Scientists skeptical of the benefits of genetically modified crops have published a study linking liver disease in rats with controversial herbicide glyphosate.

Researchers involved in the study include Gilles-Eric Seralini, whose 2012 study on rats fed GM maize and glyphosate conducted at the University of Caen caused a huge amount of contention. The researchers’ multiomics method was also adopted by same team last month to challenge the principle of ‘substantial equivalence’, used by public health watchdogs in the US and Europe as a basis for their assessments of GM crops.

In the study, released on Monday morning, rats were exposed to “field realistic”, “Ultra-low” doses of glyphosate over a two-year period. The rats developed non-alcoholic fatty liver disease, though researchers said the dose of glyphosate they were exposed to was thousands of times below what is permitted by regulators worldwide, and much lower than residues found in humans in Europe.

Following analysis using the multiomics approach (which they described as cutting edge molecule profiling) the researchers said they have evidence linking the observed effects with glyphosate in the rats’ drinking water, including alterations in rats’ livers associated with serious toxic effects. They said theirs is the first study to show a causative link between consumption of glyphosate herbicide Roundup at a real-world environmental dose and the development of a serious disease.
 
Previous research conducted in 2015 by Robin Mesnage, one of the team, uncovered evidence of organ damage in the rats, but couldn’t definitively link this with the glyphosate.

Commenting, one of the paper’s authors, Dr Michael Antoniou, said, “The findings of our study are very worrying as they demonstrate for the first time a causative link between an environmentally relevant level of Roundup consumption over the long-term and a serious disease - namely non- alcoholic fatty liver disease. Our results also suggest that regulators should reconsider the safety evaluation of glyphosate-based herbicides.”
 
Non-alcoholic fatty liver disease is a major issue in the US, where it is associated with obesity, high cholesterol and diabetes.

Commenting on the study's findings, Peter Melchett, Soil Association Policy Director said, "It is extraordinary that the world’s most widely sold weedkiller, glyphosate, in use for decades, has only now been recognised as a cause of the liver disease NAFLD (non-alcoholic fatty liver disease)... This research is the first evidence of a clear causative link between consumption of Roundup at levels that are found in the real world and a serious disease."