With scientists on both sides of the GMO debate, how can you know who’s wrong or right?

People have lots of questions about GMOs. Here’s an interesting question posed by Micky about lists of signatures against GMOs:

Q: “Are these scientists all wrong, there are over 800 scientists who all believe GMOs are a bad idea. http://www.i-sis.org.uk/list.php How many scientist believe that GMOs are good and do all of these scientist work for big agro corporations?”

And here is my Answer to Micky’s question:

Scientific arguments are not settled by counting the number of people supporting an opinion. They start with a careful search for scientifically valid evidence, and they carry this forward with open-minded and careful logical reasoning and false conclusions are eliminated from the discussion. Good scientific reasoning also takes notice of the whole body of evidence on a topic, and updates the verdict as new evidence becomes available.

 The I-SIS website mentioned in the question has a public letter with over 800 signatories. Most scientists when making a scientific judgment don’t really care about such lists, and who signed the letter doesn’t enter into their thinking. It is quite right that they take this line.

 Albert Einstein said this best (quoting Michio Kaku’s article at Encyclopedia Britannica):

 “One Hundred Authors Against Einstein was (a short book) published in 1931 [which said the Theory of Relativity is wrong]. When asked to comment on this denunciation of relativity by so many scientists, Einstein replied that to defeat relativity one did not need the word of 100 scientists, just one fact.”

 So let’s take a scientific approach and look at what evidence is presented in the I-SIS  letter, and evaluate whether the claims it makes are true.

Definitely some of the letter is wrong or out of date. In the years since 2000, when the letter was signed, many more scientific publications on the topics have come out.

 These new publications have settled many of the questions that are raised in terms of whether GMO crops are bad. These publications (numbering thousands in total) involve many thousands of scientists.  About one in four of them, or even more, are not connected with commercial seed companies selling GM crops.

 The letter claims that “GM crops offer no benefits to farmers or consumers.”

 This claim ignores the huge benefits of insect protected biotech corn and cotton which save many farmers from unnecessary exposure to toxic pesticides. Insect protected GM corn is of special value to food consumers and farmers as reduces harm to animals and people from eating moldy insect damaged corn. Such damaged corn often contains residues of a cancer causing mold toxin called fumonisin that accumulates in mold affected grain. This benefit of safer corn is especially important for poorer people in developing countries in Latin America, Africa and in China where corn is a staple item in their daily diet.  Clearly, as the evidence stands today, the 800 letter signers are wrong about the benefits of crop GMOs.


White maize — mealies — is a staple food in Southern Africa.

 The letter at the I-SIS website also publicizes worries about the “spread of antibiotic resistance marker genes that would render infectious diseases untreatable, the generation of new viruses and bacteria that cause diseases, and harmful mutations which may lead to cancer.”

 There are good reasons for believing such risks are insignificant. Some of these reasons are explained at the following website entries (which I wrote with Professor Bruce Chassy):

Much of the rest of the letter is really about a somewhat different issue than whether GMOs are good or bad. For instance the letter ends with a plea for the wider use of alternative farming practices.

Quite likely, some of the scientists signing the letter at I-SIS may have changed their minds about GMOs in the years since 2000.

 Returning to the second question posed:  “How many scientist[s] believe that GMOs are good and do all of these scientists work for big agro corporations?”

 When asked this question, most scientists would say something like—not all GMOs are bad, and some GMOs are a really good idea.

 Most modern biologists know that GMOs have been a tremendous boost to scientific research. In basic biology research areas connected with medicine, cell biology and even zoology and evolution studies, GMOs are seen by almost all knowledgeable people as an extremely useful experimental tool, and they have accelerated progress in many areas of science – for example given us new ways of making insulin that is essential for treating diabetes, or tools for discovery of drugs to manage HIV virus infections. (I personally have done this type of work, and I know that genetic engineering methods have played a hugely important role in developing treatments for virus diseases such as AIDS or hepatitis).

