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The Very Real Scaremongering of Ari Levaux

The views expressed are those of the author and are not necessarily those of Scientific American.


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Recently, food columnist Ari Levaux wrote what can only be described as a completely unscientific article in The Atlantic claiming that microRNAs (miRNAs) are a “very real danger of GMOs.” I won’t go point by point through the horrendous inaccuracies in his piece, as Emily Willingham has more than hacked them to bits. But I do want to make a short comment on this idea that miRNAs are dangerous, and thus something we should worry about when it comes to what we eat.

Every plant and animal out there produces miRNAs. We, for example, are thought to produce thousands. These teeny-tiny snippets of RNA serve regulatory roles in our cells, attaching to bits of messenger RNA and causing changes in expression of different proteins. They are far from evil: indeed, miRNAs are necessary for cells to function properly.

Can miRNAs we eat alter our gene expression? Well, yes. That was the incredible scientific discovery made by the Chinese research team that was recently published in Cell Research. But to make the leap from ‘miRNAs we eat can alter gene expression’ to ‘GMOs are dangerous’ requires unbelievable gaps in understanding about GMOs and miRNAs.

First off, there’s no reason to think that the DNA being introduced into GMOs is going to produce more/different miRNAs than it did in the original organism. Ari’s claim that “new DNA can have dangerous implications far beyond the products it codes for” simply isn’t true because miRNAs are coded for. These small RNA fragments aren’t random or accidental – they are explicitly detailed within the genome. So a stretch of DNA that didn’t code any miRNAs before isn’t going to suddenly code for a ton of them when it’s placed in a different genome. If we’re worried about potential miRNA effects, we can screen genes we are considering transferring and determine if there is any chance they produce miRNAs before we shuffle around which organism they are in. Indeed, GMOs are tested genetically, to ensure that the target gene has incorporated properly and that the organism is producing the desired protein, and not unexpected products. Genetic modification is a very precise process, and there is no reason to think it would cause a sudden burst of miRNAs.

But perhaps more fundamentally, miRNAs are found in all kinds of life, including every single species that we currently eat. There’s no logical reason that a new miRNA being produced by a GM plant is going to be more dangerous than the multitude of miRNAs we ingest when we eat the non-GM version.

In fact, the potential side effects of non-GM food is, very explicitly, what the Chinese research team showed: that of the millions of miRNAs we eat every day, at least a few make it from our stomachs into our blood, and that a specific one from ordinary rice can change the expression of genes in mice. So if miRNAs are dangerous – guess what? – you’re already ingesting them every time you eat. And, to get a little gross, let’s be clear: when we eat something, we don’t just ingest the miRNAs from the species we intentionally eat. Did you know, for example, that foods you eat are allowed to contain mold, hair, insect parts, and even rat poop? All of those bits of organisms which we inadvertently eat have DNA, and – you guessed it! – miRNAs, too. If miRNAs are so dangerous, we would never have been able to eat anything previously alive in the first place.

But we can eat other organisms, and we will continue to, because, simply put, miRNAs aren’t that dangerous.

Perhaps what ticks me off most, though, is that Ari’s scaremongering overshadows the very real and interesting implications of the science he failed to cover. The notion that miRNAs may drive some of the interaction between us and our food is incredibly new and totally cool. As the authors write, their research suggests that “miRNAs may represent a novel class of universal modulators that play an important role in mediating animal-plant interactions at the molecular level. Like vitamins, minerals and other essential nutrients derived from food sources, plant miRNAs may serve as a novel functional component of food and make a critical contribution to maintaining and shaping animal body structure and function.”

What if some of the benefits of drinking wine aren’t from the antioxidants, but from the miRNAs present in grapes? What if we can produce beneficial miRNAs, and take them like we do vitamins? Or reduce the expression of harmful ones? Suddenly, we have been given a sneak peek at a whole new facet of nutrition science that we didn’t even know existed. The amazing implications of this research – not some ludicrous and tenuous connection to anti-GMO propaganda – should have been what The Atlantic highlighted. Instead, they made a fool of themselves by allowing Ari Levaux to expose just how poorly he understands genetics.

