David Zilberman, PhD, is a professor of agriculture and resource economics at the University of California, Berkeley. He has spent much of his career studying biotechnology, pest control, the economics of innovation, climate change, and risk. Here, Dr. Zilberman shares his thoughts on one of the most controversial areas of food science today, the use of genetically modified organisms, or GMOs.
Humans have been modifying plants for centuries. How are GMOs different?
Genetic modification, or GM, is a tool scientists can use to modify a specific genome of a plant with unprecedented precision. Botanists have been developing new plant varieties for centuries by breeding them for certain traits, using rather crude techniques like irradiation to generate mutations that may lead to desired properties. Advances in genetic science now give us the ability to be much more precise, by zeroing in on a specific gene. We may insert some genes or silence others. We also have a much better idea of what the effect will be. GM is different from traditional plant breeding because it also allows us to move genes between species. We can take a gene from fish, for instance, and insert it into a plant.
That may sound like science fiction to many people. In fact, critics have called GMOs “Frankenfoods.” Are there potential risks to genetic modification?
“Frankenfoods” is a terrible word, a stigmatizing word, one that’s used only to scare people. I think the risks have been greatly exaggerated. People are afraid of GMOs for little or no reason. GM is simply a tool. Because it allows us to modify plants with far greater precision and control than before, it will be very valuable. Using GM, scientists can make crop varieties that are resistant to specific pests and thus increase crop yields. We can modify plants to produce more nutritious fruits, vegetables, or grains. We are embarking on a biotech revolution that is similar to the electricity revolution. The harnessing of electricity led to the earliest light bulbs, and eventually to lasers, computers, electric cars, smart phones. We’re at the light bulb stage with genetic modification. It’s a technology with enormous potential. As with any technology, the risks and benefits depend on how it is used.
How is genetic modification currently being used?
GM has been used chiefly to make plants resistant to certain pests or herbicides. We have genetically modified varieties of cotton, for instance, that are resistant to insects that can otherwise threaten the plant. Much of the corn and soybean crop grown in the U.S. has been genetically modified to be resistant to Roundup, used to control weeds. Farmers can spray to manage weeds without harming the crop plants. Those are just two examples. But the potential for GMOs is huge. Plants can be modified to be drought resistant or to withstand more intense heat, which could be crucial with global climate change. In the future, scientists may be able to engineer plants to produce specific medicines. We already have a genetically modified variant of rice, called Golden Rice, which is engineered to produce large amounts of vitamin A. Vitamin A deficiency is a big problem in poorer countries. It causes half a million cases of blindness. Studies show that a serving of Golden Rice can provide a significant amount of the daily requirement of vitamin A. But because of opposition to GMOs, the development of Golden Rice has been slowed and it has yet to be adopted anywhere in the world. And there are consequences to that. Our research shows that the failure to plant Golden Rice in India cost an estimated 1.4 million life years over the course of a decade. Opposition has also slowed research and development into other potentially beneficial GMOs.
GMOs have led to increased use of Roundup, which the World Health Organization recently linked to cancer in people. There’s also concern about Duo Enlist, a new combined herbicide developed for weeds that have become resistant to Roundup. Is that a worry?
Herbicide-resistant GMO varieties were created so that farmers can use more herbicides without harming food crops. Roundup has been used for years and multiple studies have shown it to be safe. If there is new evidence of health risks, we need to know about them, of course. But everything has risks and benefits, and any risks of Roundup have to be weighed against the benefits. By helping farmers control weeds more efficiently, the new GMO varieties help keep the prices of corn and soybeans down. Worldwide, GMOs have kept food prices down and allowed farmers to grow more food on less land. Low prices of these crops mean that poor people can afford protein from, say, chicken in their diets. By making plants more resistant to pests, GMOs also reduce the risk of major infestations that can destroy crops. Obviously, it’s important to make sure that the food we grow is safe, and that herbicides and pesticides don’t harm the environment. But we have an enormous number of regulations in place to do just that. You asked me if I worry. I do worry that opponents of GMOs use concern about Roundup to say we should ban all GMOs.
What do you say to critics who worry that regulations aren’t strong enough?
If anything, I worry that they are too complex and onerous. Efficient and effective regulation is essential. But too much regulation can stifle innovation. And in some countries, it can lead to corruption. At the moment, regulations regarding GMOs discourage small companies from entering the market, so it is dominated by big players like Monsanto. And the regulations discourage the kinds of innovation that could make food more affordable and provide much greater variety of healthy foods to the world’s poorer populations. If the regulations were less burdensome, we could produce far more fruits, vegetables, and grains.
Another fear among critics is that GMO crops threaten natural diversity. Is that a reasonable concern?
In fact, genetic modification can be an agent of biodiversity. It allows us to create many different varieties of plants, specifically engineered to thrive in particular environments. Global warming is likely to cause disruptions in farming as weather patterns change, for example. Genetic modification allows us to adapt quickly and specifically. The opposition to GMOs has made it much harder to develop new varieties. In that sense, it has actually resulted in less diversity in agriculture.
Critics want foods containing GMOs to carry warning labels. What’s your view?
I’m not against labels that tell people what foods contain and warn about known dangers. But what are we warning people about? There is no evidence that GMOs pose any dangers at all. Putting a warning label on a food suggests that there is a danger. It just adds to the fear that critics have generated. The people who stand to benefit most from this new technology are poor people. GMOs will help make food more affordable for them and improve their environment by using less land for agriculture. We should look to the science. And that evidence shows that GMOs are safe and can offer us enormous benefits, especially with the growing human population and the threat of global climate change.
This is obviously a very contentious topic. Smart and committed people can disagree. What’s the one message that you would like to get across to opponents of GMOs?
Genetic modification is a scientific tool. Its application holds out enormous promise. Of course, there are good applications of any new technology, and bad applications. If something created using GM turns out not to have value or to have risks that outweigh the benefits, then it shouldn’t be used. But we need to evaluate the risks and benefits scientifically. I’m convinced that this new technology, used wisely, will help us feed a growing human population, protect the environment, and address the challenge of global climate change.
This opinion does not necessarily reflect the views of the UC Berkeley School of Public Health or of the Editorial Board at BerkeleyWellness.com.