As I prepare to wade into yet another of the hottest debates on the planet, I want to approach this topic rationally. That means isolating the actual science from our feelings about economics and corporate policies. And it also means starting at the very beginning.
What’s a gene?
DNA has often been called a “genetic blueprint.” But it may be better to think of it as a recipe book. To build, say, a banana tree, you would need thousands of different proteins, and you could find a recipe for each of them within the banana tree’s DNA.
Each recipe, or gene, is a section of DNA that tells a cell how to assemble amino acid building blocks to create a specific protein. These proteins may be used for any number of purposes—to build a cell well, to shuttle things into or out of the cell, to send signals to other cells, or to fight diseases. It is the arrangement of the amino acids that determines the shape of the protein, as well as how it interacts with all the molecules around it.
Genetic recipes can be shared
99.9% of your DNA is identical to that of any other human being. But you share 85% of your genes with the dog lying beside you. And we could find 24% of your genes in the grapes used to make your glass of wine. This is called “conservation across species” in biological terms. And in general, the more similar two organisms are, the more genes they share.
All life on earth speaks the same language. A DNA sequence codes for the same protein, whether in a mouse or a cactus. That doesn’t mean that we could make a cactus grow tails instead of spines. It’s more complicated than that. But it does mean that if we give organism A the recipe for one of organism B’s proteins, organism A just might start producing it.
Gene swapping isn’t new
Bacteria frequently exchange genetic recipes. This is one way they develop resistance to antibiotics. When one organism has a mutation that improves its survival, it can share the gene with surrounding bacteria, which will then use that recipe to develop the same resistance.
A virus’s survival depends on transferring genetic material. Viruses aren’t equipped to reproduce on their own. Instead, they insert their genetic recipes into the host’s cells, using that cell’s assembly line to make copies of themselves.
All organisms are genetically-modified
Every organism has modified genes. Your children’s genes aren’t the same as yours. Trace that back a hundred or a thousand generations, and the changes are even more pronounced.
Since humans began to domesticate animals and grow crops thousands of years ago, we have been slowly altering their genes. Using the processes of selective breeding and hybridization, we have been modifying genes for centuries. We just didn’t know what we were doing.
We turned wolves into Yorkies and Mastiffs. Every breed of cow, chicken, and pig came from a wild ancestor. Small genetic changes in a single species of Brassica gave us kale, cabbage, collards, cauliflower, broccoli, and Brussels sprouts. We can enjoy seedless watermelons and bananas, or choose from thousands of varieties of apples. Nothing you eat today has been the same forever.
What’s a GMO?
The term “genetically modified organism,” as it’s commonly used, refers to a living thing that has been altered by changing one or more of its genes—often, by splicing in a gene from another species. It’s a direct and precise method of obtaining desirable traits, and it’s far more efficient than traditional methods like selective breeding. It’s probably better to use the term “genetically-engineered,” and I will use these two terms interchangeably.
What genetically-engineered foods are available?
Currently in the United States, the most common genetically-engineered foods are corn, canola, soybeans, and sugar beets. You can see a full list of approved genetically-engineered crops here, although many of them are not currently produced. There’s also a breed of genetically-engineered salmon that was approved in 2015.
Benefits of GMOs
1. Herbicide tolerance
Imagine that all plants died when exposed to songs by Coldplay. Then, one day, a farmer plants turnip seeds modified with a gene that makes them Coldplay-tolerant. Now all he has to do is park his truck in the middle of the field, roll down the windows, and blast “Yellow.” And poof—no more weeds. Only turnips.
Really, that isn’t far from the truth. In 1996, plants engineered to be tolerant to glyphosate (better known as Roundup) were introduced. These genetically-engineered crops have allowed farmers to avoid more harmful herbicides in favor of one that is broken down quickly and less toxic to aquatic organisms. However, as the use of glyphosate has increased, there have been some problems with weeds developing resistance, which is to be expected. (More on this later.)
2. Reduced need for insecticides
Some genetically-engineered crops have a gene for a protein produced by the bacterium Bacillus thuringiensis. These crops, often labeled “Bt,” essentially produce their own insecticide (one that is approved for organic farming, by the way), reducing the need for spraying. There was some concern in the late-1990’s that Bt corn was having an effect on monarch butterfly populations, but this was later disproven. What we do know is that Bt crops decrease the cost and work necessary to grow crops, and prevent loss due to insects.
3. Drought tolerance
Drought-resistant crops reduce the need for irrigation and can allow crops to be grown in less-than-hospitable environments. These are a more recent innovation, but they have a lot of potential for allowing or increasing food production in drier environments, including those with current food shortages like much of Africa.
4. Improved nutrition
A great example of how genetic engineering can improve nutrition is golden rice. This is a variety of rice that has been enhanced with a gene to produce beta-carotene, a precursor for vitamin A. In many developing nations, children are weaned from breast milk onto rice, which doesn’t provide adequate nutrition. Many of these children develop vitamin A deficiency, which can result in night-blindness and increased morbidity and mortality from infections like measles.