Christie Wilcox About the Author: Christie Wilcox is a science writer and blogger who moonlights as a PhD student in Cell and Molecular Biology at the University of Hawaii. Follow on Google+. Follow on Twitter @NerdyChristie.

The views expressed are those of the author and are not necessarily those of Scientific American.





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  1. 1. Ari LeVaux 11:34 am 01/12/2012

    True, it was not a scientific article. That’s why it was published in the Atlantic and not Nature. That’s the most important point you made in your post.

    For the record, nowhere in my article did I state, or even imply, that miRNAs are dangerous. The headline clearly did, but I had no control over that. In fact the editors chose that header over my objections.

    I did clearly point out that I thought miRNA COULD be dangerous, especially in light of the fact that they appear to survive digestion.

    Repeat: I did not say that miRNA is dangerous. I am not afraid to eat miRNA, in rice or sushi or whatever. Deal with it, you guys. By that logic I wouldn’t eat “herbal medicines” either, since I mentioned miRNA might explain some of those functions, right?

    That said, I acknowledge there were some significant scientific errors in my Atlantic piece, and my argument could have been stronger. With a lot of help from great thinkers, some of whom didn’t agree with me, my rewrite posted yesterday on Alternet.

    Here’s the link: http://tiny.cc/v9svh

    Warning: I did not write the headline to this one either!

    Link to this
  2. 2. Bora Zivkovic 11:59 am 01/12/2012

    Every time I see the “I didn’t write the headline” excuse, I want to ask:

    - did you send a suggestion for the headline with your article? (yes, they will often use yours if you just send them one)
    - did you ask to see the headline before the article goes live? (yes, they will let you know in time so you can correct)
    - did you protest if they put a bad headline anyway? (yes, they will change it if they screwed up).

    This is basic writers’ hygiene.

    Link to this
  3. 3. sireader 12:04 pm 01/12/2012

    I am no scientist but I have to ask.

    If we are still finding things that are “incredibly new and totally cool” about how the genetics of food works and affects our bodies, then is it safe to say we don’t know “everything” about the kind of impact GMOs will have in the long run?

    Is it totally impossible that something in the science of GMO might be misunderstood and cause widespread damage to existing major food crops around the world?

    You seem to know a lot about genetics, for a PhD student, but it seems to me to be common sense that “anything previously alive in the first place” was also never artificially “genetically modified”. Could you ever “naturally” combine the genetics of a cow and a fish?

    It seems to me that no matter how you slice it, we are bringing things into existence that would never have happened naturally.

    It’s one thing to confine these experiments to the lab, but you’ve got companies like Monsanto who send this stuff into the wild everyday on a huge scale.

    I’d love to know Ms.Wilcox’s take on exactly how sure of itself Genetic Science really is and how responsible she thinks companies like Monsanto are in this regard.

    However,
    @Ari, please don’t feed the faux news crowd. They don’t know the difference between reality and fiction, much less the difference between the atlantic and nature.

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  4. 4. kclancy 12:08 pm 01/12/2012

    The Atlantic covers science. I’m not sure how the piece being in the Atlantic absolves it of being accurate.

    Ari also wrote: “I did clearly point out that I thought miRNA COULD be dangerous, especially in light of the fact that they appear to survive digestion.

    Repeat: I did not say that miRNA is dangerous.”

    As Emily and Christie have already pointed out, there is no reason to think miRNA is dangerous or that GMO veggie miRNA is more dangerous than regular veggie miRNA. I’m not saying I fully embrace all GMOs. I just think we need to apply hefty skepticism to both sides of the argument.

    Also: if you aren’t really that careful in your wording, is there really a difference between saying something COULD be dangerous and something absolutely IS dangerous?

    Link to this
  5. 5. Ari LeVaux 12:08 pm 01/12/2012

    @Bora

    The suggested header was “A new mechanism for genetically modified problems.” In retrospect it wasn’t the greatest, but certainly would have not ignited the firestorm that the one that ran did.

