Glyphosate
Glyphosate is a widely used herbicide and pesticide. The EPA asserts that glyphosate is harmless to humans but research has shed light on a number of health concerns potentially linked to this chemical.
Quick Facts
Glyphosate is an herbicide, used to control the growth of grasses and weeds. It is the active ingredient in Monsanto’s RoundUp. [1] It was registered as a pesticide in the United States in 1974.
Glyphosate is non-selective meaning it will kill most plants. [2] It is used widely, especially with genetically modified (GMO) crops, which can be sprayed with glyphosate and still survive.
Glyphosate is found not only in conventionally grown food but in the air and water supply to some extent. [25-26]
A relatively new trend among farmers is to use glyphosate on crops as a desiccation or drying agent, right before harvest. [5] This creates uniform ripeness of the crop and allows harvesting to be conducted sooner. The downside of this pre-harvest application is that the glyphosate is absorbed directly into the crop and residues in food are higher.[4]
The EPA asserts that when used as instructed on the label, there are no health risks to humans. However, using glyphosate as a drying agent is an off-label use of the product.
Glyphosate Safety Concerns
Many glyphosate safety studies have been conducted over a short period of time and/or study the glyphosate chemical alone. Independent researchers state that negative effects take more time to manifest and that glyphosate is more dangerous when combined with other chemicals.
In 2015 the World Health Organization (WHO) classified glyphosate as a probable carcinogen. This means that there is limited evidence of glyphosate causing cancer in humans but sufficient evidence of cancer caused in animals.
Research has also demonstrated a host of other health conditions may potentially be linked to glyphosate, including kidney disease, diabetes, obesity, gastrointestinal issues, infertility, and birth defects. [8-15]
Glyphosate can disrupt the bacteria present in the human gastrointestinal tract. Generally, good bacteria are killed by glyphosate while pathogenic bacteria like Clostridia and Salmonella have resistance to it. [16,17]
Glyphosate use is banned or restricted in some countries in Europe, South America, and the Middle East. [3]
Foods containing Glyphosate
Glyphosate is sprayed on conventionally grown, non-organic crops and often found in the following:
Grains like wheat, barley, rice, oats, corn, and any foods made primarily with these ingredients
Nuts, beans, peas, and legumes like chickpeas, lentils, peanuts, walnuts, almonds, pecans, and pistachios
Sugar from sugar beets and high fructose corn syrup from corn
Meat and dairy products from conventionally raised animals that were fed GMO corn, soy, and alfalfa
Canola and sunflower oil
Fruits and vegetables including apples, oranges, potatoes, peaches, grapefruit, grapes, lemons, and plums [6]
The EWG calls these produce the “Dirty Dozen”
Glyphosate alternatives
The best way to avoid glyphosate is to purchase foods that are organic. By law, organic foods cannot be treated with glyphosate.
Prioritize purchasing organic for those foods that are most heavily sprayed with glyphosate, like grains, beans/legumes, and nuts.
Choose oils from plants that are not highly sprayed with glyphosates like olive oil, coconut oil, or avocado oil.
Utilize the Environmental Working Group (EWG) Shopper’s Guide to Pesticides in Produce. Each year they highlight the “Dirty Dozen”, or the top 12 produce items with the highest pesticide residues. EWG also shares the annual “Clean Fifteen”, showcasing the top 15 produce items with the least amount of pesticide residues. [7]
If you are looking for a glyphosate alternative for personal use, try Sunday!
Glyphosate & Autism in the Research
Glyphosate & Autism Risk
In children, glyphosate showed a “moderate level of evidence” in its association with ASD. [21]
Offspring's risk of ASD increases following prenatal exposure to ambient pesticides. Infant exposure could further increase risks for ASD with comorbid intellectual disability. [18, 19, 22]
Exposure to glyphosate showed fish with impaired exploratory and social behaviors consistent with increased anxiety. [20]
High glyphosate found in urine among triplets with autism; case study findings are consistent with the theory that clostridia bacteria proliferation and mitochondrial dysfunction are associated with glyphosate exposure. An organic diet reduces urine glyphosate residues by 94%. [23]
Certain hallmarks of autism can be explained by glyphosate including impaired sulfate synthesis and transport which is reduced in autism, reduced detoxification capacity, overgrowth of pathogenic gut bacteria, and deficiencies in important minerals and certain amino acids. [24]
Glyphosate & Digestive Health
This review demonstrates an association between glyphosate-resistant Clostridium bacteria colonization of the intestinal tract and ASD. [16-17]
The article proposes that glyphosate is the most important causal factor in the epidemic of celiac disease. [8]
Glyphosate residues on food could cause dysbiosis, given that opportunistic pathogens are more resistant to glyphosate compared to commensal bacteria. [11]
Glyphosate & Kidney Disease
Glyphosate's synergistic health effects in combination with exposure to other pollutants and physical labor could result in renal damage consistent with CKDu in Sri Lanka. [9-10]
Glyphosate & Fertility
While both glyphosate and Roundup exert a negative impact on male gametes, Roundup is more toxic than its main component, glyphosate. [12]
Glyphosate is toxic to male rodent's reproductive systems. [13]
Glyphosate exposure could interfere with mouse oocyte maturation by generating oxidative stress and early cell death. [15]
Glyphosate & Cancer
Evidence shows that glyphosate causes an assortment of cancers in both male and female mice and rats. [14]
References
[1] Glyphosate. EPA. https://www.epa.gov/ingredients-used-pesticide-products/glyphosate. Published March 13, 2021. Accessed May 8, 2021.
[2] Glyphosate. Orst.edu. Accessed May 8, 2021.
