Changing mind about GMOs, again?
As an environmental activist I have been protesting for years against genetically modified crops (GMOs). Until last year, when I studied the scientific literature in more detail and read about what scientists say about GMOs. I switched position, made up my mind and became a proponent of genetic engineering in agriculture in order to move towards a more sustainable and healthy food production. I wrote an article which received some media attention and eventually resulted in receiving the Skepp price for critical thinking (Skepp is the Belgian organization for scientific skepticism).
Lost week I received a long, 30 pages rebuttal of my article, written by CEO, the Corporate Europe Observatory. I like the work of CEO, criticizing the lobbying power of big corporations in European governmental institutions and warning about private industrial influences in scientific bodies and conflicts of interest in scientific studies influenced by private companies. The rebuttal to my article contained a lot of valid points of critique, including information (studies, conflict of interest of some researchers,…) that I was not aware of when I wrote my pro-GMO article last year.
When I wrote my article, and after receiving a lot of media attention, I realized that it might be very difficult for me to switch position again to the anti-GMO camp, even when the GMO opponents have valid arguments. It might make me feel looking stupid to make a second U-turn. I was fully aware that this unease might make me less receptive to the critique of GMO proponents and that it might bias me in favor of GMOs. Yet, I decided that I should be prepared that when I hear about strong arguments against GMOs, I will switch position again, no matter what emotional cost, because I prefer the truth above some kind of misleading bias.
So did the CEO rebuttal change my mind about GMOs again? Partially yes, but only very slightly. I am not yet convinced to join the anti-GMO camp again, because I do not yet perceive a strong scientific consensus that GMOs are generally dangerous, that GMOs have generally more risks than benefits or that we should be particularly worried about GMOs. The CEO rebuttal contains some studies and references that make me feel less confident in some things that I wrote in my original article. But I also have some objections to the rebuttal, which I will write about in an appendix (and in some cases the rebuttal reinforced my pro-GMO position). Next, I recently also learned about two reports written by the biggest national academies of sciences. One is the 400 pages long 2016 report by the NAS (United States National Academies of Science, Engineering and Medicine). The second is written by EASAC (European Academies Science Advisory Council, formed by the national science academies of the EU Member States). Both reports were written and peer reviewed by academic researchers (university professors) and can be considered as systematic reviews of the literature.. Unfortunately, even though the NAS report itself was not funded by the industry, a majority of its members of the Committee of Genetically Engineered Crops do have ties with the industry or have personal conflicts of interest in favor of GMOs. CEO also points at similar conflicts of interests amongst a lot of experts who wrote the EASAC report, being members of for example the PRRI, a pro-GMO lobby group. So the NAS and EASAC reports should be considered with some skepticism and we should be worried about a loss of credibility of the important scientific academies.
Some statements written in the NAS report:
“Overall, the committee found no conclusive evidence of cause-and-effect relationships between GE crops and environmental problems.”
“On the basis of its detailed examination of comparisons between currently commercialized GE and non-GE foods in compositional analysis, acute and chronic animal toxicity tests, long-term data on health of livestock fed GE foods, and epidemiological data, the committee concluded that no differences have been found that implicate a higher risk to human health safety from these GE foods than from their non-GE counterparts.”
“Emerging genetic technologies have blurred the distinction between genetic engineering and conventional plant breeding to the point where regulatory systems based on process are technically difficult to defend. The committee recommends that new varieties—whether genetically engineered or conventionally bred—be subjected to safety testing if they have novel intended or unintended characteristics with potential hazards.”
“Statistically significant differences in nutrient and chemical composition have been found between GE and non-GE plants by using traditional methods of compositional analysis, but the differences have been considered to fall within the range of naturally occurring variation found in currently available non-GE crops.”
Some statements written in the EASAC report:
“There is no validated evidence that GM crops have greater adverse impact on health and the environment than any other technology used in plant breeding. There is compelling evidence that GM crops can contribute to sustainable development goals with benefits to farmers, consumers, the environment and the economy.”