    I did not ask to see the story. I’d love to. Eds don’t seem to like to share that with me. I’m always trying to change photos and headers.

    I did protest. The only modification I got was a slight change to the subhed, substituting “microRNA” for DNA after @ejwillingham pointed it out in her post.

    Thanks for sharing the basic writers’ hygiene. I love it.

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  6. 6. kclancy 12:10 pm 01/12/2012

    Also sireader, what does “You seem to know a lot about genetics, for a PhD student” mean, exactly? That getting a PhD gives you more knowledge? I have a PhD, in a science no less, and probably know a tenth as much about genetics as Christie.

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  7. 7. Bora Zivkovic 12:11 pm 01/12/2012

    We have been genetically modifying our food for tens of thousands of years. Have you seen the difference between corn and its ancestor teosinte?

    Also, you tried to be snide, but just a reminder that someone who’s gone so far along in research to be a PhD student in genetics, is an EXPERT in genetics.

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  8. 8. Ari LeVaux 12:13 pm 01/12/2012

    @kclancy

    “miRNA could be dangerous” does not equal “miRNA is dangerous.”

    Sorry.

    Link to this
  9. 9. jctyler 12:59 pm 01/12/2012

    LeVaux’ error on miRNA is easily shredded, therefore not a problem. The real problem is to write that ‘Genetic modification is a very precise process’. Understanding the mechanical process well enough is not sufficient to qualify the whole as a ‘very precise process’ because ‘very precise’ means that all consequences are understood. Which they are not by any stretch of the imagination. The article gives the impression that because LeVaux made a mistake genetically modified food is ok. One superficial look at for example Monsanto’s activities in this game and the consequences should be sufficient. LeVaux’ mistakes do not justify the basis of the rebuke. Clinched by ‘What if we can produce beneficial miRNAs, and take them like we do vitamins?’ It’s so USamerican, shovel a handful of vitamins into your system to digest your genetically modified corn and you will live happily and healthily forever. If GM and vitamins are the solution, why are you a nation of mass obesity? The world doesn’t need genetically modified food, there is plenty of natural food around, but tell that to a nation that daily eats a ton of carbohydrates, another ton of proteins, a third ton of artifical sugars but only a few grams of fruits and vegetables a day. I look at these two articles and I can only shake my head. Ah well, here we go, a little mozzarella, two tomatoes, some olive oil, basilicum, I break off some ciabatta and fill my glass with some red wine…

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  10. 10. Michele_Busby 1:01 pm 01/12/2012

    Hi Christie,

    A couple points.

    -First off, there’s no reason to think that the DNA being introduced into GMOs is going to produce more/different miRNAs than it did in the original organism.

    Yes there is. The genetic modifications that have already been introduced into the food supply (i.e. with FlavRSav tomatoes) use RNAi knockdown, and amiRNAs which are artifical miRNAs have been developed with an eye towards agriculture and may be on the horizon.

    The FlavRSav tomato, if I understand this correctly and my expertise in this area started yesterday, was the first GM product on the shelf and it used a knockdown that used a reverse compliment of the gene that they were knocking down. This reverse compliment strand was not produced by the original tomato, so the small RNAs in the tomato were never in the original plant. The problem is not that spurious novel small RNAs may accidentally entering the food supply, it is that they are being intentionally added without, Ari thinks, and adequate safety check.

    -But perhaps more fundamentally, miRNAs are found in all kinds of life, including every single species that we currently eat. There’s no logical reason that a new miRNA being produced by a GM plant is going to be more dangerous than the multitude of miRNAs we ingest when we eat the non-GM version.

    That is true, but they do not have to be more dangerous to make the approval process illegitimate. They just have to be biologically active. The approval process for GM foods approves new foods based on the idea that they are substantially equivalent to the food they replace. If there are biologically active agents that are in the new food that haven’t been eaten before then the GM food has to undergo more stringent safety tests.

