Genetically modified foods are scary. They’re mutants. Not naturally of this earth. (Well, I suppose neither is Coke, but that’s besides the point…) GMOs are like Frankenstein and they’re making us sick. But are they really? Or is it just Gwyneth Paltrow-style hype?
(Fair warning, this post is long, but it’s really important so keep reading…)
What does genetically modified mean?
Two scientists that wrote a report in 2013 on the changes of GMO crops in the past 20 years define GMO (or transgenesis) as:
Transgenesis involves the insertion of a designed genetic cassette with a known DNA sequence intended to produce a prescribed gene product (typically a protein) to achieve a desirable trait through a known mechanism. The transgenic insert in the plant is sequenced to determine if it has been inserted as intended and to confirm that it codes for the desired gene product. The flanking endogenous plant DNA is also sequenced to understand if any native genes or regulatory elements are disrupted. Finally, the plant genome is probed to ensure that only one insertion site exists.This contrasts with traditional breeding by which many genes are randomly recombined and/or many mutations are generated with little or no knowledge of the genetic changes that are induced or the mechanism behind the traits that are selected. It has been acceptable with traditional breeding for many undescribed genes from wild relatives with no history of safety to be incorporated into new crop varieties to obtain novel or improved agronomic traits such as pest resistance.
Don’t skim over that. If you did, go back and read it again. And pay attention. I’ll wait...
In the modern world, there are two reasons main reasons for GMOs, or transgenesis:
- Pest Resistance: Which, by reducing the detrimental effect of plant eating pests, is intended to yield more crops and bigger fruit/veggies. These are the majority of GMO crops on the market.
- Nutrient Enhancement: Which is intended to insert or boost nutrients into plants which may not always be there. These types of crops are not typically marketed yet.
There are a million reasons why you may be for or against GMOs. The environmental impact, healthfulness, crop yield, feeding the poor. The need for these crops, and subsequent consequences, is complicated and globally complex. Add in the disdain for major corporations, lawsuits over proprietary rights, labeling laws gone awry, and Golden Rice Scandals and you’ve got a serious rat’s nest.
There are environmental issues, to be sure. The propogation of superweeds (i.e. weeds that are resistant to Monsanto’s RoundUp) is real. However, the rise of superweeds from conventional herbicides and pesticides is also on the rise (i.e. the pest and virus killers sprayed on non-GMO plants). In fact, more than twice as many conventionally induced superweeds are out there as compared to RoundUp resistance weeds. What’s more, because you have to use less herbicide and pesticides on GMO plants, there was a 6.1% reduction in overall use between 1996 and 2011. This resulted in an 8.9% improvement in the environmental impact that these GMO crops had, when compared with conventional plants. Now, I’m not going all PollyAnna on you with this one. As a result of the increase in superweeds, farmers have also had to start using more and more RoundUp and other herbicides on their crops to keep the weeds at bay. As a result, a Penn State study estimates that total herbicide use will most likely double by the year 2025. There was no estimate in this study on what the increase would be with the use of conventional pesticides and herbicides only (but, based on the abundance of conventional superweeds, you can imagine it would also go up by necessity).
But, let’s just stick to nutrition. Specifically, plants. Transgenic animals can be a post all its own. Environmental and global farming issues aside, are these crops safe to eat?
First, I think we need to address the difference between the modified crop itself and the herbicides and pesticides that are sprayed on them. At the end of the day, this is really important because it separates scientific intention from agricultural practice. This is a controversy over which even scientists come to serious blows, because it’s really hard to use laboratory models to predict how these plants will affect human health when unknown farming practices are also in the mix.
So, the use of pesticides and herbicides aside, let’s just look at the modified plants themselves.
