Science in Society Archive

Marked Deterioration of Public Health Parallels Increase in GM Crops and Glyphosate Use, US Government Data Show

The steep rise in incidence of 22 chronic diseases in the US correlates strongly with the increase in GM crops and the application of glyphosate-based herbicides Prof Peter Saunders

Ample evidence of glyphosate toxicity already exists

Despite what the manufacturers say, there is ample evidence to show that glyphosate, the active ingredient of Monsanto’s Roundup, Syngenta’s Touchdown, Dow’s Durango and many other herbicides, is highly toxic and a serious hazard to human and animal health. There is documentation of miscarriages, birth defects, carcinogenesis, endocrine disruption, DNA damage, neurotoxicity, and toxicity to liver and kidney at levels well below recommended agricultural use (See, for example, first Chapter of [1] Ban GMOS Now , ISIS special report, [2]  Glyphosate and Cancer, SiS 62). Several countries, among them Denmark, The Netherlands, France, El Salvador and Sri Lanka have recognised the dangers imposed total or partial bans on the use of glyphosate, though the ban in Sri Lanka was lifted under pressure from the manufacturers (Sri Lanka Partially Bans Glyphosate for Deadly Kidney Disease Epidemic  [3]) .

Other countries, especially those with large chemical and biotech industries and/or a major commitment to industrial farming, take a totally different view. The US Environmental Protection Agency (EPA) recently increased the permitted tolerance levels for glyphosate residues in food. The European Food Safe Agency (EFSA) has recommended the re-approval of glyphosate for use in Europe with an increase in acceptable daily intake (ADI) from 0.3 to 0.5 mg per kg body weight. It is not surprising that EFSA reached this decision; the review was in fact carried out by a ‘Glyphosate Task Force’ (GTF) made up of a consortium of chemical companies including Monsanto, and based its conclusions largely on reports submitted by the manufacturers (Scandal of Glyphosate Re-assessment in Europe [4]).

The industry does its best to keep evidence of glyphosate toxicity out of the public’s view and the public record. The recent improper unilateral retraction of a published paper by Séralini and his group ([5],  Support Séralini Team for New GMO and Pesticide Risk Research [6], Retracting Séralini Study Violates Science and Ethics [7] ) is a case in point.  It followed the appointment by the journal of a former Monsanto employee to a newly created editorial post. Unusually, it was done in the open. We know of other cases that were not made so public, and possibly many more that we have not even heard about.

That’s not all. Confidential papers obtained from the US EPA by Moms Across America under the Freedom of Information Act contain studies carried out by industry showing that glyphosate is lethal to shrimps, fish, oysters and canaries after 96 hours, and at concentrations of <1 to hundreds of parts per million (ppm), to which humans are routinely exposed [8].

Millions of Americans are said to have been eating GM food with no ill effects

The argument that the  industry relies on most heavily is that for fifteen or more years, millions of Americans have been eating GM food, or food that have been sprayed with glyphosate, or both, and they have not been harmed; and this surely proves beyond doubt that neither GMOs nor glyphosate are hazardous to health [9]. This is obviously a totally unscientific statement; because there has been no GM labelling in the US, it is impossible to tell how much GM food anyone has eaten. Nevertheless, physicist and former scientific adviser to the US Navy Nancy Swanson realised that it is possible to examine the health status of the nation before and after the introduction of GM food and the sharp increase in glyphosate herbicides that went with it. What she and her colleagues found was devastating.

Over the past fifteen or twenty years there has been a large increase in the number of Americans suffering from a whole range of chronic diseases. This is the same period over which there has been a very large increase both in GM crops and in the use of glyphosate-based herbicides [10]. The team have made use of the best available government data from the Centers for Disease Control (CDC) for the incidence of diseases, and the Department of Agriculture (USDA) for GM crops grown and glyphosate herbicide used. 

Because there are records for each year, it is possible to compare how both GMOs and glyphosate on the one hand and the various diseases on the other have changed over time. And the results are striking. Graph after graph showed the same parallel increases over time. On example is given in Figure 1 for liver and intrahepatic bile duct cancer.

Figure 1   Incidence of liver cancer, % GE corn & soy, and glyphosate applied from 1975 to 2009

Note that the increase in liver cancer incidence rises sharply above the long term trend that goes back to the 1970s. In other words, while liver cancer had been increasing for some time, the rate of increase accelerated at about the same time that GM crops appeared and glyphosate use rose more sharply. The incidence is now about double what it would be if it had continued to rise at the pre-1990 rate.

Table 1 shows the correlation coefficients between each of the conditions and the amount of glyphosate used, and % of GM maize and soya. None of the 44 correlation coefficients falls below 0.8 - the conventional minimum level for a correlation to be called ‘strong’ - and all but seven are greater than 0.9.