    Prior to the Zhang study, Monsanto’s argument which you can see in one of their history of safe use paper, is the same one you are using: that these small RNAs are eaten great quantities, and not likely to be aborbed in high enough quantity to affect human health and therefore can be treated as a class of safe molecules.

    If the Zhang paper is right (and I know this is a big IF) and that one small RNA was lowering LDLs then you can’t logically treat small RNAs as an inherently safe class any more because if that one is lowering LDLs it’s reasonable to worry that another is raising LDLs. So you should treat each small RNA as an individual chemical entity, and assess its safety as an individual food additive, basically.

    By analogy, you can’t logically argue that proteins are present in high quantities in the foods we eat therefore you can integrate botulism toxin into GM food.

    I am convoluting RNAi and miRNA here, of course. I think this is OK because they are close but also because Monsanto seems to use this logic themselves to defend small RNAs in their history of safe use paper.

    I actually would have written the same blog post yesteday after I first read Ari’s article, but I talked to Ari a little bit by e-mail yesterday and I’m coming around to his line of thinking. It’s acutally kind of a legalistic argument about the approval process that I don’t think was conveyed in the orginal article.

    I wrote a blog about it here but I just said everything that’s in it.

    http://michelebusby.blogspot.com/2012/01/ari-wrote-post-arguing-that-new.html

    But at the bottom Karl put a link to a GMO guy and he has the reference for the Monsanto paper.

    Play nice kids.

    Michele

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  11. 11. Bett 1:06 pm 01/12/2012

    It’s very easy to state strongly and surely that “Genetic modification is a very precise process . . . ” as Ms. Wilcox does above. However saying something in such definite terms does not make it true. I’ve also seen scientists who state equally strongly that genetic modification is anything but a precise process, and that some of what is currently being let out into the wild can be very harmful. Also, much of the GMO crops currently being grown allow huge amounts of pesticides and chemicals to be dropped on the earth and into our waters and air. Caution would seem to be indicated here – a caution that appears to be missing in the actions of many companies who engage in genetic modification and use of GMO species, as well as the actions of regulatory bodies. I don’t believe that genetically modified organisms are ready for release into the wild. Time will tell, and I’m afraid we may not like what it says.

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  12. 12. Aur_ora 1:09 pm 01/12/2012

    “True, it was not a scientific article. That’s why it was published in the Atlantic and not Nature. That’s the most important point you made in your post.” -> I’m sorry, Ari Levaux, but are you implying that because it’s not a scientific journal, The Atlantic shouldn’t strive for accuracy?

    I hope The Atlantic’s editors think differently.

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  13. 13. KKloor 1:15 pm 01/12/2012

    Ari,

    You’re still sounding defensive about this whole affair, especially with your claim about there supposedly being some sort of distinction between Nature and The Atlantic. As kclancy points out in #4, the criteria for editorial accuracy remains the the same.

    Which leads me to ask: Was this story fact-checked by anyone at The Atlantic before it was published online? In my own blog post on your article, I speculated it wasn’t. I’d just like to confirm.–Keith Kloor

    Link to this
  14. 14. Ari LeVaux 1:52 pm 01/12/2012

    Keith,

    I don’t know if it was fact-checked. I’m going out on a limb and saying no.

    I’ve been very open in acknowledging that there were errors in my science and holes in my argument. That’s why I rewrote the original piece, and posted it this time yesterday here:

    http://tiny.cc/v9svh

    With some errors adjusted and my argument shored up, perhaps the discussion can move to the points I was trying to make.

    Link to this
  15. 15. lordsimon69 1:52 pm 01/12/2012

    Every time I read such a discussion, I always wonder why people protecting us against possibly-dangerous-food do not protect us first against all those foods which cause atherosclerosis, diabetes, obesity and cancer (and which they actually eat). It really fascinates me.

    Link to this
  16. 16. Indigo 2:12 pm 01/12/2012

    Ari, I opened and reviewed your revised attempt. It still is loaded with massive amounts of errors and unsubstantiated assertions that aren’t backed up by scientific evidence. For instance, you use the word “implicated” quite often, yet you never indicate the credibility or reliability of those making such “implications”. You made a fool of yourself the first time, and only certified it with the responses and the attempt to clarify.

