No more “debates” about GMO safety–thanks to trillions of data points

GMO-protestAs I’ve written a few hundred times before, there’s really no such thing as a “debate” in science, at least in the sense that two sides argue in front of the public, and then there is vote on who is “right” or “wrong.” All that matters in science is the quantity and quality of evidence, that’s it. Yes, sometimes scientists do argue about evidence, but that’s usually done in peer reviewed articles, notes, and other forms of communication. It is mostly civil. And eventually, the evidence drives to a consensus.

Only to the public is there a delusion that there are debates on science. You might think there are debates about anthropogenic global warming, evolution, vaccines, HIV/AIDS, and GMO/biotechnology, but there really isn’t. Scientists aren’t sitting in bars across the world throwing bottles of beer at each other because everyone is divided between pro and anti-GMO. Because that’s just plainly not happening.

When I read that 97% of climate scientists support the fact of global warming or that 99.4% of natural scientists agree with the fact of evolution, it implies that there’s some sort of vote. But if there were, it would be, what we call in US elections, a landslide. But in reality, scientists come to a consensus about broad principles over time, and that is based on published evidence, not logical fallacies or bad data.

Scientific consensus

Scientific consensus isn’t based on personal preferences or political expediency. It is based on the agreement of experts about a scientific idea based almost exclusively on what is published. There isn’t a board of Scientific Consensus appointed by the world political leaders, it is done by the experts in the field.

As an aside, it is important to note that there isn’t a distinct line between a consensus and a scientific theory. There is a continuum from an early consensus to an accepted scientific theory (which sits at the top of scientific knowledge). And sometimes it’s when a new idea is introduced, the actual consensus is against it, but enough data builds up over time to move some obscure crazy idea to a widely accepted scientific theory. Data matters. Not your opinion. Not a laughable political debate. Not cherry picking data to support your personal point of view. The consensus is developed by ignoring confirmation or observation bias, and seeing what the wealth of data says.

There’s a scientific consensus on climate change. For example, here is the consensus position of the American Association for the Advancement of Sciences (AAAS) on climate change:

The scientific evidence is clear: global climate change caused by human activities is occurring now, and it is a growing threat to society. Accumulating data from across the globe reveal a wide array of effects: rapidly melting glaciers, destabilization of major ice sheets, increases in extreme weather, rising sea level, shifts in species ranges, and more. The pace of change and the evidence of harm have increased markedly over the last five years. The time to control greenhouse gas emissions is now.

The AAAS isn’t some mysterious organization inventing ideas about scientific issues. The American Association for the Advancement of Sciences is an international non-profit organization that has as its stated goals to promote cooperation among scientists, to defend scientific freedom, to encourage scientific responsibility, and to support scientific education and science outreach for the betterment of all humanity. It is the world’s largest and most prestigious general scientific society, and is the publisher of the well-known scientific journal Science

And the AAAS has also released another statement of consensus science on genetically modified foods (pdf):

The science is quite clear: crop improvement by the modern molecular techniques of biotechnology is safe … The World Health Organization, the American Medical Association, the U.S. National Academy of Sciences, the British Royal Society, and every other respected organization that has examined the evidence has come to the same conclusion: consuming foods containing ingredients derived from GM crops is no riskier than consuming the same foods containing ingredients from crop plants modified by conventional plant improvement techniques.

Although many of my readers will agree with both of those statements, ironically, there will be one group who will accept the former and ridicule the latter or vice versa. The thing is, the scientific basis of both are so solid, so overwhelming, so beyond reproach, that I have strokes when I read someone who has lambasted anti-GMO activists, based on the science, but then will attack anyone who supports human influenced climate change. I know it’s ridiculous to want people to be consistent about science, but I can hope.

Scientific evidence and systematic reviews

As I’ve said several times here, the only thing that matters is evidence. Not magic. Not your own cognitive bias. And the quantity of evidence is almost as important as the quality of evidence. Too many times, people who want their point of view, their beliefs, to be the consensus (as delusional as that is) will pick the pieces of data that supports their conclusion, instead of looking at all the data and developing a conclusion from that.