 As far as how many scientists support crop GMOs that provide benefits to fight malnutrition, more than 6,500 scientists recently signed a petition to protest against destruction by activists of GM rice field trials in the Philippines. This rice has potential to prevent diseases that occur in people with vitamin A deficiency that is widespread in many regions where rice is a staple food. (See Global scientific community condemns the recent destruction of field trials of Golden Rice in the Philippines)

 There is a wide range of scientific investigations on seed breeding, food safety, and food improvement using GMO crops that have been and are currently being done outside seed companies. Many government-funded studies have been carried out in the EU for example

 I personally know many University and non-corporate scientists who are extremely enthusiastic about GM crops and are busy developing GM crops that help the poor. These include mineral and vitamin fortified crops that can alleviate micronutrient malnutrition.


If more people knew about the many non-commercial research GMO crop efforts which are deliberately targeted to help the poor, I am sure they would get wide support inside and outside the academic community from both scientists and non-scientists.  They certainly dispel the impression that GMOs are only of interest to large seed companies.

(Original Post at GMO Answers website)

David Tribe is an applied geneticist, teaching graduate/undergrad courses in food science, food safety, biotechnology and microbiology at the University of Melbourne.


Want to write for The Biofortified Blog? Click here to find out more!

33 comments to With scientists on both sides of the GMO debate, how can you know who’s wrong or right?

  • Andre

    The question was well drafted: « Are these scientists all wrong, there are over 800 scientists who all believe… »

    Belief is not in the realm of science!

    The open letter has only marginally to do with science.

    « Most scientists when making a scientific judgment don’t really care about such lists, and who signed the letter doesn’t enter into their thinking. It is quite right that they take this line. »

    Well, most scientists also have a look at such lists to gauge the credibility of the letter. The verdict is obvious in this instance.

    Many signatories do not qualify as scientists, or have no qualification in the area at issue. Well, actually, close to none has expertise in patents.

    Open letters like this should be taken for what they are: an expression of an opinion and a political request by people who happen to claim that they are scientists.

    • A fraction of them are also dead now. It’s a really stale item.

      • Joel

        Continue blithly eating food products containing GM ingredients and you too will be a stale, if not dead, item. Have you heard of the Precautionary Principle? The lesson of Pandora’s Box? The concept of co-evolution? If your attention span allows, I highly recommend contemplating deeply the interaction of these three ideas. Like most humans, you probably eat all day, every day so you should also consider BIOACCUMULATION.

        • What evidence do you have to support your idea of ‘bio-accumulation’?

          Pandora’s box was a myth for folks that believe in a god that caused earthquakes and another one that threw lighting bolts.

          If we were to apply the precautionary principal to other things, there would not be a computer on your desk or a cell phone in your pocket. TV would still be a ‘new’ technology. No one would EVER drive anywhere. I have had 2 friends involved in major wrecks in less than a week. Driving is DANGEROUS. Applied to everything, man would still be living in caves, eating raw meat and wearing the skins he stole from predators

        • Joel, proclaiming that people will be dead if they continue eating safe foods is really not very logical, and runs counter to respectful dialog. Not everything bio-accumulates, so invoking the term does not help your position.
          Also, Pandora’s Box is a myth, one in which the gods who gave the jar (not box) to Pandora instructed her never to open it, but did not have the foresight to tell her why she should not, so her curiosity got the better of her ad she opened it. The lesson to be learned is if there is an innocent act that has dire consequences, that those in the know (be they gods or mere mortals) should explain to the person in charge of the proverbial jar so that they understand what the real danger is. Of course, the Pandora’s Jar analogy fails when you consider that making wild claims of crazy danger without regard for the consequences (see you suggestion about staleness and death) when there is none can itself lead to dire consequences. The appropriate analogy is shouting Fire in a crowded theater. You undoubtedly did not exercise the precautionary principle when uttering those words about death (and lets not forget staleness).
          Co-Evolution. You use the term, but it does not mean what you think it means.

        • Ewan R

          The lesson of Pandora’s box.

          Because when making important life decisions it is very, very important, to base your decisions on Greek mythology.

