Genetically engineered crops are safe, but new regulations are needed as the definition of GE organisms becomes blurred, according to a group of American 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 this week 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 produced.
New Zealand’s Science Media Centre has gathered and published expert commentary on the report:
Prof Barry Scott, Institute of Fundamental Sciences, Massey University:
“This is an impressive analysis of “past experiences and future prospects” of genetically engineered crops by the US National Academy of Sciences. This lengthy tome provides a rigorous examination of the risks and benefits of previously grown genetically engineered (GE) crops and signals a pathway forward that provides even greater rigour for the assessment of future crops be they derived from either conventional or GE breeding.
“Importantly, the report highlights the flaws in making sweeping statements about GE crops given the multi-dimensional nature of the issues that need to be assessed and the increasingly blurred distinction between crops developed by GE versus those developed by conventional plant breeding. The report also highlights the flaws in regulatory processes that are based solely on the type of genetic process used to develop the new crop.
“This book challenges the current regulatory process that we have in New Zealand, as prescribed by the HSNO Act 1996, that focuses solely on crops developed by GE and overlooks crops developed by conventional breeding. An important conclusion from this report was the finding that there was no “substantiated evidence that foods developed by GE crops were less safe than foods from non-GE crops.
“This document should trigger a re-examination of how crops developed by new technologies are regulated in New Zealand. There is a wealth of information here that has been peer reviewed for the regulators in government and the general public.”
Prof Peter Dearden, Director, Genetics Otago, University of Otago:
“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 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:
“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. ‘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 NAS report that new techniques are blurring the lines between what occurs in ‘conventional breeding’ and what might be achieved in the laboratory. This might in the future make knowing how a GMO is made less important for a risk assessment. The NAS report makes two careful caveats to this view.
“First, their recommendation is coupled with the routine use of the new ‘omics’ techniques in risk assessments. That would require a change in current practice both in the US and here. Previous NAS reports have made very clear that a critical reason for process-based risk assessment is the difficulty in detecting unintended changes in GM plants compared with other ways plants can be developed. The current NAS report authors believe that the problem may be addressed if routine use of omics techniques becomes standard practice. However, such techniques are not routinely used and our regulatory authorities do not require them to be. Guidelines for their use should be developed and required by regulatory authorities.
“Second, the NAS 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.”