There have been some difficulties getting golden rice strains to be as productive as traditional strains, as well as a great deal of resistance from GMO critics. But golden rice has potential to decrease suffering and death for children around the globe, and it also represents a new technology that could enhance the nutrition of a variety of other foods.
5. Longer lasting fruit
A Canadian company recently introduced genetically-engineered apples that won’t turn brown when sliced–well, at least for a couple weeks. That can decrease waste and make your kids more likely to eat the fruit you packed in their lunchboxes.
6. Increased yield
Up until now, there haven’t been any genetically-engineered crops designed specifically to increase crop yield. Sure, they can do this indirectly by decreasing inputs or allowing production in drier environments. But you can see how targeted genetic modifications could open the door to engineering higher-yield crops.
But there is one organism designed specifically to increase production: the AquAdvantage salmon. This is a farm-raised fish with a gene mutation that allows it to grow year-round rather than for only part of the year. That obviously allows them to reach the desired size faster, and should eventually decrease the cost of production and allow higher yields.
Concerns about GMOs:
In case you haven’t noticed, some people worry about genetically-modified foods. Here are some common concerns:
There, I said it. Monsanto is a large, multinational corporation that was founded in 1901 as a chemical company. More than a century has past since that time, and their company has evolved, as all companies do. Today, their primary business is in biotechnology—producing seeds for agriculture, as well as the pesticide glyphosate. A large percentage of farms in the United States and around the world use seeds produced by Monsanto.
The corporate practices of Monsanto and other biotech companies are valid topics for discussion, but I will not address them here but to say that without the potential for financial gain, there would be little incentive for progress. The regulatory fees and research and development costs in the biotech industry are enormous, and without an expectation of substantial profit, companies would be foolish to make those investments.
As a side note, those who think that there are no money-hungry corporations behind the “Certified Organic,” “Non-GMO,” and “Pasture-raised, grass-fed, antibiotic-free” labels are sadly mistaken.
To oppose GMOs because you disagree with Monsanto’s business practices is like refusing to use an Epi-Pen because you think Mylan charges too much. By all means, let’s address the other issues. But let’s not conflate those issues with the science.
2. They’re not natural
I love nature. But nature will kill you. Depending on where you live, nature is either too hot or too cold, too wet or too dry. Nature, as beautiful as it is, is not your friend. Very few of us possess the knowledge and skills required to survive in nature—to forage, hunt, or scavenge for food; to start a fire using nothing but friction; to collect an adequate amount of fresh water; and to build a shelter to provide protection from the elements. And even if we did, nature is patrolled by predators that don’t have a problem eating humans, and it’s teeming with bacteria and viruses that have killed billions of people.
We all benefit from innovations that overcome nature—technologies like fire, clothing, shelter, agriculture, sanitation, refrigeration, antibiotics, vaccines, vasopressors, and ventilators. To argue that a thing must be good because it is “natural” is to argue out of ignorance. And to define the word “natural” is a more difficult challenge than you might imagine.
Everybody is afraid of chemicals. But everybody is made of chemicals. A chemical is defined as “a substance produced by or used in a chemical process.” Every single molecule inside your body is a chemical, and they are interacting with each other constantly.
What many people (not including chemists) mean when they use the word “chemical” is a substance that was made in a lab. But if the atoms are arranged in exactly the same way, it makes no difference whether the substance came from a lab or from nature (which, as I discussed above, would be no guarantee of safety).
The word “chemical” is frequently used by people who understand very little about chemistry to scare you into buying their juice cleanse, avoiding vaccines, or picking their produce over the competition’s. As a marketing term, the word “chemical” is essentially meaningless, and it’s almost always a reason to question the person using it.
When people discussing GMOs refer to “chemicals,” they probably mean pesticides, which are used to control insects, fungus, weeds, and other undesirable organisms. The whole goal of farming is to grow healthy plants that produce as much as possible, while requiring minimal inputs. An “input” is anything necessary to get a plant from seed to harvest: fertilizer, compost, soil amendments, irrigation, tractor fuel, and so on.
Pesticides dramatically reduce crops lost to disease or insects, and they keep weeds from consuming the nutrients intended for the crops. Pesticides are absolutely necessary to large-scale agriculture—and yes, even organic farmers use them (just different ones).
Concerns about GMOs and pesticides center around glyphosate-tolerant (or “Roundup-ready”) crops. There has been a great deal of talk about the use of glyphosate and cancer risk, especially since 2015 when the International Agency for Research on Cancer labelled glyphosate as “probably carcinogenic.” But the better studies (which the IARC failed to consider), as well as large meta-analyses, show no evidence that glyphosate causes cancer. And in any case, these studies are looking at farm workers who apply pesticides, and would be exposed at a significantly higher dose than the general public.
