​​Devang Mehta received a deluge of reader questions to his essay in March about why he is pivoting away from GMO research after years devoted to the topic. Here is a sampling of questions multiple readers asked. Questions have been edited for brevity.

Tampering with very complex systems can have unintended consequences. Why are you convinced of the safety of the genetic modifications you make?

I am convinced about the safety of the GMOs that are on the market and that are created in my lab for two reasons. First, we understand the biology of the genes we introduce into plants very well. These genes have been studied for decades, and it is difficult to think of ways in which they might conceivably harm us. Secondly, GMOs reach the market only after extensive safety testing by multiple government agencies, like the European Food Safety Authority in Europe or the EPA and FDA in the US. This review article covers the types of testing that current GMOs have passed.

How can we change public opinion on this topic, especially since a lot of the opposition seems driven by a vision of nature as being pure and vulnerable?

I think the answer is better school-level education. Most non-biologists don’t realize (and haven’t been taught in school) about how messy nature really is. A better understanding of how science works – the process of experimentation, rigorous peer-review, and constant re-examination – and more updated biology curricula in school could help.

Monsanto is very predatory in the US, so it is not at all surprising that many find their products questionable. I’ve also read many of Vandana Shiva’s articles about the impact of GMOs in India. What are your thoughts about them?

I’m not sure what you mean by “predatory.” Monsanto is not the only seed provider in the US and in the food industry as a whole; it isn’t even that big a company (Whole Foods, for instance, has the same amount of revenue as Monsanto). I think it is important to recognize that only one GM trait (RoundUp Ready, which makes crops resistant to the herbicide RoundUp) is associated with herbicide use. Overall the use of GM crops has reduced chemical pesticide use by 37 percent. As for the herbicide glyphosate, which is used with RoundUp Ready crops, recent research has shown that while its use has gone up due to the adoption of RoundUp Ready GM crops, its lower toxicity compared to other herbicides means that its use has actually decreased chronic and acute toxicity associated with herbicide use. The paper concludes by saying that, “if glyphosate use were discontinued (as was recently proposed in the EU) the resulting displacement of glyphosate by other herbicides is likely to have a negative impact on chronic health risks faced by pesticide applicators.”

Regarding Vandana Shiva, as an Indian scientist I am ashamed that her brand of pseudoscience has been so widely disseminated and well received in Europe and the US. I refer you to her profile for the New Yorker by Michael Specter for an overview of her methods (ignoring research that doesn’t fit her ideology, publicizing conspiracy theories and even opposing food aid during a natural calamity in India), which I personally find abhorrent.

What are your three strongest arguments that you think could change someone’s negative perceptions of GMOs?

I wish I could give you three arguments to change someone’s mind. Unfortunately I’ve found that everyone has a different concern with the technology, so the only way forward is to listen to individual concerns, find some common ground (a shared interest in social justice, or in environmental protections, for example) and then answer specific queries and criticisms.

Some resources I have found useful are: 

a. Statements by societies like the Royal Society or the National Academy of Sciences on GMOs, especially the question of GMO safety. The Royal Society in particular has some very nice explanatory videos on the topic. So does the Youtube channel Kurzegesagt.
b. This great study that shows that nature also occasionally dabbles in genetic engineering of food crops.
c. These two meta-analyses on the environmental and health effects of GMO adoption: Klümper and Qaim, 2014 and Pellegrino et al, 2017.

I’m a scientist who worked for Monsanto. You seem critical of private enterprise in this field. If so, why? And if you had been around in the 1990s, what do you believe could have been done to win public acceptance?

I should preface my response by saying that as an undergrad I, in fact, interned at Monsanto’s Research Center in Bangalore for a month. It was a formative experience for me career-wise, and I really appreciated the mentorship of the many fantastic scientists there. However, I’ve come to see that a lot of the failure in terms of winning public support for biotechnology seem to stem from some of Monsanto’s early decisions, such as leading with herbicide-tolerance technology. Then there’s the (relatively few, I know) lawsuits filed by Monsanto for license violations that I think were unnecessary. I also think Monsanto was far too conservative with GM-tech development. To produce only two major traits (both farmer-facing, and one of which profits the chemicals arm of the company and encourages monoculture) after so many years seems underwhelming. I think leading with a consumer-facing nutrition trait would’ve probably have helped (but hey, hindsight is always 20/20).

Finally – and this is something I’ve also heard from other publicly funded researchers – Monsanto (and the other large enterprises) have little to gain from a lowering of regulatory barriers on GM technology. Expensive regulatory processes only entrench the monopoly of the few seed companies on commercial GM traits making new entrepreneurship and publicly funded releases almost impossible. So I’m not convinced that public labs and companies like Monsanto are completely on the same side in this debate.

Do you regard the issue of glyphosate overuse as a separate issue from GMO safety, or do scientists from your field of work sympathize with anti-GMO activists on this specific concern?

