Confession of liberal, organic food consumer-scientist: ‘I support GMOs’

I love organic foods. My favorite local restaurant serves only organic food and I frequent it several times a week. The chefs are wonderful; food is fresh, local and delicious. While more expensive than other foods, I am blessed with the resources to eat there. My “significant other” cooks and eats only organic and I love her food. I eat these foods because they taste good. I don’t con myself into thinking they differ nutritionally (I am familiar with the Stanford University meta-study). And from my colleagues who work in the area of sustainable agriculture, I am well aware of the bacterial outbreaks from fecal material in organic foods. I know organic foods are not completely safe, but safe enough.

I eat organic foods because I enjoy them. I also like free range eggs. I like the dark yellow yolk although I try not to think about the fact that roaming chickens like to pick at animal droppings on the ground when they eat.

I grew up on a small to medium sized farm in Indiana. We had a cow, a riding horse, some chickens, some sheep and some hogs. We raised corn and hay. My mother had two large gardens. Hogs roamed the fields and were birthed in small barns for each sow. We spread manure on the fields, installed terraces to minimize soil erosion and didn’t use herbicides. I attended college at Purdue University and the University of Wisconsin.

My confession: I am a strong proponent of genetically engineered foods. My position comes from two perspectives: (a) growing up on a farm and remaining an active family member in its operations and (b) being a professor of Plant Molecular and Cellular Biology at the University of Florida.


At Wisconsin, I received a PhD in Genetics. I then joined the faculty at Florida in January 1974. This was about the time restriction enzymes were being discovered. These enzymes allowed the synthesis of recombinant DNA molecules. I remember the moratorium scientists placed on this technology and watched the scientists develop safety practices for the manipulation of recombinant DNA. Soon after this discovery, methods were developed to insert these recombinant DNA molecules into other organisms. Scientists again developed methodologies for the safe study of these recombinant organisms. Hence my career has spanned the time of plant biotechnology. I have watched and participated from the beginning.

I strongly support this technology for one main reason. Plant improvement programs are needed to feed a growing human population in the face of climate change on a smaller carbon footprint. Biotechnology is simply a technique that can be used for plant improvement. It provides food for hungry people and keeps food prices as low as possible for all of us. I should also mention that this technology allows us scientists to gain a much deeper understanding of how plants work.

The criticisms of this technology have been mind boggling, bewildering and frustrating. I suspect that most criticisms come from people with a political or checkbook agenda but I could be wrong. In my view, each of the popular criticisms of this technology has a fatal flaw and can be dismissed with a few scientific facts and common sense. I address the main ones below.

GMO foods put more pesticides into our food and hence should be banned or at least labeled


There is the famous study published in 1990 in the Proceedings of the National Academy of Science by Dr. Bruce Ames and colleagues showing that most human carcinogens or cancer causing chemicals come from pesticides in food. Many scientists cite this paper. However, what is often omitted from the public discussion is that Ames and his colleagues noted that that 99% plus of the cancer causing pesticides are not added by man; rather, they are synthesized by the plant. That plants produce pesticides makes sense because plants cannot get up and move when they are in danger. Plants that do not evolve such defense mechanisms go the way of the dodo bird.

Pesticides differ of course in their toxicity. One pesticide produced by some plants is the very toxic molecule cyanide. When an insect chews on a plant tissue, cell integrity is lost and the enzyme making cyanide is mixed with the substrate for this toxin. So, here is the question I ask myself: Would I want to eat a food plant that protects itself by producing cyanide or by producing the Bt protein engineered into soybean, corn and potato seeds to protect against certain destructive insects? The Bt protein has been used by the organic industry for years and is considered safe by them. But many critics advocate banning or at least labeling plants producing the BT protein. I will take Bt over cyanide any day of the week.

Herbicide resistant genes lead to super weeds and hence should be banned or at least labeled

That weeds resistant to glyphosate (originally sold under the Monsanto trade name Roundup) now exist is a fact. The evolution of so-called ‘super weeds’ was predicted. Spraying weeds with a weed killer provides a phenomenal selection screen for the rare resistant plant. While mutation occurs at extremely low rates, the rare resistant plants have a huge selective advantage. They grow and reproduce with virtually no competition. Perhaps a good analogy is the past overuse of antibiotics and the selection of antibiotic resistant microbes in hospitals.


The point often forgotten in this debate is that it is irrelevant where the resistance gene in the food plant came from. It could be a transgene or it could be a rare mutation the breeders selected in that plant species. Selection is selection and Mother Nature really doesn’t care where the gene came from. The history of traditional plant improvement and breeding programs is filled with cases of weeds or pests overcoming the man-selected resistance in the plant because of a rare mutation occurring in the weed or bug.

Roundup resistant plants cause cancer and early death and hence should be banned or at least labeled

Many critics of crop biotechnology highlight the work of French scientist and anti-GMO campaigner Gilles-Eric Séralini and colleagues that purportedly demonstrated that corn containing the Roundup Ready gene and sprayed with glyphosate causes cancer and early death in rats. This work is highly controversial; was published, then retracted and then published in a pay-to-publish journal. Major criticisms have been detailed elsewhere. Those of the anti-GMO crowd argue that the retraction was caused by undue pressure from the food, chemical and seed industries.

One approach is simply to accept Séralini’s conclusions and ask if they apply or have predictive value to other animals. Dr. Alison Van Eenennaam and colleagues at the University California, Davis did just that and concluded in a massive review of data that there was no adverse effect. Their meta-analysis involved millions of farm animals, a sample size infinitely larger than that used by Séralini and associates.


On our home farm we now produce and sell about 13,000 hogs per year (a number also larger by several orders of magnitude compared to the Séralini rat study). Before 1996 they ate only non-GMO feeds; now they eat 100% GMO feeds. The health and the production of our hogs are at an all-time high. By any common sense comparison the Séralini study comes up wanting.

