National Academy forum challenges anti-GMO claim that DNA in food 'invades' bloodstream

"Science knows it doesn't know everything. Otherwise, it'd stop."

Dara O'Briain's quip during a science comedy performance from a few years back succinctly summarized one of my favorite aspects of science. We're always making more of it. It never runs out. Unlike dogma--which Francis Crick amusingly misused to describe his hypothesis once—it's not fixed in place and time in some historical tome. Science keeps moving, keeping the valuable bits, discarding the unreliable bits, testing things, improving strategies and learning more about how we all exist in this universe.

If you aren’t participating in some field of science, though, it can be hard to keep up with the rapid pace of the research. Some of the data is also difficult to understand as an outsider. Relying on the news media is uneven—they may write catchy headlines touting single studies with dramatic claims—but typically they don’t return to follow up in a few years to see how those claims played out. This has been deemed “single study syndrome”. As a result, bad story piles on bad story, often tracing to an original poorly reported news account. Some responsible journalists are trying to draw attention to the problems of this type of reporting. But it continues to happen almost every day.

An illustrative example of the kind of single-study drama in genomics can be traced to a 2012 piece by Ari LeVaux in The Atlantic: "The Very Real Danger of Genetically Modified Foods". This article claimed that micro-RNA (miRNA) from normal rice was somehow damaging gene expression in mice. The actual researchers who performed this preliminary work had claimed that the small, fragile nucleotide molecules from rice were somehow capable surviving numerous barriers of digestion and absorption to ultimately turn down gene expression in mouse livers, possibly impacting their cholesterol levels (Zhang et al, Cell Research, 2012).

The piece was filled with errors, capably described and deconstructed by scientist and science journalist Emily Willingham, and other experts in the field were very wary of the claims of the process of how the process worked. LeVaux was forced to back away from the irresponsible statements such as:

The Chinese RNA study threatens to blast a major hole in Monsanto’s claim. It means that DNA can code for microRNA, which can, in fact, be hazardous.

Although the original research had nothing to do with genetic modification, LeVaux’s misleading interpretation of it took on a life of its own. It was widely adopted as dogma among folks who seek reasons to trash-talk biotechnology.

Some of the wildest and most irresponsible claims emanated from the same “green” and “progressive” web sites that regularly challenged the safety of vaccines. A typical example: “GM Wheat May Damage Human Genetics Permanently,” announced GreenMedInfo, a scientifically-thin but popular website frequented by alternative medicine advocates.

No study, no matter how well executed it appears to be, should stand alone. Research gains credibility or is discarded based on its ability to be reproduced. But it takes time to plan, fund and perform subsequent experiments, publish them and examine their context among other work in the field. Science journalists are rarely patient enough or able to publish follow up pieces on research findings that say—well, that didn’t seem to work out.

LeVaux never did, but at least there were some attempts to follow up, to examine the science and unscare people who might have been unnerved by the earlier claims amplified by the Atlantic fiasco. Virginia Hughes, writing at National Geographic, reviewed subsequent research indicating that sequence contamination likely explained why the original findings were not reliable.

And sometimes the data didn’t make sense — they found miR-168, for example, in animals that had never eaten food containing miR-168, suggesting that it could have been the result of a contamination....

Willingham also followed up with more details on the failures to replicate the initial claims, which also appear to include mistaken identity of the sequences.

They found, through a critical application of a new technique for identifying the RNA, that the alleged plant RNA was more likely to be native animal RNA, not RNAs ingested in the diet.

The GLP's Jon Entine also addressed the claims and the complicity of some mainstream organizations, such as Consumers Union, whose GMO policy is guided by Michael Hansen, and the Union of Concerned Scientists, where Doug Gurian-Sherman directed research before decamping to the anti-GMO Center for Food Safety. to circulate them.

Don’t hold your breath for rollbacks of their disgraceful journalism and public comments by LeVeaux ... Gurian-Sherman, Hansen and others whose statements have ranged from credulous to intellectually dishonest to fraudulent manipulation and misrepresentation of results. Expect chief GMO demonizer Jeffrey Smith—who is a charlatan—to continue to hype this unproven danger in his “analysis” of the “dangers” of GMOs. They are single study syndrome sycophants.