[3] Germany + 13 other countries say no to glyphosate: What about the US? Organicconsumers.org. Accessed May 8, 2021. https://www.organicconsumers.org/news/germany-13-other-countries-say-no-glyphosate-what-about-us
[4] The Cornucopia Institute. Glyphosate use as desiccant doubles human contamination. Cornucopia.org. Published October 31, 2017. Accessed May 8, 2021. https://www.cornucopia.org/2017/10/glyphosate-use-desiccant-doubles-human-contamination/
[5] Subedi M, Willenborg CJ, Vandenberg A. Influence of Harvest Aid Herbicides on Seed Germination, Seedling Vigor and Milling Quality Traits of Red Lentil (Lens culinaris L.). Front Plant Sci. 2017;8:311.
[6] GLYPHOSATE use EPA-HQ-OPP-2009-0361-0064.pdf. Google.com. Accessed May 8, 2021. https://drive.google.com/file/d/0B-pJR4cGo9ckb3k4UDczbVdiT1E/view
[7] Environmental Working Group. Check out @EWG’s 2021 Shopper’s Guide to Pesticides in ProduceTM! #DirtyDozen #CleanFifteen. Ewg.org. Accessed May 8, 2021. https://www.ewg.org/foodnews/summary.php
[8] Samsel A, Seneff S. Glyphosate, pathways to modern diseases II: Celiac sprue and gluten intolerance. Interdiscip Toxicol. 2013;6(4):159-84.
[9] Gunatilake S, Seneff S, Orlando L. Glyphosate's Synergistic Toxicity in Combination with Other Factors as a Cause of Chronic Kidney Disease of Unknown Origin. Int J Environ Res Public Health. 2019;16(15):E2734.
[10] Abdul KSM, De Silva PMCS, Ekanayake EMDV, et al. Occupational Paraquat and Glyphosate Exposure May Decline Renal Functions among Rural Farming Communities in Sri Lanka. Int J Environ Res Public Health. 2021;18(6):3278.
[11] Barnett JA, Gibson DL. Separating the Empirical Wheat From the Pseudoscientific Chaff: A Critical Review of the Literature Surrounding Glyphosate, Dysbiosis and Wheat-Sensitivity. Front Microbiol. 2020;11:556729.
[12] Nerozzi C, Recuero S, Galeati G, Bucci D, Spinaci M, Yeste M. Effects of Roundup and its main component, glyphosate, upon mammalian sperm function and survival. Sci Rep. 2020;10(1):11026.
[13] Cai W, Ji Y, Song X, et al. Effects of glyphosate exposure on sperm concentration in rodents: A systematic review and meta-analysis. Environ Toxicol Pharmacol. 2017;55:148-55.
[14] Portier CJ. A comprehensive analysis of the animal carcinogenicity data for glyphosate from chronic exposure rodent carcinogenicity studies. Environ Health. 2020;19(1):18.
[15] Zhang JW, Xu DQ, Feng XZ. The toxic effects and possible mechanisms of glyphosate on mouse oocytes. Chemosphere. 2019;237:124435.
[16] Argou-Cardozo I, Zeidán-Chuliá F. Clostridium Bacteria and Autism Spectrum Conditions: A Systematic Review and Hypothetical Contribution of Environmental Glyphosate Levels. Med Sci (Basel). 2018;6(2):E29.
[17] Rueda-Ruzafa L, Cruz F, Roman P, Cardona D. Gut microbiota and neurological effects of glyphosate. Neurotoxicology. 2019;75:1-8.
[18] von Ehrenstein OS, Ling C, Cui X, et al. Prenatal and infant exposure to ambient pesticides and autism spectrum disorder in children: population based case-control study. BMJ. 2019;364:l962.
[19] Pu Y, Yang J, Chang L, et al. Maternal glyphosate exposure causes autism-like behaviors in offspring through increased expression of soluble epoxide hydrolase. Proc Natl Acad Sci U S A. 2020;117(21):11753-9.
[20] Faria M, Bedrossiantz J, Ramírez JRR, et al. Glyphosate targets fish monoaminergic systems leading to oxidative stress and anxiety. Environ Int. 2021;146:106253.
[21]Ongono JS, Béranger R, Baghdadli A, Mortamais M. Pesticides used in Europe and autism spectrum disorder risk: can novel exposure hypotheses be formulated beyond organophosphates, organochlorines, pyrethroids and carbamates? - A systematic review. Environ Res. 2020;187:109646.
[22] de Souza JS, Laureano-Melo R, Herai RH, et al. Maternal glyphosate-based herbicide exposure alters antioxidant-related genes in the brain and serum metabolites of male rat offspring. Neurotoxicology. 2019;74:121-31.
[23]Shaw W. Elevated Urinary Glyphosate and Clostridia Metabolites With Altered Dopamine Metabolism in Triplets With Autistic Spectrum Disorder or Suspected Seizure Disorder: A Case Study. Integr Med (Encinitas). 2017;16(1):50-7.
[24] Samsel, A, Seneff, S. Glyphosate’s Suppression of Cytochrome P450 Enzymes and Amino Acid Biosynthesis by the Gut Microbiome: Pathways to Modern Diseases. Entropy. 2013; 15(4), 1416-1463.
[25] Tzanetou E, Karasali H. Glyphosate residues in soil and air: An integrated review. In: Kontogiannatos D, Kourti A, Mendes KF, eds. Pests - Classification, Management and Practical Approaches [Working Title]. IntechOpen; 2020.
[26] Environmental Working Group. EWG’s tap water database: Contaminants in your water. Ewg.org. Accessed May 12, 2021. https://www.ewg.org/tapwater/contaminant.php?contamcode=2034
Authors
Brittyn Coleman, MS, RDN/LD, CLT