“[T]he current slow and expensive regulatory situation surrounding GM crops in the EU encourages monopolies. It is important to explore ways to stimulate open innovation and reformulate the regulatory framework so as to encourage smaller companies and public sector activities.”
“Statements about the adverse impacts of GM crops have too often been based on contested science.”
“Taken together, the published evidence indicates that, if used properly, adoption of these crops can be associated with the following:
- reduced environmental impact of herbicides and insecticides;
- no/reduced tillage production systems with concomitant reduction in soil erosion;
- economic and health benefit at the farm level, particularly to smallholder farmers in developing countries;
- reduction in greenhouse gas emissions from agricultural practices.”
The same conclusion can be read in the European Commission’s A decade of EU-funded GMO research which press release states: “According to the projects’ results, there is, as of today, no scientific evidence associating GMOs with higher risks for the environment or for food and feed safety than conventional plants and organisms.”
Also the Q&A report by the British Royal Society states: “There is no evidence that producing a new crop variety using GM techniques is more likely to have unforeseen effects than producing one using conventional cross breeding.”
“Is it safe to eat GM crops? Yes. There is no evidence that a crop is dangerous to eat just because it is GM.”
“Crops do not damage the environment simply because they are GM. Some farming practices, such as the overuse of herbicides resulting in the excessive eradication of wild plants from farmland have been shown to harm the environment. These problems are similar for non-GM and GM crops.”
“GM crops are more extensively tested than non-GM varieties before release (see Q14) both for their environmental effects and as foods. They also tend to have fewer genetic differences from their predecessor than new non-GM varieties.”
Taking together the reports by the scientific institutions, the fact that a vast majority of Nobel laureates in medicine support GMOs and that a vast majority (88%) of members of the American Association for the Advancement of Science declare GMOs to be generally safe to eat, I still tend to perceive a scientific consensus about GMO safety (in terms of environmental and human health), although some points raised in the CEO rebuttal decrease my confidence in the existence of such a consensus. I definitely do not perceive a scientific consensus that GMOs are generally unsafe (in the sense that for example current commercialized GMOs on the market are worse than conventional crops and that newly developped and tested GMOs are more likely to be worse compared to newly develloped crops using other breeding technologies). At most, if people do not believe in a consensus about GMO safety, we can say that science is undecided at the moment. And given the current state of the evidence and the positions by major scientific institutions, there is a high probability (but not a certainty) that science will move towards a consensus in favor of GMO safety in the future.
The analogy I previously made between climate change denialism and GMO opposition is not entirely correct, because scientific studies about the safety of GMOs often have conflicts of interest (e.g. sponsored by the industry), whereas scientific studies about the dangers of burning fossil fuels do not have similar levels of conflicts of interest. When it comes to climate change, the scientific consensus goes against the motives of the fossil fuel industry, which makes it more likely that the science is independent. When it comes to GMOs, the possible scientific consensus about safety fits well with the agenda of the food industry and the big corporations.
Even if the CEO rebuttal decreases my confidence in some statements I made in my original article, I still feel very confident in the conclusions that I wrote.
- Environmental and social justice organizations should drop the word ‘GMO’ in their campaigns, and focus instead on the problems such as expensive seed patents, polluting pesticides, inefficient market monopolies and vulnerable crop monocultures. These problems are not intrinsically related to GMOs. For every newly developped crop, whether the result from genetic manipulation or not, we should do a case by case risk assessment based on the properties of that crop and not on the process how that crop was develloped.
- Independent organizations (like CEO) should continue warning us about the dangerous influence of big corporations and private companies in science and politics. We should make sure that academic research (at universities) becomes more independent and impartial, that there are no longer financial or political conflicts of interest.
- New GMOs that are being developed can offer many environmental and health benefits and can be an asset in sustainable agro-ecology.
The impressive CEO rebuttal demonstrates that the environmental movement has arguments against GMOs that are not so unreasonable. I do not consider it very unlikely that GMOs are bad for health and environment. But protesting against GMOs is not likely to be an example of effective environmentalism.