But these takedowns and few others didn’t have the reach and impact of the initial publication’s megaphone. As a result, these claims still show up on anti-GMO websites and are sometimes repeated in the mainstream press.

The study lived on in other ways. Some researchers really hoped that the original researchers had happened upon a mechanism that would allow delivery of therapeutic miRNA to cells, so work continued, even resulting in the filing of patents and companies hoping to capitalize on this research, if it should hold up. However, patents and companies’ basic research are not peer-reviewed and do not constitute evidence.

A recent scientific review of the work in this field noted that conflicting results, low levels of detection and non-physiological levels of miRNAs required for impacts suggest that “gastrointestinal uptake of dietary plant miRNA is not occurring in healthy consumers”. However, this story—that humans should not be concerned about absorbing foreign DNA from ingested food—did not exactly make its way into the headlines.

Another researcher recently told much the same story to the National Academy of Sciences panel investigating genetically-engineered crops with expectations of issuing a summary statement on GMO safety sometime next year. Stephen Chan, MD/PhD, Assistant Professor of Medicine, Harvard Medical School, is very interested in non-coding RNAs in his cardiovascular research and had been enthusiastic about the possibility of the delivery of miRNA to humans. Chan, like other researchers, became hopeful that diet-delivered sequences could have positive impact on humans.

In his talk Chan provided helpful context about the field of miRNAs and their possible functions, and the early claims about cross-species effects. He went on to note, though, that in the years after the original splashy study, “additional studies reveal systematic discrepancies” with the claims. His own lab was among those unable to replicate the initial research group. His research team looked at bees, mice and humans to locate any transfer of miRNAs across species. Levels of miRNAs that could have impact on gene expression simply weren’t found. (“Ineffective delivery of diet-derived microRNAs to recipient animal organisms”) This also did not grab headlines in the media, let alone at The Atlantic, which had run the original, now clearly discredited, story.

On one particularly effective slide, Chan summarized how much dietary miRNA would need to be present to have impact on gene expression in humans (~26 minutes).Mangan

Chan noted that you would have to eat over 1600 kilograms of cantaloupe to get the necessary 1015 copies of plant miRNA into the digestive tract. And that doesn’t even account for the fact that few miRNA would survive the harsh gastrointestinal environment to make it into the body’s tissues. It’s just not realistic.

“We’re not even in the realm of possibility of seeing the number of copies of miRNA, at least in the normal diet, in order to see this type of effect,” he said. Chan then pointed to other studies that suggest contamination of samples may explain some of the other instances of previously-described presence of plant sequences in other organisms.

In typical cautious scientific language, Chan concluded that the claims in the original work were driven largely by a single lab’s results, whose data has not been replicated in other labs. The miniscule miRNA levels detectable show that the original study’s findings were neither a “robust nor widespread” occurrence, and were more than likely the result of contamination artifacts. In one of the most telling statements, during the question period, he said that his lab has abandoned this work because it seems…well, fruitless, it sounded to me. Although he acknowledged there may be some special situations and other ways to deliver extraordinary amounts of miRNA, and that it’s fine for others to pursue investigations of such situations, this mechanism of dramatically affecting mammalian biology by ingesting miRNA from plants was unlikely.

And so, science moves on. But you won’t hear this ‘corrected science’ from anti-GMO activists and it’s unlikely to be reported in the media. In fact, some people continue to push the unsound early claims without telling you about the unsuccessful subsequent efforts to replicate them. For example, activist Jeffrey Smith peddled more iterations of the claims well after they were proven wrong:

And it’s now been shown that they can be taken up after digestion of the food into our blood supply,” he said. More importantly in a groundbreaking study conducted in China in 2012, dsRNA fed to mice “transferred to the liver and down-regulated an important liver enzyme".

Don’t let them play their shell game on you—where they point to one nugget, and wave their hands frantically to distract you from the real science. In the meantime, responsible scientists will continue to do the hard work, usually without fanfare or headlines. It’s hard to keep current in science, but it is crucial to making the best decisions to have the all the information. I applaud the National Academy of Science’s efforts to seek out the best and most current thinking on these issues. And I look forward to their synthesis of the evidence in their report and recommendations.

