• Question: GM researchers say that global use of GM shows it is safe - where is the big paper or meta study that shows this? Wouldn't that be a useful way to answer critics?

    Asked by quizzical to Andy, Cathie, Jules, Les, Ricarda on 25 Jun 2012.
    • Photo: Andy Stirling

      Andy Stirling answered on 25 Jun 2012:

      This is a neat question. But – to be fair on GM – it is very difficult to imagine how any scientific study could ever be undertaken on a scope and at a scale sufficient definitively to demonstrate complete safety. This is true not just of GM, but of any food.

      A key general point about science is, that it is at its most powerful in falsifying assertions, not in proving them. As history repeatedly shows, ideas once thought to be proven repeatedly turn out to be incorrect. This power of falsification is partly why science is such a fantastic way to build knowledge.

      So: it is possible for a single well-designed study to falsify a claim to safety – by demonstrating harm. But even the best study in the world could not fully prove safety. There would always be the possibility that particular circumstances could give rise to some specific kind of problem that the original study was not designed for.

      And a key point about safety, is that no kind of food – or food production system – can ever be considered entirely safe. It is unfair to expect (and misleading to claim) that GM – or any other technology – can deliver this. The point is more about the kinds of adverse effects that seem more or less possible – and the particular kinds of uncertainties that are introduced.

      As I try to answer in another question (‘what is GM?’), tho’, GM does raise some very particular uncertainties that are simply not a factor for other food production technologies.

      One final point to make in this, is to think about a related kind of claim that is sometimes made about GM food. This is, that “X million people have been happily eating GM foods for Y years and no bad effects have been proven.” Well, this is not irrelevant. But in order to know how relevant it is, we have to think about how much effort is being spent on monitoring for any possible adverse health effects.

      Sure, current levels of GM consumption in many parts of the world mean we can be pretty confident for existing products that it is unlikely there are any general effects that are so acute or serious or universal in scale as to be immediately noticeable across an entire population. But the crucial issue is the relative absence of systematic monitoring of a kind that might pick up some possible kinds of health effect. So, as with other foods, it does remain possible that there exist adverse effects of some GM products that might affect relatively small groups of people.

      This is not a reason to panic. In itself, it is not an argument against GM. But, just like the difficulties in ever fully demonstrating safety, what this does mean is that we have to be careful about accepting claims that the evidence shows there is “no harm”. On both issues, the science is typically more complicated.

    • Photo: Julian Little

      Julian Little answered on 26 Jun 2012:

      Hi quizzical, I was asked a similar question by ljrn42 earlier. There is no single answer to the question because safety is a relative term. You cannot say that anything is safe because you have to add “as long as” or “compared to”. Hence walking along the path is safe… as long as there isn’t someone riding a bike the other way, or… food a week past it’s sell by date is safe… compared to food a month past it.

      Having said all that the European Commission (which is not known for a pro-GM stance) published a report detailing the 120 projects it had funded over the last 25 years with 500 research groups (http://ec.europa.eu/research/biosociety/pdf/a_decade_of_eu-funded_gmo_research.pdf ). It’s conclusion? “That biotechnology, and particularly GMOs, are not per se more risky than, eg conventional plant breeding technologies”.

      But safe? Well it is certainly possible to make an usafe GM crop, just as you can make an unsafe crop through conventional breeding. What you need is good science-based regulation to ensure that the unsafe crop doesn’t get to the market. And with GM crops that is what we have. Interestingly, no such system exists in Europe for unsafe crops bred conventionally….

    • Photo: Les Firbank

      Les Firbank answered on 26 Jun 2012:

      There isn’t a single, definitive study of the safety of GM crops. This is because there is no single thing called GM – each crop type, and each type of GM, needs to be looked at separately. One type of GM poases different risks to other types. ALso, there can be no overall summary of research because new evidence comes up all the time. Also, scientists have to be critical about what counts as ‘evidence’. Some research on GM has been very controversial because some scientists consider that the data are not valid, the experiments were not done properly.

    • Photo: Ricarda Steinbrecher

      Ricarda Steinbrecher answered on 26 Jun 2012:

      Sorry to say there is no big paper or meta study that shows this. Such claims are based on assumptions rather than on facts or research.

