Archive for November, 2012

Why you should vote No on Proposition 37: The Scientific Case

(This is the second of two posts on why Proposition 37 is a bad idea, focusing on the science of GMOs. For the more “political” arguments against this measure, check out the first post in this series.)

In my earlier post on Prop. 37 I started to get into the non-technical reasons why I think Prop. 37 is a poor idea: among other things, the initiative process is a bad way procedurally to make law, especially in complicated matters like biotechnology, and it doesn’t even really fully protect consumers from purported harm from GMOs. But I left off without getting into the main case against separate labeling, namely: there is virtually no evidence showing that GMOs are harmful to human health.

I want to pause for a minute for some historical context. As Chris Mooney amply demonstrated in The Republican War on Science, American liberals have mostly fully embraced using real science to inform public policy, disdaining the movement conservative war on empiricism. This is of course a good thing. However, there’s only one  major exception to this general trend, and that’s GMOs. There’s a segment of left-ish thought that has fully bought the woo line on GMOs, and on this charge of moonbattery I’m afraid some liberals (especially in the Bay Area where I live) are indeed guilty.

The reason I’m bringing this up is not really to argue ad hominem (“you shouldn’t believe these people because they’re liberals of the nutso variety”) but to give some history that’s necessary to fully understand how we got to where we are today. The main Yes on 37 proponents – California Right to Know – have actually retreated from saying in public the crazy stuff they’ve long believed about GMOs without reason, and thanks to some slicker marketing have held fast this cycle to the line that you simply have the right to know what’s in your food. In other words, they don’t really make any factual argument in public about the empirical case against GMOs, preferring to instead let others do that by word of mouth after they’ve planted the seeds with subtle nods here and there to “foreign genes” and a healthy amount of guilt-by-association with Monsanto’s spending on this measure. So there’s not a whole lot on their website that can be debated with. So I’m going to go beyond the current, mostly argument-free current website of Yes on 37 and also look at some of the rawer stuff these same folks were saying 10 years ago, on their former website.

OK, enough of that. So what do the people making the loudest case for Yes on 37 believe?

FACT: Genetic engineering (GE) and conventional breeding are worlds apart. Breeding does not manipulate genes; it involves crossing of selected parents of the same or closely related species.

Oy. This is just embarrassing to anyone who’s studied plant biology for even a minute. Breeding absolutely manipulates genes. When farmers began breeding wild mustard until they consistently got it to produce swollen stems (kohlrabi), big leafy heads (cabbage), florets (cauliflower), and little heads on a big stem (brussels sprouts), how did all these varieties acquire and keep their desired traits? It wasn’t magic! Agriculture has for thousands of years been wreaking massive genetic changes in crops. These changes have been far, far more radical than what most modern genome tweaking does. Yeah. More radical. The stuff we are doing in the lab to plant genomes is very subtle and targeted compared to what selective breeding does to them.

Now, it’s true that genetic engineering has allowed us some shortcuts in how we go about this, bringing in genes from distantly related species to express more traits that are useful to human beings. But that’s a far cry from saying such shortcuts must be harmful. The anti-GMO crowd has never conclusively demonstrated such a thing; instead they’ve simply resorted to luddism and arguments about “playing God” with food as substitutes for hard facts.

“GE usually employs virus genes to smuggle in and promote the inserted genes.”

Scare tactics. If I said that GE used microscalpels made out of steel to move in the genes, would you be equally terrified? Viruses and bacteria are useful tools to the biotechnologist, just like microscopes and autoclaves. If you want to get genes out of one cell and into another, using a virus is a very handy way to do it, as that’s what they’ve naturally evolved to do. (Also, generally, there aren’t virus genes per se used in the process, but whole viruses. ) The new DNA doesn’t just get there via a miracle. You have to snap it into the new organism’s genome, and lab-manipulated viruses are excellent vectors for accomplishing this, putting the new pieces of DNA where you want them to go. Implying that you might be harmed by a virus from coming into contact with the progeny of GM organisms is lunacy, akin to saying you’re going to get a viral disease because your long-deceased great-great-great-great-great grandfather contracted it two hundred years ago.

 The function of only a small proportion of the DNA in an organism is known…[genetic engineering] may result in random and unexpected changes in the functioning of the cells.

I’m actually sympathetic to this line of thinking – or rather, would be, if it had ever been demonstrated in any organism that these unexpected changes are bad. Unfortunately for anti-GMO folks, it hasn’t. While we don’t fully know everything about corn’s genome (or our own, for that matter), we do know quite a lot about toxins, mutagens, and allergens. If GMOs produced these at levels detrimental to human health, we’d find out pretty quickly. Furthermore, it’s not like extant human foods don’t produce toxins, mutagens, or allergens; stone fruit contain traces of amygdalin (readily converted by your body into hydrogen cyanide), citrus has formaldehyde, and if you really want a good time, try reading about Jamaican vomiting sickness and ackee. The anti-GMOs are appealing to a notion of a sort of primordial wisdom: if people ate it since time immemorial, the reasoning goes, it must be safe. But reality is more complicated.

Worried about toxins, mutagens, and allergens in your food? Good! By all means let’s test food for them. But don’t hold GMOs to a double standard here. If our best tests can’t find these things in GM crops, which are tested much more rigorously, then it’s fair to presume as a starting point that they’re just as safe as regular crops. If we discover that they produce heretofore-unknown, harmful molecules, I’ll be the first to call for restricting such varieties as food. But there’s no real reason to think that such a thing is likely.

Existing molecules may be manufactured in incorrect quantities, at the wrong times, or new molecules may be produced.