    Link to this
  17. 17. Ari LeVaux 2:19 pm 01/12/2012

    Indigo,

    Since we’re defining terms, I’d like to hear your definition of “quite often.”

    Since the word implicate was used once in my article, we can assume that you believe “once” means “quite often.”

    Link to this
  18. 18. Christie Wilcox in reply to Christie Wilcox 2:34 pm 01/12/2012

    Michele:

    RNAi and miRNA are VERY DIFFERENT. Inhibitory RNAs are antisense to the entire mRNA for a gene, which is extremely specific. Although we can and should scan for any cross reactivity, the odds that a inhibitory RNA for a gene for any other plant or animal would attach to one of our mRNAs is extremely slim. While we might have homologous genes to other species, the actual sequences of these genes are very different, and an RNAi would not be able to bind to the same kind of gene in a plant and a person. But even more importantly, inhibitory RNAs are small in one sense of the word, but compared to miRNAs, they are not small – that is, they are the size of an entire gene, or a good chunk of it. Thus they are far too large to get past our digestive system and into our bloodstream in the first place. For example, the antisense RNA produced in FlavRSav tomatoes is 1.8 kb – that’s 1800 base pairs, almost 100 fold larger than the 20 or so base pairs of miRNAs.

    But let’s just say that Monsanto does develop and want to sell a food product containing a truly novel miRNA. For substantial equivalence to apply, they first need to show that the miRNA is safe, just like they would with any protein product they wish to insert, which means – yes – they have to test its effects. I never argued that they shouldn’t safety test new genetic elements (or any of their plants, for that matter). But that is very different from saying that all GM foods are suddenly more suspect because they contain miRNAs.

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  19. 19. KKloor 2:38 pm 01/12/2012

    Ari (14)

    You write: “With some errors adjusted and my argument shored up, perhaps the discussion can move to the points I was trying to make.”

    Not just yet, but you do get props for your openness and willingness to make corrections. That said, this corrective process is not over yet. See my new post on this:
    http://www.collide-a-scape.com/2012/01/12/corrections-not-necessary-in-botched-atlantic-story/

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  20. 20. Indigo 2:43 pm 01/12/2012

    You’re correct, Ari, I misspoke. Instead I should have just stuck to the point that you use dissembling words quite often. Would that have been more specific? “Often”, “sometimes”, “usually”, “perhaps” and on and on and on. It doesn’t read like a scientific article, it reads like a guessing game. But please, do get defensive and digging a deeper hole for yourself. May I suggest that you attempt to write about intelligent design being equivalent to evolution, or how the anti-vaccine contingent uses valid arguments against vaccinations? Those seem to be really great places for your style of writing and defensiveness.

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  21. 21. Michele_Busby 3:45 pm 01/12/2012

    I’m no expert in RNAi, which is why I find these discussions helpful.

    But aren’t you comparing the length of an unprocessed dsRNA to the length of a processed miRNA? Unprocessed miRNA’s are about 70-100 base pairs, which is smaller than 1.8K but still a very big molecule.

    As I understood from this reference the FlavrSav tomato interference was caused by that RNA that was cleaved by dicer into 20 bp siRNAs.

    http://hortsci.ashspublications.org/content/43/3/962.full#ref-15

    -Although we can and should scan for any cross reactivity, the odds that a inhibitory RNA for a gene for any other plant or animal would attach to one of our mRNAs is extremely slim.