      Concerning health effects, it’s almost impossible to do a global assessment of GM foods due to the lack of labelling in GM producer countries such as the US, Canada, Argentina, Brazil, Paraguay. Actually I think it’s only the EU that has done the regulatory step to accept the right to choose of its consumers – and that requires labelling of GM food.

      Concerning socio-economic and livelihood impacts, there have been many negative impacts reported from countries such as India, Argentina, Paraguay, Brazil, South Africa. Some are immediate and some only emerge when GM has been grown for a number of years. Argentina has seen thousands of farmers driven off the land, often violently. Later the health impacts of aerial spraying of chemicals began to affect those who stayed behind, often with intimidation if they tried to speak out about their problems. Even farmers of the US and Canada have reported problems due either to the lack of availability of good quality non-GM seed on the market or due to the contamination of their fields. Some saved their non GM seeds as usual and found themselves sued by the patent right holder such as the biotech company Monsanto for illegally growing their GM seed. The reason was more often that the seed saved by the farmer had been contaminated by GM pollen from neighbouring farms. Instead of offering compensation, the company sued the farmer for using company property, the GM seed, without paying for it. The Percy Schmeiser case in Canada is probably the best known case.

      Concerning biodiversity, the environment, and ecosystems – negative impacts are being reported in particular from areas of large scale GM soya and maize production, such as Argentina and Brazil. There has also been fragmentation and destruction of forests in both countries. Similar problems are reported for Paraguay and Uruguay.
      Other issues are the emergence of secondary pests and the spread of herbicide tolerant weeds. There is also the compaction of the soil due to extremely heavy machinery, contamination of water supplies with pesticide and fertiliser run-off.

      So, an all encompassing reliable mega study to answer the concerns of critics? Given the information, data and evidence I have investigated, of which the above samples are just a few, such a report seems unlikely.

Comments

  • Photo: joseph110

    joseph110 commented on :

    This is an interesting question. There have been 2 recent scientific reviews of available studies on health effects of GM foods:
    1. Diels, J., M. Cunha, et al. (2011). “Association of financial or professional conflict of interest to research outcomes on health risks or nutritional assessment studies of genetically modified products.” Food Policy 36: 197–203.
    Since the first commercial cultivation of genetically modified crops in 1994, the rapidly expanding market of genetically modified seeds has given rise to a multibillion dollar industry. This fast growth, fueled by high expectations towards this new commercial technology and shareholder trust in the involved industry, has provided strong incentives for further research and development of new genetically modified plant varieties. Considering, however, the high financial stakes involved, concerns are raised over the influence that conflicts of interest may place upon articles published in peer-reviewed journals that report on health risks or nutritional value of genetically modified food products. In a study involving 94 articles selected through objective criteria, it was found that the existence of either financial or professional conflict of interest was associated to study outcomes that cast genetically modified products in a favorable light (p = 0.005). While financial conflict of interest alone did not correlate with research results (p = 0.631), a strong association was found between author affiliation to industry (professional conflict of interest) and study outcome (p < 0.001). We discuss these results by comparing them to similar studies on conflicts of interest in other areas, such as biomedical sciences, and hypothesize on dynamics that may help explain such connections.

    2. Domingo, J. L. and J. G. Bordonaba (2011). "A literature review on the safety assessment of genetically modified plants." Environ Int 37: 734–742.
    In recent years, there has been a notable concern on the safety of genetically modified (GM) foods/plants, an important and complex area of research, which demands rigorous standards. Diverse groups including consumers and environmental Non Governmental Organizations (NGO) have suggested that all GM foods/plants should be subjected to long-term animal feeding studies before approval for human consumption. In 2000 and 2006, we reviewed the information published in international scientific journals, noting that the number of references concerning human and animal toxicological/health risks studies on GM foods/plants was very limited. The main goal of the present review was to assess the current state-of-the-art regarding the potential adverse effects/safety assessment of GM plants for human consumption. The number of citations found in databases (PubMed and Scopus) has dramatically increased since 2006. However, new information on products such as potatoes, cucumber, peas or tomatoes, among others was not available. Corn/maize, rice, and soybeans were included in the present review. An equilibrium in the number research groups suggesting, on the basis of their studies, that a number of varieties of GM products (mainly maize and soybeans) are as safe and nutritious as the respective conventional non-GM plant, and those raising still serious concerns, was currently observed. Nevertheless, it should be noted that most of these studies have been conducted by biotechnology companies responsible of commercializing these GM plants. These findings suggest a notable advance in comparison with the lack of studies published in recent years in scientific journals by those companies. All this recent information is herein critically reviewed.