Sometimes, it’s hard to determine the quality of evidence, so I wrote about a hierarchy of quality of evidence. At the bottom, anything written in anti-science publications, like Mike Adam‘s Natural News. But sticking with published science, there is a hierarchy there too. Too often, writers will take a single piece of primary research (that is data from one study, not repeated anywhere else) as if it is gospel. Moreover, much primary research is in very small populations for clinical studies, or are strictly animal data. I hate repeating myself, but science has discovered a cure for cancer thousands of times in mice. Only a microscopic portion of animal research ever becomes relevant clinically to humans.

At the very top of the hierarchy of evidence are Systematic Reviews. The reason why “systematic reviews and meta-analyses are so important: we need to bring together all of the evidence on a question, not just cherry-pick the bits that we stumble upon, or intuitively like the look of.” (See Goldacre, Ben. Bad Pharma: How Drug Companies Mislead Doctors and Harm Patients, p. 18. Faber & Faber. Kindle Edition.) Systematic reviews and meta-analyses bring together data from numerous studies, rolling up the data into one giant analysis, hopefully eliminating bias and errors. A study of a medication that might have 3000 patients is good, but if a researcher then analyzes the 20 studies of the same drug, it now includes 60,000 patients. By doing so, one might uncover a rare adverse effect in a specific group that should be known by prescribing physicians. Or one can uncover a specific disease improvement using a different dose.

Systematic reviews are incredibly powerful tools, as long as the study is unbiased and includes data points from all but really poorly done studies. The Cochrane Collaboration is world renowned for their systematic reviews, but almost every top-notch scientific journal publishes those reviews, especially in controversial or topical research areas.

And systematic reviews become the basis of the scientific consensus. The AAAS did not issue their statement about the consensus of global warming or GMO’s because of a public debate with politicians, deniers, and some guys in the pub drinking beer. No, they based it on published evidence that represents the totality of knowledge in the field.

There have been more than 2,000 studies, including over 100 that form the basis of scientific consensus, that have documented that GMO foodstuffs do not pose a threat to human health, the environment or other animals. Genetically modified foods are as safe or safer than conventional or organic foods. Despite that high quality evidence, despite the lack of any plausible physiological hypothesis that would explain how a GMO food could possibly effect a human being or environment, and despite the lack of real evidence that GMOs might cause harm (unless you think that Séralini’s retracted article counts for something), there remains significant concern in the public about GMO foods.

100 billion livestock

Recently, an article was published in the Journal of Animal Science, that reviewed the impact of genetically engineered (GMO) feedstuffs on livestock. Given that livestock consume 70-90% of genetically engineered foods, it’s like a giant clinical trial of GMO foods. Geneticist Alison Van Eenennaam and research assistant Amy E. Young, both from the University of California-Davis, systematically analyzed nearly 29 years of livestock productivity and health data prior to and after the introduction of genetically engineered animal feed.

The study examined data from nearly 100 billion livestock (which represents trillions of GMO meals), a robust amount of data by any classification. According to the authors,

Several recent comprehensive reviews from various authors summarize the results of food-producing animal feeding studies with the current generation of GE crops. Studies have been conducted with a variety of food-producing animals including sheep, goats, pigs, chickens, quail, cattle, water buffalo, rabbits and fish fed different GE crop varieties. The results have consistently revealed that the performance and health of GE-fed animals were comparable with those fed near isogenic non-GE lines and commercial varieties (emphasis mine).

Now this study isn’t perfect (but only in the world of false dichotomy of anti-science is evidence supposed to be “perfect”). The study is observational, meaning that there was no control for confounding factors, such as location, or type of feed, or anything. But, and this is a very important but, when n=100 billion, the data and statistics become so powerful, that it overwhelms potential weaknesses of the study. For example, it would be a wonderful world, if science could study a new medication by enrolling a billion patients (ignoring expense and time). Yes, data becomes stronger with size, and 100 billion is approaching infinity from a statistical point of view.