In the past decade, we saw the rise of a growing international movement of effective altruism. Effective altruists use evidence based science, critical thinking and reason to look for the most effective things one can do to make the world a better place. These altruists are a perfect combination of scientific skeptics and altruistic activists. The effective altruism movement focuses primarily on improving human health, reducing poverty, improving animal well-being and reducing existential risks. But there is a small part of the movement that focuses on environmental issues: effective environmentalism.
Effective environmentalists look for the most effective things one can do to improve the environment, reduce biodiversity loss, improve sustainability and reduce global change of ecosystems and climate systems. Looking at the critique raised by the scientific skeptics against the environmental movement that opposes GMOs, it is likely that doing actions against GMOs is an example of ineffective environmentalism at best and counterproductive environmentalism at worst. The same can possibly be said about the opposition against some new nuclear energy technologies. A lot of effective environmentalists do not seem to be strongly opposed to nuclear energy and often are in favor of new nuclear energy technologies.
Other examples of rather ineffective environmentalism, are the promotion of local and organic food and the opposition against old nuclear energy technologies. As with human health and poverty reduction interventions, there is possibly a large spread amongst environmental measures in terms of effectiveness. A small minority of health interventions can be 100 or 1000 times more cost-effective than the vast majority of health interventions, and probably the same is true for environmental interventions.
So what are the most effective things we can do for the environment? This hasn’t been studied yet, but there are some interesting measures that are not only very effective for the environment but also offer many other co-benefits: a reduction of the consumption of animal products, a green tax shift (or a cap-auction-trade system of resource use and pollution) and an investment in family planning. Also other strategies like investments in scientific research to improve e.g. agricultural sustainability might be very effective.
We can compare the effectiveness of opposing animal products (promoting a plant-based diet) with the effectiveness of opposing GMOs.
Consumer health: there is no clear evidence or scientific consensus that GMOs are generally worse for consumer health than conventional food, but there is very clear evidence and a strong consensus that animal products (in particular red and processed meat) are generally worse than plant-based products such as fruits, vegetables, nuts and seeds.
Producer health: there is no clear evidence that GMOs are bad for the farmers (some evidence indicates that GMOs require less insecticide use and hence results in less insecticide poisonings), but clear evidence that livestock farming is one of the most dangerous professions and that slaughterhouses are amongst the most dangerous industries.
Public health: there is no evidence that GMOs are dangerous for public health, but clear evidence that livestock farming is dangerous in terms of zoonotic infectious diseases (flu viruses and antibiotic resistant bacteria) and food security (more food waste by using edible crops as animal feed).
Ecosystem health: animal products (in particular beef and dairy from cropland intensive agriculture) are generally worse for the environment than plant-based protein sources, but there is no clear evidence that GMOs are in general worse for the environment than conventional agriculture. There is clear evidence that the production of animal protein involves higher levels of land use, pesticide use, water use, greenhouse gas emissions, eutrophication, acidification and pollution compared to plant-based protein. The UN Food and Agriculture Organization wrote in its 2006 report Livestock’s Long Shadow: “Indeed, the livestock sector may well be the leading player in the reduction of biodiversity, since it is the major driver of deforestation, as well as one of the leading drivers of land degradation, pollution, climate change, overfishing, sedimentation of coastal areas and facilitation of invasions by alien species.” There is no environmental trade-off when we reduce the consumption of animal products. Reducing the consumption of GMOs can generate environmental trade-offs: probably higher land use, tillage or pesticide use.
Animal health: meat production and slaughtering animals is obviously bad for the health of animals, but there is no clear evidence or scientific consensus that GMOs are bad for livestock animals.
The difference between campaigning against GMOs and campaigning against animal products is a perfect example of the difference between ineffective versus effective environmentalism. If the environmental movement wants to be more effective, it should stop its protests against genetic engineering and GMOs, because there is definitely no scientific consensus that GMOs are generally unsafe or harmful. The environmental movement should better focus on those things of which there is a strong scientific consensus of harmful effects. It is also arbitarry to protest against some crops (GMOs) and not other crops (from conventional breeding) when there is no reason and no evidence that the former kind of crops are more dangerous just because they were obtained in a specific way (using some genetic engineering processes).
