22 April 2014 – A study published in the Journal of Environmental & Analytical Toxicology tested glyphosate residues in urine and different organs of dairy cows as well as in urine of hares, rabbits and humans using ELISA and Gas Chromatography-Mass Spectroscopy (GC-MS). The use of this global herbicide – toxicant, in agriculture is increasing, over 650,000 tones were spent in 2011 worldwide.
Dairy cows – Glyphosate excretion in German dairy cows was significantly lower than Danish cows, and represents a different intake from feed. Cows kept in genetically modified free area had significantly lower glyphosate concentrations in urine than conventionally fed cows. Organic production prohibits the use of GM crops and particularly GM soy in dairy cows feed, and therefore reduces the presence of glyphosate. But unfortunately, organic producers do not live isolated from the rest of the world and the very low levels of glyphosate found in these samples are attributed to pervasive glyphosate pollution through air and rain.
Glyphosate was detected in various organs of slaughtered cows: intestine, liver, muscles, spleen and kidneys, which is old news to the scientific community (the bioaccumulation of glyphosate is known since 1985). Dairy cows absorb about 35-40% of glyphosate from feed, part of which is permanently stored in bones as glyphosate is known chelator of calcium, macro and micro-elements.
Hares and rabbits – Hares showed significantly lower glyphosate residues in urine than fattening rabbit which are widely fed GM soy.
Humans – Results of an independent study conducted in 2013 showed that traces of glyphosate and its degradation product AMPA were present in peoples of all 18 countries participating in the study.
An earlier study carried out in December 2011 tested the urine of Berlin’s urban population to find glyphosate. The people tested were city workers, journalists, lawyers, all of them did not come into direct contact with glyphosate and do not work in agriculture whatsoever. The study has shown presence of glyphosate in all urine samples in the range of 0,5 to 2 ng / ml of urine – while the upper limit in drinking water is 0,1 ng / ml!
The present study shows that glyphosate was significantly higher in urine of humans who consumed conventionally produced food compared with consumers of organic food. The mean value of glyphosate in people who consumed organic foods was about 1 ppb. Earlier studies that followed farmers and their families, those who are most exposed, showed a mean value of 3 ppb with a maximum of 233 ppb glyphosate in the urine. Values increased when farmers did not use protecting gloves while working with the herbicide.
Furthermore, all the persons in the current study were grouped into healthy and chronically ill. The results have shown that chronically ill persons showed significantly higher glyphosate residues in urine than healthy population.
Glyphosate is a herbicide for many food and non-food crops as well as non-crop areas where total vegetation control is desired. The three predominating uses of glyphosate, in descending order, are: stubble management, pre-sowing application and pre-harvest application (desiccation). Glyphosate is also used to prevent weeds in fields with GM crops such as soybeans, rapeseed, corn, and others. Since 1996 the amount of GM crops has grown rapidly throughout the world, and it is estimated that 90% of transgenic crops today are resistant to glyphosate.
Glyphosate is sprayed on the same crop 2-3 times a year to remove weeds and desiccation before sowing cereals (corn, wheat). Every part of GM modified plants such as soybeans, and conventional plants will absorb glyphosate: leaves, stems, fruit, seeds. Glyphosate can not be removed by washing and it is not destroyed by cooking. The processed, frozen and dried food retains glyphosate for more than a year. Glyphosate as environment pollutant was detected in water, rainwater and air in large US agricultural areas (states of Mississippi and Iowa).
The European Union has approved genetically engineered soybeans for food and animal feed in 1996, and the agricultural use of glyphosate in 2002. Animals and man consume glyphosate directly and indirectly through soy fed animal products (meat, milk, dairy), and the herbicide is constantly entering our bodies. Right now food producers are not obligated to control glyphosate residues in tissues and organs of animals that are fed GM soy and corn. They are not obligated to monitor residues on agricultural products where glyphosate was sprayed, and therefore the actual quantity ingested by people through diet is not quanified – but it is a fact.
Glyphosate mode of action
Glyphosate in plants inhibits the enzyme 5-enolpyruvyl shikimate 3-phosphate synthase. This enzyme governs the synthesis of aromatic amino acids in higher plants, algae, bacteria and fungi. Since animals do not have the shikimate pathway, the current biotechnology dogma states that glyphosate is not toxic to animals and humans.
Therefore, it is not surprising that up until now, there has not been any long-term testing of small dose glyphosate intake in vertebrates. Although vertebrates do not have shikimate synthase enzyme, it does not mean that glyphosate does not act on their cellular enzymes. It is observed that glyphosate:
-inhibits Cyp450 aromatase which is crucial for sex steroid hormone synthesis,
-interferes with cytochrome P450 enzymes which include numerous proteins able to metabolize xenobiotics,
-disrupts the biosynthesis of aromatic amino acids by gut bacteria – destructs the beneficial gut microflora,
-impairs sulfate transport in serum,
-shows genotoxic, citotoxic (in vitro) and teratogenic effects.
More scientists have suggested that gastrointestinal disorders, obesity, diabetes, heart disease, depression, autism, infertility, cancer and Alzheimer’s disease are associated with Western diet and food production. Glyphosate may have contributed to the Parkinsonism due to its chemical similarity with glycine, a co-factor required for activation of the N-methyl-d-aspartase (NMDA) receptor, which controls excitatory actions in the central nervous system and is also involved in memory and learning.
Glyphosate is a new environmental neurotoxin (along with lead, ethanol, glutamate, botulinum and others). This neurotoxin in mammals causes the reduction of mitochondria membrane potential and aids the formation of oxidative stress in the brain and liver.
Recent studies have pointed out the danger of glyphosate to human and animal health. Residues in foods and humans are well documented now, but are still neglected in comparison to the huge amount of herbicide used. There is more and more glyphosate that reaches animals and man through food, part of it is retained permanently, part is excreted in the urine.
Presence of tiny glyphosate concentration in urine and its accumulation in animal tissues is very alarming for todays and future generations. Glyphosate did not exsist 40 years ago (it was synthetised in 1974), and some scientists are describing glyphosate as “worse than DDT“.
Kruger M. et all: Detection of Glyphosate Residues in Animals and Humans, Journal of Environmental & Analitical Toxicology, 2014, 4:2, January 31, 2014.
Brändli D, Reinacher S: Herbicides found in Human Urine, Ithaka Journal 1/2012: 270–272 (2012), ithaka-journal.net