GMOs are very controversial. It is one reason I have stayed away from the topic in this blog. Instead of discussing the topic in detail, I will present a number of GMO myths and if the reader is interested in more detail they can look at the references. Consider this to be a summary of facts.
If you have formed an opinion on GMOs based what you have read on popular web sites and in newspapers, you have probably reached the wrong conclusion. The anti-GMO movement is strong and based almost entirely on emotion and fear. Science does not back up most of their claims.
What is a GMO?
It always amazes me that people form opinions and have strong views on topics without ever taking the time to understand the basic facts. I’ll bet that less than 1% of people, with an opinion about GMO, actually know what a GMO is. For quite some time I was one of the 99% that thought they knew what a GMO was – I was wrong.
GMO stands for Genetically Modified Organism. In its simplest terms any organism that has had its DNA changed is a GMO. Based on this definition all of the fruits and vegetables you eat are GMOs. We seldom eat native fruits and vegetables that have not been bred to make the food better.
The above definition is not very helpful so people started redefining the term. A plant GMO was redefined as a process that a) takes place in a lab, and b) has DNA from a different type of organism (ie not a plant) placed into the DNA of plants. For example, some fish genes were moved into Christmas trees, which then glowed. These would be GMO plants.
This last definition seems to be the one that is used by most people.
What is the Real Definition of GMO?
What about a lab procedure that adds DNA from one plant into another plant – other types of organisms are not involved? Is that a GMO? Some might say yes since it was done in the lab. But what if plant species A is pollinated by plant species B and the offspring have new DNA genes? Is there really any difference just because it was done in a lab? Not really.
There is a French wheat called Renan which was produced by breeders who bathed wheat and two other species of plants in a carcinogen, colchicine, which affects the way chromosomes connect to each other. They then exposed them to X-rays to further alter the DNA. This produced a very disease resistant wheat containing DNA from all three species and it was clearly produced in the lab. It has been grown in Europe for years but it is not a GMO according to the EU because it did not use the gene transfer technology, transgenesis, that has been used for modern day gene manipulation. So being done in a lab is not an important part of the definition.
Consider the sweet potato. When scientists studied the DNA of the sweet potato they found that it contained DNA from a bacteria genus called Agrobacterium. This DNA has been there for thousands of years. Agrobacterium uses a method of transferring its DNA into other species that is very similar to the method used to make GMOs. The sweet potato is a natural GMO, produced by nature. It has DNA from both plants and bacteria (ref 1). Should the sweet potato be called a GMO?
Monsanto developed Roundup resistant seed by transferring DNA from a Agrobacteria into plants. Sounds very similar to how nature made the sweet potato? (ref 3).
The last couple of examples show why the previous definition of GMO are not correct. A GMO may or may not have been made in the lab – nature can make GMOs all on her own. A GMO may or may not have DNA from a different type of organism.
It is very difficult to find a suitable definition for GMO. In some ways GMO is a lab procedure, transgenesis, and when this technique is used the resulting organism is a GMO organism. But we now have new and improved procedures like gene silencing, mutagenesis and CRISPR. Should plants produced by these new procedures also be called GMO? Right now they are not GMOs and they are not controlled by GMO laws and regulations. For a more in-depth discussion about the definition of GMO have a look at . ‘s article on Grist
I find it amusing and concerning that people have such strong views about something that is not well defined!
Gardeners Can Not Buy GMO Seed
I see comments about this all the time. Gardeners are concerned that they will get GMO seed when they buy a package of seed. This completely unfounded fear has caused most seed companies to stamp their websites and catalogues in big letters; ‘NO GMO’.
The whole thing is stupid. The only way to buy GMO seed is to sign a contract with the supplier of the seed. They won’t do that for a $3 package of seed.
Besides, only a few types of seed are available as GMO. The common things like tomatoes, carrots and beans are not available as GMO seed even to farmers. I think tomato GMO seed has now been developed but it is not on the market yet. When it is, it won’t be sold in small packages to gardeners.
Non-GMO Seed may Not be Produced Naturally
New varieties of some non-GMO seed is produced naturally. Growers have fields of plants and they let nature pollinate the plants or they help by moving pollen with a small paint brush. The seed develops naturally and becomes non-GMO seed. The resulting plants are then selected for desirable traits and if named, you have a new cultivar.
The larger producers of new varieties do not produce seed this way. What they do is use a lab technique called mutagenesis. The seed is exposed to either chemicals or radiation to scramble the DNA in the seed. This can lead to new mutations and improved seed lines. This is a much faster way to produce new cultivars. Seed produced this way is NOT GMO seed.