Briefly, my colleagues and I have a complicated relationship with glyphosate! We do think that the overuse of any single herbicide is bad since it contributes to the development of resistant weeds. However, glyphosate is also by far the least toxic herbicide available to farmers. So we still prefer glyphosate use compared to the alternatives that farmers will start using if it’s taken off the market. Further, the use of herbicides like glyphosate allows farmers to save on labor and energy, reduce soil erosion, and practice no-till agriculture, which reduces CO2 emissions from the soil, which is obviously good for the environment.

Here are some references.

What is your answer to those who say that the problem of the lack of food is only social and political and that we can feed 9 billion people without GMOs?

I tend to agree that a lot of the barriers towards feeding the hungry are socioeconomic, from uneven trade barriers to general poverty and its manifold effects. However, I do think that better access to agricultural technology, including GMOs, is part of the solution to this problem.

What do you think of projects that highlight the possibility to connect GM technology with organic agriculture?

I am a fan of new agro-ecology methods of farming such as the ones Professor Pamela Ronald (UC Davis) and her husband advocate in their book, Tomorrow's Table. I think a lot of the problems with organic start with it’s focus on “naturalness” rather than environmental protection. Agro-ecological farming (essentially, farming with a focus on the impact on the local ecosystem) uses some very similar methods but in my opinion approaches the problem more scientifically. Interestingly, the spouses of both my supervisor as well as another biotechnologist in my lab are organic farming researchers! The two worldviews can and do co-exist :)

How can you guarantee that transgenics are safe? Is there even a remote chance that my friends who suffer from seafood allergies could have life-threatening reactions to eating corn or tomatoes modified with genes from fish some day?

I cannot guarantee the safety of any and all future transgenics. However, transgenics that are currently on the market have undergone extensive safety testing, including for allergens. It is important to realize that a single gene from any organism will only code for a particular protein, and not carry over other properties of the source organism, including allergens. Please see this article for a more detailed discussion about GMOs and allergenicity.

Sure, many organizations are saying that GMOs are perfectly safe for human consumption, but much “science” was shoved down our throats about tobacco and sugar and many other issues that turned out to extremely harmful to people.

I’m not sure tobacco and sugar are fair comparisons. Monsanto, for example, is nowhere near as big as some of those industries. In the case of GMOs (like with vaccines and climate change), several publicly funded scientists and organizations like the National Academy of Sciences have conducted in-depth reviews of the topic before coming to the conclusion that they are safe.

I am not against GMOs at all. I am against GMO patents and would love a frank, non profit-driven discussion about them.

Non-GMO plants are and have been routinely patented for decades (even before GMOs made it onto the market). Plant varieties take decades to develop by breeders (many of them at publicly funded institutes), and patents allow breeders to monetize their creations. This has nothing to do with GMOs in agriculture.

The main issues I have with GMO is the patenting of crops, specifically those that are introduced to third-world countries which are typically sterile, causing the farmers to have an ongoing dependence/obligation to the patent holders.

The patenting of plants predates GMOs and actually, the majority of patented plant varieties are non-GMO. Also, GMO plants are not sterile. A lot of GM plants are hybrids and like with all hybrids (even non-GMOs) their offspring do not maintain the same traits. This is why Monsanto’s (and other non-GM hybrid seed providers) agreements with farmers do not allow for replanting  —  they don’t want liability for trait failure in offspring.

My main gripe is with foods that are genetically modified to make them resistant to herbicides. Indoor growing and hydroponics is the best solution to this from my point of view.

There is an environmental advantage to herbicide tolerant crops (GMO or not).

While indoor farming/hydroponics is great for crops that are mainly water (think tomato or lettuce), it's much less so for staple, energy-rich, calorie crops like corn, rice, or wheat.

My son is just starting out in college to study biotechnology. Do you have any advice for him?

Biotechnology is an extremely exciting field of study right now (yes, even plant biotech!). Here are some concrete pieces of advice for anyone starting in college in this field.

1. Be open-minded. Biotechnology is progressing very rapidly, so don’t confine yourself to a single course of study such as biomedicine, immunology, or plant science. Try to get a broad-ranging view of the field (with a deep-dive in a subject you like best) so you’re ready to pivot when new science comes around.
2. Work on your writing skills. A surprising amount of science/technology (both in industry and academia) requires great writing skills (both technical and non-technical writing) in addition to other professional skill sets.
3. Most biology/biotechnology work requires some computing/programming skills. So learn to code and frame algorithms!
4. Think long and hard about going to grad school. It’s not for everyone (despite how much professors try to recruit), and there are great opportunities in industry without a PhD too. But if you love the science and you find a great advisor, grad school can be amazing.
5. There are several opportunities now to get more practical experience with biotechnology, even in your first year as an undergrad. For example, look into whether your uni has an iGEM team. It can be a life-changing experience.