Busting a few GMO Myths
I'm reposting this from a discussion on my Facebook wall.
A little while back, I posted the attached link about Jane Goodall, and it sparked a conversation about GMOs. Some of the things that people were saying are frequently-repeated misconceptions about genetic modification, so I think my attempt to clear up the confusion is worth reposting here. I'll update, maybe, as the conversation evolves. I'm bolding the (edited) claims, and leaving my responses unformatted.Claim: Science doesn't say things like "GMOs are safe." Anyone advocating GMOs is a business person, because scientific claims are more contextual than that, and there's no preponderance of evidence.
That's absurd. There's a tremendous amount of peer reviewed evidence that GMOs are in no way harmful. Asserting that anyone disputing claims that they pose health risks is a "business person" is just as crazy as saying that anyone claiming that climate change is a real problem is being paid off by the government (or whatever). It's a conspiracy theory, and it's irrational.
The parallels between climate deniers and GMO skeptics are striking and obvious. In both cases, there's a strong scientific consensus about the right answer to some question, along with a popular rejection of that scientific consensus. Virtually every study done on GMOs has shown that they pose absolutely no additional health risk to human beings; asserting that GMOs are safe is absolutely a scientific position. I'm not sure what you mean when you say that "science is contextual." Yes, of course we haven't done every single test possible on the health risks associated with consuming GMOs in every possible circumstance. We don't know if they pose a health risk when consumed on Mars, while standing on your head, while sitting in a bathtub full of homemade gin, and so on; to be skeptical of their general safety on that basis is totally insane, though.
By every indicator we have, they're perfectly safe, and it's reasonable to base our opinion on the best science we currently have. Claiming that any scientist (that includes me, by the way!) who agrees that GMOs are safe is a shill for agribusiness is exactly
the same thing as claiming that any scientist who claims vaccines are safe is a shill for "big pharma." It's a completely unwarranted conspiracy theory. Of course science can't make a claim like "All GMOs are completely risk free for every person in all circumstances," but that's a strawman--no one is making that claim. The claim is that based on all the evidence we have, GMOs are pose no more health risks than non-GMO crops for the majority of people. There are, of course, people out there who might have allergies to some component in GMO foods, just as there are people who have allergies to some components of vaccinations. However, that has absolutely no bearing on their general safety, and (again) we have strong
evidence that they are indeed safe.
Just as with climate change, it's really, really important that people keep abreast of the genuine research on this issue before making claims like this. In both cases (as well as with vaccinations), the body of scientific literature is extensive, and the evidence is firmly on one side of the issue. Climate change is real, GMOs are safe, and vaccines save lives. Disputing any of those points is to go against the scientific consensus. In all cases, of course, research is ongoing and always evolving. It's possible that we'll discover some hidden danger associated with GMOs, just as it's possible that we'll discover that we've been entirely mistaken about anthropogenic climate change. Basing beliefs or public policy on the unsupported supposition that future research will overturn the current consensus, though, is crazy.Claim: Glyphosate is incredibly dangerous. It's been linked to Celiac disease (citing http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3945755/), as well as the widespread die-off of honeybees.
The first (and most important) point here is that even if
glyphosate is actually dangerous to humans (a claim for which there is virtually no evidence), that's a problem with glyphosate
rather than with GMOs. Saying that pesticide resistant GMO crops are inherently dangerous because of the pesticides is absurd--if there's a risk there, it's a risk associated with the pesticide itself, rather than with genetic modification. This is similar to the point about monoculture that I mentioned above--we can say that some of the farming practices associated with GMO agribusiness are suspect without that implying that GMOs themselves
are suspect. If I engineer an organism to grow better in the presence of arsenic, and people become sick after consuming the arsenic covered crops, that doesn't show that it was the genetic modification that made people sick--it was the arsenic. Again, there's a strong parallel with climate change here. The fact that some approaches to dealing with global warming (say, geoengineering) carry substantial risks themselves is not evidence that global warming isn't happening, nor is it an argument against trying to deal with the problem in some way.
All that aside, the study that you linked to is itself suspect in a number of different ways. A quick review of the article shows that the authors are basing their conclusions on a single paper out of India from 2009 (http://cropandweed.com/vol5issue1/46.1.html
) in which the investigators exposed fish
to a "glyphosate containing
" (emphasis mine) compound. The researchers found changes in the fish's digestive tract which (in their words) "appeared to resemble Celiac disease." That's not much of a link. I did a little more digging, though, and things are even more suspect. The particular compound that they used in the 2009 study is a commercial compound called "Excel Mera 71" (EM71). EM71 is a terrestrial
herbicide--not designed for use in water--that contains, in addition to glyphosate, a number of other compounds--most notably a couple of surfactants. Surfactants aren't used in non-terrestrial applications, as lots of aquatic animal life is known
to be vulnerable to it, and the damage associated with surfactants is the sort that the authors noticed in this study. In fact, the National Pesticide Information Center notes that "pure glyphosate is low in toxicity to fish and wildlife, but some products containing glyphosate may be toxic because of the other ingredients in them." Every other study conducted shows that glyphosate is minimally harmful to fish, but compounds that it is mixed with can
be harmful, which is why those formulations aren't used in water. The 2009 study on which the Celiac claim is based doesn't take this into account, and fails to control for damage that might have been induced by other compounds in EM71. That's bad science, but jumping from that single study conducted on fish that found damage that looked like
Celiac disease to the researchers to the claim that glyphosate causes
Celiac disease in humans
is beyond bad science: it's fear-mongering that's completely without basis in reality.