One way scientists describe differences in GMO crops versus conventional crops (like corn, say) is to compare the nutritional properties of each. So, they use some pretty sophisticated machinery to break down all of the nutrients in each plant and lay them side by side. Because DNA and RNA themselves are generally not considered food safety risks, mostly what scientists look at are the proteins that the DNA and RNA code for. What they find, for the most part, is that GMO crops look almost exactly like conventional crops from a nutritional standpoint (minus whatever nutrient they’re inserting). GM- Cotton, rice, and soybeans (among several others) have all been analyzed and show remarkably similar nutrient and protein composition to their conventional counterparts. Interestingly, it actually seems as though there is more variation between conventional crops due to environmental conditions (i.e. Why an orange from Florida tastes slightly different than an orange from California) while the GM crops remain fairly stable.
It’s worth noting that over time, conventional crops show more unintended genetic variation due to old-school breeding programs and naturally occurring mutations when compared to GM crops. So think about it this way, when you go to the nursery in the spring to pick out your tomato plants for the year, you’ve got choices. Big boy, Roma, Beefsteak, Cherry. All of these plants have been conventionally bred (i.e. modified) to enhance certain characteristics: sweetness, size, color. This is not a naturally occurring process, and results in many more unintended mutations than GMO crops exhibit.
So, if the nutritional content is the same and perhaps even stabilized or enhanced (like in crops designed to boost nutrients like apples with more polyphenols, or rice with more iron and resveratrol, or corn with more lysine), then are they actually safe to eat? Does messing with the DNA have unintended consequences?
Here is where the story actually starts to become a little tricky, and it mostly has to do with GM crops that are altered for herbicide and pesticide use (like Bt Corn) not so much with enhanced nutritional content (like resveratrol rice).
In order for scientists to determine if these crops are safe for people to eat, they conduct randomized controlled animal studies on mice, rats, hamsters, and ferrets. One group of animals gets their normal food, one gets the conventional crop (like organic corn) and one gets the transgenic crop (GMO-corn). It’s not a perfect model because each animal has it’s own quirks (for example, we use ferrets to look at B-carotene metabolism because mice don’t absorb it well from food). But, it’s close enough that we can get a good idea if a food (or drug for that matter) is helpful or harmful. Without getting into the moral merits of animal models (I know it’s controversial) I believe this type of research is completely necessary in the modern era of rapidly changing food (and drug) technology. Testing out GMO-soy on a mouse is infinitely better than tossing it straight into your already colic-y infant’s Gerber Soy Formula.
With regard to GMO safety, there is a consensus of animal research that says the food is perfectly safe and maybe even helpful. In fact, with an enhanced polyphenol profile in apples, researchers in New Zealand have shown improved gut bacteria levels and reduced metabolic syndrome; modified wheat seems no more allergenic than conventional; GM-Rice has no adverse effects on GI health or body composition when compared to conventional; transgenic peas seem fine; GMO-soy was no more detrimental to rat reproductive organs that organic; even GMO-corn that is grown for both nutritional enhancement and pesticide tolerance seems ok. In fact, a full review of 24 such studies completed in 2012 concluded that GMO crops were essentially safe for consumption.
But, I know you’ve heard otherwise, so don’t stop reading just yet.
There have been a few very public and damning reports of increased health risk with GMOs. In a study published in 2012 in rats, a group of French scientists determined that Round Up Ready Corn eaten by a certain strain of rats resulted in 5x the growth of tumors of those fed normal rat chow. Unfortunately, you can’t read this study anymore because it was retracted by the journal after being subject to some pretty (in my opinion warranted) criticisms of study design and scientific rigor. At the end of the day, the scientists used a strain of rats that is prone to tumor development and teasing out whether the actual corn or the Round Up is to blame for the development of the tumors is difficult. You can read the authors response to this criticism here.
The original study that caused a ruckus in the GM world was done by a Scottish scientist named Pusztai. He found that potatoes that were genetically modified to produce more lectin (which naturally wards off pests in many plants) was highly detrimental to the intestinal linings of rats. Unfortunately, because of industry backlash and governmental kowtowing, his career was ruined. However, given that lectins have since been shown to pretty tough on human digestive tracts too, he was certainly onto something. (n.b. One thing to note, is that lectins are naturally occurring substances found in many conventionally grown plant foods that we eat and, if cooked, are not harmful). Indeed, this type of enhancement should be a well heeded warning of enhancing properties in food that are not tested for consumption in high doses, but it does not disqualify the practice as a whole.