Table 1:  Pearson correlation coefficients between the incidence in the US of 22 chronic diseases since 1995 and (a) the amount of glyphosate applied to maize and soy  (b) the percentage of maize and soy planted that was GM (from [10])

ConditionGlyphosate use%GM
Diabetes prevalence0.9710.983
Diabetes incidence0.9350.955
Lipoprotein metabolism disorder0.9730.955
Senile dementia0.9940.918
Multiple sclerosis0.8280.876
Inflammatory bowel disease0.9380.812
Intestinal infections0.9740.901
End stage renal disease0.9750.958
Acute kidney failure0.9780.967
Thyroid cancer0.9880.938
Liver cancer0.9600.911
Bladder cancer0.9810.945
Pancreatic cancer0.9180.841
Kidney cancer0.9730.940
Myeloid leukaemia0.8780.889

There is clearly a strong correlation between the conditions on the one hand and GMOs and glyphosate use on the other. This does not by itself prove there is a causal relationship, but it is certainly evidence in favour of one. When we add to it the evidence that glyphosate has led to birth defects in humans, that it has been found to harm laboratory rats, cattle on farms, and other animals as well, that it interferes with an important metabolic pathway in animals, that it adversely affects beneficial gut bacteria, that it acts as an endocrine disruptor, and more besides, the case against glyphosate becomes very strong indeed (see [11] A Roundup of Roundup Reveals Converging Pattern of Toxicity from Farm to Clinic, SiS 65, for the most up-to-date review).

To conclude

There have been all too many examples in the past of substances where there was compelling evidence that they were dangerous to health or the environment or both and yet they continued to be produced and used because of pressure from the manufacturers and weak regulators and governments. These include tobacco, asbestos, lead, polychlorinated biphenyls (PCBs), benzene, and many more [12, 13]. If governments continue to rely on advice from the industry and ignore the growing body of evidence, glyphosate will be yet another example of serious harm that could have been avoided.

Article first published 10/12/14


  1. Ho MW & Sirinathsinghji E.Ban GMOsNow. Health and Environmental Hazards Especially in Light of the New Genetics. ISIS Special Report, 2013.
  2. Ho MW. Glyphosate and cancer. Science in Society 62 12-14, 2014
  3. Sirinathsinghji E. Sri Lanka partially bans glyphosate for deadly kidney disease epidemic. Science in Society 62 18-21, 2014.
  4. Swanson N and Ho MW.   Scandal of glyphosate re-assessment in Europe.  Science in Society 63 8-9, 2014.
  5. Séralini G-E, Mesnage R, Gress S, Defarge N, Malatesta M, Hennequin D and  de Vendômois JS (2012),  Long term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maize. Food and Chemical Toxicity.  (This paper was improperly retracted by the journal but has been republished)
  6. “Support Séralini team for new GMO risk research”. I-SIS Report. 21 November 2014
  7. Ho MW and Saunders PT. Retracting Séralini study violates science and ethics. Science in Society 61 20-21, 2014.
  8. “Mom receives glyphoste task force studies on glyphosate submitted to the EPA”, Zen Honeycutt, 2 December 2014,
  9. Monsanto. What Independent Experts are Saying about GM crops. 2014. 6/12/14
  10. Swanson NL, Leu A, Abrahamson J and Wallet B. Genetically engineered crops, glyphosate and the deterioration of health in the United States of  America. Journal of Organic Systems 2014, 9, 6-37.
  11. Sirinathsinghji E. A Roundup of Roundup reveals converging pattern of toxicity from farm to clinic. Science in Society 65 2015.
  12. Harramoës P, Gee D, MacGarvin M, Stirling A, Keys J, Wynne B and Guedes Vaz S (2002). Late lessons from early warnings: the precautionary principle 1896-2000 European Environment Agency, Copenhagen. ISBN 92-9167-323-4.
  13. European Environmental Agency. Late Lessons from Early Warnings: Science, Precaution, Innovation. 2014.

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Brian Sandle Comment left 11th December 2014 18:06:54
Need to do some partial correlations with soy and corn consumptions which have also increased. Soy has partially replaced animal protein and has antinutrients (less so if fermented to tempeh, natto, fluffy tofu). It is anti-thyroid and lacks sulfur containing amino acids and high in phytoestrogens and not recommended by the NZ Health Ministry for infant food. Corn is high on inflammatory omega-6 fatty acids. Could get some data from faostat.

