Genetically engineered crops are safe, but new regulations are needed as the definition of GE organisms becomes blurred, say US academies.
An extensive study by the US-based National Academies of Sciences, Engineering, and Medicine has analysed the costs and benefits of genetically modified crops, drawing on almost 30 years of research.
The key findings of the 400-page report published today include:
• No substantiated evidence of a difference in risks to human health between current commercial GE crops and conventional crops
• No conclusive cause-and-effect evidence of environmental problems from GE crops
• Evolved resistance to current GE characteristics in crops is a major agricultural problem
Looking to the future of GE crops, the report
notes that new genetic technologies are blurring the line
between conventional and GE crops, and that the U.S.
regulatory system needs to assess crop varieties based on
their individual characteristics, not the way they are
The Science Media Centre gathered the following expert commentary on the report.
Assoc Prof Peter Dearden, Director,
Genetics Otago, University of Otago, comments:
"The US National Academies report indicates that many of
the proposed problems with GM crops have either not
eventuated, or not been significant. They find no issues for
human health, no clear evidence for environmental effects
and favourable economic outcomes for producers using GM
crops. The biggest issue they indicate is the development
of resistance to insecticide-carrying crops, something which
is of no surprise.
"In my opinion these finding are
not surprising. When large scale studies of the effects of
GM crops have been undertaken there has been little evidence
of harm, and some evidence of benefit, and this report
reflects that. This report indicates that the GM crops
currently grown are safe, but has no implications for future
products, which must, as these have been, be extensively
"Perhaps the key aspect of the report is the recognition that new genome editing tools have changed the game with GM crops, and that this has huge consequences for New Zealand. Alongside this, the development of novel DNA sequencing technologies have allowed a much better understanding, and screening for, the unintended consequences of genetic manipulation.
"I believe that, with these tools in hand, New Zealand should take the route, as suggested in the report, for regulating novel crops on the basis of their characteristics rather than by the process by which they were developed."
Prof Jack Heinemann, School of Biological Sciences, University of Canterbury, comments:
"The summary of the report is not out of line with what I would have expected. The report authors have said that it is not possible to extrapolate the safety of all GMOs based on the track record of currently released GMOs, which are mainly plants, only a few kinds of plants, and predominantly only two traits: herbicide tolerance and insecticides. They advocate ongoing risk assessment.
"The authors also acknowledge that it is possible to create potentially harmful characteristics in plants by other means. Thus, avoiding a particular process should not automatically exempt a product from a safety assessment just as using a particular process should not indicate that the plant is necessarily harmful in particular ways. Note though that the US regulatory system is not the same as here [in New Zealand]. ‘Process' there means such things as the source of the genes, not just the techniques. We need to be cautious about wholesale adoption of report language.
"On the benefit side of the equation, the report finds some limited evidence of benefit depending on what other farming choices are made. There was no indication that adoption of GMOs is of a uniform net benefit in any or all agroecosystems. For example, if GM cropping is compared to high input monocultures without crop rotation, there can be a benefit, but not necessarily a benefit if it is compared with some other management systems. Importantly, they confirm observations that many of us have made that the adoption of GM cultivars has not so far contributed to increases in yield.
"The last comments I’ll make are on the suggestion by the report that new techniques are blurring the lines between what occurs in ‘conventional breeding' and what might be achieve in the laboratory. This might in the future make knowing how a GMO is made less important for a risk assessment.
"...the report says that purely scientific issues of effects on the environment and human health are not the only relevant issues of risk, harm or benefit. For example, GMOs are not used in isolation from prevailing and very different intellectual property rights restrictions and farm management techniques. Therefore cultural, economic, legal and social effects (including those with indirect effects on the environment and human health) also are legitimately considered by a society adopting these products."
Our colleagues at the UK SMC collected the following comments.
Government Chief Scientific Adviser, Prof Sir Mark Walport, comments:
“This is a thoughtful contribution by the US National Academies on the role that GM technologies may play in resolving global food challenges. I welcome the recognition that GM is just one of many agricultural technologies.