Appendix: rebuttal of the rebuttal
Although I consider the CEO rebuttal to my original article very worthwhile, I have some objections. Below I give an incomplete list of comments that I have.
About the IAASTD statement that the safety of GMO food is controversial due to limited available data: this doesn’t imply that there is a scientific consensus that GMO foods are generally unsafe. I also consider the safety of for example coffee as controversial due to limited data. The IAASTD statement is in line with the abovementioned NAS and EASAC statements about the lack of validated evidence that GM crops have greater adverse impact on health than any other technology used in plant breeding. The British Medical Association mentioned unanswered questions about long-term health impacts, but the same can be said about conventional crops and food products that entered the market the past few decades. The long-term health effects of recently developed varieties of fruits and vegetables have not been studied.
About the 21 scientists condemning the AAAS statement on GMOs: a 2014 Pew Research Center survey mentioned that 88% of AAAS scientists say that GM foods are generally safe to eat. http://www.pewinternet.org/2015/01/29/public-and-scientists-views-on-science-and-society/
About the health of people in the USA worsening after the introduction of GM food: first of all correlation does not imply causation. The Swanson study referred to by CEO only looks at correlations in the US (i.e. no control groups). As skeptics pointed out: there is also a strong correlation between the rise of organic food consumption and some diseases. Some authors of the Swanson study also have conflicts of interest, as they are related to the organic food sector. Second, the recent NAS report states: “The committee found no evidence of differences between the data from the United Kingdom and western Europe and the data from the United States and Canada in the long-term pattern of increase or decrease in specific health problems after the introduction of GE foods in the 1990s.”
About the WHO statement that individual GM foods should be assessed on a case-by-case basis: that is a statement on which proponents and opponents of GM food can agree (that is why I didn’t have to mention it in my original article). However, opponents often act as if there is something intrinsically risky to GM food compared to other foods. I recommend that opponents of GM food delete the word ‘GM’ and focus on the product instead of the plant breeding process. As the NAS report indicates: not only GM foods should be assessed on a case-by-case basis. All foods should be assessed like that.
About the “Big Lists of Studies” (the Nicolia review study and other review studies with 1000+ articles): the abovementioned EASAC report states: “A recent comprehensive assessment from the Swiss National Science Foundation (2012), reviewing more than 2000 studies, confirms that no health or environmental risks have been identified related to GM technology.” (Reference: Swiss National Science Foundation (2012). Benefits and risks of the deliberate release of genetically modified plants. National Research Programme NRP 59.)
About the animal feeding studies: a systematic review containing 12 long-term studies concluded: “No sign of toxicity in analyzed parameters has been found in long-term studies. No sign of toxicity in parameters has been found in multigenerational studies.” Snell C, Bernheim A, Berge JB, et al. (2012). Assessment of the health impact of GM plant diets in long term and multigenerational animal feeding trials: a literature review. Food and Chemical Toxicology 50, 1134–1148. http://www.sciencedirect.com/science/article/pii/S0278691511006399
About surveys indicating a scientific consensus: CEO refers to two surveys of medical doctors and dietitians. These are not necessarily scientists, so strictly speaking they do not indicate a scientific consensus. And then there are the results of the abovementioned Pew Research Center survey: 88% of AAAS scientists say that GM foods are generally safe to eat. Even if this 88% is an overestimation because some scientists might have conflicts of interests or might not be experts in the field, there is no evidence of a scientific consensus that GMOs are generally unsafe. The Pew survey is also consistent with the positions of most science academies (the abovementioned EASAC report and the NAS and Royal Society reports referred to by the Interacademy Partnership, a global network of science academies), with the positions of many other scientific bodies and independent institutions (see for example A decade of EU-funded GMO research) and with the 110 Nobel laureates signing a letter in favor of GMOs.
