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
• 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 produced.
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 tested.
"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
"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
"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
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,
"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."