Mary Mangan, Ph.D., received her education in microbiology, immunology, plant cell biology, and mammalian cell, developmental, and molecular biology. She co-founded OpenHelix, a company providing training on open source software associated with the burgeoning genomics arena, over a decade ago. All comments here are her own, and do not represent her company or any other company. You can contact Mary via twitter: @mem_somerville

  • RobertWager

    Great read. thanks.

  • Amelia Jordan

    Bookmarking for later use!

  • mem_somerville

    Yes, Ena, the Boulder Weekly is a widely respected science publication. I know they get NIH grants all the time.

    Did you notice that the person in that article is the one that started that company that is linked above? Maybe she has financial interests in those things being true.

    But we’ll have to see how it goes. I look forward to her future work in the Boulder Weekly.

    • agscienceliterate

      Mem, do you mean the author of that puffy piece in the Boulder Weekly is a … a… a….. shill?? For her own company? I am deeply shocked.

      • A foil lined hat will protect you….

        • My real name is Jim Gordon, retired in Zephyrhills, Florida. Easily verified by anyone with basic computer skills.
          I need no degree to access the sum total of all English language data on the web. None of it legitimately supports your witch hunt.

          • An animal hospital is not your home address. I rely on unbiased privately funded peer reviewed science exclusively while you are spouting the ignorance of conspiracy theories. You fool no one here.

          • Good4U

            Ena seems not to understand that “sloppy” transgenics is happening all the time, and has happened since the beginnings of life on this planet. She seems ignorant of the fact that all living things share and trade genes at random, every second of every day. It’s happening in & on her own body, and in the soil, and in the entire environment in which she lives. She hasn’t the slightest clue about the pervasiveness of it, and will remain clueless for as long as she can draw a breath. A lost cause.

          • JoeFarmer
          • Andy

            Technically, Good4u’s comment was more of an “appeal to nature” and your comment was a “naturalistic Fallacy”.

            The fact that it does happens in nature often, shouldn’t imply that its inherently good or safe, but neither should novel RNA present any unique risk whether it was a product of natural mechanisms or human ‘intervention’.

            The illusion of risk, especially in decision making made by our(humans) own hands, is a fundamental part of the heuristic errors we often make, and should strive to avoid if we hope to have any bit of objectivity on developing technologies.

            Just an observation in an attempt to clean up the dialogue.

          • Bouldergeek

            The Boulder Weekly LOVES conspiracy theories! Rock on, Ena!

  • Andy

    Ena, “I’ll plant some science for your edumification, right here.” Pun Intended?

    @mem_somerville:disqus hey… don’t mock Boulder, i’m a local! lol
    Though honestly, the article doesn’t do much in supporting the argument made Ena, i believe served more as political rant, THOUGH it shows how divided industries can be, especially with the ending comment (rootworm comment) being void of any real practical understanding in agriculture. As the article correctly points out, BOTH the medical and Agro industry obviously have dogs in this fight, and I would not be surprised to find some sort of bias confirming their perceptions of trans-kingdom cross barriers. Fortunately, science exist outside the 2 industries and doesn’t rest on either’s assumptions of the implications or the lack thereof.

    Back to Ena:
    I must ask… are you intentionally setting up a false dilemma with the comment “I’ve seen no compelling evidence yet disproving trans-kingdom gene regulation by RNAi-that you are trying to deny”? Where did article state it denied ‘trans-kingdom gene regulation” ? It seems you are misinterpreting or perhaps misrepresenting the article. And I fail to see what relevance the studies you’ve posted have on the topic discussed in the article. Are you suggesting these studies are analogues to human ingestion? If you could clear that up, id appreciate greatly.

    Further, I am bit concerned with your last comment “Your arguments, I am afraid- don’t compensate for the lack of rigor and precision in the sloppily engineered plants currently on the market…”

    I am curious as to, in your opinion, what constitutes ‘sloppily engineered plants’?

    I’m trying my best to grasp what you are attempting to communicate with you comment as a whole.