About industry funding (conflicts of interest): also anti-GMO studies of Séralini and Carman involve some conflicts of interest. Concerning Gilles-Eric Séralini: he had (undisclosed) conflicts of interest, because his research is partially funded by (and he is consultant of) Sevene Pharma which sells homeopathic(!) remedies against glyphosate. And Judy Carman’s pig study has conflicts of interest as well (http://www.marklynas.org/2013/06/gmo-pigs-study-more-junk-science/). The CEO rebuttal referred to a review study about the association of financial and professional conflicts of interest to research outcomes (http://www.sciencedirect.com/science/article/pii/S0306919210001302). CEO first of all fails to mention that the study found that financial conflict of interest alone (i.e. academic research funded by the industry but without some of the authors having professional ties to the industry) did not correlate with research results (but perhaps this is due a lack of data because only 8% of the studies received funding from the industry). And secondly, a 74% majority of papers in which none of the authors had professional ties to the biotech industry, i.e. no professional conflict of interest (39 out of 53 papers) concluded safety (12 found problems and two had neutral conclusions). Also the abovementioned EASAC study is based on scientific literature, 90% of which was non-industry funded.
About Judy Carman’s pig study: not only Mark Lynas, but a lot of scientific skeptics have criticized Carman’s study, which is rather a hypothesis seeking exercise than a hypothesis testing study. Giving too much weight to Carman’s study is untrustworthy in the eyes of scientific skeptics.
About the analogy with climate change deniers: mentioning climate change deniers who are pro GMO can also be considered as a dishonest PR trick. In my original article I referred to climate activist Mark Lynas instead of the climate change deniers Owen Patterson and Patrick Moore.
About the reduction of the use of pesticides, in particular Bt: the reduction of Bt use on GM crops might as well be an underestimate, because non-Bt users might benefit from GM Bt-crops. The abovementioned EASAC reports says: “For example, the large-scale adoption of insect-resistant Bt cotton and maize varieties has caused area-wide declines in major pests in the USA (Carriere et al., 2003; Hutchison et al., 2010) and China (Wu et al., 2008). Thus, Bt cotton paved the way for a successful eradication programme against the invasive pink bollworm, originating in Asia, thereby eliminating a problematic pest from the south-western USA (Naranjo and Ellsworth, 2010). Economic analysis revealed that the decline of the European corn borer in areas planted with GM crops has also led to significant benefits for non-Bt maize growers (Hutchison et al., 2010). In addition, evidence is beginning to emerge (Lu et al., 2012), that a beneficial consequence of applying less external pesticide to plants engineered to resist pests is the increase in natural insect predators that thrive and spread. Hence, environmental benefits are extended to neighbouring landscapes. Knock-on effects can also be measured at the macro-economic level. Spill-over of crop yield benefits and cost reductions are important globally as – through trade – they influence prices for countries importing GM crops. Models estimate that world food price increases would be higher by 10–30% in the absence of GM crop cultivation.”
About herbicide resistant superweeds: it is true that before the rise of glyphosate tolerant GMOs, there were no glyphosate resistant weeds. The massive use of glyphosate tolerant GMOs resulted in resistant weeds. But glyphosate is but one herbicide, and looking at all the herbicides, we see that conventional non-GMO farming also resulted in weed resistance. Furthermore, the number of glyphosate resistant weeds is still low compared to other herbicides such as triazines, even if glyphosate is the most used herbicide. (http://www.nature.com/news/case-studies-a-hard-look-at-gm-crops-1.12907). (As an additional note, some researchers are investigating the possibility of combating resistant weeds and pests using genetic engineering based on the crispr/cas9 gene drive technique.)
