Used by farmers and agricultural workers across the globe, glyphosate is the active ingredient in herbicides. It is one of the most common environmental pollutants, with glyphosate residues being found in personal care products, tap water, rainwater, sports fields, public parks, lawns, waterways, animal feed, and many of the conventional foods you eat every day. (25) The stance that glyphosate is harmless to humans has been long maintained, with claims even stating it is “safer than table salt”. (2)
What is glyphosate?
In recent news, several lawsuits over glyphosate’s link to various cancers have been lost by companies who have paid billions of dollars in settlements. (28) With the American Cancer Society adding glyphosate to their list of “Known and Probable Human Carcinogens” and the World Health Organization categorizing glyphosate as “probably carcinogenic to humans”, it’s important to encourage additional research into investigating the safety of glyphosate and its link to cancer in humans. (1)(26) Research has already revealed how this pesticide can negatively impact the gut microbiome in ways that may cause significant metabolic issues, creating the perfect environment for the development of chronic diseases. (18)
Foods with high glyphosate residue
Research has revealed some of the most common foods that contain glyphosate at high levels, including:
- Apples
- Canola
- Celery
- Cherries
- Corn
- Grapes
- Kale
- Pears
- Potatoes
- Processed foods (such as cereals, granola bars, snack bars, potato chips, and oatmeals)
- Soy
- Spinach
- Strawberries
- Sugar beets
- Tomatoes
- Wheat (6)(18)(23)
Why is your microbiome important?
Your gut microbiome helps with producing nutrients and proteins needed to make neurotransmitters and hormones; influences inflammatory responses, genetic regulation, immunity, and energy production; and plays a role in liver detoxification, anti-oxidant production, brain health, and behavior. (4)(10)(17)(18)(21)
Altering effects of glyphosate on the microbiome
Glyphosate’s mechanism of killing weeds and other problematic organisms is through the inhibition of a metabolic pathway that does not exist in humans but is found in plants, fungi, and bacteria. (3)(5) This pathway is called the shikimate pathway and it is present in the trillions of microorganisms that colonize your body and make up your microbiome. (19)
Similar to the effects of an antibiotic, (19) chronic glyphosate exposure affects the delicate balance of bacteria in the gut and can lead to microbiome alterations. Research has shown that glyphosate exposure may lead to notable imbalances and decreased microbiome diversity in mammals. (18)(19)(22) We now know decreased diversity is associated with many chronic health conditions. (27)
Altered gut microbiome health conditions
When the gut microbiome is affected, many health conditions are associated to this change. These conditions include:
- Depression
- Alzheimer’s disease
- Anxiety
- Autism
- Cancer
- Cardiovascular disease
- Diabetes
- Inflammatory bowel diseases
- Metabolic syndrome
- Nonalcoholic fatty liver disease
- Obesity
- Parkinson’s disease
- Weight gain (9)(14)(15)(19)(24)(27)
Microbiome alterations and metabolic issues
Glyphosate’s disruption of the gut microbiome causes a cascade of other metabolic issues down the line. This is because gut microbes aid the body in the production of dozens of nutrients and are involved in the synthesis of neurotransmitters/hormones such as serotonin, epinephrine, dopamine, and thyroid hormones. (3)(19)
Glyphosate may also impair the function of certain liver enzymes involved in disposing of substances through bile acids. These disruptions may affect the production and metabolism of various nutrients that depend on these pathways, including:
These nutrients, hormones, and neurotransmitters are needed for hundreds of metabolic processes that occur in the body and control everything from energy production to bone integrity. Chronic glyphosate exposure has the potential to contribute to vitamin/mineral deficiencies, mood disorders, thyroid issues, gastrointestinal disorders, hormone disturbances, (19) infertility, sleep disturbances, (18) and immune disorders. (12)
Microbiome alterations and fertility
One of the most notable downstream effects of the metabolic disruption glyphosate creates are the fertility issues. (11)(16)(18) Puberty has been occurring at much earlier ages than ever before, (7) and infertility, (11) PCOS and other hormone imbalances are on the rise. (8) New research suggests that glyphosate has an impact on erectile dysfunction and male fertility by decreasing sperm count. (11) Not only can glyphosate cause changes in estrogen production and fertility problems in both men and women, but higher exposures to glyphosate during pregnancy may increase the risk of low weight, premature babies. (11)(13)(16)(18)
The bottom line
Current evidence regarding the safety of glyphosate suggests that there may be long-term consequences to our health, ecosystems, and the environment. Eating organic food may be a more significant factor in maintaining health and avoiding chronic disease than has been previously recognized. (1)(18)(26)- American Cancer Society. (2019, August 14). Known and probable human carcinogens. Retrieved from https://www.cancer.org/cancer/cancer-causes/general-info/known-and-probable-human-carcinogens.html
- Attorney General of the State of New York. (n.d.). Assurance of discontinuance pursuant to executive law § 63(15). Retrieved from https://big.assets.huffingtonpost.com/fraud.pdf
- Boocock, M. R., & Coggins, J. R. (1983). Kinetics of 5-enolpyruvylshikimate-3-phosphate synthase inhibition by glyphosate. FEBS Letters, 154(1), 127–133.
