Annual Incidence of Diabetes (age adjusted) – Swanson et al. 2014

By Andre Leu, President, IFOAM

IF you are involved in agriculture or gardening you have probably heard the claims about glyphosate that ‘It is so safe that you can drink it’.

A few days after the World Health Organization (WHO) classified glyphosate as the second highest level of cancer causing compounds, a spokesperson for a major chemical company stated in a TV interview that it was so safe that you can drink it. When challenged by the journalist to drink some in front of him, the spokesperson stood up and walked out saying that he was not stupid. The clip went viral across the internet.

There are numerous independent peer reviewed scientific studies showing the multiple health problems caused by the levels of glyphosate currently permitted in our food and water. The question that needs to be asked is; why are we being treated as stupid by being unknowingly forced to consume it in our food and water?

Glyphosate is the most widely used pesticide in the world. It is used in food production, sprayed along roadsides, in children’s playgrounds, on footpaths and in parks and gardens. Testing shows that its residues are widespread and persist in our food, water, rain and the air.

The World Health Organization’s International Agency for Research on Cancer (IARC) classified glyphosate (the active ingredient in Roundup) as a carcinogen, based on several scientific studies showing that it causes a range of cancers including non-Hodgkin’s lymphoma, renal cancers, skin cancers and pancreatic cancer. It published the information in The Lancet Oncology Journal, the world’s premier scientific journal for cancer studies.

Seventeen independent experts from 11 countries reviewed the scientific studies and gave glyphosate the second highest classification of 2A. IARC has five classifications for the carcinogenicity of substances:

  • Group 1: Carcinogenic to humans
  • Group 2A: Probably carcinogenic to humans
  • Group 2B: Possibly carcinogenic to humans
  • Group 3: Unclassifiable as to carcinogenicity in humans
  • Group 4: Probably not carcinogenic to humans

Group 1 is for substances like tobacco, alcohol, asbestos and benzene where there are numerous scientific studies showing that they cause cancer in humans. Only around 100 substances out over 900 studied have been placed in this category.

Group 2A is for substances where there is sufficient evidence of causing cancer in animals and limited studies in humans. According to IARC, the 2A classification was because ‘strong mechanistic evidence; for malathion and glyphosate, the mechanistic evidence provided independent support of the 2A classification based on evidence of carcinogenicity in humans and experimental animals.’

Thirty years ago in 1985, the United States Environmental Protection Agency (USEPA) classified glyphosate as a carcinogen. In 1991 the US EPA reviewed the studies, and in the opinion of several experts manipulated the interpretation of the data to state that there was no evidence of cancer. Several members of the review committee refused to endorse the final document, even writing that they did not concur with the conclusion. The latest review by the experts of IARC committee concluded that these early studies did show clear evidence of glyphosate causing cancer.

Age Adjusted Deaths from Senile Dementia - Swanson et al. 2014
Age Adjusted Deaths from Senile Dementia – Swanson et al. 2014

An overview of some of the studies showing that glyphosate is linked to multiple damage to health

The huge growing body of independent scientific studies show that levels of glyphosate far lower than the levels found in our food and water and currently found in human breast milk and urine are linked to numerous health problems.


There are other scientific studies linking glyphosate to breast cancer, thyroid cancer and liver cancers as well and the possible cause of many other types of cancers due to the way it causes cell-cycle dysregulation which is the precursor to most cancers.

Several animal and human studies have shown that glyphosate can cause cell damage, gene mutations and chromosomal aberrations. These types of genetic damage can be the precursors of cancer.

A study published in 2004 found that glyphosate-based herbicides caused cell-cycle dysregulation, which leads to cancers.

According to the researchers, ‘Cell-cycle dysregulation is a hallmark of tumor cells and human cancers. Failure in the cell-cycle checkpoints leads to genomic instability and subsequent development of cancers from the initial affected cell’. The researchers tested several glyphosate-based pesticides and found that all of them caused cell-cycle dysregulation.

A case-controlled study published in March 1999 by Swedish scientists Lennart Hardell and Mikael Eriksson showed that non-Hodgkin’s lymphoma (NHL) is linked to exposure to a range of pesticides and herbicides, including glyphosate.