About the biodiversity of non-targeted invertebrates on GM Bt-crops: according to the meta-analysis published in Science, the biodiversity on GM Bt-crop fields was lower than on non-GM fields without Bt use. However, the yields are typically lower on the latter fields. The abovementioned NAS report states: “The committee examined results of experiments conducted on small plots of land that compared yields of crop varieties with Bt to yields of similar varieties without Bt. It also assessed surveys of yield on large- and small-scale farms in a number of countries. It found that Bt in maize and cotton from 1996 to 2015 contributed to a reduction in the gap between actual yield and potential yield (Figure S-2) under circumstances in which targeted pests caused substantial damage to non-GE varieties and synthetic chemicals could not provide practical control.” Lower yields means higher land use and more deforestation, resulting in a negative impact on biodiversity as well. The overall impact on biodiversity remains uncertain. Furthermore, organic farming is not necessarily Bt free: Bt spraying is allowed on organic farms.
About the claim that natural Bt sprays are more harmful to non-target insects than GM Bt-crops: this was demonstrated by the abovementioned meta-analysis in Science. GM Bt-crop fields had higher biodiversity of non-target invertebrates than non-GM Bt-sprayed fields. The CEO rebuttal acknowledged this result, so there seems to be an inconsistency in the CEO rebuttal. The fact that the natural Bt protoxin in sprays is turned into Bt toxin when ingested, is irrelevant, because non-target insects also ingest the Bt protoxin when Bt is sprayed.
About the ethics of animal experiments: the Séralini rat studies probably contained unnecessary animal suffering because the researchers used rats that were genetically vulnerable to cancer and the rats with painfully growing tumors were not quickly euthanized. The studies were also criticized by the Oxford Centre for Animal Ethics: “Researchers carried out a carcinogenicity test on GM maize using rats. They fed 200 rats for their entire lifetime (two years) a diet of one of the bestselling strains of GM maize produced by agricultural biotechnology giant Monsanto along with the company’s popular weedkiller Roundup in order to induce cancer in the animals. The rats developed large, cancerous tumours that led to multiple organ damage and premature death in 50 per cent of males and 70 per cent of females. No mention of pain relief was given (Séralini et al., 2012).” Similar concerns of unnecessary animal suffering can be raised in Judy Carman’s pig study: the majority of pigs in both the GMO-feed group and the control group suffered from pneumonia, which means that the pigs were probably held in very bad conditions.
About natural genetic engineering: the claim about horizontal gene transfers in nature was obviously about naturalness, not about safety.
About GMOs reducing food waste: the very first GMO on the market, the Flavr Savr tomato, was engineered to be more resistant to rotting. Developing GMOs that spoil less quickly have nothing to do with maintaining a cosmetic appearance of freshness and there is no reason to assume that those GMOs will lose many of the nutrients. On the contrary: the rotting process reduces nutritional value.
This is not a comprehensive list of my rebuttals. Nevertheless, the CEO rebuttal does raise important issues and refers to good studies (e.g. the concerns raised by some scientific institutions such as the British Medical Association, the surveys of medical doctors, the industry bias in favor of GMO safety, the concerns about recent weed resistance to herbicides and bollworm resistance to Bt-insecticides, the IARC-WHO statement of carcinogenicity of glyphosate, the problem that GMOs are not always based on the highest yielding cultivars, the difficulties involved in making claims about economic performance, the use of some outdated data in some meta-analyses, the Bt cotton yields in India, the conflict of interest of the Carpenter biodiversity study, the fact that herbicide tolerant GMOs might have only contributed a little to the adoption of no-till farming and the fact that no-till doesn’t store more carbon and that it might raise the Environmental Impact Quotient of pesticides). After examining those comments, I feel less certain about some statements I made in my original article (e.g. statements about benefits in terms of biodiversity), but I keep confidence in the general conclusions.
Addendum (2019): about the IARC-WHO statement of carcinogenity of glyphosate: many other health and regulatory agencies (the U.S. EPA, the European Food Safety Authority, the WHO-FAO, the German Federal Institute for Risk Assessment, Health Canada, Australia’s Pesticides and Veterinary Medicines Authority) state that glyphosate is not a health risk. The CEO might have a conflict of interest bias: seeing the conflicts of interests of scientists paid by the GMO or pesticide industries, but not seeing conflicts of interests of scientists paid by law firms that use IARC judgments in litigations against industries.