Issue 32 / 24 August 2015

AUSTRALIA’s food standard agency says the public should not be worried about the herbicides used to treat genetically modified crops, but two experts have serious concerns about health risks.
Dr Judy Carman, director of the Institute of Health and Environmental Research in Adelaide, told MJA InSight that the safety assessments of genetically modified organisms (GMOs) in Australia were “woefully inadequate”, and there were no requirements to do any valuable animal or human feeding studies.
Dr Carman said the use of the herbicide glyphosate on GM crops was a significant concern, particularly as the WHO’s International Agency for Research on Cancer (IARC) recently upgraded its listing of glyphosate to “probably carcinogenic to humans”. (1)
The continued use of this herbicide on GMOs was putting both crop farmers and consumers at risk, Dr Carman said.
She was responding to an article published in the New England Journal of Medicine which said the move by the IARC to list glyphosate as a probable carcinogen and another herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), as a possible carcinogen, indicated that GM foods might pose hazards to human health that had not been previously considered. (2)
“These classifications were based on comprehensive assessments of the toxicologic and epidemiologic literature that linked both herbicides to dose-related increases in malignant tumors at multiple anatomical sites in animals and linked glyphosate to an increased incidence of non-Hodgkin’s lymphoma in humans”, the NEJM authors wrote.
Fresh concerns were raised about the safety of GM crops when a new combination herbicide of glyphosate plus 2,4-D was approved in the US in 2014. The NEJM authors said this decision was “based on poorly designed and outdated studies and on an incomplete assessment of human exposure and environmental effects”.
They wrote that the US National Academy of Science had recommended the development of new risk-assessment tools and postmarketing surveillance of GMOs, but these recommendations “have largely gone unheeded”.
Professor Stephen Leeder, emeritus professor of public health and community medicine at the University of Sydney and chair of the Western Sydney Local Health District Board, told MJA InSight that GM crops were often engineered to enable the concurrent use of herbicides to reduce weeds that could contaminate the primary crop at much higher doses than would be tolerated by crops that had not been modified.
“Now the problem is that the weeds that are killed by the herbicides are developing resistance, and so more herbicide is needed, and additional herbicides are brought into the battle”, Professor Leeder said.
“[This is] not nice stuff to have on your food.”
However, in a written statement to MJA InSight, Food Standards Australia and New Zealand (FSANZ) said the Australian public did not need to be concerned about these herbicides, saying “all GM foods must be assessed as safe and approved by FSANZ before they can be sold in Australia and New Zealand”. (3)
The statement said that residues of agricultural and veterinary chemicals could only be legally present on food if they complied with maximum residue limits.
“Regular monitoring by FSANZ of residues in ready-to-eat foods shows that residue levels are generally very low and do not pose any health concerns to consumers.”
The NEJM authors have called on the US Food and Drug Administration to revisit the labelling of GM foods, which would “deliver multiple benefits”. “It is essential for tracking emergence of novel food allergies and assessing effects of chemical herbicides applied to GM crops”, they wrote.
However, the FSANZ said this did not apply to Australia, where GM food labelling laws “are some of the most extensive in the world”, requiring any product in which GM material (novel DNA or novel protein) was present to be labelled.
“Highly refined products such as oils and sugars are unlikely to require labelling because DNA and protein, whether novel or not, have probably been removed as a result of processing”, the FSANZ said.
However, Dr Carman said the Australian system was flawed because it assumed “that you can’t find GM DNA in animals that have eaten a GM crop, so you don't have to label the meat, milk or eggs from animals that have eaten a GM crop”.
Dr Carman said FSANZ premarket assessments on GM products needed to be more rigorous and incorporate studies that actually looked for end points that were relevant to human health.
“Before a GM crop is fed to a billion people you should do animal feeding studies to investigate allergies and reproductive outcomes, you should do long-term toxicology studies, you should feed the crop to lab animals for long enough for cancers to develop.”
Dr Carman led a study which randomised 168 pigs to receive either a mixed GM soy and GM corn diet, or an equivalent non-GM diet, for 22.7 weeks, which was the entire commercial lifespan of the pigs. (4)
The research found that the pigs fed the GM diet had heavier uteri and a higher rate of severe stomach inflammation than pigs fed a comparable non-GMO diet.
Dr Carman said that given pigs had a similar gastrointestinal tract to humans, these observed adverse health outcomes of a GM diet needed to be recognised in safety reviews.
(Photo: oticki / shutterstock)


Are you concerned about the use of potentially carcinogenic herbicides on genetically modified crops?
  • Yes – it must be a health risk (61%, 117 Votes)
  • No – safety measures are in place (21%, 41 Votes)
  • Maybe – the research is not clear (18%, 34 Votes)

Total Voters: 192

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18 thoughts on “GM safety concerns

  1. Sue Ieraci says:

    “PGD” – I don’t think the use of glyphosate is limited to GM crops. Do you?