Adding any new gene to a plant is dangerous, just wrong and should not be allowed or at least labeled

No doubt the strongest criticism of the new gene technology is that it is just wrong. It is unnatural. It is not the way Mother Nature intended it to be. Each organism has its own set of genes and that’s it. But when we look to the products of Mother Nature, we find a totally different picture. Because of newly developed techniques of gene technology, we now know that there are genes NOT found in all members of the species. In corn, which is my research focus, there are thousands of genes found in some but not all corn plants. In fact, “factories” located within the plant itself are now known to make new genes. The new genes are composed of pieces of old genes and are put together haphazardly. Hence, we have always been eating foods containing brand new — but totally uncharacterized —genes.

Related article:  Talking Biotech: Toxicologist on flawed approach of IARC's glyphosate evaluation

The only thing different about genes inserted by man is that we study them extensively and therefore we know what they do, whether their products are allergenic and whether they have affect composition. I will take the latter type any day of the week. In other words, we can monitor what the “man-inserted” gene can do because we know what that gene is. We cannot monitor the genes the plant inserts simply because, until recently, we didn’t know this type of plus/minus gene polymorphism existed.


Plant biotechnology allows companies to patent life and hence should be banned

Often I hear the criticism that seeds (any seed) should be free to everyone to save and palnt. It’s said that farmers have the right to the seed they produce. The argument goes that biotechnology and the companies that produce GMO seeds changed all of that, that farmers and plant growers lost their rights because of biotechnology.

Regardless of the validity of the argument concerning lost rights, let us be clear that this so-called “loss” was not caused by biotechnology. President Hubert Hoover signed into law the Plant Protection Act — in 1930. It allowed for the patenting of seeds. The argument for this was that companies had invested lots of time, effort and money to produce superior plants. Because one could reproduce this superior material simply by growing it, seed companies were not receiving any reimbursement for their years of risky and expensive research.

Analogies to the present day software industry are obvious. Similar arguments supported the Plant Variety Protection Act that was signed in 1970. It is important to note that seed companies must be proactive in protecting the plants they develop and unique genes combinations that resulted from years of research and effort. They must file all the paperwork for these patents. Some companies producing for example soybean varieties did not file for patent protection and hence farmers were free to save and replant these plant materials. Corn on the other hand exhibits something called inbreeding depression (the same reason you do not marry your first cousin) so farmers learned a long time ago that saved seed did not perform nearly as well as the seed they bought from the seed company.


People have the right to know whether their foods contain genes inserted by man

Anti-GMO groups point to polls saying that the vast majority of the people want their food labelled. (There is also a poll showing that just as many people want their food labeled if it contains DNA!! That is why I am investing my retirement funds in companies selling DNA free salt!!). The antis argue that while the government says these foods are safe, they base their conclusions on data furnished by the company wanting to sell the plant—an allegation refuted by most scientific groups. Interestingly, so far, when labelling laws have appeared on state ballots they are generally defeated. So there seems to be a disconnect between polling and balloting results.

In my mind, the “big unknown” in all of this is the cost of labeling. Plant ingredients would have to be segregated from harvest on. This would be hugely expensive. Also, what level of contamination is acceptable? The idea of GMO-free is simply not in the cards. To guarantee a food lacks a transgene is impossible. The only way to make sure every single tomato, ear of corn, head of lettuce, etc. lacks a transgene would require that every single tomato, ear of corn, head of lettuce, etc. be sampled. Because these tests are destructive, no produce would be left to sell.

How do we test for transgenes? Early in the history of plant biotechnology, virtually all transgenes contained some common DNA sequences. These sequences could be then used for identification. In contrast the newer transgenes lack these sequences so older tests will not detect them.


Are there lists available for all the transgenes placed into foods? While only a few transgenes have been “deregulated” for commercial use, there have been literally thousands of genes placed into each of the major crops for experimental purposes. Do we have to test for each one of them? If so, is there a list of all these genes? I think not.

What type of infrastructure would be required to quickly test all foods we consume? Having experience in the area, I know it would be huge and terribly expensive. How do we handle perishable produce? The delay required for testing fruits and vegetables will have significant negative effects on the sweetness and flavor of the produce. Is that what the consumers want?

Do farmers really want government inspectors and samplers out in their fields? Most farmers, especially the organic ones, are pretty independent and want to do things their way. I seriously doubt if they want “government people” in their fields.

Personally, I just don’t’ think society would want or will pay for the system outlined above. Perhaps I am wrong, too pessimistic, too connected to the science and technology. Maybe enough people want (and will pay) to have their foods labeled. Maybe the best solution then is for society to figure out the level of GM mix they will tolerate and pass the law. Then let the private sector take over. Companies can sell foods with a label that gives the probability that this food contains a transgene at a percentage equal to or less than that determined by the voice of the people. If people want it and will pay for it, the company will do well. If people don’t want to pay for it, the label will disappear.


The advantage to such a voluntary label is that people (like me) who don’t want to have to pay more for their food won’t have to. In contrast, mandatory labelling requires everyone to pay regardless of their need for the information.

These are interesting times. From a personal perspective, my life would have been much simpler (and just fine) had recombinant DNA and transformation systems not been invented. But that is not the world we live in. We now have a technology that can do many many good things for society. I look forward to the time that all of these nonsensical arguments disappear and we can put 100% of our efforts into using (rather than defending) the new technology.

Curtis Hannah is a University of Florida Research Foundation professor in the Horticultural Sciences Department focusing on molecular biology and plant genetics. Contact him at [email protected]

News on human & agricultural genetics and biotechnology delivered to your inbox.
glp menu logo outlined

Newsletter Subscription

* indicates required
Email Lists