Since it is not GMO seed it can be sold almost anywhere in the world including Europe. I suspect that some of this seed is sold to gardeners in small seed packages.
Organic Gardeners ARE Allowed to Use Genetically Modified Seed
Organic farmers are not allowed to use GMO seed, but they can certainly use genetically modified seed. Seed produced by mutagenesis is allowed.
At the moment they are also allowed to use seed produced by the other newer gene modification procedures. This may change in time.
Organic gardeners growing sweet potatoes are growing a GMO and that is quite acceptable.
GMO Food is NOT Safe to Eat
There is absolutely no scientific evidence that this statement is true. There has been some research done showing GMO food causes tumors in rats, but that research has been completely debunked (ref 2). The author, Gilles-Eric Séralini, was forced to withdraw the work due to poor experiment design and a refusal to release data. But the anti-GMO movement still presents it as fact. It is not.
Consider this for a moment. The procedure used to make a GMO, transgenesis, moves a couple of very specific genes from one organism to another. The process is very controlled, the scientists know exactly which genes are being moved and the DNA in the resulting organism is well tested.
Compare that to natural plant breeding where you mix and shake thousands of genes and have no idea what is in the new organism. This is considered to be perfectly safe to eat. In mutagenesis the radiation scrambles the DNA so that we have no idea what it has done to the genes. In fact the damage is so great that most treated seeds don’t even develop properly – their DNA is so damaged that they can’t grow. We also consider this food to be perfectly safe to eat.
GMO food is extremely well tested. Natural genetics and mutagenesis undergoes almost no testing.
I have no problem with people being against genetically modified food, but the reason for this fear should not be based on food safety. GMO food is perfectly safe.
Naturally Produced Plants May Not be Safe to Eat
Most people think that natural breeding and selection produces completely safe foods. Farmers have been doing for hundreds of years – how can this cause a problem?
Naturally bred potatoes, called Lenape, had to be taken off the market because they contained toxic levels of alpha-solanine and alpha-chaconine, which are human plasma cholinesterase inhibitors (ref 6). These are not sprayed pesticides. Alpha-solanine and alpha-chaconine are natural pesticides produced by all varieties of potatoes – they are in every french fry you eat, even the organic ones. Selective breeding just increased the amounts to toxic levels.
RC Beier, in a recent study (ref 6) reported that “A new celery cultivar (a result of plant breeding to produce a more pest-resistant variety) was responsible for significant incidences of phytophotodermatitis of grocery employees.” Natural breeding produced a variety of celery that caused blistering and rashes on skin.
Natural breeding is not any safer than genetic engineering. Each method can produce food that is toxic to us. Each plant produced should be properly tested. But new cultivars produced by natural breeding get no testing at all – until you eat it.
GMOs are All About Roundup
A phrase such as, ‘I am against GMOs because I don’t want Roundup to be used” is very common. People associate GMO and Roundup, but that is mostly a false association and shows a lack of understanding about GMO.
It is true that Monsanto developed Roundup and they developed some of the the first GMOs. It is also true that Monsanto developed GMO corn and soybean that is ‘Roundup Ready’. This means that the growing plants can be sprayed with Roundup and it won’t kill the crop plants.
However, most GMO plants have nothing to do with Roundup. Most GMO plants are not Roundup Ready.
The majority of GMO plants have been developed to reduce the effects of pests and disease.
Non-GMO Herbicide Ready Seeds
Selling Roundup Ready seeds is big business. Why? Because it adds a lot to the profit of the farmer and the seed company. Europe banned GMO seed and therefore farmers in Europe could not buy such seed.
Not a problem. Companies soon developed herbicide resistant seeds using mutagenesis. These work just as well as GMO seed, they are developed in a lab, they have not been as closely tested as the GMO seed, but they are not banned in countries who have banned GMO seed. Even organic farmers can use them.
As an example, Clearfield is a variety of canola that is herbicide resistant but it is not a GMO.
The point here is that Roundup and GMO really have nothing to do with each other. They are different topics and risks and fears associated with them should be discussed separately.
GMOs Increase Herbicide Use
Andrew Kniss looked at the relative toxicity of herbicide use in the US from 190 to 2015. He found that herbicide use increased on genetically engineered gylphosate resistant corn, cotton, rice, and wheat. But the increase on non genetically engineered rice and wheat increased at a faster pace.
The use of GMOs is actually reducing the rate at which herbicide used.
