Category Archives: Bt crops

Organic Lies About Bt Sweet Corn

Take this simple test to determine whether or not Bt corn is equivalent to a hand grenade for you: Are you a larval-stage European corn borer? No? Well, probably not, then.

A couple of my facebook friends are among the 755 people* who’ve shared this image, originally posted by the Maine Organic Farmers and Gardeners Association (MOFGA). It’s part of a broader campaign against Monsanto’s Bt sweet corn that’s starting to heat up because the first commercial crop is poised to debut in supermarket produce bins this summer.

Important disclaimer: I’m not a fan of Monsanto. I think they represent some of the worst tendencies of monopolistic, profit-driven enterprise. They bully farmers to buy their seeds every year and sue the ones who don’t if patented seed gets into their fields anyway, whether or not the farmers wanted it there (see: Food, Inc., The World According to Monsanto, Knight-Ridder/Tribune, They risk their workers’ health and pollute the environment, often at great public cost (see: Wikipedia, Washington Post, Environmental Working Group). They have fired whistle-blowing scientists willing to talk to journalists about the potential health risks of their products (see: New York Times). Their PR is Orwellian in a way that strikes me as somewhere between darkly hilarious and seriously unnerving (see: their website**). They’d make an outstanding movie villain.***

In fact, Monsanto is so stereotypically evil that I totally understand why people are willing to believe that food grown from their seed is dangerous, that Monsanto could be aware of this but try to sell it to you anyway, and that the regulatory agencies who ought to stop them have probably been effectively bought off.^ However, that’s not what’s happening here. I’m reasonably certain that Bt sweet corn is totally safe for human consumption. If it’s not and Bt is a real threat, then no sweet corn you can buy is safe for human consumption because Bt insecticides have been used by organic farmers for over 50 years.

How Bt Works

What’s wonderful about Bt-toxin is that it’s only toxic to insect larvae. Rather than referring to Bt compounds as “toxins,” it would probably be more accurate to call them proteins.^^ Unless you happen to be a larval-stage weevil or gypsy moth, in which case the description of what happens in the ad is fairly accurate: it binds to your gut, ruptures your intestines and you die.

These larvae-killing proteins occur naturally in the spores of a soil bacterium called Bacillus thuringiensis. The proteins are activated by the digestive juices of vulnerable caterpillars, and here’s James McWilliams’ account of what happens next: 

Precisely what happens with the Bt-toxin is, in its own way, a masterpiece of natural adaptation. Certain insects that ingest the bacterium cease processing potassium. As a result, they become paralyzed and die as their cells drown in a cascade of water. As so often happens with life down in the dirt, one organism’s demise is another’s meal ticket. Indeed, the besotted gut mucosa of the dead insect becomes a fertile breeding ground for millions of Bt spores, which proceed to grow exponentially, catch a gust of wind, and dust the topsoil with a layer of natural repellent. If anything can be called natural, this would seem to be it. (Just Food p. 87)

Top: unprotected peanut plant ravaged by cornstalk borer larvae; Bottom: Bt peanut plant--the larva has crawled off the plant and died just above the center leaf. Source: wikipedia  Bt insecticides are also highly specific. Each Bt strain is only effective against the larvae of a handful of species. They’re not even effective against the adults of those species, let alone other kinds of insects (including agriculturally-useful ones like bees). So it’s not true that Bt is designed to rupture the stomach of “any insect” that feeds on it. Nor does it matter if it breaks down before it gets to your dinner table, although it probably does because it breaks down pretty easily, especially when exposed to UV light (source: UCSD Aorian Laboratory).

According to the Environmental Protection Agency, Bt is so safe that the EPA has exempted Bt insecticides from its food residue tolerances, groundwater restrictions, endangered species labeling and special review requirements. Bt has no known effects on fish, birds, or mammals, with one exception: if you apply it directly to rabbits’ eyes, they get irritated. Researchers note that that may be caused by the formulation tested and not the Bt itself (source: UCSD Aorian Laboratory).^^^

So this isn’t some crazy, newfangled technology. We have no idea how old the bacterium is, although it probably evolved along with the larvae it attacks, which may have evolved along with the plants they target. It was first discovered in 1901 by a Japanese biologist. In 1911, it was independently discovered in Germany and identified as the cause of a disease affecting flour moth caterpillars. It’s been used to control insect pests since the 1920s and was first developed for commercial use in 1958. It’s not synthetic, doesn’t accumulate in the soil, and poses no threat to wildlife, water, or human health, so it has always been compatible with the current restrictions on pesticides approved for “organic” farming (sources: Wikipedia and UCSD).