          I, for one, always carry a mirrored shield, try not to tie anyone onto my ship lest they be a greek god &c.

          Like most humans, you probably eat all day, every day

          I think you’re confusing humans with large ruminants or other grass/leafeaters. Is your piece perhaps geared towards elephants? Panda bears? Some other creature who actually spends the bulk of their waking time eating? (Even if I am a standard deviation or two below the norm for human eating behaviour I’d say I spend less than 1/20th of my day eating, thus it’d be highly probable that even someone two standard deviations in the other direction isn’t even coming close to spending the bulk of their day eating)

          Continue blithly eating food products containing GM ingredients and you too will be a stale, if not dead, item.

          Continue blithly writing nonsensical blog replies and you will also wind up dead (your ideas, apparently, are already stale). It is alas an inevitability (not all humans who have ever lived have died, but it’s a pretty good bet that this is simply indicative that the species isn’t extinct, and thus that we’ll share the same fate eventually).

  • Gahan

    Without vouching for the validity of the open letter, I think what the question is really getting at is how is the lay public to know which scientists to believe when there is difference of opinion among scientists? Scientists obviously have evidence-driven methods for arriving at their conclusions, but for those of us who don’t have the tools or wherewithal to perform the same type of data analysis that scientists do, what tools are available for separating the junk science from the real deal? The author dismisses “counting the scientists” on each side as unscientific, yet presumably when we are told that there is a “scientific consensus” about something, there has to be some counting going on at some level.

  • David Tribe


    Presenting scientific opinion as a “consensus” is not really being scientific. It’s how the evidence falls that matters.

    And there can often be some conflicting evidence to any well supported “model” for the real world. Often its just errors of one kind or another, or background variation in irrelevant conditions such as temperature or genetic variation.

    There is a lot of evidence for general safety of GMOs used for food, and yest, a relatively small amount of evidence that could support unexpected events from GMOs, or alternatively is just irrelevant noise inherent in the way the experiments were done and designed. In other words results that are also expected if the food is safe. Usually scientists don’t take much notice of those kinds of results because they waste a lot of effort for little gain. Most investigations have some inconclusive evidence.

  • CareAboutIt

    This is my biggest fear.. When they finally admit that gmos do cause health problems and cause dire environmental damage, it may be too late..
    “David Suzuki is a geneticist. He’s one of the top scientists in Canada, his textbook is one of the most widely-used in the world, he’s published more than 30 books. So when David Suzuki speaks, I listen..
    Putting genes back in bottles.. How do you clean up a potential GMO mess? You don’t.
    The difference with GM food is that once the genie is out of the bottle, it will be difficult or impossible to stuff it back. If we stop using DDT and CFCs, nature may be able to undo most of the damage – even nuclear waste decays over time. But GM plants are living organisms. Once these new life forms have become established in our surroundings, they can replicate, change, and spread; there may be no turning back. Many ecologists are concerned about what this means to the balance of life on Earth that has evolved over millions of years through the natural reproduction of species.”

    Spread of genetically engineered plants out of control in many countries

    • David Suzuki has been out of professional genetics for decades. He is no longer authrr of that textbook.


      Evolution depends on gene rearrangements to generate biodiversity, and analogous changes to that that are created in the lab occur abundantly in nature. Whatever is meant by “balance of nature” (it is an obsolete ecological concept) , natural genetic rearrangement events pose similar disturbances to nature as lab ones.It’s called evolution.
      See e.g.


      Most crops die out when farmers don’t look after them. GM crops are not an exception.

      • Loren E

        Hello David,
        Your first sentence brings up an important point for me. Many of the experts trotted out by the anti-GM movement really have no credibility in this area at all–for example Jeffrey Smith, Vandana Shiva or even Jeremy Rifkin. Some of the others DID actually work in the field but have been distanced for quite some time. In addition to David Suzuki, Thierry Vrain has been retired for 10 years, Belinda Martineau’s claim to fame is that she worked on the Flavr-Savr, but according to her CV she hasn’t been in the lab since 1996. These folks constantly trot out the same claims that we’ve been hearing for 10-15 years. And it plays well when preached to that particular choir.