  2. Phillip Duguid says:

    GM grown crops have been heavily sprayed with glyphosate which acts by binding(chelating) nutrients in the soil depriving vital plant energy system pathways  and so the plant dies.Any food grown subsequently will be nutrient deficient and we have the same problem contributing to poor health outcomes in whoever (animal or human) eats this “food” -not me

  3. Sue Ieraci says:

    “PGD” – I agree that many chronic diseases can result from a poor diet – but that has little to do with GM – it’s about fresh food vs professed, nutrient-free “food” – GM or not. It’s not fresh GM plant-based food that is causing this disease – it is packaged, processed non-food, with hidden salt, sugar and fat. 

    Certainly we need realistic risk-assessment for GM crops, but let’s not forget the risks associated with non-plant-derived “foods”.

  4. Phillip Duguid says:

    I applaud Dr Judy Carman and  her professional research into GM food and whether it is safe for us to eat.As a practicing general medical practitioner for 30+yrs it still surprises me the lack of knowledge and understanding  people have with respect to  food production – 60-80% of every problem I see every day would be improved significantly if people ate good quality food full of vitality.There needs to be a generational change to food knowledge and appreciation in Australia NOW.

    The independent trials/results on GM potatoes done by Arpad Pusztai at the Rowett Institute in the UK in late 1990’s for the British Govt. are  of very serious concern and demand further investigation.

    “Our food should be our medicine,our medicine should be our food” and adding GM food to our food I am certain will cause more ill health in our  society.I certainly  do not  want to eat GM tainted nutrient deficient “food”


  5. Jon Singleton says:

    I believe Dr Carman is correct in her judgement of FSANZ.  Working knowledge of the analysis by Dr Nancy Podevin and Professor Patrick du Jardin of the European Food Safety Authority (EFSA) and how it theoretically relates to an EPA New Zealand report on horizontal gene transfer (HGT) and research of Sandor Spisak of Harvard Medical School and colleagues, is evident in Dr Carman’s statement on comprehension flaws in the Australian (and NZ) systems.  FSANZ is continuing to ignore peer-reviewed research published since the Generic Issues Report, “Risk assessment of horizontal gene transfer from GM plants to bacteria and human cells” was released in 2006 by ERMA [now EPA] New Zealand.

  6. Marcus Aylward says:

    Should be a snap: though once we have applied the labelling that the food is non-GM, biodynamic, Kosher and Halal, not sure there’ll be much left to eat (if we can afford it).

  7. Gillian Vaughan says:

     The option to simply choose whether or not we wish to eat GM is surely a fundamental right of Australian consumers. FSANZ appears to be putting the Australian public at great risk with weak labelling laws.

    To paraphrase the excellent, commonsense comment by Els Bakker: Until exhaustive, independent research provides complete assurance of safety, surely it is wise to be cautious and not risk the health of the population.

  8. Fran Murrell says:

    The wheels are falling off the GMO cart. It was introduced in 1996 with the promise of higher yields and fewer pesticides. Instead it has created super pests and super weeds and an ever more toxic treadmill. This is because the two main GM traits are herbicide tolerance (the crops are sprayed with herbicide to kill weeds while the crop survives) and insect resistance (the plant produces a toxin to kill certain insects by damaging their stomachs, this toxin can’t be washed off). Science is now showing us that minute traces of pesticides can harm us and developing babies and children are most at risk.

    Farmers have been led down a costly, damaging path leading to market rejection by the chemical companies who profit from GM. Regulators like FSANZ have betrayed public trust by not insisting on long-term, multigenerational testing of GM crops. They also do not consider the chemicals sprayed on the GM crops assuming the APVMA approval of chemicals is sufficient to cover the increasingly complex mix of pesticides we are eating. This is inadequate. 

    It is time to change track and once again make food and farming healthy. The biggest report into how to feed the world, by the IAASTD, said we need to rapidly change our agriculture and use less toxic, more sophisticated systems like agroecology that rely on farmer knowledge and cutting edge science not poisons.