Using GM seed as a delivery mechanism for the protein is newer, although that’s been happening for the better part of two decades with no apparent negative effects. In 1987, the gene that produces the insecticidal protein in the bacterium was successfully transferred to tobacco and cotton. Transgenic Bt food crops including commodity corn and potatoes have been grown in the U.S. since 1996. The only thing that’s new and different about Bt sweet corn is that it’s designed for immediate human consumption rather than cattle feed or high fructose corn syrup. Since there’s no reason to believe that Bt is bad for you, before or after it passes through a cow’s gut or refining plant, there’s no reason to believe that Bt sweet corn is some kind of strange, new, scary thing. Unless you happen to be an organic farmer who grows sweet corn, in which case you may be relying on the far-less-efficient process of applying Bt insecticides externally via spraying, which must be repeated at least half a dozen times throughout the growing season. Then, I imagine you might indeed feel threatened by farmers who can grow plants that produce the very same proteins themselves. 

So What’s With the Rats Whose Organs Failed?

The short answer is there are no such rats.

The claim that rats fed GM corn showed organ failure is probably a reference to this study published in the International Journal of Biological Sciences. Discover Magazine already pointed out a number of problems with the paper: 1) The authors got Monsanto to give them some data from studies they ran on three varieties of GM corn, and the authors themselves admit that the data are insufficient to reach any meaningful conclusions about the health effects of GM corn, 2) They found between 20-30 significant effects out of about 500 measurements, which is actually statistically likely when you’re running that many tests looking anything with a 5% chance of occurring randomly because 5% is not 0%, 3) The statistically-significant correlations that they found were not linear; for example, rats fed GM corn as 11 percent of their diet showed a (barely) statistically-significant effect of having large unnucleated cell count, but the rats fed 3x as much GM showed no similar effect, 4) Measurements like that were interpreted as "signs of organ failure,” although no actual organ failure was involved, and 5) The authors offer no possible explanation for any of the correlations, and there’s no corroborating research to suggest that the effects were causal or meaningful.

This doesn’t even rise to the relatively low bar of “suggestive findings that should prompt further research.” It was a bad study that no one would have paid any attention to unless they were actively looking for a way to cast aspersion on GM crops. Also, it doesn’t even involve Bt sweet corn (or in some cases Bt corn, because the data also included Roundup-ready seed). So this is emphatically not a situation where a bunch of rats fed the product coming to market this summer died from liver failure but the research was swept under the rug. Instead, this seems to be a case where a few publication-hungry scientists ran SPSS on a found data set until they got a handful of results with a p value < .05 and slipped it into an obscure and poorly-vetted journal. Is it really any wonder Monsanto is reluctant to release their data for that kind of “independent analysis” more often?

What About the Pregnant Women?

Ignoring for just a moment the fact that literally hundreds of compounds that are actually toxic to humans can probably also be “detected in pregnant women,” that part of the ad is probably a reference to this study from Quebec published in Reproductive Toxicology last year. It was designed to see if there was any correlation between the consumption of genetically modified foods and fetal exposure to herbicides like glyphosate, aka Round-up. In other words, the presence of Bt proteins was being used as a marker of GM consumption. No one has any reason to believe that Bt is harmful to pregnant women, or their fetuses, or anyone else who isn’t a corn-boring caterpillar. Instead, the researchers appear to be concerned about the potential effects of fetal exposure to Roundup, or more accurately, how to safely measure those potential effects. The main conclusion of the study was that the technique they used seems to be a good way to measure pesticide exposure: “This is the first study to reveal the presence of circulating PAGMF in women with and without pregnancy, paving the way for a new field in reproductive toxicology including nutrition and utero-placental toxicities.”

It’s not clear from the ad what its designers thought would be so sinister about the mere presence of Bt proteins in pregnant (or non-pregnant) women. Wouldn’t that just show that Bt proteins are already in our diet, even before a single ear of Bt sweet corn has been consumed? Perhaps it’s included as “evidence” to counter the claim attributed to Monsanto that “the toxin will break down before the corn makes it to your dinner table.” Which, again, it probably will, not that it matters. Aside from the hysteria-inducing reference to pregnant women, I suspect that what they were really trying to do was activate fears related to pesticides like DDT, whose persistence in the ecosystem and presence in human bodies might legitimately be a cause for concern. Never mind that Bt insecticides and transgenic seed are exactly the kinds of agricultural innovations^^^^ that can prevent the use of pesticides like DDT.

If You Want to Be An Informed Consumer, Act Like It

Organic farmers have commercial interests and organizations aimed at protecting those interests, just like conventional agribusiness. If this campaign is any indication, they’re no more trustworthy than Monsanto, just far less powerful.