- Cryan, J. F., & Dinan, T. G. (2012). Mind-altering microorganisms: The impact of the gut microbiota on brain and behaviour. Nature Reviews Neuroscience, 13(10), 701–712.
- de María, N., Becerril, J. M., García-Plazaola, J. I., Hernández, A., de Felipe, M. R., & Fernández-Pascual, M. (2006). New insights on glyphosate mode of action in nodular metabolism: Role of shikimate accumulation. Journal of Agricultural and Food Chemistry, 54(7), 2621–2628.
- Environmental Working Group. (n.d.). #DirtyDozen fruits and vegetables with the most pesticides – @EWG’s shopper’s guide to pesticides in produce. Retrieved from https://www.ewg.org/foodnews/dirty-dozen.php
- Farello, G., Altieri, C., Cutini, M., Pozzobon, G., & Verrotti, A. (2019). Review of the literature on current changes in the timing of pubertal development and the incomplete forms of early puberty. Frontiers in Pediatrics, 7, 147.
- Ganie, M., & Kalra, S. (2011). Polycystic ovary syndrome – A metabolic malady, the mother of all lifestyle disorders in women – Can Indian health budget tackle it in future? Indian Journal of Endocrinology and Metabolism, 15(4), 239–241.
- Halfvarson, J., Brislawn, C. J., Lamendella, R., Vázquez-Baeza, Y., Walters, W. A., Bramer, L. M., … Jansson, J. K. (2017). Dynamics of the human gut microbiome in inflammatory bowel disease. Nature Microbiology, 2, 17004.
- Jandhyala, S. M., Talukdar, R., Subramanyam, C., Vuyyuru, H., Sasikala, M., & Reddy, D. N. (2015). Role of the normal gut microbiota. World Journal of Gastroenterology, 21(29), 8787.
- Kaur, R. P., Gupta, V., Christopher, A. F., & Bansal, P. (2015). Potential pathways of pesticide action on erectile function – A contributory factor in male infertility. Asian Pacific Journal of Reproduction, 4(4), 322–330.
- Nakashima, K., Yoshimura, T., Mori, H., Kawaguchi, M., Adachi, S., Nakao, T., & Yamazaki, F. (2002). . Chudoku Kenkyu, 15(2), 159–165.
- Parvez, S., Gerona, R. R., Proctor, C., Friesen, M., Ashby, J. L., Reiter, J. L., … Winchester, P. D. (2018). Glyphosate exposure in pregnancy and shortened gestational length: a prospective Indiana birth cohort study. Environmental Health, 17(1), 23.
- Patterson, E., Ryan, P. M., Cryan, J. F., Dinan, T. G., Ross, R. P., Fitzgerald, G. F., & Stanton, C. (2016). Gut microbiota, obesity and diabetes. Postgraduate Medical Journal, 92(1087), 286–300.
- Razavi, A. C., Potts, K. S., Kelly, T. N., & Bazzano, L. A. (2019). Sex, gut microbiome, and cardiovascular disease risk. Biology of Sex Differences, 10(1), 29.
- Richard, S., Moslemi, S., Sipahutar, H., Benachour, N., & Seralini, G.-E. (2005). Differential effects of glyphosate and roundup on human placental cells and aromatase. Environmental Health Perspectives, 113(6), 716–720.
- Rooks, M. G., & Garrett, W. S. (2016). Gut microbiota, metabolites and host immunity. Nature Reviews Immunology, 16(6), 341–352.
- Samsel, A., & Seneff, S. (2013). Glyphosate’s suppression of cytochrome P450 enzymes and amino acid biosynthesis by the gut microbiome: Pathways to modern diseases. Entropy, 15(4), 1416–1463.
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