You should always wash your produce, even if it’s organic. But glyphosate won’t give you cancer.
Dietary allergies are triggered by proteins in the food we eat, and it is certainly possible that by adding genes that create new proteins in a food, we could introduce a new allergen. But we can also be introduced to new, potentially allergenic proteins through more traditional breeding methods, or simply by trying a new food.
Nobody is splicing genes for the proteins that cause shellfish or peanut allergies into zucchini, and there’s no reason to think that a person would be more likely to develop an allergy to genetically-engineered food than he would to anything else. It’s also important to remember that people are allergic to plenty of non-GMO foods, so unless genetically-engineered food increased the baseline risk, there wouldn’t be cause for concern.
This is a valid concern, but one that isn’t unique to genetically-engineered crops. In the same way that bacteria become resistant to antibiotics, weeds develop resistance to glyphosate. This can happen through random mutations and subsequent selection, or by hybridization between the weeds and the crops. Similarly, insects may eventually become tolerant to the proteins produced by insect-resistant plants.
There is a continual arms race to develop new innovations before pesky organisms figure out a way around them—but this problem exists in conventional agriculture as well, and genetic engineering gives us another tool to work with. Rejecting GMOs because of the potential for resistance is as absurd as saying we should never use antibiotics. Rather, we should use them prudently, and we should continue to develop new ones with the knowledge that in the future, our current technology will fail us.
There are some concerns about the effects that GMO crops could have on other forms of life—whether we’re talking about genetically-engineered plants outcompeting other plants, or the effects of insect-resistant crops on local insect populations. Like the resistance concerns, these aren’t unique to genetically-engineered crops, and we could easily cause just as much damage to insect populations by spraying insecticides. We should absolutely monitor for significant effects and take steps to limit our impact on wildlife, but we have to keep in mind that other types of agriculture affect local plants and animals as well.
7. Other concerns
A quick Google search will provide you with websites claiming that GMOs cause a seemingly unending stream of problems: cancer, obesity, autoimmune diseases, liver damage, infertility, diabetes, ADHD, etc. These claims lack a plausible mechanism—there’s no reason to think that they would be true, and they certainly lack solid scientific evidence.
Many people seem to expect the same type of testing for genetically-engineered foods as we would perform for a new drug. But those two things are simply not the same. We don’t do double-blind, randomized, placebo-controlled trials on canned corn.
Regulations around new GMO crops involves three different organizations.
- The USDA looks into whether there are potential issues with creating “plant pests.” An example would be if the crop could cross with a local weed to produce an invasive or noxious plant.
- If there are any pesticide-related aspects to the specific genetic modifications, the EPA must investigate and approve the new crop.
- And the FDA is tasked with approving the crop for human or animal consumption.
Because the anticipated level of risk is low (just as low as any other method used to produce new strains of produce), the FDA uses a standard called “substantial equivalence.” If you genetically engineer a carrot that is resistant to a particular pesticide, we can pretty much expect that it’s going to be “substantially equivalent” to a carrot. The FDA reviews information about the specific genetic modifications, looks for any similarities between new proteins produced and known allergens or toxins, and compares the nutritional quality of the new food to similar crops.
If these approvals are received, the manufacturer may begin to market the crop for production.
Those who oppose GMOs have fought for years to label all food containing genetically-engineered ingredients. Their assertion has been that people “have a right to know what’s in their food.” That makes sense, on one level. I’m allergic to shrimp, and I’d certainly like to know if my fries were cooked with it. Vegans have a right to know if somebody decided to mix bacon grease with their tofu.
What it really comes down to is the level of detail we should reasonably expect. Do people “have a right to know” exactly which varietal of tomato was used in their pasta sauce? What type of compost was used? Which insecticides or herbicides were sprayed over the field? On what day their cucumbers were harvested? I’m exaggerating to make a point, but if there are no known risks to GMOs, does it really matter? Perhaps they just want GMOs labelled because people will assume that’s a bad thing and choose their products instead.
Whatever their true motivation, Congress passed a bill in 2016 that will require foods containing genetically-engineered ingredients to be labelled–but you may have to use your smartphone to read the label.
As appealing as growing one’s own food on a suburban homestead may seem, it simply isn’t sustainable on a global level. There are many climates where it isn’t an option at all. People around the world are already dying from starvation and malnutrition. This isn’t a problem of the future; it’s a problem now. And reverting to 19th Century agricultural practices wouldn’t help that problem. Genetically-engineered crops provide a way to maximize our food supply, improve nutrition, and farm in otherwise inhospitable environments. GMOs can help us feed the world.
Genetic engineering is neither good nor evil. It’s a technology. It’s a tool. And like any other tool, it has potential to change our lives for better or for worse. To have concerns about new technologies is prudent. But to continue to oppose them without valid evidence is both unjustified and unwise.