When not referring to carbon-based compounds, “organic” is a marketing term, not a scientific one. In the U.S., it refers to products grown or made without synthetic fertilizers and pesticides or a few other disallowed things including transgenic seed, as certified by one of the roughly 100 USDA-accredited agencies (source: USDA). It doesn’t mean it’s produced without any fertilizers or pesticides, which would make farming all-but-impossible anyhow. Many organic-permissible fertilizers and pesticides are actually worse than conventional ones in terms of how much energy they take to produce, how they affect the environment, how effective they are, and how they affect the health of farmers and people living downstream. Obviously, if you want to buy organic-labeled things anyway, that’s up to you, but I wouldn’t go around feeling smug about it or anything.

What really makes the veins in my temples throb uncomfortably is when people post things like the ad above with a tagline like “This is why it’s so important to know where your food comes from!” I don’t expect people to be experts on Bt, or any other aspects of farming and food production. Most people have more pressing things to do with their time than actually find out whether the organic berries at the store were grown using sodium nitrate mined in South America that leached perchloride into surrounding waterways, which might interfere with the human thyroid gland if it seeps into drinking water. Or if this or that brand of organic wine was protected from fungus with copper sulfate, which is toxic to fish and accumulates in the soil and in the breastmilk of vineyard employees (see: the section of Just Food titled “Chemicals” pp. 62-72).

But if you insist on posturing as an informed consumer, the least you can do is pay attention to the sources of your information and attempt to verify suspicious claims. Especially if someone has a clear profit motive for getting you to believe something or is trying to sell you on an idea by making emotional appeals, like gesturing towards oblique threats to pregnant women, google that shit.

Extraneous Asterisked Babble

*As of 6:43 pm Sunday, May 20.

**From the innocence of their logo, designed to look like the border’s been hand-sketched, to their high-production quality commercials about how they’re working to fight hunger and help farmers around the world, featuring lots of wide-eyed non-white people, including schoolchildren obediently raising their hands in class (well-fed and ready to learn—Thanks, Monsanto!), to the boilerplate that shows up below the website in a google search: “If there were one word to explain what Monsanto is about, it would have to be farmers. It is our purpose to help them meet the needs of a growing population,” you would almost think they’re a non-profit anti-hunger organization instead of a company that specializes in the production of herbicides applied by the truckload and growth hormones administered to industrial livestock via syringe and whose gross annual profits last year were US$11.822 Billion. Profitability and noble social causes aren’t inherently incompatible, but Monsanto’s litigation history leaves little doubt about which one of those they prioritize.

***I’d be surprised if they weren’t the inspiration for U-North, the corporation in Michael Clayton (Tony Gilroy, 2007). On the other hand, I’m sure many of the people who run and work for Monsanto are decent people who genuinely believe they’re doing more good than harm, and depending on how you quantify “good,” maybe that’s even true. According to the National Center for Food and Agricultural Policy, in 2001 the most common biotech cultivars being planted—corn, cotton, soybeans, and virus-resistant papaya and squash—were solely responsible for a national pesticide reduction of 46 million pounds. GMO Bt corn alone reduces annual pesticide use to battle the corn borer by about 2.6 million pounds (source: Tomorrow’s Table p. 72).

The possibility of reducing pesticide dependence is especially promising for poor farmers around the world who still rely on chemical cocktails including DDT applied from leaky backpack sprayers. Not that Monsanto is actually concerned about those farmers, but I’m not sure it’s reasonable to expect corporations to pursue social good over profits. If we want Monsanto, or any other corporations, to behave more ethically, we need to pass legislation and arm regulatory bodies with the power to enforce it. And I know that’s hard, especially when the corporations have so much more money (see below), but as far as I can tell, concerned rich people shopping at farmer’s markets and Whole Foods instead of Wal-mart is not a particularly effective alternative strategy.

^Annual lobbying expenditures vary by year. Monsanto spent $US 8.83 Million on lobbying in 2008 and $US 6.37 Million last year (source: Open Secrets). They also wield their influence in other ways—the current head of the FDA is Michael Taylor, a former Monsanto lobbyist.

^^Unfortunately, the bacterium used in GM seed is actually called “Bt-toxin,” because the person who named it probably wasn’t in advertising.

^^^I wonder if this disclaimer actually means anything more sophisticated than: “We can’t really tell, but we think maybe rabbits just don’t like getting stuff in their eyes.”

^^^^If you’re against the very idea of “agricultural innovation” and think we should only allow people to farm the way they did 100 years ago, but you’re reading the internet… I give up.