“When considering GM the questions should always be: ‘what gene?’, ‘in what organism?’, and ‘for what purpose?’. The report also rightly recognises the importance of the role of public dialogue on these technologies.”
Dr Joe Perry, former Chair of the European Food Safety Authority GMO Panel, comments:
"Put simply, this very extensive NAS report draws conclusions that should be no surprise to those who have followed GM plant cropping in north America.
"Firstly, GM Bt crops are both environmentally friendly and good for growers, resulting in yield increases and pesticide reduction. Second, the picture is not nearly so rosy for herbicide tolerant (HT) crops, which, because of the profligate and lightly regulated way they are used in the USA, don't increase yields and can lead to problems with weed resistance. But the report hints at how such problems can be overcome, by using the ecologically-based approach known as 'integrated pest management' (IPM).
“The message for Europe is clear. Several crops have been risk assessed by the European Food Safety Authority and deemed safe. The EC should give approval for the Bt maize crops, MONJ810 and Bt11, which require very light regulation. The EU should also approve maize 1507, although with slightly more stringent conditions, as 1507 is more toxic to butterflies. Then the EU should approve crops such as the HT maize GA21, but with conditions such that it is used within an IPM context, with strict regulation to avoid the onset of resistance.
“There is no longer any scientific reason to delay approval for these crops - the only reason for delay is purely political.”
Prof Denis Murphy, Professor of Biotechnology at the University of South Wales, comments:
“Unlike Europe, the USA has grasped the nettle of new gene editing technologies and come up with a commendably rapid verdict. In contrast Europe has been paralysed by indecision.
“This means that the USA stance is likely to set the agenda for other large GM producers that now include India & (very soon) China as well as several African countries.
“Europe is in danger of becoming an even greater backwater for new breeding technologies than it is already.”
Prof Jonathan Jones, Plant Scientist at The Sainsbury Laboratory, comments:
“This comprehensive, balanced and transparent report from the US NAS is essential reading for anybody who is concerned about the merits or otherwise of GM crops. It reviews past experience and assesses future scenarios, commenting on the challenge of appropriate regulation of rapidly advancing technology in a multi-jurisdiction world.
“I heartily endorse this key quote from the executive summary: ‘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 US-based Genetic Expert News Service also collected the following comments (full comments here):
Dr Norman Ellstrand, Professor of Genetics, University of California, Riverside, comments:
"The 2016 GE Crop NRC report is a well-researched instant classic and bound to influence policy for years. It appears that most of the star-studded team of scholars have put a pound of flesh into a thoughtful and carefully crafted tour de force. The conclusions are state of the art, focusing on the products, rather than the process, of the spectrum of current techniques, some of which may or may not fall into the definition of 'genetic engineering'.
"More than two decades of scrutiny reveals that genetic engineering, like any other crop improvement methodology, is a tool that has the potential to create useful, useless, or problematic products. As humanity faces a host of looming problems, the report notes 'genetic engineering alone cannot address the wide variety of complex challenges that face farmers'. It is implicit that we need to use the entire toolkit skillfully and mindfully."
Dr Ruth MacDonald, Professor and Chair of the Department of Food Science and Human Nutrition, Iowa State University, comments:
"The NAS report on GE crops summarized a substantial amount of information relative to the potential effects of GE foods on human health. The committee reviewed research and compared demographic data related to the potential for GE foods to affect a wide range of human health issues. They concluded that there is no evidence that GE foods have caused any negative effects on health. Based on comparisons in disease incidence in the US and Europe, for example, rates of cancer, obesity and celiac disease were similar, suggesting that consumption of GE foods has not influenced these conditions. Similarly, they found no evidence for higher rates of allergies or risk of changes in intestinal microorganisms associated with GE foods.
"The committee recommended that public research funding be provided to allow more extensive studies of new GE products and technologies to ensure that human safety continues to be protected. I would certainly hope the report will reduce public concern about the safety of GE foods. This is yet another document that adds to the long list of those that have reached the same conclusion that there is no evidence that GE foods are a risk to human health."