Source:Séralini GE, E Clair, R Mesnagea, S Gress, N Defargea, M Malatesta, D Hennequinc, J Spiroux de Vendômois. 2012. Long term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modifed maize. Food and Chemical Toxicology 50:4221–4231.
This article describes the results of an experiment whereby rats were fed corn, GM corn or corn with herbicide residue for two years. At the end of the feeding period, the rats eating GM corn or exposed to herbicide had higher tumor and mortality rates.
The main reasons –out of many– why this paper fails:
- The type of rats used is famous for getting tumours as they age. The tumor rate reported in this paper is within the normal tumor rate for this rat.
- The experiment was designed for a 90-day study, not a 2-year study. Extending the duration of the study adds complications that were not accounted for.
- The data and experimental details were not made public.
- Inappropriate use of statistics; unequal sample sizes between treated and untreated animals.
- In toxicology, cause-and-effect is established when there are more symptoms with higher doses; i.e., the dose makes the poison. Such a relationship was absent in the results.
- Animal use and care ethical standards that require animals to be euthanized before tumors got too big were ignored- thus ensuring sensational photos were available.
- When the statistics are corrected for multiple comparisons, as is standard, the negative effects disappear.
Note added 26 September 2019: As of now the European Union has funded two studies, and the French Government has funded one, spending a total of €15 million. None of them could repeat the results reported by Séralini. For a review of all the events associated with this publication and the ensuing aftermath, see The Séralini Affair – The Dead-End of an Activist Science.
Additional expert assessments:
- Repeating the study could not find the same results- GRACE
- Seralini Rat Study At A Glance
- Statement by Health Canada
- Initial review by the European Food Safety Authority
- Final review by the European Food Safety Authority
- Response by Food Standards Australia & New Zealand
- Rebuttal by six French academies of science
- Plurality of opinion, scientific discourse and pseudoscience: an in depth analysis of the Séralini et al. study
- Critical remarks on the long-term feeding study by S̩ralini et al. (2012). Does the study provide proof of health threats posed by genetically modified foods?, EFFL РEuropean Food and Feed Law Review 3, pp. 176-187
- A comprehensive archive of rebuttals, by GMO Pundit
- A comprehensive list compiled by Vegan GMO
- Q&A – Seralini et al 2012, by PRRI
- Independent Review of the Seralini GMO-Roundup Rat Study