Research published in the peer-reviewed scientific journal Food and Chemical Toxicology in 2013 found that glyphosate at residue levels commonly found in people caused a five to thirteen-fold increase in the multiplication of estrogen-sensitive human breast cancer cells.

This is a significant study as around 80 per cent of breast cancers are estrogen-sensitive.

A long term feeding study found that rats fed a diet that contains a proportion of GM maize or minute residues of Roundup has resulted in significantly higher increases of cancers, kidney disease, liver damage and other negative health effects.

The study led by Professor Gilles-Eric Seralini and published in Environmental Sciences Europe has found that both the GM maize and Roundup acted as endocrine disrupters and resulted in the females dying 2 – 3 times more than the control animals.

The females that were fed either GM maize or non GM maize with minute Roundup residues, developed large mammary tumors almost always more often than and before controls. All the non-control females, except for one that had ovarian cancer, had mammary hypertrophies (enlarged mammary glands) and in some cases hyperplasia with atypia (nodules in the mammary glands).

The pituitary gland was the second most disabled organ and the sex hormonal balance was modified in females fed with the GMO and Roundup treatments. The treated males presented four times more large palpable tumors than controls and these occurred up to 600 days earlier.

The treated males had liver congestions and necrosis that were 2.5 – 5.5 times higher than the controls as well as marked and severe kidney nephropathies (kidney damage) that were also generally 1.3 – 2.3 greater than the controls.

Cell damage – precursors to cancer and birth defects

Research has shown that glyphosate can cause genetic damage, developmental disruption, morbidity, and mortality even at what are currently considered normal levels of use.

The article ‘Differential Effects of Glyphosate and Roundup on Human Placental Cells and Aromatase’ published by Richard et al. in Environmental Health Perspectives, revealed evidence that glyphosate damaged human placental cells within eighteen hours of exposure, even at concentrations lower than those found in commercially available pesticides and herbicides. The scientists stated that, “this effect increases with concentration and time or in the presence of Roundup adjuvants.”

Researchers of a study published in the journal Toxicology studied four different commercial glyphosate formulations and observed breaks in 50 per cent of the DNA strands in human liver cells at doses as low as five parts per million. This damage affects the way DNA sends messages to several physiological systems, including the endocrine system. The researchers stated that this is significant because the liver is the first detoxification organ and is sensitive to dietary pollutants.

Urinary/Bladder Cancer incidence (age adjusted)- Swanson et al. 2014
Urinary/Bladder Cancer incidence (age adjusted)- Swanson et al. 2014

Teratogenicity (birth defects) in animals

Clements et al. published a study in 1997 showing damage to DNA in bullfrog tadpoles after exposure to glyphosate. The scientists concluded that glyphosate’s “genotoxicity at relatively low concentrations” was of concern.

A 2003 study by Lajmanovich et al. found that up to 55 per cent of tadpoles exposed to a glyphosate herbicide had deformities to the mouth, eyes, skull, vertebrae, and tails.

A 2003 study by Dallegrave et al. found that the offspring of pregnant rats dosed with glyphosate had increased skeletal abnormalities.

A 2004 study conducted by biologists at Trent University, Carleton University (Canada), and the University of Victoria (Canada) showed that concentrations of several glyphosate herbicides at levels found in the environment caused developmental problems in tadpoles. The exposed tadpoles did not to grow to the normal size, took longer than normal to develop, and between 10 and 25 per cent had abnormal sex organs.

A 2010 study found that almost 60 per cent of tadpoles treated with Roundup at one part per million had malformations such as kyphosis, scoliosis, and edema.

A 2012 study by Relyea found that tadpoles exposed to concentrations of Roundup that are found in the environment had changes to their tails.

Paganelli et al. in 2010, found that both Roundup and glyphosate by itself caused severe malformations in the embryos of chickens and frogs and that this could occur in frogs when exposed to less than 0.5 parts per million.

Research by Mesnage et al. found that Roundup from 1 ppm to 20,000 ppm causes cells of the human body to die through necrosis. At 50 ppm it delays the cellular apoptosis that is essential for the normal functioning and regeneration of cells, body tissues, and organs.

