” meaning which crop you’re talking about and what trait is created, as the technology can be used to develop any number of specific traits for specific reasons.

The first generation of GE crops: producer benefit. These crops were designed to be more resistant to pests and weeds hence increase yield using fewer inputs. In theory, this would lead to reduced exogenous application of pesticides and herbicides thereby delivering such potential benefits as less damage to the environment, less exposure to farmers, and so forth. In essence, the crops were designed to benefit those who grow food and to feed a growing population more efficiently.

An example: Bt cotton. The most predominant GE crop today is Bt cotton. (Bt refers to Bacillus thuringiensis, the bacteria used to enable cotton to synthesize the pesticide itself due to genetic engineering, rather than have it be applied externally by farmers.) The plants are then able to effectively fight off a wide array of insects. Because they are less susceptible to insect damage, these GE crops increased crop yields and decreased the use of applied pesticides.

The second generation of GE crops: consumer benefit. These crops have been designed to provide a direct consumer benefit, whether through biofortification to enhance the nutrient profile of a food, prolong shelf life. or even create a colorful pet (though that’s another story altogether).

An example: Golden Rice. Golden rice, which includes genes to allow rice to create beta carotene, was created as a way to deliver vitamin A to impoverished and malnourished populations in the developing world. A major public health nutrition problem, vitamin A deficiency (VAD) affects approximately 250 million children globally: 250-500,000 each year become blind, half of whom die. VAD is the leading cause of nutritional blindness and it is completely preventable.


GMOs have been planted in wide scale since 1996. Data from the USDA National Agricultural Statistics Services (2012) indicate 88% of corn, 94% of cotton, and 93% of soybeans planted in the US planted are GE varieties. The vast majority are used for animal feed or non-food crops (like cotton). However, given corn and soy are used as base ingredients in commonly consumed foods, especially corn, it’s estimated that at least 70% of foods in supermarkets contain GM ingredients. Globally, 146 million hectares in 29 countries (10% of cropped area) planted with GM crops, the main four being corn, cotton, soy, and canola (rapeseed). Half of production is in the developing world.


In brief, the benefits depend on the trait, you now understand. For first generation crops, benefits could include more favorable conditions for producers, as noted. Crops are also developed to grow under difficult environmental conditions, such as drought. Still others have been modified to be resistant to viruses: many agree that the papaya industry in Hawai’i was saved due to the GMO fruit. (More here, or google around.) Other potential benefits include protecting the health of farm workers and the environment. For example, Bt corn, cotton, and soy have in some cases led to decreased used of pesticides and herbicides, which in turn reduces agricultural run-off and improves water quality in addition to reducing chemical exposures among farm workers. GE crops can also safeguard natural resources by reducing soil erosion, improving air quality, conserving arable land or even increasing biodiversity, which has been shown in some fields in the US and Australia using Bt cotton. In essence, GE technology could be used to help address many of our current problems in the food system related to lack of sustainability and climate change.

For second generation crops, the idea is to provide consumer benefit, whether for longer shelf life, enhanced nutritional profile, or whatever. I’ve already highlighted Golden Rice, and there are numerous other examples. Focusing on nutrition, note that fortification has been used for more than a century to enhance the nutrient content of foods in the US and other places in the world, in many cases leading to fewer deaths from micronutrient deficiencies (e.g., iodization of salt to prevent iodine deficiency) and, more recently, fewer children born with preventable birth defects due to folate fortification of grains and cereals. The point here is that GE is simply a tool, a method, that can be used to create more nutritious foods to improve health and prevent disease.