    I guess slim is subjective, but if I understsand this paper right there are 270 endogenous rice small RNAs with exact matches in the human genome.

    http://www.sciencedirect.com/science/article/pii/S0278691508006571

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  22. 22. Christie Wilcox in reply to Christie Wilcox 3:55 pm 01/12/2012

    dsRNA = double-stranded RNA: it is what occurs after the RNA used to inhibit the mRNA transcript binds to the mRNA. The 1800 base pairs is the antisense single-stranded antisense RNA that was used to interfere with the target gene. The reason an antisense RNA causes interference is because the cell targets dsRNA for degradation, by, yes, chopping them up into little pieces, so when the antisense RNA binds to its sense counterpart (the mRNA target), it makes dsRNA that the cell digests. In terms of the gene product from expression of a miRNA DNA sequence, though, you are talking 70 or so bp to start (single stranded, mind you), 20 bp or so when finished, which then bind to 20 or so bp of a target mRNA. Only the small product has the potential to get into our bloodstream. Small RNAs are different than antisense RNAs: they are much closer to the size of miRNAs. When I talked about the odds of an inhibitory RNA matching ours, I was referring to antisense RNAs, not the siRNAs or miRNAs. The point of that science paper is that even though a large number of small RNAs match our genome, we eat them every day and they have no negative effects – which flies in the face of Ari’s original argument that these miRNAs are a serious health risk.

    To clarify, part of the confusion comes from my use of RNAi: RNAi actually means any and all RNA molecules that cause some kind of interference. So RNAi can be accomplished with RNAs from 20 to 2000 base pairs. I should have specified that I was talking about the kind of RNAi molecules that were used in the tomato example, which is antisense RNAs used for knockdowns of specific genes, which are, by definition, larger RNA strands.

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  23. 23. Michele_Busby 4:21 pm 01/12/2012

    Uh, this is my source of confusion. What happened, I believe with the FlavRSav tomato is that they thought they were using a double stranded knockdown. But when they did that they produced those double stranded RNAs that inadvertently turned on the RISC pathway. So the small siRNA products were in the tomato.

    http://www.nature.com/nbt/journal/v23/n3/full/nbt0305-287b.html

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  24. 24. Michele_Busby 5:42 pm 01/12/2012

    Accidentally.

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  25. 25. Christie Wilcox in reply to Christie Wilcox 10:21 pm 01/12/2012

    Michele – sort of. They intended to use anisense mRNA to bind to the sense mRNA and sequester them, thus preventing translation, not to trigger the RNAi pathway. But instead, they ended up having larger RNAs – 3.6 kb – produced, which are thought to have either folded on themselves or bound to the other RNAs. In either case, these large transcripts led to dsRNA molecules which made it out of the nucleus turning on the RNAi pathway, part of which involved chopping up of the dsRNA into 21 bp fragments, which are the siRNAs. These fragments then separate, and with the help of proteins, attach to mRNAs, and then those mRNAs are destroyed, too. So if you chop up an antisense RNA of a gene in the RNAi pathway, even if it was bound to part of itself and not the mRNA it is the antisense of, it ends up suppressing the regular gene, too, since the original antisense RNA fragment that was cleaved (now an siRNA) will still bind to the regular gene’s mRNA.

    If you’re interested, there’s a really good video to explain the difference between miRNA and siRNA and how they work: http://www.itsokaytobesmart.com/post/14315702537/animation-of-rnai-from-basic-background-to

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  26. 26. Michele_Busby 12:17 am 01/13/2012

    So I still don’t understand why you would say that an siRNA generated from RNAi would be expected to behave inherently differently than a naturally occuring miRNA if it were eaten.

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  27. 27. Christie Wilcox in reply to Christie Wilcox 12:57 am 01/13/2012

    Well, I make the distinction in that, to my knowledge, siRNA does not travel as a chemical messenger, as miRNA can. They must be delivered through nanoparticles, viral vectors, etc, while miRNA can enter the bloodstream and target cells unaided. siRNAs for therapeutics, for example, have to be specifically modified to travel in serum (e.g. http://www.sciencedirect.com/science/article/pii/S0006291X06003366)

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  28. 28. Chad Harder 11:16 am 01/13/2012

    I sure hope the people modifying the genes in my food are not as arrogantly dismissive about the unknowns of this new field as those commenting here.

    In fact, this thread reminds that geeky know-it-alls (student or otherwise) are really not the folks I want futzing with the genetic make-up of the food I plant in my garden, or feed my family.