  • Mr Tillier

    GM agrobusiness is not cost effective. geneticians earn 4 times the wages of a farmer and requires expensive labs, computer security, site security, scanning the potential “snowdens”, legal lawyers for the patents, the lobbyists, the PR, etc… and all that waste of money for food that has lower yield, is less tasty, does not provide lower food prices for the customers and is only just about “substantially equivalent”. No achievement at all to start with. It is a non business in the first place. Goldman Sachs selling sub-prime mortgage equals selling food securities insurances to farmers. Farmers&society cannot afford to pay higher costs and that misleading expensive agrobusiness for a produce only substantially equivalent. More subsidies, debt and shutdown to come. 1/3 of the food being wasted, better distribution is more of a priority. They are not being pragmatic.

    • One of the things I find rather remarkable about statements that GE crops don’t make financial sense for the farmer is that it doesn’t explain their high adoption rate.

      I take issue with the claim about “no achievement at all to start with”, because many people do not know that maintaining yields and production while pests, disease, and climate changes IS an achievement. Improving things and not losing ground in agriculture is an achievement.

      Personally, I think the debate about improving genetics versus reducing waste is that the correct answer is both, not either-or.

      • OrchidGrowinMan


        I call it “The Epidemiological Argument.” If, for example, microwave ovens rendered everything dramatically toxic, even water, wouldn’t we NOTICE? Something can’t simultaneously be so blatant that it is the Danger of the Times and also so subtle that only a few people (DGaPs [Drunk Guys at Parties]) can notice it.

  • Eric Bjerregaard

    Thanks for helping folks wade through the crap the antigmo activists are constantly posting.

  • Eric Bjerregaard

    Are you the ones that tried to get Don Huber to provide samples of the mysterious “life form” that he claims is so dangerous? If so, is there any chance he is telling the truth?

  • Joel

    Bottom line, in the Precautionary Principle sense, when you hear about an alleged consensus on the safety of GM food products refer them to this for a clearer picture than any one person can give, invested or not.
    There IS a consensus, but not the one the GM crop industry wants to hear: The consensus of 230 science people is that there is no consensus on the safety of GMO consumption.

    These are the signatories to the statement “There Is No Scientific Consensus On GMO Safety”, all two hundred and thirty — 230 international, experienced, medical and science professionals – MDs, PhDs, DVMs:

    A good write up on the statement:

    The statement:

    ENNSSER is European Network of Scientists for Social and Environmental Responsibility

    Outline of Statement (each point is explicated at the link above):
    1. There is no consensus on GM food safety

    2. There are no epidemiological studies investigating potential effects of GM food consumption on human health

    3. Claims that scientific and governmental bodies endorse GMO safety are exaggerated or inaccurate

    4. EU research project does not provide reliable evidence of GM food safety

    5. List of several hundred studies does not show GM food safety

    6. There is no consensus on the environmental risks of GM crops

    7. International agreements show widespread recognition of risks posed by GM foods and crops

    • Signing statements from a minority of scientists in (multiple) fields aren’t a substitute for evidence. We wrote about scientific consensus here: http://www.biofortified.org/2013/10/20-points-of-broad-scientific-consensus-on-ge-crops/

      • Joel

        This is a consensus that there is a LACK of evidence, by a plethora of reputable scientists. It is more than enough to trigger the Precautionary Principle in relation to the ingestion of genetically modified crops.

        • Amigo Joel
          A plethora means an unhealthy quantity of. Eg. see

          According to that definition of plethora it is enough to trigger the Precautionary Principle to IGNORE the calls of the scientists because they are making unhealthy recommendations.

          • Joel

            You’re absolutely right David, plethora implies excessive. I should have used “multiplicity” as in,
            • a large number : his climbing record lists a multiplicity of ascents.
            • a large variety : the rain forests and the multiplicity of species that they harbor.