John Fryer Comment left 11th December 2014 20:08:14
After many years of développent another ORGANOPHOSPHORUS chemical GLUFOSINATE ammonium was accepted in USA circa 1994 for use in GMO crops. This chemical permanent l'y disables the glutamine synthetase enzyme. First described by Denmark as praticable non toxic to humans circa 1986. In 1999 the UK PSD described it not be used above levels of 20ppb and demanded further HUMAN studies. Today we know the destruction of GS is at the root cause of a dozen and more illnesses affecting almost everyone. No action yet by government and régula tors while its use hasincreased five food in 5 years.

warren kruger Comment left 18th December 2014 04:04:45
Where is the data showing the relationships of these diseases and time in countries where GMO is banned (i.e. Europe). I suspect, If you do the same analysis you will find that there is the same increase in all these diseases. Frankly, this study should not have gone through peer review without this data. The hype this "study" was given is not justified based on the poor quality of the science.

Nancy Swanson Comment left 18th December 2014 06:06:21
To Warren Kruger: People seem to think that Europeans don't have exposure to GMOs or glyphosate, therefore their health statistics could be used as a control for comparison to the U.S. Such is not the case. It is true that some European countries have banned the growing of all GMO crops (Bulgaria, Italy & Switzerland). Some European countries have banned the growing of some GMO crops Germany--ban on cultivation of maize MON 810, Austria--ban on cultivation of maize MON 810, MON 863 and T25, Hungary-- ban on cultivation of maize MON 810 & BASF potato,Luxembourg-- ban on cultivation of maize MON 810 & BASF potato, France--ban on cultivation of maize MON 810, Greece--ban on cultivation of maize MON 810). It is true that most European countries require labelling of food containing GMOs (not including animals and animal products where the animals were fed GMO feed). This is not the same as being GMO-free, as is commonly assumed here in the U.S. In addition, the practice of spraying grains and dried legumes with glyphosate as a pre-harvest treatment has spread to Europe. The Monsanto document, "The agronomic benefits of glyphosate in Europe" outlines uses from pre and post-harvest weed control, crop desiccation, crop ripening agent and roadside and aquatic weed control. In 2004 glyphosate was used to treat 13% of the wheat in the United Kingdom (UK) and by 2006, 94% of UK growers used glyphosate on 40% of cereal and 80% of oilseed crops for weed control or harvest management. According to a 2012 report on glyphosate residues in food in the UK, residues as high as 1.1 parts per million [ppm] were detected in whole wheat flour. Lesser residues were detected in a wide range of breads. Residues of 0.6 ppm were found in dried lentils and peas, 2.7 ppm in dried beans, and 11 ppm in dried chickpeas. Glyphosate AND AMPA have been detected in the urine of city dwellers all over Europe. Urine samples were collected from volunteers in Austria,Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, France, Georgia, Germany, Hungary, Latvia, Macedonia, Malta, Poland, Spain, Switzerland, The Netherlands, and the UK. A total of 80/182 samples tested were found to contain glyphosate. Says Adrian Bebb of Friends of the Earth Europe, "Most people will be worried to discover they may have weed killer in their bodies. We tested people living in cities in 18 countries and found traces in every country. These results suggest we are being exposed to glyphosate in our everyday lives, yet we don't know where it is coming from, how widespread it is in the environment, or what it is doing to our health.” Their exposure must be through the food or the water. The European Union (EU) is re-evaluating glyphosate this year. German regulatory authorities act as the registrar on glyphosate in the EU authorization process. They have found no problems with glyphosate and are recommending re-approval, along with a suggestion to the EU that the acceptable daily intake for glyphosate be raised. The UK, like the U.S., has declared a war on weeds with glyphosate as the weapon of choice. According to Dr. Rosemary Mason, “The level of glyphosate in one Welsh river draining from areas of Japanese knotweed spraying was 190 parts per trillion (ppt) and local tap water was 30 ppt.” Glyphosate and GMOs have spread across the planet like a plague. There may not be a control group. Certainly not in Europe.

Phil Kortis Comment left 17th December 2014 01:01:49
Vegetarians that had relied on soy for ages were suddenly told they had soy allergies in the early 2000's. 1 in 10 young people have gluten reactions. And then they switch to corn, only to run into similar problems. And what of correlations with rises in mental illnesses? The grocery stores were stacked high with GM products by 1998, so the babies fed then are only 17 years old now, just wait till they mature into parents and the effects are passed onto their children. We've been observing this unfolding horror for far too long. Kudos to all who try to inform the public & get GMO BANS on the national agendas. These so-called foods should never be on the grocery shelves to be labeled in the first place, when they finally are the Genetic Storm has progressed too far. I belong to a group called THE ELEMENTS, and we have observed this horror unfolding on Earth for way too long.

Warren Brodey M.D. Comment left 29th December 2014 20:08:30
What can we do to inform more people of the dangers described above. Centralized control powerful newspapers, governments, waited til proof was undeniable and many, many millions were dead...murdered by tobacco and the additives used by industry to encourage addiction to cigarettes.How can we encourage those willing and able to send personal messages to their friends, and communities re the killing. It should be possible. Creative suggestions are needed.Now! Creative action is even better. Tell others what you are doing. Explore. What we learn can be useful.