More importantly, GMOs are also reducing the toxicity of the herbicides used. Farmers using GMO seed are able to use Roundup instead of the more toxic herbicides they used to use.
Many reports look at the weight of pesticide used and try to do comparisons, but this is mostly a silly, pointless exercise because they ignore the toxicity of the product being used. Consider this simple example. Assume only two pesticides are used. Pesticide A is 100 times more toxic than pesticide B. If I report that total pesticide use has gone up in terms of weight – what does that tell you? Not much. If the total weight has gone up, but the amount of A is down, the situation is much better for the environment.
From a herbicide point of view, GMOs are reducing the environmental impact of herbicide use.
Insect Resistant GMOs Reduce Insecticide Use
As stated above most GMOs have nothing to do with Roundup. Most have been developed to create plants that produce more natural insecticides. Plants keep from being eaten by producing hundreds of natural pesticides. By genetically altering the DNA, plants can be created that produce more insecticide than normal. If they produce more insecticide, farmers need to spray less often.
This is precisely what Monsanto has done. They developed a soybean called Intacta which requires far less spraying. Jack Kaskey reports that “Soybean growers in northern Brazil who normally make six to 10 insecticide applications a season require only one or two sprays with Intacta crops. “.
The reduction in insecticide use has been so dramatic that “DuPont said it won’t restart a Texas factory that makes Lannate insecticide partly because insect resistant crops ( ie GM crops) have eroded sales” (ref 4).
If you are anti-GMO, you are also anti-pesticide reduction!
What about Super Weeds?
Spraying a lot of Roundup does produce super weeds. These are weeds that have become resistant to Roundup.
Many people think that the reason for such weeds is that the GMO Roundup Ready crops are cross pollinating with weeds, which in turn produce GMO offspring. That is not very likely with most crops since the crops and weeds are too genetically different to breed. There is a slight chance this might happen with oilseed rape and sugar beet (ref 5).
Super weeds are produced the old fashion way. A genetic mutation occurs in a single plant that makes it Roundup resistant. It then survives a spraying event and passes on its genes to future offspring. This type of natural selection has been documented well before the introduction of GMOs.
An increased use of GMOs has resulted in increased Roundup use, and this could lead to more super weeds.
But this is a problem with the use of Roundup, not with the GMO technology itself. Remember that most GMOs have nothing to do with Roundup.
Conclusions about GMO
The GMO technology and the food produced from it is perfectly safe to eat. In fact it is much safer than traditional breeding of plants and it is safer than other technologies like mutagenesis, although neither of these alternatives are high risk.
Some 89% of scientists agree that GMO food is safe and 57% of Americans say GMO food is NOT safe (ref 5). This drastic disconnect is both interesting and troubling. The difference may be due to the fact that people do not trust science. It might be due to the fact that the anti-GMO movement has done a tremendous brain washing job. It is probably a bit of both.
Each GMO plant should be evaluated on its own merits. It is foolish to clump them all into one bucket and call them bad. The new Golden Rice is a GMO that will prevent thousands of children in poor countries from going blind. There is no science to show it has any harmful effects and the seed will be given to farmers free of charge. There is no large company to blame for getting rich. But people sitting in countries with lots of food on the table are trying to block its use. I find that despicable.
GMO is here to stay. If it is not this technology it will be another one, but genetic manipulation is not going away. We might as well learn to understand it, and start making intelligent decisions about it.
Ignore the fear mongers!
GMO is such a controversial topic that I will not post people opinions. If you have facts to present, or references to add to the discussion I will be more than happy to include them in the comment section below.
- Sweat Potato Naturally Genetically Modified; https://www.sciencedaily.com/releases/2015/04/150421084204.htm
- Study Linking Genetically Modified Corn to Rat Tumors Is Retracted; https://www.scientificamerican.com/article/study-linking-genetically-modified-corn-to-cancer/
- Why Roundup Ready Crops Have Lost their Allure; http://sitn.hms.harvard.edu/flash/2015/roundup-ready-crops/
- Insect resistant GMO soybeans dramatically reducing pesticide use in Brazil; https://www.geneticliteracyproject.org/2016/04/08/insect-resistant-gmo-soybeans-dramatically-reducing-pesticide-use-in-brazil/
- AAAS Scientists: Consensus on GMO Safety Firmer Than For Human-Induced Climate Change; http://www.huffingtonpost.com/jon-entine/post_8915_b_6572130.html
- Natural Pesticides and Bioactive Components in Foods; https://www.ncbi.nlm.nih.gov/pubmed/2404325
- Photo source for GMO banana; Antoine.Couturier