            Yes, that could certainly leat to such a twisted example of following the PP, an imaginatively ludicrous even Orwellian extrapolation. I believe your equation is faulty as you have not factored in with the PP the lesson of Pandora’s Box and the concept of co-evolution (“The Botany of Desire” movie is nicely illustrative of co-ev). These are interrelated and connected to the GMO experiment. Bottom line: the laboratory shouldnt be in my gut, it should be contained until perfected. Maybe 50 years? … certainly not now.

  • Van

    This is a good article. The anti-GMO nonsense I’ve seen posted on Facebook and other parts of the internet have convinced me that the people opposed to GMOs must feel they are losing the argument and have resorted to nonsensical scare tactics. It’s bad in a way because some of them have good ideas about sustainable agriculture. But instead, much of the movement has gone to the quacks.

  • Gavion

    I am against GMO’s. The reason is it makes food unhealthy and it takes away the nutrients away from the food. Corn is a great example of this. I believe they should grow crops in the area by the farm not from another state. This is also a very good site for information on this topic.

  • Laura

    Karl – Bear with me – gene splicing isn’t my area of expertise. I do know a fair amount about plant sex, as botany subjects were among my favorites in college. As I see it; 1.the biggest problem with Monsanto is their “GM police” – the people that take corn from farmer’s fields and test for GM genes(corn – being a wind-pollinated grain – trespasses onto farmer’s fields who have chosen to NOT grow GM corn),then Monsanto sues, putting the small farmers out of business. To have food security, farmers need the choice to save seed, and if they choose to save seed, they shouldn’t be penalized for pollen trespass.
    2.I would be more likely to believe provision of healthier foods via genetic modification was Monsanto’s goal if Monsanto allowed outside laboratories to perform long term testing to verify safety. Flies in the face of our “right to choose”. Organic farmers lose their organic standing, or are sued because some of the GM genes are present in the seeds the farmer saved. Small farmers don’t usually have the resources to go to trial. Monsanto has a few attorneys on their payroll.
    3. It seems that Monsanto is part of an oligopoly working to have world food control. The consumer is losing free informed choice; one of those things the United States is supposed to provide. I was stunned the anti-label folks in Washington state used the rational that ‘it will cost too much to label’, when I see labels change every time I go to the grocery store. I want food to say it contains ingredients from genetically modified organisms if it does.
    4. I appreciate the role GM plays in the production of insulin. Insulin production is a valuable use of a genetically modified organism.
    5. Roundup ready corn isn’t healthier or nutritionally different, it is resistant to roundup, has increasing the use of roundup on our nation’s fields, and consequently aided the development of roundup ready weeds. Evolution in nature will continue – we’ve just enhanced the development of roundup ready weeds by eliminating their competition.

  • Sarah

    I agree with what Laura has written above. My concern is less about human health than about the economic and political control exerted by a few large companies. Here in Iowa we hear all about how GMOs are necessary to feed the world. But our cropland, which accounts for about 90 percent of our land, isn’t devoted to food. We are growing ethanol and cattle feed and corn sweetener. Ag policy, including subsidies, may be what is keeping us from feeding the world. Many scientists have good intentions to develop foods that have nutrients or other features that would benefit people, but the science is only on element in the equation of what moves forward into development. The bottom line is really what will earn corporations the most money. So GMO corn and soybeans in the US, along with our subsidies for ethanol, have pushed up the price of these crops so much that the land formerly devoted to Conservation Reserve Program has been converted to crops–equal to something like a 6-mile swath from the western border to the eastern border of the state. Everything is sprayed with glyphosate and what little pollinator habitat we have is destroyed such that the monarch (and who knows what less visible species) are on the verge of extinction.

  • you know I believe that you are all wrong, GMOS are actually just “Zombie” plants, they are plants that have died and then the voodoo guy Joseph Kony Heals the plants and so that they are edible again. It’s cool.

    • First off all, ever heard of something called grammar? Second, where did you even get that from? Third, you think eating your so-called “Zombie Plants” is cool?! You don’t suppose they might turn YOU into a zombie?

Leave a Reply




You can use these HTML tags

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>