  9. Urban Sundvall says:

    I find it interesting that the loud disrupter who will only use a letter to signify his family name queries who Dr. Carman is. It took me all of 10 seconds on google to find the following:

    Dr Judy Carman has a Bachelor of Science, an Honours Degree in Organic Chemistry, a PhD in Medicine in the field of nutritional biochemistry and metabolic regulation, and a Master of Public Health specialising in epidemiology and biostatistics. She has worked in the fields of human nutrition (including at the CSIRO), HIV/AIDS in Sydney, national injury surveillance and analysing data from Divisions of General Practice. She was the Senior Epidemiologist in the Communicable Disease Control Branch of the South Australian Department of Health, investigating outbreaks of disease in the state. She has many years of experience teaching at various tertiary institutions, including an agricultural college, and Senior Lecturer positions at both Flinders and Adelaide Universities.

  10. Jessica Harrison says:

    Before the predictable chorus of the pro-GM lobby sweeps logic from this discussion, let’s stick to the facts : the WHO IARC defined glyphosate as a probable carcinogen. In Europe and here, we avoid feeding our families products from plants doused in this herbicide. That is why there is a premium on non-GM canola in Australia. There is a growing body of evidence showing the harm of GMOs. See

    The tired “Feed the World” mantra fails to impress the populations of the countries supposedly in need of GMOs, like Africa and India, where farmers prefer agroecology to the dead hand of Big Chemical Ag.



  11. daman langguth says:

    This is a disgrace being published in this journal without saying who Dr Carman is. As above comments show the research iis bunk and antiGMO campaigners are up there with antivaxxers!!!

  12. Els BAKKER says:

    I have been involved in horticulture all my life and depair at the lack of open and honest discussion and or/knowledge issues like chemicals in food production, control of GM crops by large corporations etc.immunization. This is what happens when you do diligent research for years due to having a child with an illness the worldwide medical community cannot be bothered with and put in the too hard basket.

    You will find that the research will give you more questions than answers. 

    Unless research indicates safety, by several independent research teams , maybe it is time to be a little more on the cautious side regarding the health of the population.

    Untold damage has already been done over the past 50 years.



  13. Brian F Sullivan says:

    I have been involved with agriculture all my life and dispair at the logic of those supposedly educated. One can be confident that the same names pop up representing organic food, immuniasation, and green politics. The sad part is that they create fear amongst the community who have little understanding of science. Wouldn’t it be good if those creating the fear could be held to account for the concern they cause

  14. Christoph Ahrens says:

    I don’t understand why it is so difficult to see the obvious. Glyphosate has a lot to do with GM crops. The crops were modified to withstand Glyphosate. That means due to developing resistance of weeds, you can hammer more Glyphosate onto the food that you later eat. Bon-Appetit

  15. Ian Cormack says:

    I am surprised to find this article here as it links  GM to herbicides that have nothing whatever to do with GM. Glyphosate (which may well be a potential carcinogen, as is barbecued food and many other food products) is widely used by farmers to control weeds, instead of tillage which is costlier (and the diesel smoke produced by tractors is also a proven carcinogen). Glyphosate is also widely used by councils to control weeds in parks and footpaths, where city kids play, and I have used in in my suburban garden, and with average luck, will live long enough to use it again.

  16. Darcy McFarland says:

    There is not one argument against GMOs that cannot be attributed to non-GMO plant species.
    Judy Carman’s study was inherently biased. It was basically a fishing expedition – no hypothesis was generated, a huge battery of examinations were done on autopsy to identify any difference in the two groups with no real rhyme or reason as to why these were chosen. She is also a prominent anti-GMO activist.
    Stomach inflammation was determined by a vet on autopsy via a gross examination (a poor indicator for actual inflammation) and although “severe inflammation” was statistically significant, nil, minor, and moderate inflammation was not, and neither were presence of erosions or stomach ulcers. 
    As for glyphosate – it is one of the safest pesticides used today. It was classified as a “probable carcinogen” at production stage – meaning those using it are at risk (i.e. farmers). The levels in food consistantly are magnitudes below the safe limits set by the governing body. Why people are so bothered by glyphosate when known carcinogens, such as alcohol, caffeine, and sunlight, are taken daily by many australians.
    Banning or regulating GMOs will not decrease pesticide use. Banning glyphosate will lead to more dangerous pesticides being needed. 

  17. Marcus Aylward says:

    By hook or by crook GM will be demonised. There has never been a credible peer-reviewed study showing danger from GM foods, so now we will go after the pesticides (which are presumably only used on GM crops??)

    GM crops provide possibly the only means to support the projected future world population.

    Pity that exhortations to respect the science in some spheres does not extend to pet hates in others.

  18. Dr P Stowell says:

    And this article does not address the very mirky (at best) ethics and the corporate uncaring greed behind much GM Food and herbicides 

    Dr P S 

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