Steven Novella, at Neurologica Blog, basically says the “debate” (again, only in the public conversation, hardly at all in the scientific community) is over:

We now have a large set of data, both experimental and observational, showing that genetically modified feed is safe and nutritionally equivalent to non-GMO feed. There does not appear to be any health risk to the animals, and it is even less likely that there could be any health effect on humans who eat those animals.

In order to maintain the position that GMOs are not adequately tested, or that they are harmful or risky, you have to either highly selectively cherry pick a few outliers of low scientific quality, or you have to simply deny the science.

Here is a comprehensive list of animal feeding studies. Many of these studies are independent. The list included systematic reviews, all of which conclude that GMO feed is safe.

There is as strong a scientific consensus that GMOs do not present any novel health risk, that those in current use are safe, and that they pose no health risk to animals or humans, as there is a consensus for the safety and efficacy of vaccines or that humans are contributing significantly to global warming.

There’s really nothing else to add.


  • The scientific consensus says that GMOs are safe.
  • Only a few cherry-picked published outliers contradict this consensus. And those are awful studies of poor quality.
  • A robust study published in a high impact factor journal looked at 100 billion livestock of all kinds (fish, cattle, pigs, etc), and found no adverse effects
  • Denying the safety of GMO’s use the same logical fallacies and poor science as global warming deniers. The exact same.
  • GMOs are safe

Key citations:

The Original Skeptical Raptor
Chief Executive Officer at SkepticalRaptor
Lifetime lover of science, especially biomedical research. Spent years in academics, business development, research, and traveling the world shilling for Big Pharma. I love sports, mostly college basketball and football, hockey, and baseball. I enjoy great food and intelligent conversation. And a delicious morning coffee!

37 Replies to “No more “debates” about GMO safety–thanks to trillions of data points”

  1. Skeptical Raptor blog emailed me and said “I use the red flags of pseudoscience all the time. You invent straw men arguments because, you don’t have scientific evidence. YOU are a lazy little ignorant punk. You lack basic knowledge.” other places you said to others: “Because you’re not very intelligent. You’re just a fucking dumbass”. Hard to argue with that kind of scientific high tech type of talk . Calling people names – that’s my red flag. You didn’t think there was mercury in some if not most HFSC – here’s my answer to Warren Lauzon

    Warren Lauzon emailed me from Disqus commenting on my comment about HFCS contaminated with mercury from the NaOH used to make it and said “That whole mercury thing is just silly. I would be curious as to where you got that information.” Not sure how this “DIsqus” thing works but after a barrage of personal insults from the Skeptical Raptor’s blog blogger I figured screw you guys. You are most likely Shills for the industry trying to stop any intelligent discussion by demanding “peer reviewed journal articles”. Here’s where mercury gets into NaOH: Corn starch is extracted from corn in a process that soaks the corn in an acid solution and the liquor is neutralized with NaOH prior to centrifuging or there is an alkali process that uses sodium or potassium hydroxide. Mercury is probably coming from industrial mercury cell process alkali. Mercury also comes from dental fillings so I guess it is safe (not). Detecting mercury in humans is not all that easy as you may or may not know. The levels of mercury in foods is easier and foods containing HFCS have been shown to contain mercury. I did not do the testing but I believe I have read this in enough reliable places to think there is probably something to it:

    I would also point out that there is a phony case of a person dying from GMO tomatoes that contained a fish protein – the guy supposedly died as a result of anaphylaxis from fish allergen. He had no idea the tomato was really part fish..Ha ha, just the type of red herring stuff used to throw people off a potentially real problem with GMOs:. food allergy is going up and up. Shills have been exposed. I don’t think that tomato story is too far from what could actually be happening in some people with bt toxin or another actually real protein that cause sensitive people to suffer. I don’t want my rice to give me botox. The issue for me is that I don’t want to eat glysophate soaked food. Glysophate is the neurotransmitter Acetylcholine made toxic with the addition of a phosphono on the Nitrogen. Looks kinda like a neurotransmiter and in fact is an acetylcholinesterace inhibitor. There are may other examples of why GMO and non-GMO are not the same and the logic used to “convince” people they are is laughingly mathematically ridiculous, saying basically “because any mutation can happen in nature, any mutation that we cause is no different than what can happen in nature – Yea, in a trillion years maybe, completely ignoring survivability and long tern historical nutritional functionality. GMO is not the same as non-gmo but arguing intelligently or mathematically or scientifically with you guys and your name calling is impossible. Go ahead, eat that crap and cover it with a healthy portion of corn syrup.

  2. You might have missed something on the “Trillion-Meal” study. The study author, Alison L. Van Eenennaam, is an ex-Monsanto employee, and there’s also this :

    “Nearly 95 percent of the approximately 100 billion animals in the
    study are broiler chickens. These chickens would have a natural lifespan
    of about 5 years, but they don’t live anywhere near that long in food
    production. Most are killed in their first 49 days.

    In other words, this isn’t a long-term study of animals living a full
    life-cycle. Instead, it’s mostly a study of 19 years’ worth of data on
    49 day-old chickens.”

    From here, where the study is classed as junk :

    1. Interesting, Rob. Do you think that someone’s professional background—someone who actually is familiar with the topic—disqualifies them from addressing this subject? Have you considered that someone who is familiar with a field might actually have a relevant opinion? Or do you trust someone like a plumber (rather than a brain surgeon) to have a more valid opinion about brain cancer because they have no experience in the field?

      Honestly, not meaning to sound personal, but if you are going to raise the topic of someone’s professional background, it would help for you to tell us more about your own. Rather than speculating about people’s motives or integrity (just as it would be futile to speculate about your motives or integrity), I would encourage you to discuss the specific merits of the subject.

  3. Excellent piece, ‘raptor. The challenge is how to reach the members of the general public who need to understand your argument. Even harder is to point out people’s ignorance without making them wrong or pissing them off. Scientists are especially comfortable dealing with ignorance and ambiguity—that’s their job—but this is unpleasant territory for most people.

    I suspect that it is no accident that many of the most vociferous anti-GMO activists are not scientists: there is probably far less cognitive dissonance to cope with. The challenge is no longer science, but politics, which is fundamentally about controlling opinions and actions, and much less about what is objectively true. This is where many of us scientists are out of our depth.

    One comment. A lot of what looks like “consensus” in science is actually just an unquestioning acceptance of small, seemingly-consistent observations. Being human, scientists are also plagued by confirmation bias.

    I think you may be putting top-tier journals like Science or Nature on too much of a pedestal. Research papers are typically what an author believes to be true, for which there is some evidence, and which persuade a couple of reviewers. If you pick a 20 year old biological research paper at random, chances are that a lot of it turns out to be untrue, or hopelessly simplistic. This is why true consensus depends on multiple observations from many different research groups, over a substantial period of time. One day, someone may yet discover a hidden flaw in GM plant technology, but for now, the consensus is clear. In any case, it’s just a “technology” or tool, not a fundamental scientific principle. I have no doubt that one GM crop, some day, will turn out to have problems—and the solution will probably involve applying some better technology.

  4. Yeah but what about that genetically modified celery in Colorado that they spliced with the genes of an internet troller and it got away and has been pestering people on the net ever since? Do we really want more of those running around? – half way through typing that i realized that i just found my new Disqus profile description – BRB!