There’s a sort of food OCD at work here in much of the animating beliefs of the anti-GMO movement: the idea that there is some fixed, “correct” amount of nutrients and other substances in existing foods is needless to say, not supported by the evidence. On the contrary, there’s reason to  believe that fruits and vegetables, conventional and otherwise, are getting less nutritious per weight of the food – probably because our relentless breeding for size has added lots of water to them and thus reduced the concentration of everything else in them. Food changes. That the anti-GMO crowd has never been able to specifically identify a provably undesirable compound or unhealthy concentration of a compound in GMO plants, only speculated that such things might be there, cuts through a lot of the absurdity embedded in this idea.

 No independent, long-term testing of the safety of GE foods has been conducted in the U.S.

Again, a misleading double standard. I’m pretty sure that virtually no long-term testing of the safety of non-GM foods has been done either – it’s just assumed that since we’ve eaten them for hundreds of years with no obvious ill effects, they must be fine to eat. (Let’s not pay too close attention to the recent studies linking traditional Southern Chinese high-pickled-vegetable diets to stomach cancer…) In the absence of information suggesting short-term ill effects and no suspicious molecules identified, it’s reasonable to conclude for now that there’s not special cause to worry about GMOs.

Virtually no GE food marketed to date has been shown to be more nutritious than non-GE food.

Not true – or, to be fair, falsified by events after this was published. Golden rice most certainly does contain lots more Vitamin A than conventional rice, and although it’s true that it has not been “marketed” just yet, it likely will be within the next three years. Two other additional points: first, GM food hasn’t been shown to be less  nutritious than non-GM food, either, so this claim is just misleading. And the golden rice case highlights the absurdity of making wildly uninformed claims about technology – just because a technology hasn’t exhausted all its touted possibilities yet doesn’t mean that achieving those possibilities is, in fact, impossible.

 The money for scientific research on GE here and overseas comes from either the biotechnology companies or the government. Both are committed to the promises of biotechnology. This means that even when scientists have concerns about the safety or commercial application of the technology, it is often hard for them to risk their careers by being openly critical.

Oh, Lord. This is the worst kind of conspiracy theorizing, on the level of saying that climate scientists are all making up data showing warming trends because their careers will be jeopardized if they blow the whistle. We liberals are supposed to be better than this. There’s plenty of non-corporate research being done on these foods.

Walmart is now selling Monsanto’s sweet corn that has been genetically engineered to contain an insecticide, but consumers don’t know because it’s not labeled.

One hallmark of the anti-GMO lexicon is to throw around words like “pesticide” and “insecticide” in an attempt to frighten people who’ve never studied biochemistry. So let’s talk about Bt corn. The Bt toxin is a protein molecule that’s very effective at killing some (not all) types of bugs. It’s made naturally by some varieties of the bacteriaBacillus Thuringiensis, which live in soil. This protein has been pretty carefully studied and tested over about a hundred years, and from what we can tell so far, it has no effect at all on vertebrates. A nasty hydrocarbon-based pesticide this is not. You’d be hard-pressed to find a bug-killing molecule that’s more targeted to affect only insect physiology. In fact, as Eric Sawyer notes here, even certified organic farms (the main beneficiaries and exempted parties under Prop. 37) are permitted to use Bt on their crops under the terms of their certification! So there’s no real reason to think that corn that’s engineered to produce its own Bt is going to be in any way bad for you.

While it’s prudent for the FDA to monitor Bt usage to err on the side of caution, there’s not really a good reason to single out Bt corn for a label that says “THIS CORN PRODUCES INSECTICIDES” considering that a) the insecticide appears quite safe for human health and is not especially different from other insect-killing molecules produced by food crops without human intervention, b) other uses of harsher insecticides (like spraying) don’t have mandated labeling either. Come to think of it, if you really want to people to know what’s in their food, why haven’t we started with requiring sprayed crops to display lists of the sprays used? To me, that seems much more informative than simply telling the consumer that the organism is GM.

Crops engineered to contain their own pesticides will produce increased resistance in the targeted species…Crops engineered to be resistant to specific herbicides may encourage more liberal use of those herbicides…There is evidence that crops engineered to produce their own insecticide can kill beneficial insects….[paraphrasing] Monsanto controls the GM industry and they are bad even if the technology can do good things.

These are reasonable concerns. But labeling foods a la Prop. 37 is a nonsensical solution to these problems. If herbicide use is shown to be hazardous to consumers (not the case for Roundup, as yet) then you need to regulate the damn herbicides, not pass food labels. And the same is true of tackling the problem of pesticide resistance and its related environmental issues – food labeling is at best a very clumsy, indirect way to address these things, especially because they aren’t exclusive problems to GMO crops. The pro-37 people seem to think that agribusiness is so powerful, and the FDA so corrupt, that herbicides will never be effectively regulated, so the best strategy is to make an end run around them by whipping consumers into an anti-GM hysteria. This is likely to lead to bad, bad agricultural policy.

And of course, arguing against Monsanto’s particular uses of genetic engineering shouldn’t extend to all such possible uses of these valuable techniques – but that’s what will be stigmatized if the public turns decisively against the whole idea of GMOs.

I want to reiterate that I feel completely icky agreeing with agribusiness on this ballot proposition. But food policy needs to be based on the facts, not anti-scientific hysteria. Planting the idea in voters’ heads that GM techniques are by their very nature suspect and dangerous doesn’t give them a factual understanding of the issues in play, and is likely to lead to an undue curbing of the uses of these techniques. If you care about using the ever-expanding realms of what we know about plant genetics to do real good in the world, that’s a serious setback. It’s pretty striking to see technologically-minded people who think self-driving cars and robot butlers are just dandy freak out at the idea that our understanding of the life sciences could cause similar leaps in food, too. Food is just different to a lot of people, and I get that. But if you really consider yourself someone who thinks public policy should be made based on a rational understanding of the world, you should vote No on Proposition 37 on Tuesday.