    Thank you

    • Define how ‘sloppy’ compares to the absolutely random mutations of every sort that occur in nature. How many ‘sloppy’ mutations have happened in the last 4.3 billion years and how many of those somehow circumvented the natural selection process?

    • Loren Eaton

      “Sloppily engineered plants contain backbone of vectors, superfluous DNA, truncated DNA, multiple transgenes, truncated proteins, unclassified fusion proteins and expressed latent allergens….” Really? In my world, such plants never make it to the greenhouse much less to the field or the market. Got any data to back this up? Oh and most of the putative allergens can be detected by sequence before they ever make it into the lab. We transformers never see these.

    • Andy

      I understand that… I looked at the figures you cited. I fail to see your argument/point. You seem to be arguing against a point in the article that doesn’t exist.

      and now you say…”please post some studies on the commercialized GMOs as well as studies proving that commercialized GMOs aren’t inadvertently silencing animal and human genes, given the fact that there isn’t a single study anywhere showing that dsRNA gets degraded in a mammalian gut.”

      Why are you putting the burden of proof on me? Did i make an assertion to contrary? You seem to be resorting to an argument of ignorance, as you’re implying that the lack of a “single study anywhere showing that dsRNA gets degraded in a mammalian gut…” supports your previous assertions.

      Thank you for the citations… clearly verifiable information. But the hypotheticals or things that haven’t been “ruled out” are not my concern at the moment. I’m concerned with what is empirically proven.

      Btw, if this were true, the implications would be far bigger than ‘GMOS’, most food products would need to be re-examined… dont you think? Its misleading to suggest there’s some inherent random risk that doesn’t exist within other breeding techniques or natural mechanisms.

      You’re clearly educated enough to understand the data, but i’m not sure your education speaks to your objectivity on the subject.

      Btw, i’m not trying to be complicated here. I’m seriously just trying to grasp your argument. It feels like connect the dots, and in my field of study, that typically implies some sort of confirmation bias. I’m very critical of opinions the more critical the opinions are.

      • Andy

        Thanks for clearing that up.

        So basically, you are arguing for the validity of the ‘zhang study’ and suggesting their is an inherent risk found in ‘gmos’ that should be researched before they hit the market?

        Is that correct?

    • Bouldergeek

      Andy, we both see a lot of political rant in Boulder!

  • Bouldergeek

    The Boulder Weekly??? That’s a laugh! Not exactly a pro-science journal. It’s a lib-rag with lots of woo woo. Only one writer in there who respects science.

    What in the heck do you mean by “edumification”? Never heard of it. It sounds scary. Let’s label stuff with edumification in it. Or better yet, write an article about edumification in the Boulder Weekly, urging a ban! Yeah!

  • Good to see that Ena is training for The Onion.

  • You forgot to mention those microscopic swastikas and devil horns that can be seen with a scanning electron microscope on the strands of evil GMO genes…

  • mem_somerville

    Ena, dear, it’s not enough to read literature. You need to try harder to keep up. That was sort of the point of this article.

    I saw your other references. They were older than the prestigious Boulder Weekly article. My piece specifically asks folks to join in keeping up with progress in science.

    I know that since you aren’t in research, this is probably harder for you. But it’s really important that you try if you are going to be making claims about the science. Or, alternatively, don’t. That’s fine. Regulators are clearly doing that, and it will just make your rants easier to dismiss.

    • mem_somerville

      Oh, c’mon, we all you are licensed to prescribe things. I’m sure–quite sure–you have access to whatever makes you write what you do all the time.

  • Bouldergeek

    Oh, yes; like the Boulder City Council will SO approve “fortifying our municipal water supply with tumor suppressing miRNA.” ( It would benefit your bottom line if they did, tho, right?)

    Will putting it in our water suppress “edumification” you refer to?

    What are you smoking?? Like Jon sez, your comments are perfect for the Onion.

  • amused observer

    Its interesting to observe that only one person attempted to engage Ena in a discussion about science, the rest got defensive in all manner of ways. Perhaps it is those people who deflected her question who are not literate on the complexity of genetic modification. Maybe it should be called the genetic illiteracy project?

  • JoeFarmer

    “I wont be answering you at all.”

    But then you did. You’re a real genius!

Send this to a friend