  5. I’m disturbed by the lack of unbias science or real science at all, and the fact that no sudies or references have been noted to support the ignorant statements made above except a generalized reference to scientific concensus and how this is achieved in America. I think the question should be what are the souces of the published sudies? and once you know that over 95% of the research in the field of GM crops is by the exact companies (whether hired third party or not) that profit from positive outcomes, you may start to feel differently. the 95% makes for a great confidence interval and easily brought to a consesus of scientist that are only analyzing data infront of them and not the unpublished papers on studies that have been suppressed by defamation and slander suits by deep pockets of huge multinational corporations.. Does this artical or topic in general even make sense to debate; huge corporations trying to be do gooders and save the world from hunger as if a corporation would even care about starving kids in Africa? The US feeds over 85% of GM corn and Soya to animals in factory farm…these corporations aren’t sending the cattle overseas to irradicate kwashiorkor (serve protein deficiencies) America is getting fatter, animals are force feed and the starving children overseas don’t see a dime from the profits that have skyrocketed in the last 20 years in agrabusiness. And you propose that we, the PEOPLE, have hidden agendas or are being delusional? Wake up my friend and look for the truth, not what slanted statistical analysis will give you the consences vote. My lastquestion would be; who paid you?

    1. 1. Search my blog. I have well referenced articles on GMO’s. If you’re too lazy, that’s on you.
      2. Generalized statements about consensus. Bullshit. I said the AAAS, the American Association for the Advancement of Science, the most prestigious scientific society on the planet, the group that publishes the journal, Science, the most prestigious scientific journal on the planet, established the consensus on GMO. It’s up there in THIS article, but apparently you are too lazy to read it.
      3. You conflate “open-mindedness” with what you do. You are close-minded to science, which is a process to evaluate evidence, and then determine whether a particular hypothesis is supported or nullified by said evidence. It’s a thinking process, which is completely open minded.
      4. You provide NO EVIDENCE of any kind that supports your ignorant viewpoints.

      Otherwise, you’re just a close-minded ignorant fool. Hard to have a conversation.

  6. I’m Pro-GMO when it comes to making human hormones for medicine (like insulin using e-coli) – However, saying GMO food is safe for everyone, sneeking it into everyone’s food and using the “Science red flag tactics” (see ) that are all over the “pro-GMO for everyone” advocates web pages to discredit anyone (ludites, global warming deniers, cherry pickers) (“The anti-GMO crowd is mostly lazy. (Don’t they say that about indians and negros?) They have this luddite belief that all technology is bad….”) Someone who worries that eating bt toxin and extra glyphosate might just not be the best thing for their children given that DES and thalidomide were FDA approved might not be such stupid lazy ludites!

  7. So feedlot cows are healthy for the whole 90-120 days they eat GMOs before we kill them. How is that relevant to a human unknowingly fed GMOs for YEARS? We don’t send our kids to the slaughterhouse after 3 months. The logic is not that difficult. You can argue about safety til the cows come home. My beef is about transparency and informed consent.

    1. You didn’t read the study. It was not “feed lot cows.”

      And please provide one single plausible physiological pathway that might, just might, cause a GMO plant to affect a human. I’m waiting, because there isn’t one. You’re trying to fear monger based on some ridiculous notion, called the Argument for Ignorant, that if someone can’t prove A in all possible scenarios, then it must therefore be B.

      I don’t care about politics in science. I loathe left-wingers that deny GMOs. And I loathe right-wingers who deny climate change and evolution.

      Science answers questions through logic and a defined, unbiased process. YOU have a conclusion, and accept data, as rare as it is, that says GMOs are bad, and reject data that says GMOs are probably. You are NOT scientific. Your blog post was filled with logical fallacies and complete science denial.

      Greenpeace is a terrorist group. They think climate change is real. Oh fuck, I better change my mind, because I’m so illogical and lazy, it’s clear that only terrorists are in support of climate change. That’s YOUR illogical pathway.

      Here’s the thing. The AAAS, the most prestigious, most scientifically responsible group in the world, stated that the scientific consensus is that genetic modification of plants, something we’ve been doing for 10,000 years, is utterly safe, and important for feeding the planet. You get off your fat, privileged, wealthy ass, go to a real college, get a Ph.D. in a biomedical science, do research that supports a hypothesis separate from the consensus, publish, and then argue with the top scientists on the planet. If you do that, I’ll bow to your brilliant mind.

