I’m so excited to bring you this post! Guesting today is Mommy PhD, a mom and scientist who has thoroughly studied the food she feeds her family. I met her via Facebook a few months ago and it seems only fitting that Mommy PhD and Daddy’s Tractor would teaming up to help your family make informed decisions! 😉
While the scientific consensus about the safety genetically engineered crops (GMOs) is very well established, many people remain unconvinced, largely based on misinformation spread by activists and organizations funded by the organic industry. Anti-GMO activists often ask scientists to prove that GMOs are 100% safe.
However, this is the wrong question.
It is impossible to prove anything is 100% safe and, in reality, nothing is 100% safe. Everything comes with a risk and safety is always relative. The real measure of risk regarding GMOs is the relative risk compared to non-GMO food. The question that should be asked is:
Are there increased risks associated with each GMO product compared to its non-GMO counterpart?
Science has told us the answer – GMOs are at least as safe as non-GMOs. There is essentially no difference between the two in terms of risk.
Let’s take a step back from the details of the science and talk a bit about general concepts of risk and risk assessment to understand what this means in terms of GMOs.
The basics of risk assessment
Humans, on the whole, are intuitively terrible at assessing risk in our own lives (even those who are trained in statistics). Just look at the popularity of casinos! We make bad assumptions and make the wrong comparisons when we consider risk in our own lives.
Emotions cloud our assessment of risk.
We are bad at assigning value to long-term risks and benefits; we have an innate tendency to focus on the short-term. We also think in very small sample sizes (after all, what happens to me and my family must be most important, right?) and not in terms of populations (which is how epidemiological statistics are calculated). We overestimate the risk of the unfamiliar and what we don’t understand. A familiar example of our innate misapplication of risk is that we tend to be less apprehensive about getting in the car every morning than we do about getting on a plane. In reality, the risk of injury or death from a car accident is much higher than the risk from flying on a plane, which is the safest mode of transportation in the US.
Let’s consider the example of heart disease and smoking (with some made up numbers) to understand the essentials of risk assessment in health and safety. Our natural tendency is to look at the risk of heart disease in smokers and attribute the entire risk in that population to smoking. However, the risk due to smoking is only the risk that occurs in excess of the rate of heart disease in the general population.
Looking at the graphic, let’s pretend the top group is non-smokers (or the general population) and the bottom group is smokers (or people in some other at risk group). The people in yellow do not have heart disease and the people in red have heart disease. The base rate is 2 in 100 or 2% in the general population. The absolute risk in smokers is 8 in 100 or 8%. The relative risk is 4 because we divide 8% by 2%. In this example, smoking increases the risk of heart disease by 4. This relative risk is the magic number that tells us how much additional risk of heart disease is attributable to smoking.

This gets more complicated when you consider that most behaviors, medications, and other choices we make have both risks and benefits. Some treatments have side effects. Some behaviors that are good for you might also have risks (for example, you might have a greater risk of injury if you exercise). So now we have to consider many more variables. We also have to weigh how much risk is tolerable to gain a benefit and the risks and benefits of doing nothing.
What does this all have to do with GMOs?
What all that risk assessment stuff above means for consumers and is that safety is relative to whatever you would do otherwise.
So the relevant question is not: “Is this GMO crop safe?” It is: “Is this GMO crop at least as safe as its non-GMO counterpart?”
Or, in science-speak, “Are there increased risks associated with this GMO crop compared to those associated with its non-GMO counterpart?” We ask what the base level of risk is and assess whether any particular GMO poses any risks in excess of that base level.
This question has been answered for all currently available GMOs.
The risks are assessed compared to the alternative. GMOs are the most well studied and tested food in our food supply. Layla Katiraee at Biofortified wrote a great description of how these studies are designed and carried out earlier this year. GMOs undergo intense scrutiny by the EPA, USDA and EPA prior to deregulation (meaning before they can be sold to consumers). In contrast, non-GMO crops require no approval no matter what genetic modification techniques were used to create them, even if genetic engineering techniques change far fewer genes than other techniques (this actually represents a higher risk from non-GMOs compared to GMOs, although still very small). We also do not screen these non-GMOs for allergens, even when a large number of genes are changed. In contrast, allergen screening for GMOs is extensive. For non-GMOs, we recognize that even if we change a large number of genes, an apple is still an apple and these do not require any testing. However, for GMOs, even if we change one base in one gene, we subject this crop to years (sometimes decades) and millions of dollars worth of testing.
This stringent scrutiny of GMOs is unscientific and arbitrary. However, it does provide us with an awful lot of data about GMOs. What all this data shows us is that there is no increased risk associated with any current GMOs – for allergies, for food safety, for nutritional content, for environmental impact – compared to their non-GMO counterparts. In fact, for some nutritionally enhanced crops (like Golden Rice), they can actually be healthier. This is why every major scientific and regulatory agency that has reviewed the data on GMOs has found that all currently available GMOs are at least as safe their non-GMO counterparts. This information isn’t hidden or secret. GENERA (Genetic Risk Engineering Atlas) is a public database of over 1,000 studies of GMOs assembled by Biofortified, an independent non-profit.
Let’s revisit our question: Are GMOs at least as safe as their non-GMO counterparts?
Yes. As I explained above, the evidence shows, over and over and over, that there is no increased risk associated with growing or eating GMOs.