Compared to traditional methods of crop production, rDNA techniques are relatively new and any novel technology always carries with it potential risks, recognized by scientists from the outset. Potential risks range from human health to the environment and beyond. A few examples: toxicity, antibiotic resistance, allergenicity, and excessive vitamin intake on the human health front and superweeds, superbugs, cross-pollination of GE crops with non-GE crops, and loss of biodiversity in the agricultural domain. While the majority of research studies have shown that GE crops do not behave differently from those developed using traditional methods, especially regarding human health, we can’t really know what long-term effects this technology might have on complex ecosystems. Indeed, the biggest risk in my own mind is that genetic engineering is based on reductionist thinking that can at times prove to be overly simplistic. For all of these reasons, additional research and post-market monitoring continues once crops are in use to measure any unintended adverse effects.

Do remember, however, that these same externalities (i.e., unintended consequences) can also occur using traditional breeding techniques. And have.

(For a more comprehensive discussion of the potential benefits and risks of GMOs, see the FAQ segments at the World Health Organization or Center for Science in the Public Interest.)


A number of governments, scientific academies, and international organizations have concluded that crops grown using GE technology are no different than those grown using conventional breeding and do not create a risk to humans. The World Health Organization and the Food and Agriculture Organization of the United Nations as well as a number of non-governmental organizations and consumer groups like Center for Science in the Public Interest, agree that the foods created using genetic engineering are safe and could be used to greatly benefit human health and the environment. (Links here.)

While a considerable body of research has tested these crops for safety, critics state correctly that there have been no long-term studies that have followed human beings over time, as noted. Such studies, while optimal, are simply not realistic for most new technologies (like, say, cell phones), and policies often can’t wait for such studies to be performed. Sometimes the best we have is field testing, experimental studies, and short-term animal and human studies to guide decision making. Indeed, hundreds of published studies on various GE crops have been performed, comprising a substantial body of literature.


Whether about GMOs or other issues that impact the public health, it is critically important that consumers consult credible scientific sources to inform their opinions and decision-making. Unfortunately, the lack of focus on science education in the US in over the years has compromised the public’s ability to differentiate science from opinion, fact from fiction. Much (mis)information that people receive is imbued with political biases and moral objection; individuals should be aware of their own values that color where they get their guidance and how they interpret the evidence. We all have feelings and beliefs beyond science that make us human beings, and if someone has a reason other than health concerns for not consuming GE foods, by all means, refrain: it’s a free country, and you can select USDA labeled organic foods that by law do not contain GMO ingredients. 

Sure, there are examples of studies showing some negative effects and externalities, but consumers need to be savvy about falling prey to single study sensationalism: scientific conclusions and public policyare drawn only after a compelling body of literature exists. Under-reported and seldom-appreciated is that unintended effects such as food allergies or superweeds due to physical application of herbicide also arise from non-GE crops. Yet, it is a profound statement when many major scientific bodies in the international arena agree that GE crops are no different from non-GE crops and pose no additional risk to human health than their traditional counterparts. While the technology should continue to be monitored, many agree that genetic engineering could be among the methods used to address our multifarious food problems, farm to fork.


There’s a big world beyond Prop 37, with incredible problems related to food production, climate change, sustainability, nutrition, health promotion, and disease prevention that need to be solved as we creep towards a population of nine billion in 2050. In my view, we should look to all the tools available—ecology to technology, traditional breeding to genetically engineered—to keep our precious planet and its inhabitants healthy.

This is the final piece in my three-part series on GMOs; Part I is here and Part 2 is here.

Learn more about food personality and health expert Dr. PK Newby here, or her experience as a nutrition scientist, professor, and consultant here. Or click here if you just want to ogle food porn featuring plant-based, globally inspired cooking.


Dr. P.K. Newby is a nutrition scientist, speaker, and author with expertise in all things food, farm to fork, whether preventing obesity and other chronic diseases through diet or teaching planet-conscious eating. As a health expert and food personality, she brings together her passions for food, cooking, science, and sustainability to educate and inspire, helping people eat their way towards better health, one delectable bite at a time. Healthy Hedonism (TM) is her philosophy: Because healthy food shouldn’t suck.

Copyright © 2011-2020 P.K. Newby. All Rights Reserved.

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