Unfortunately, the literature stops at animal studies. I could not find any studies yet on humans and GMO consumption (although, I wish there were and I truly hope they are being conducted). Nor could I find any reputable studies on cows or pigs that are now mostly fed GMO-crops and risks of cancer or disease (if someone has actual research on this, not anecdotes or supposition, please send it and I will add/reference). There was one study done on inflammation of pigs' stomachs with GMOs (which has gotten a significant amount of unwarranted press), but the results were all over the map, so I hesitate to even bring it up. However, in an effort for full disclosure, there was no difference in the organs of non-GMO vs. GMO pigs except in the stomach and a possible false positive in the uterus. Many non-GMO pigs demonstrated mild to moderate inflammation (n=60) compared to GMO (n=41). Some GMO pigs demonstrated severe inflammation (n=23) while less non-GMO were severe (n=9). Overall, equal amounts demonstrated stomach inflammation. But, twice as many GMO had NO inflammation (n=8) compared to non-GMO (n=4). Further, no actual scientific testing was done, inflammation was determined by the eyeball of a veterinarian. Lastly, all of the pigs were really sick, probably because they were kept together in huge numbers on cement. If you want to read a pretty thorough going-over of the study, read here. I take nothing from it. Nothing.
But here’s a fairly convincing argument for the overall safety of GMO crops. In addition to doing interventional studies on animals and humans, scientists use population based studies of naturally occurring events in order to determine whether a policy with direct effects on humans results in any change. In America, we eat A LOT of GMO-corn, whether we know it or not. It’s estimated that almost all corn in processed foods is GMO. However, cancer rates in the United States are almost identical to that of Europe, who previously ate far less GMO corn than we did and now eat almost none due to legislation.
I’m not necessarily giving GMOs a health pass. I think there is enough research out there on the harmfulness of pesticides and herbicides to be concerned (which are the typical reason for implementing GMO crops on a massive scale and should be a post of its own). But that concern holds true for conventional crops as well as GMOs, which also use massive amounts of pesticides and herbicides. My skepticism has very little to do with the modification of the plant itself.
We do need to take in mind though, as our massive global population grows to over 7 billion and results in exponentially more livestock mouths to feed, we do need to use science and technology to avert a world-wide food crisis. Utilizing our brains to enhance foods to alleviate nutritional deficits, reduce poverty related hunger, and perhaps even enhance the health of people shopping at grocery stores in America, is important and, arguably, a moral necessity for the health of our ever expanding population.
Are these GMO foods safe? As far as the research says today….yes, they’re safe. A few rogue studies does not a consensus make (although more studies do arguably need to be conducted). Are they natural? No. But neither is taking vitamins, putting wrinkle cream on your face, or chewing gum. Should we be skeptical? Of course. We should always insist that our safety is taken seriously by the companies that feed us and we should demand the highest level of scientific testing (made available to the public) with subsequent stringent regulations based on the results. Is it scary because you don’t quite understand the specific science behind it? Maybe. But, that fear is simply based on the unknown of the process, and should not be of the science itself. Are you fearful of how your dry whey protein is extracted from liquid milk? Or how food companies add folate to your bread? Or how your sugar alternative is distilled from a plant from ancient Taiwan? These are all scientific advances in food production that you trust everyday.
If you want labeling, fight for a bill and then vote for it. I’m game. I think we should have transparency and choices in our food markets. However, we should not demonize an industry that is truly necessary to feed the massive human and animal populations in the world based upon anecdotes, ideology and conjecture. Being afraid of GMOs because your trainer, or neighbor, or Gwyneth Paltrow told you they're unsafe is akin to not vaccinating your children because Jenny McCarthy claims vaccines cause autism (they don't). Do your homework, follow the facts, and pay attention to the research. As always.