Deaths due to Thyroid Cancer (ICD C93 & 193) - Swanson et al. 2014
Deaths due to Thyroid Cancer (ICD C93 & 193) – Swanson et al. 2014

Endocrine disruption

Endocrine disruption is where chemicals mimic hormones and interfere with the normal hormonal balance causing numerous health problems. The study by Seralini, mentioned earlier, found that glyphosate caused endocrine disruption.

Thongprakaisang et al. found glyphosate acted like estrogen to cause the multiplication of estrogen-sensitive breast cancer cells.

Gasnier et al. in 2009 reported endocrine disrupting actions of glyphosate at 0.5 ppm. According to the authors this is “800 times lower than the level authorized in some food or feed.”

Disruption of metabolic pathways

One of the most significant studies was published, in 2013, by Samsel and Seneff, in the peer reviewed scientific journal Entropy.

This comprehensive review, titled ‘Glyphosate’s Suppression of Cytochrome P450 Enzymes and Amino Acid Biosynthesis by the Gut Microbiome: Pathways to Modern Diseases’ showed how glyphosate disrupted numerous biochemical pathways within the human body, including gut microorganisms, and consequently could lead to numerous diseases.

The evidence in the scientific paper is voluminous and compelling and opens up significant areas where research is needed on glyphosate and other chemicals’ potential to adversely affect human health.

The scientists stated that exposure to small amounts of glyphosate in our diet caused: ‘Consequences are most of the diseases and conditions associated with a Western diet, which include gastrointestinal disorders, obesity, diabetes, heart disease, depression, autism, infertility, cancer and Alzheimer’s disease. We explain the documented effects of glyphosate and its ability to induce disease, and we show that glyphosate is the “textbook example” of exogenous semiotic entropy: the disruption of homeostasis by environmental toxins.’

Disruption of the gut microbiome

Samsel and Seneff ’s paper identified how glyphosate disrupted the gut microbiome, causing the suppression of biosynthesis of cytochrome P450 enzymes and key amino acids. In a later paper, “Glyphosate, Pathways to Modern Diseases II: Celiac Sprue and Gluten Intolerance” Samsel and Seneff showed how the current increase in celiac disease and gluten intolerance in people was linked to glyphosate’s adverse effects on the gut microbiome. They highlighted that glyphosate is patented as a biocide, and consequently it kills the beneficial gut bacteria, leading to a rise in intestinal diseases.

Krüger et al. showed that glyphosate has this effect in the microbiome of horses and cows. Shehata et al. found the same effects in poultry; the researchers state, “Highly pathogenic bacteria as Salmonella Entritidis, Salmonella Gallinarum, Salmonella Typhimurium, Clostridium perfringens and Clostridium botulinum are highly resistant to glyphosate. However, most of beneficial bacteria as Enterococcus faecalis, Enterococcus faecium, Bacillus badius, Bifidobacterium adolescentis and Lactobacillus spp. were found to be moderate to highly susceptible.” The researchers postulated that glyphosate is associated with the increase in botulism mediated diseases in these domestic farm animals.

Kidney disease

According to Jayasumana et al., glyphosate’s strong chelating properties allow it to combine with heavy metals and arsenic in hard waters, resulting in damage to renal tissues and thereby causing chronic kidney diseases.

Age Adjusted Deaths due to Obesity (ICD E66 & 278)- Swanson et al. 2014
Age Adjusted Deaths due to Obesity (ICD E66 & 278)- Swanson et al. 2014

Oxidative stress and cell damage

Oxidative stress is an imbalance between free radicals and the body’s ability to repair the damage caused by free radicals. It has been linked to Alzheimer’s, cancer, and Parkinson’s disease, among other health issues.

Cattani et al. found that both acute and chronic exposure to Roundup induced oxidative stress resulting in neural cell death and neurotoxic effects in the hippocampus region of the brain in immature rats.

Lushchak et al. found that a 96 hour exposure to low levels of Roundup in water caused oxidative stress to the cells in the brains, livers, and kidneys of goldfish.

36Studies by El-Shenawy and de Liz Oliveira Cavalli et al. confirm that Roundup and glyphosate caused oxidative stress and necrosis in cells, including the liver, testis, and Sertoli cells in rats.