    Christie Wilcox, are you a farmer? And are you so confident with other random “PhD students” and their current but evolving understandings of miRNA, siRNA, etc as to trust them fiddling with your family’s dinner?

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  29. 29. Ica Crawford 12:29 pm 01/13/2012

    Okay I read the article concerning MiRNA’s in genetically modified foods and the arguement is solely based on the MiRNA’s exist in everything, this is true. It also points to the fact that MiRNA’s do have the ablity to alter genetic express…ion, this is also true. So when you deal with the idea of eating genetically modified foods and one of the details I think this article fails to point out is this. We intake vast variences (excuse my spelling now) in MiRNA intake whether it be through vegetables, meats, minerals in our environment. These MiRNA have not been tested by “scientists” but by eons of ancestors as nutritional and benifical to humans. We all seen what happens when you over indulge in anything. The bodies processes begin to work over time in order to expell the over abundance of that substance from our bodies,and depending it will discharge the waste or it will weakien the body sometimes causing death through various heath reasons. I would like to first point out that the MiRNA”s found in genetically modified foods ( I hate when people say “GMO” because it’s like a cleaver nickname they give these things when there real name leads to less marketablity), are unknown.. In other words they will not disclose the actual source of these MiRNA strands. Populations of unknown bacterium are now floating around in you vegetable oil, (really soybean oil, where all the ugly soybeans give there lives). Secoundly I would like to address the issue out amounts of MiRNA’s in various food products. If intake of different MiRNA over time may not have the ablity to alter our gene course, but large amounts in staples like rice, oils, grains, vegetables have the potiental to have real and lasting effects on our health as well as our genetic expression.

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  30. 30. Michele_Busby 1:36 pm 01/13/2012

    I don’t know Christie.

    Do you still think his worries are farfetched?

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  31. 31. Christie Wilcox in reply to Christie Wilcox 3:06 pm 01/13/2012

    Yes. My main point is that even if miRNAs have effects, there is no heightened risk from GMOs than from everything else we ingest. The end result of this find, in my opinion, is that we’re going to learn that the foods we eat every day affect how our bodies function in ways we never realized. I think miRNAs, siRNAs and similar technological advances are going to be much more important in therapeutics than in causing harm. As I said before, though, if a GMO is created to express a novel small RNA, it doesn’t meet the requirements of substantial equivalence, and should be safety tested.

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  32. 32. christophian 1:11 pm 01/14/2012

    I think a scientist can become so focused on specific science that they can forget that “If something can happen it will” which the author of the paper you are berating understood. Most of GMO products introduced miRNAs MAKE TOXINS. I read a paper on a study some time ago that showed how GMO grains changed the testicles of rats. Thinking that crap doesn’t transfer to us is short sighted at least.

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  33. 33. hanmeng 5:09 am 01/16/2012

    “If something can happen it will”. So if miRNAs are dangerous, since you’re already ingesting them every time you eat, you’d better stop eating.

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  34. 34. christophian 2:57 pm 01/16/2012

    I don’t eat GMO food.

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  35. 35. christophian 3:00 pm 01/16/2012

    If you had read my post properly you would see that I am only referring to miRNAs artificially introduced in GMO foods.

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  36. 36. Jen_Angela 3:09 pm 01/16/2012

