Food Science and Nutrition Myths: How Dangerous are GMOs?

From the Lecture Series: Medical Myths, Lies, and Half-Truths — What We Think We Know May Be Hurting Us

By Steven Novella, M.D., Yale School of Medicine

How dangerous are GMOs? Just about all the plants and animals that you think of as food have been extensively cultivated over centuries, or even thousands of years by human ingenuity. They never existed in nature before extensive human tampering. How much cultivation therefore is required before food no longer considered natural? Is any amount okay?

Hand with magnifying glass examining broccoli with GMO label
(Image: zimmytws/Shutterstock)

Consider a Carrot

How dangerous are GMOs? Let’s start by taking the example of the carrot. This is a very interesting historical example because we still have wild carrots around today. You probably have seen them. They’re a very common weed. In the United States, they’re known as Queen Anne’s Lace. It has a pretty white flower on top. If you’ve ever pulled one out of the ground—I remember doing this when I was even a young boy—and smell the root, it smells like a carrot. I recognize the familiar smell of a carrot on the root of this plant.

Queen Anne's lace, a North American wildflower, growing in rural America.
Wild carrots are a common weed in US known as Queen Anne’s Lace. These plants have a small, bitter, and nutritionally marginal root(Image: Verena Joy/Shutterstock)

In the wild, these plants have a small, bitter, and nutritionally marginal root. You can eat it and gain some nutrition from it. But, parts of it are too fibrous to eat and the amount of nutrition you get out of it is minimal. However, this wild carrot has been cultivated for centuries to be larger, sweeter, and less fibrous until eventually, we end up with the carrot that we are familiar with today. Even then, by the 15th and 16th century, there were white, yellow, purple, and black carrots.

The orange carrot emerged at least by the 16th century, perhaps earlier; it’s still not clear. At some point along the line, probably in a cultivar of yellow carrot, there was a mutation which dramatically increased the amount of beta carotene in this crop making the carrot orange. This became popular then because the orange cultivar is much more nutritious because of the beta carotene.

This is a transcript from the video series Medical Myths, Lies, and Half-Truths: What We Think We Know May Be Hurting Us. Watch it now, on The Great Courses Plus.

Modern Day GMs

But, what about genetically modified food now? We can dramatically change plants by cultivating them. Is genetic modification any different? It is a lot quicker and more powerful. We can take genes even from distantly related species, like even bacteria. We can take a bacterial gene and put it in a crop plant. Therefore, there are differences between genetically modifying food and just cultivating them. But, it is still just another technology or thing that humans do to alter, even significantly, food.

Some people object to the very notion of GM food. There are other issues and some political issues such as the ownership of that food. That’s not what I’m talking about. I’m talking about just the health and safety of the food itself. The point is that, whether it’s the result of natural evolution, cultivation, or genetic modification, the product is what matters the most—not necessarily how we got to that product.

Learn more about the importance of whole foods and fiber

Food Irradiation

What about irradiating food? Again, some people oppose the notion of passing radiation through food because it’s not natural and it may alter the food from its natural state. However, it’s a myth that irradiated food is radioactive. It is not. The radiation passes through the food. There is no radioactive material in the food itself. But, that is not the extent of concerns that people have about irradiated food.

Cobalt-60 irradiation facility is used to test irradiation as a tool to ensure food safety.
It is a myth that irradiated food is radioactive (Image: By, US Department of Energy/Public domain)

This is a quick review of what this technology entails. There are several different types of irradiation of food. There is gamma irradiation technology which uses very high energy gamma rays that are emitted from radioactive material like Cobalt 60 or Cesium 137. There’s electron beam irradiation which uses beta rays. There’s also x-ray irradiation which is deeper penetrating than electron beam radiation. It also doesn’t require any radioactive material or source; therefore, it is easier to use.

Irradiating food is very effective in preserving food because it kills most of the bacteria that’s in the food. In fact, it’s so effective that you can store irradiated milk in the cupboard. It doesn’t even need to be refrigerated and it won’t spoil for weeks. It is true that irradiation, because you are passing very high energy particles through food, may breakdown some nutrients like thiamine, for example. But, overall there is a minimal effect on the food itself. These effects are similar to cooking in terms of, for example, production of oxidants in the food. It’s not much different than just cooking the food itself.

Learn more about the controversies surrounding genetically modified plants

Benefits of Food Irradiation

The CDC, the Centers for Disease Control, estimates that, if we irradiated 50 percent of the meat and poultry in the United States, this would prevent nearly 900,000 cases of infection, 8500 hospitalizations, and over 6000 catastrophic illnesses with 350 deaths each year. The effectiveness of irradiating food is not in question. But, most of the opposition to it seems to be based upon the notion that it’s doing something harmful to the food and altering it from its natural state.

Learn more about some common fallacies about the “natural foods” you find in almost any grocery store around the world

Common Questions About the Dangers of GMOs

Q: What is the reason for GMO products?

GMO’s are often made to enhance the traits of the original plant and to create a product that must be purchased repeatedly.

Q: Which scientist discovered GMOs?

Herbert Boyer and Stanley Cohen were the first engineers of genetically modified organisms in 1973.

Q: How many GMO crops exist?

26 species were identified as GMO in 2015. In 2018, it is proposed that only 10 are GMO.

Q: Who started Monsanto?

John Francis Queeny started Monsanto on September 26, 1901, in St. Louis, MO.

This article was updated on 8/30/2019

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