Glyphosate linked to numerous diseases

A peer reviewed study into glyphosate and human health by Swanson et al. (I am one of the co-authors) found strong correlations between the rapid increase in glyphosate and GMO crops and 22 diseases in the US.

Glyphosate use has increased dramatically since the introduction of Roundup Ready GMO crops. Since the introduction of GE seeds in 1996 the amount of glyphosate used on crops in the US has increased from 27 million pounds in 1996 to 250 million pounds in 2009. Charles Benbrook showed that there was a 527 million pound (239 million kilogram) increase in herbicide use in the United States between 1996 and 2011.

The study found strong correlations for cancers of the liver, kidney, bladder/urinary and thyroid and found good correlations between pancreatic cancer incidence and deaths from acute myeloid leukaemia.

The debate has started to ban glyphosate

Since the decision by IARC, many countries are reviewing it with aim of banning it or restricting its use. Sri Lanka and El Salvador have banned it due to the studies showing that it is linked to an epidemic of kidney damage that has killed or severely disabled thousands of farmers and workers in both countries.

According to Reuters, March 24, 2015, Monsanto, the manufacturer of Roundup, is trying to put pressure on IARC to retract its findings on the basis that the scientific studies they used were ‘invalid’.

In my opinion the studies that should be invalid are the ones provided by the chemical manufacturers as they can be seen as a conflict of interest over the peer-reviewed studies conducted by independent scientists and researchers that are published in reputable journals.

It is good to see a credible scientific body using these independent scientific studies over the non-peer reviewed ‘commercial in confidence’ studies provided by the manufacturers. Regulators such as the APVMA in Australia and the US EPA tend to only use the manufacturers studies rather than studies by independent researchers. The full data from these studies by the manufacturers are rarely available to the public as they are commercial in confidence.

It is time for regulators like APVMA to stop using these hidden non-peer reviewed studies and start using the numerous published studies in the open literature. Regulators need to use transparent systems, based on studies published in open journals as we have a right to know what data is being used to make the decisions on the safety of chemicals, rather than the current closed system that can be seen as collusion between regulators and manufacturers.

It is only recently that there has been testing for glyphosate. It is still not included in food pesticide residue testing. Glyphosate and its degradation product, aminomethylphosphonic acid (AMPA) have been detected in the air, surface water, soil and seawater. These studies show that glyphosate and AMPA persist in the soil and water, and the amounts detected are increasing over time with increasing agricultural use.

Because glyphosate is in air, water and food, humans are likely to be accumulating it in low doses over time. Glyphosate residues of up to 4.4 parts per million (ppm) have been detected in stems, leaves and beans of glyphosate-resistant soy, indicating uptake of the herbicide into plant tissue. Reports from Germany of glyphosate in the urine of dairy cows

rabbits and humans ranged from 10-35 ppm. According to the study “Chronically ill humans had significantly higher glyphosate residues in urine than healthy humans.” Furthermore, the cows were dissected and glyphosate residues in the tissues of the kidney, liver, lung, spleen, muscles and intestines were comparable to that found in the urine.

This means that the glyphosate is not being passed through the urine without affecting the organism and that meat and dairy are an additional source of dietary glyphosate for humans. Glyphosate has been found in human breast milk, to cross the placenta and to damage human placental cells raising massive concerns about its effects on the fetus and new-born children, one of the most vulnerable groups to minute levels of chemicals.

The classification of glyphosate with the second highest level of carcinogenicity by IARC means that its wide spread use in GMO crops, as a crop desiccant, in orchards, food production, in children’s playgrounds, sidewalks, roadsides and in home gardens needs to stop. It is time this highly dangerous chemical was banned.

– ANDRÉ LEU, President, IFOAM
International Federation of Organic Agriculture Movements
May 7, 2015



  • Carcinogenicity of tetrachlorvinphos, parathion, malathion, diazinon, and glyphosate, Lancet Oncology 2015 Published Online March 20, 2015 S1470-2045(15)70134-8
  • The Myths of Safe Pesticides, Acres USA.
  • Swanson N L, 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, 9(2), 2014.