      Global warming deniers and anti-GMO types are one and the same. They are entitled, wealthy people who only care about themselves. They do not care about their fellow man.

      GMOs feed the planet. Oh wait, I know, you want to convert the world to “natural” food, so that 3.5 billion people will starve and die. And you’re entitled liberal ass will run the planet. Damn, that’s the same exact thinking of the entitled conservative asses who want the rising seas to kill off the poor and dark-skinned so they can run the planet.

      Both of you are sociopaths.

      1. “global warming deniers and anti GMO types are one and the same”

        100% correct. what do you suppose it is that causes them to behave this way? My dad is the worst, he has absolutely no business ties that would cause him to need to get so worked up about atmospheric pollution but he insists that he for some reason or another knows better than 98% of the scientific community. The anti GMOers are just as bad. Its like there is some large emotional tie coming from somewhere. This is a first world problem gone horribly wrong, not only do we live a life that allows us to stick our nose up at food we don’t like but we also have people so selfish that they will travel to starving countries and tell them to stick their nose up to food that doesn’t meet their overfed standards. I simply don’t get them.

  8. “when n=100 billion, the data and statistics become so powerful, that it overwhelms potential weaknesses of the study”

    no it doesn’t. what it does is make a poorly controlled study more an more subject to type 1 errors (because you are artificially inflating the n to reduce the variance). that is, assuming that the non-controlled for factors could be skewing the data in unexpected ways.

    c’mon, you should know that basic truism of statistics, right?

  9. “Published evidence that represents the totality of knowledge in the field” seems nowhere near sufficient to make a claim of safety. I refer you to a quote from Craig Venter … one of the first to sequence the human genome … “As a civilization, we know far less than one percent of what will be known about biology, human physiology, and medicine. My view of biology is, ‘We don’t know shit’.” As a technologist myself (computer engineer of ~30 years) I can speak volumes of the importance of understanding all of the relevant details before suggesting deployment. Especially since we’re talking about genetic changes that aren’t possible to recall.

  10. Nope I will stick with my NON-GMO foods. Something about eating something that has a gene in it to cause a bug to explode just doesn’t seem like a thing I want to eat. Its a choice.

    I do find it funny though that 30 years ago the consensus was we were heading for a new ice age. What ever happened to that one?

        1. Yeah, it made the cover of a few magazines because the idea was new & it sold issues….but when you looked at the actual Science, it was easily refuted and the consensus & evidence backed what we have today.

    1. We’ve been doing this for 10,000 years. It’s just that 10,000 years ago, we had to artificially select for genes that showed up by “natural” mutation. Or those ancient farmers figured out how to induce mutations.

      And there was no consensus about a new ice age. Most climate scientists thought that we’re heading for global warming in the 70’s and 80’s. You’re conflating weather and climate, like most deniers do.

  11. Unfortunately, Doctor, with the exception of a few outliers, you’re preaching to the choir here. We have long known GM tech is safe, human-caused (can’t spell the actual term) Global Warming is real & happening, and that vaccines are safe & save millions (billions?) of lives.

    We need to get this information out to the widespread media. Is there some way to reach out to Dr. Tyson, and/or Seth McFarland, and get this on Cosmos, or something similar?

    Heck, maybe with a show like Cosmos there could be an episode, or two, ridiculing fools like Mike Adams, Vadana Shiva, “Dr” Oz, Vani Hari, Joe Mercola, Deepak Chopra, Jenny McCarthy, Rob Schneider, and their ilk. Maybe that would convince people not to listen to them.

    One can hope, right?

          1. Ummm, hate to be picky, but cows are fed wheat. if you get a poor crop or if it is damaged, frost, hail, etc. you just bale it and sell it as feed for cows. Happens all the time.
            Other than that I love all your other responses. Keep up the good work.

        1. “Cow killing wheat”. Hmm OK. How about: it was not wheat, it was Bermuda grass, and it was not GMO grass. Not to mention that there is no GMO wheat commercially grown, only some test fields.

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