2013 Glyphosate Breast Cancer Study
A study published in the June 2013 edition of Food and Chemical Toxicology found that glyphosate drives breast cancer proliferation. Researchers in Thailand compared glyphosate’s effect on both hormone-dependent and hormone-independent breast cancer cell lines, finding that the herbicide stimulates hormone-dependent cancer cell lines in “low and environmentally relevant concentrations.
Specifically, the glyphosate breast cancer study found that glyphosate can drive estrogen receptor mediated breast cancer cell proliferation in the parts per trillion concentration range. Put simply, infinitesimal concentrations of glyphosate had a carcinogenic effect on the studied breast cancer cell lines (T47D).
Another disturbing finding in the glyphosate breast cancer study was that genistein, a naturally occurring phytoestrogen in soybeans, exhibited “an additive estrogenic effect” when combined with glyphosate. The finding raises more questions about whether genetically-modified soybeans are adding to the breast cancer epidemic in the U.S., where GMO soybeans are heavily consumed.
Glyphosate Induces Human Breast Cancer Cells Growth Via Estrogen Receptors
Siriporn Thongprakaisang 1, Apinya Thiantanawat 2,3, Nuchanart Rangkadilok 1,3,
Tawit Suriyo 3, Jutamaad Satayavivad 1,3,4
1 Environmental Toxicology Program, Chulabhorn Graduate Institute, Kamphaengphet 6 Road, Laksi, Bangkok 10210, Thailand
2 Applied Biological Sciences Program, Chulabhorn Graduate Institute, Kamphaengphet 6 Road, Laksi, Bangkok 10210, Thailand
3 Laboratory of Pharmacology, Chulabhorn Research Institute, Kamphaengphet 6 Road, Laksi, Bangkok 10210, Thailand
4 Center of Excellence on Environmental Health and Toxicology, Office of the Higher Education Commission, Ministry of Education, Bangkok 10400, Thailand
Food Chem Toxicol. 2013 Jun 8. Epub 2013 Jun 8. PMID: 23756170
2013 Paper on Glyphosate Cancer Causation
In a 2013 paper published in the journal Entropy, two scientists familiar with glyphosate’s effects on a wide range of biological processes in plants and animals review the pathways by which glyphosate exposure may contribute to disease in humans, including breast cancer and multiple myeloma. (In multiple myeloma the body continually produces abnormal plasma cells, a type of white blood cell. These cancerous cells accumulate in the bones and damage them.) Authors Anthony Samsel and Stephanie Seneff focus on two main areas in which glyphosate could have negative effects in the human body:
- Disruption of an important enzyme (Cytochrome P450, or CYP) that plays a critical role in the body’s ability to get rid of unwanted chemicals and environmental toxins.
- Adverse effects on key bacteria in the digestive tract that are also involved in detoxification and immune system function.
It has been claimed that glyphosate is not toxic to humans, since it harms plants by disrupting a biological process that does not exist in humans. (The process, known as the “shikimate pathway,” is the means by which plants, bacteria, fungi and algae, manufacture certain amino acids, the building blocks of protein.) But that process does exist in the trillions of bacteria in the gastrointestinal tract, or “gut,” and those bacteria play a central role in human health. Doctors tell us that it is important to have a balance of different gut bacteria. When that diversity is upset, inflammation and disease appear to follow.
Citing evidence from animal studies, Samsel and Seneff argue that glyphosate disrupts intestinal tract bacteria creates an imbalance of toxin-producing bacteria in the gut. This leads to chronic inflammation and obesity, both of which are known to be risk factors for many diseases, including several types of cancer.
The authors also discuss glyphosate’s effect on CYP enzymes in the liver. Several different CYP enzymes are essential for one of the liver’s main jobs – ridding the body of toxins. Studies from animals, plants, and human cells demonstrate that glyphosate inhibits the activity of CYP enzymes. This inhibition, Samsel and Seneff believe, results in a disruption of the body’s ability to remove toxins.Two other CYP-dependent processes that take place in the liver – the synthesis of cholesterol and vitamin D3 – may also be affected.
Samsel and Seneff also make an observation that is supported by other researchers: Roundup herbicide is much more toxic than glyphosate alone. Roundup contains additional chemicals (called adjuvants) that assist glyphosate in doing its job. For example, surfactants in Roundup help glyphosate spread across and penetrate the leaf surface. Though glyphosate is said to be the only “active” ingredient in Roundup, scientists have found that surfactants and other adjuvants in Roundup contribute greatly to its toxic effects.
This paper provides a wealth of evidence tying glyphosate’s toxic effects to many common health problems, including diabetes, heart disease, autism, and Alzheimer’s.
Glyphosate’s Suppression of Cytochrome P450 Enzymes and Amino Acid Biosynthesis by the Gut Microbiome: Pathways to Modern Diseases
Anthony Samsel, Independent Scientist and Consultant and Stephanie Seneff, Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA.
Funded in part by Quanta Computers, Taipei Taiwan, under the auspices of the Qmulus Project
2014 Meta Analysis Roundup Cancer Study
In this 2014 Roundup cancer study, two researchers published the results of their analysis of nearly thirty years of epidemiological research into the link between non-Hodgkin lymphoma (NHL) and exposure to agricultural pesticides on farms and in related occupational settings. They used a statistical procedure known as meta-analysis, in which researchers combine data from several different studies. The increased pool of data and the large number of cases allows scientists to detect significant effects that might not show up in smaller studies.
Forty four papers were included in the meta-analysis. Of these, 20 papers gave estimates of associations with herbicides or active ingredients in herbicides, including glyphosate. The scientists found that several different types of herbicides were associated with non-Hodgkin lymphoma. They included:
- Phenoxy herbicides (2,4D, MCPA)
- Aromatic acid herbicides (dicamba)
- Organophosphorus herbicides (glyphosate)
Ortho® Weed B Gon® weed killer contains three of these chemicals—2,4D, MCPA and dicamba. Spectracide Weed Stop contains 2,4D and dicamba. Glyphosate, of course, is the active ingredient in Roundup.
Schinasi and Leon found significant associations between glyphosate and non-Hodgkin lymphoma and an even stronger association between glyphosate and a common subtype of NHL, B cell lymphoma. (Glyphosate exposure doubled the risk of non-Hodgkin lymphoma.)
“B cell lymphoma was positively associated with … the organophosphorus herbicide glyphosate.”
The authors point out that different subtypes of non-Hodgkin lymphoma may be more likely to be caused by pesticide exposure (including insecticides and herbicides) than others, but relatively few studies examine associations at the subtype level. They believe more studies are needed to determine which subtypes of NHL are most strongly associated with exposure to pesticides.
Non-Hodgkin Lymphoma and Occupational Exposure to Agricultural Pesticide Chemical Groups and Active Ingredients: A Systematic Review and Meta-Analysis
Leah Schinasi and Maria E. Leon, Section of Environment and Radiation, International Agency for Research
International Journal of Environmental Research and Public Health, 23 April 2014; 11(4): 4449-4527.
Grant from the Office National de l’Eau et des Milieux Aquatiques—ONEMA, France.
2015 IARC Roundup Cancer Study
In 2015, the International Agency for Research on Cancer (IARC) published the results of a year-long investigation into the link between several different insecticides and herbicides, including glyphosate and cancer. The group concluded that glyphosate is “probably carcinogenic to humans.”
For a more detailed review of the IARC monograph on glyphosate, as well as the Roundup cancer study summary and links to the monograph itself, please refer to the IARC glyphosate study page.