So, there are three major things wrong with the claim that GMOs are dangerous because glyphosate might cause Celiac disease: (1) If that's true, it's a risk associated with glyphosate, not GMOs. (2) The proposed glyphosate/Celiac link itself is based on a single study of EM71's damage to fish, and (3) the fish study itself was methodologically suspect. That's very unconvincing.
Honeybee colony collapse disorder is indeed worrying, but I've never seen a single plausible paper suggesting that it's linked to GMOs directly. There are a lot of proposed mechanisms on the table, and we're still trying to figure out what's going on. However, none
of the proposed mechanisms blame genetic modification. In fact, the biggest metastudy done on that question (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2169303/
) found that there is no discernable link between GMOs and honeybee health. Even when exposed directly (and exclusively) to Bt crops, bee fertility, larvae viability, or adult lifespan. Blaming colony collapse on GMOs is completely unwarranted speculation that isn't backed up by science.Claim: Saying "GMOs are no more dangerous than other crops" isn't the same as saying "GMOs are safe." Some GMOs are bred to require more water, or encourage more pesticide use. Pesticides can run off into the water supply, and that's really bad.
I suppose "no safer than non-GMO food" isn't the same as "safe," that's true. That seems like sort of a peculiar point, though. There are risks associated with agriculture, especially the large-scale industrial agriculture (which is one of the largest contributors to climate change, incidentally) that we practice in much of the world now. I'm happy to admit that, and I share your concern about water table contamination and water use--I'm quite worried about that stuff as well.
However, I think framing this stuff in terms of GMO vs. non-GMO food muddies the water (so to speak) of the debate, and distracts from the very real problems associated with industrial farming practices. Worrying that genetic modification as a practice
is dangerous, or claiming (as Goodall does here) that we're "poisoning ourselves" with GMOs confuses one problem with another, which makes it harder to solve the real problem. Genetically modified food itself
poses no health hazard, according to the best scientific evidence we have. GMOs are not poison, or even risky as far as we can tell.
Now, if it's true that some GMO crops need more water to grow (a claim for which I'd like to see a citation), that's a concern. However, framing the problem in terms of an issue with GMOs themselves
also blocks off a potential avenue for solving the problem: engineering crops that require less water to thrive. A cursory Google search shows that at least some people are actively working on this idea (http://12.000.scripts.mit.edu/.../genetically-modified.../
). That's wonderful. If the public narrative is dominated by claims that GMOs are inherently
unsafe, though, that makes it that much harder for these sorts of crops to come into wide use, which makes the problem significantly worse.
Similarly, if we're worried about pesticide runoff into lakes and rivers (which we should be!), framing the problem in terms of a risk associated with genetic modification just makes it that much harder to solve. A significant number of genetic modifications are actually designed to produce crops that don't
require pesticides in virtue of allowing the plant itself to produce proteins that harm local pests. This piece from the New York Times discusses one such crop, a genetically modified species of eggplant being grown in some places in Africa, which has been engineered to be toxic to the most pervasive local pest: http://mobile.nytimes.com/.../how-i-got-converted-to-gmo.
Using that crop seems unequivocally great. It's helping the environment by decreasing the use of pesticides, and it's helping a small subsistence farmer make a better living. However, the crop has met with considerable resistance from environmental activists who oppose its use purely
on the grounds that it is genetically modified. This reflects a lack of scientific understanding on the part of the activists, and has the potential to do a lot of damage, both environmentally and economically. That's the problem with framing this debate in terms of GMO-associated dangers. It obfuscates the real problem, and can prevent real, helpful solutions that benefit both people and the environment.Claim: I guess I'll just have to trust you on this
No, don't trust me on this! I'm incredibly untrustworthy in general, but at least when it comes to climate change I've done an extensive amount of real original work on the issue, and am an expert in my own right. I'm not an expert on GMOs. However, I am a scientist and I have a tremendous amount of trust in the scientific method and institution. I'm happy to put my faith in my colleagues working on this issue, just as I'd hope that they'd put their trust in me and my fellow climate change researchers when it comes to AGW. I'm basing my claims here on the existence of a strong consensus among those who are
experts on this issue. That's the only reasonable position to take with respect to any complicated issue in which I'm not an expert. If the people who know the most about this stuff overwhelmingly say that it's safe, I'm very inclined to believe them. #GMO #gmofree #environmentalism #scienceeveryday