If you were going to be part of a huge science experiment, you might like to know about it. At least that's our guess. And that is the bottom line in our review; you're probably eating Genetically Modified Organisms (GMOs) every day, don't know it, and exactly what the health effects might be, frankly, nobody really knows. There have not been enough GMO studies, but extremely disturbing facts have arisen from the ones we have.

To start, what is genetic modification? Farmers have long cross-pollinated plants species or cross-bred animals to get a new variation with desirable characteristics of both "parents." This is simple modification, though nature is participating.

What scientists have been doing in recent decades is splicing genes out of the DNA of one species and inserting them into another to create things that could never have happened otherwise. In one early example, fish genes were inserted into a tomato. Agribusiness concerns, led by Monsanto, have been busy tinkering and effectively inventing new life forms at an accelerating pace.

While we weren't paying attention the last 10 years, monstrous quantities of our food supply in the U.S. turned into Genetically Modified (GM) crops. Eighty percent to 95 percent of all corn, soybeans, and cotton grown in the U.S. are now GM crops.¹ Canola, sugar beet, alfalfa, and more are close behind. The net result is that most (yes, most) of the food in the grocery store has GMOs in them, and the animals that your meats come from have fed on them. It is enough to make anyone sit up and want to understand this a little more.

Genetic modification, like so much science, may offer wonderful promise. Proponents of the technology point to their ability to create food variants that consume less water, resist pests, look better longer, and are generally helping to produce more food, cheaper.

But deeper investigation turns up, well, a lot. You may know a recently converted GMO activist, so highly excited that you wonder if they are just another off-the-deep-end alarmist with the latest conspiracy theory. And there are plenty of blogs and websites citing claims without substantiating them, but putting in some effort turns up enough supported information that you begin to understand the anxieties.

So, just what are some of the concerns with genetic modifications?

Environmental Havoc

Two primary GM corn variants are good examples of the problems. Bt corn has been genetically engineered to contain the Bacillus thuringiensis bacteria that endows cells of the plant with a toxin that kills any pest that feeds on it. Sounds like this should increase yields and limit the need for applying pesticides (since it is one itself). What we are learning now is that more insects than the targeted pests are being decimated, not only from eating the Bt corn plant, but also other plants that have had the pollen of Bt corn land on them. Studies have found links to the large-scale disappearance of monarch butterflies and caddisflies, and the collapse of bee colonies may also have a connection.^{2, 3} It is clear that we cannot target which insects we affect, and this approach is simply mucking up ecosystems that are more complex than we are appreciating.

The other variant is HT corn (for herbicide tolerant) and takes a different approach. These strains have been genetically modified to be tolerant of the herbicides glyphopsate (Roundup) or glyfosinate. This allows farmers to use these pesticides with some abandon and not worry that the corn will be damaged. Besides the perhaps obvious concern of increased pesticide use (that ends up on your plate and in your soil and water), the growth in use also has spawned newly resistant weeds. Dubbed "superweeds," this has translated into greater use of even stronger pesticides and other problems. And because nature will always adapt, we also are seeing insects newly resistant to Bt corn, as well.⁴ Additionally, winds blow seeds, and birds transport them, and we now have accidental cross-breeding with non-GMO crops on a massive scale.

Human Health Risks

GM seed producers have long claimed that new genes introduced through GM food are harmless because they are effectively dissolved in the intestines. But there is a rising tide of studies that are suggesting that these alien genes can indeed be transferred into the blood, with some even demonstrating ill effects on human cells.^{5, 6, 7} The assembled independent science also is becoming clear that tampering with the genetic code has unintended consequences and cascading mutations.^{8, 9} The ensuing scientific debate wonders exactly what kind of mutations of our own genes will result.

It was said at the outset that not enough definitive study has been done, and it is worthy to note that very little of what has been accomplished has been done in the United States. Some would charge that agribusiness is writing the laws. Indeed, not only do we not require any substantive testing of GM crops, U.S. regulations actually require the GMO patent holder's permission for any study to be done on their product.

Yet, there are dozens of studies in recent years with damning implications. Animal studies show mounting evidence that GMOs disturb function of the kidney, liver, heart, adrenals, spleen, pancreas, blood, and links to sterility and infant mortality.^{10, 11} Human studies have demonstrated GMO links to pesticides in pregnant women, and suggestions that GMOs may play a role in the exploding rates of allergies, autism, diabetes, and more.^{11, 12}

What does Europe know that we don't? Most GMO studies are being conducted in Europe and there is a dramatically different regulatory environment. The EU was first to require labeling of food with GM components back in 1998, and that is now law in 61 countries, including China, Russia, and Saudi Arabia. Dozens have deeper restrictions, from outright bans to significant restrictions. California almost passed a labeling law last year with Proposition 37, but deep-pocketed corporate interests poured money into narrowly defeating it (by 1 percentage point).

Taking a different approach, upscale grocer Whole Foods made news in early 2013 when it announced that it would require all products containing GMOs sold in its stores to have labeling within five years. But what are you to do if you want to opt-out of eating GMOs today? It's not easy, given the overwhelming prevalence of GM foods in the U.S. today. Really, the only sure means is to buy organic-certified foods, as that disallows any GMO content. So there's one more, really powerful reason to go organic.

To be sure, this brief assessment only scratches the surface of an intensely complex topic. But we've been eating GM foods for more than 10 years now, unknowing participants in a grand and uncontrolled science experiment. How you feeling, lab rat?

Learn more

Non-GMO Shopping Guide

Institute for Responsible Technology

Non-GMO Project