    RE: post 26 and 27 on inhibitory RNAs creating siRNAs.
    An siRNA is made by Dicer protein that processes the double stranded RNA that is formed when the inhibitory reverse or antisense strand anneals to the messenger RNA target. In the case of using a long (1800 kb) inhibitory RNA, siRNAs are made in the cell so they do not require modification or delivery chemistries (Whitehead et al., Nature Reviews Drug Discovery, 2009; Broderick and Zamore, Gene Therapy, 2010). The siRNAs will be loaded in Argonaute proteins, just as a endogenous microRNAs are loaded into an Argonaute protein. Argonaute proteins are required for the target messenger RNAs to be silenced. The Zhang et al. study has yet to be replicated by another lab. With that in mind, we do not know if plant microRNAs or siRNAs are transferred to animal cells before or after they are loaded in an Argonaute protein or whether plant Argonaute proteins are functional in mammalian cells (Melnyk et al., EMBOJ, 2011). If the small RNAs—either “accidentally” made siRNAs or microRNAs that were always present in the plant cell— have complementarity to 7 or 8 nucleotides of human messenger RNA, then there is potential for silencing the expression of a messenger RNA (Lewis et al., 2003, 2005; Brennecke et al., 2005; Krek et al., 2005). This effect is concentration dependent, meaning that if there is a lot of target messenger RNA and very little complementary small RNA it will not have a significant impact on the expression of the target. If target messenger RNA is very low compared to the amount of small RNA that ends up in the animal cell, then the potential impact on expression of the messenger RNA is greater. As for toxicity, we can clone and identify the small RNAs made intentionally or unintentionally in plants after introducing foreign genes or inhibitory RNAs. If a small RNA is cloned that has complementarity to the human genome then it can be tested for its ability to silence animal mRNAs by analyzing the expression levels of potential target messenger RNAs, proteins, small RNAs and non coding RNAs in animals before and after ingesting the transgenic plant.

    Link to this
  37. 37. Jen_Angela 3:11 pm 01/16/2012

    correction to last post: 1800 bp, not 1800 kb.

    Link to this
  38. 38. mounthell 11:02 pm 01/16/2012

    With all the chatter about GMO topics, we forget that genetic processes are very parochial, specific to the evolutionary/adaptive history of the organism of interest. DNA and biological process is not remotely comparable to the deterministic switching of computer programs with their virus issues, despite the baffle-gas issuing from some reduction-minded propeller heads.

    Here’s an example that illustrates how variable _specific biological systems_ can prove to be: This is post-transcriptional editing of messenger RNA (mRNA): Sandra Garrett and Joshua J.C. Rosenthal “RNA Editing Underlies Temperature Adaptation in K+ Channels from Polar Octopuses” _ScienceExpress_ (online early) 5 Jan. 2012.

    As it happens, polar and tropical octopi are genetically “alike” at first glance. However, in this case, just before the polar octos’ mRNA is translated into its literal protein sequence, it is “extensively modified” == edited == by very particular enzymes operating in a very particular cellular/molecular environment. The authors observe: “Thus A-to-I RNA editing can respond to the physical environment.”

    The chance of getting all the biological planets to align to give someone genetic problems from errant GMO RNA or that of intronic DNA from Aldebaran 3 (if they survive the chemistry) is zip.

    However, the real problem with GMOs is in the genetic pollution transferring to other (similar) plants, the horizontal transfer (HT) issue. That’s why GMO is truly “fooling with Mother Nature.”

    Link to this
  39. 39. zhiyan-le 1:10 pm 01/18/2012

    I support the Atlantic arguments, no matter the writer is a scientist or not, for they told the truth.

    microRNA is a two-way knife, — it can cut beef and fruit, so can it kill people.

    microRNA is dangerous, GMO food is dangerous, extremely dangerous. There are many scientific papers to support this fact-telling.

    The so called “I am not afraid to eat GMO food” is a sort of personal believe rather than a science.

    There is a fundamental difference btw natural and GM crops in terms of gene-transfer. Otherwise, please just give me one example that proves a Gpyph element can naturally get into crops in the last ten thousand or million years.

    Link to this
  40. 40. zhiyan-le 1:19 pm 01/18/2012

    p.s.: “substantial equivalence” is a commercial made by Monsanto. Leave it that way, fine. However, if it were called science, then it is a pseudoscience.
    Besides, Monsanto cafeteria does not supply GMO but organic food. The company does not take “substantial equivalence” at all.

    Link to this
  41. 41. zhiyan-le 1:57 pm 01/18/2012

    p.s. 2: science journals have many fake papers and fraud data/stat.
    HT soy serves sales of chemicals, and Monsanto has made a huge profit from that integration. Thus, it is not surprise to see that the USDA chemical stat/data have been fraud or even blank since 2008.

    Link to this

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