    • Photo: hmimina_gabriel

      hmimina_gabriel commented on :

      Well, concerning the first study you quoted, it also shows that most of the studies which were analyzed are favorables, even in the academic group, and that most of theses are conducted by people without professional conflict of interest.

      Concerning the second one, it doesn’t show what’s you are quoting, which seem pretty unlikely. Just look at the pubmed or google scholar results ; I wouldn’t say most of them are from the industry.
      And since I read it, this review does not seem accurate. It’s reffering to highly controvertial articles while ignoring most (or all) of the scientific controversy. Speaking about Seralini or Malatesta’s work without pointing out the fact that their methodology was shown to be inadequate is quite misleading.

      • Photo: joseph110

        joseph110 commented on :

        Diels’ conclusion: “the existence of either financial or professional conflict of interest was associated to study outcomes that cast genetically modified products in a favorable light”, ie studies that concluded GM food was safe were more likely to be GM industry-affiliated.
        Domingo’s conclusion: “most of the studies demonstrating that GM foods are as nutritional and safe as those obtained by conventional breeding, have been performed by biotechnology companies or associates, which are also responsible of commercializing these GM plants.” Similar conclusion to Diels.
        Your comment, “concerning the first study you quoted, it also shows that most of the studies which were analyzed are favorables”, ignores the fact that most of the scientific studies published, even in the peer-reviewed literature, are in some way industry-affiliated and so have inherent conflict of interest. It is well known that the independent research base on GM food safety is tiny, as few will fund it. The authors of the study recognise this fact and are trying to investigate possible bias; hence their review is NOT on the number of studies that were done, but on who funded them. This is very clear from the papers.

  • Photo: dingo

    dingo commented on :

    Here’s a study that reviewed the peer-reviewed evidence on health risks from GM foods: A. Dona, and I. S. Arvanitoyannis, ‘Health Risks of Genetically Modified Foods’, Crit Rev Food Sci Nutr, 49 (2009), 164–75: As genetically modified (GM) foods are starting to intrude in our diet concerns have been expressed regarding GM food safety. These concerns as well as the limitations of the procedures followed in the evaluation of their safety are presented. Animal toxicity studies with certain GM foods have shown that they may toxically affect several organs and systems. The review of these studies should not be conducted separately for each GM food, but according to the effects exerted on certain organs it may help us create a better picture of the possible health effects on human beings. The results of most studies with GM foods indicate that they may cause some common toxic effects such as hepatic, pancreatic, renal, or reproductive effects and may alter the hematological, biochemical, and immunologic parameters. However, many years of research with animals and clinical trials are required for this assessment. The use of recombinant GH or its expression in animals should be re-examined since it has been shown that it increases IGF-1 which may promote cancer.

  • Photo: reinhard

    reinhard commented on :

    There is a nice review study published in 2009 called BEETLE (2009): Long-term effects of genetically modified (GM) crops on health and the environment (including biodiversity): prioritization of potential risks and delimitation of uncertainties. http://ec.europa.eu/food/food/biotechnology/reports_studies/docs/lt_effects_report_en.pdf

    Here’s the conclusion:

    1) In the BEETLE study, genetically modified (GM) crops with traits already on the market in
    the EU or possibly so in the near future were assessed with respect to potential long-term
    (10-20 years) adverse effects on environment and health. They included the following major
    crop/trait combinations:
    – Maize: insect resistance (IR) – Oilseed rape: herbicide tolerance (HT)
    – Sugar beet: herbicide tolerance (HT) – Potato: starch modification (SM)
    2) Information sources:
    • more than 700 scientific publications about GM crops and their potential effects on the
    environment including biodiversity, and more than 100 publications about GM crops and
    their potential effects on human and animal health, which were published mostly during
    the last decade, were analysed,
    • contributions to online surveys from 100 of 167 invited environment experts and 52 of
    185 invited health experts, representing a wide range of expertise with focus on the EU
    were received,
    • potential ways forward for reducing uncertainty regarding environmental effects were
    discussed with 27 invited international experts in a CREA Space Workshop,
    • input and guidance was received from a Peer-Review Committee of international experts
    throughout the study.
    3) In more than 20 years of experimental field releases and more than 10 years of commercial
    cultivation, adverse long-term effects reported in the scientific literature concern (i) the
    development of resistance in Bt crop target organisms and (ii) tolerance in weeds to complementary
    herbicides used in HT crops. No other adverse long-term effects have yet
    been established. However, other potential long-term effects are discussed in the relevant
    scientific literature and in scientific fora in general.
    4) Resistance development in plant pests targeted by GM crops expressing protective Bt
    proteins, and tolerance in weeds to complementary herbicides used on HT crops, are
    long-term effects which were already anticipated from the risk assessments.
    5) There is at least 10 years experience of cultivating GM crops worldwide and only few established
    long-term effects have yet been reported (insect resistance development in Bt
    crops, feralization of GMHT oilseed rape). Due to the nature of potential long-term effects,
    it is not yet possible to quantify the long-term risks associated with GM crops. However,
    the BEETLE study has identified a qualitative priorization concerning the processes linked
    to GM plants that could have long-term effects on the environment (including biodiversity)
    and health.

  • Photo: dingo

    dingo commented on :

    OK now I’ve looked at the BEETLE paper and it is not reassuring. “Long-term effects on animal or human health linked to GM crops have not yet been identified.”–er, could this be because they have not been tested for?

    Also: “It is not yet possible to quantify the long-term risks associated with GM plants as experience
    is lacking. However, in more than 20 years of experimental field releases and more than 10
    years of commercial cultivation, adverse long-term effects reported in the literature have
    concerned the development of resistance in Bt crop target organisms and tolerance in weeds
    against complementary herbicides used in HT crops.”

    Wow, this is not a good advert for GM safety.

    • Photo: hmimina_gabriel

      hmimina_gabriel commented on :

      Well, the same could be said about just any non-GM new variety.

      At least, GMO are tested for acute toxicity. I don’t know how it works in your country, but in mine, event mutated varieties, which have an unknown number of totally new genes, are not tested.

      • Photo: dingo

        dingo commented on :

        The longest tests that are done in the EU on GMOs are subchronic medium term rodent studies of 90 days. Not long-term. The GM companies themselves commission the tests and analyse the data. I am not sure what you mean by “event mutated” varieties but if you are talking about radiation-induced mutagenesis breeding, the Canadian govt requires that these crops be tested and regulated as novel foods because of the risk of harmful mutations.

  • Photo: hmimina_gabriel

    hmimina_gabriel commented on :

    Ms Ricarda Steinbrecher, you said there were negative socio-economic and livelihood impacts reported in India : what are your sources on this issue ? All the study I’ve read about the indian case where rather positives.

    And you’re talking about the Percy Schmeiser case as if his fields were contaminated by GM pollen : that’s not the case, during his trial, he admitted he selected glyphosate-resistant seeds and sowed them on all his fields. Which is how he attained a 95% or more “contamination” rate, and which is why he was found guilty.

  • Photo: jamesskinner

    jamesskinner commented on :

    I recommend Googling the web-site of the Institute for Science in Society (www.i-sis.org.uk) for scientific information on these questions. There is also a factual first-hand account of the experiences of a pig farmer in Denmark using GM soya as pig feed, which is worth looking at on http://www.gmfreecymru.org. I can send a pdf copy if anyone is interested. There seems to be an increasing number of worrying reports coming in from people who have observed various results of glyphosate to human and animal health. This seems to be partly caused by the fact that there is increasing immunity to glyphosate (Roundup), as a result of GM soya planting on a wide scale. This in turn leads to ever increasing quantities of glyphosate having to be used (good news for the manufacturers). There is information about this on the isis site. The original idea was of course that GM would reduce rather than increase the amount of chemicals to be used, but that does not seem to be working out quite as predicted

  • Photo: dingo

    dingo commented on :

    I agree with Julian Little that safety is a relative term. And GM foods have been found to have more ill effects on laboratory and livestock animals in feeding trials than their non-GM equivalents. In other words, these studies show that GM foods are less safe. There’s a list of relevant studies in section 3 of this report:
    http://www.earthopensource.org/index.php/reports/58-gmo-myths-and-truths