Glyphosate, a common herbicide, is often discussed in the context of food safety, health, and environmental impact. In this blog, we’ll discuss clear information about what this herbicide is and address popular concerns. Additionally, we’ll discuss its potential impact on functional health and offer research-backed guidance on how it may affect your diet and well-being.
What is Glyphosate?
Glyphosate is an herbicide widely used in agriculture to control weeds. It’s the active ingredient in products like Roundup. Farmers and gardeners use it to maintain weed-free crops, ensuring a more consistent food supply. This herbicide works by inhibiting an enzyme pathway found in plants but not in humans or animals, making it effective against unwanted plant growth.
Common Concerns About Glyphosate
Here are some of the main concerns people have about glyphosate, supported by research findings:
Cancer Risk
In 2015, the International Agency for Research on Cancer (IARC) classified glyphosate as “probably carcinogenic to humans” (Group 2A). This classification was based on limited evidence in humans and sufficient evidence in animals. However, subsequent reviews by regulatory agencies such as the U.S. Environmental Protection Agency (EPA) and the European Food Safety Authority (EFSA) have concluded that this herbicide is unlikely to pose a cancer risk to humans at levels typically found in food.(1-3)
Environmental Impact
Research indicates that glyphosate can have adverse effects on non-target plant species and aquatic organisms. Additionally, its extensive use has led to the emergence of glyphosate-resistant weeds, posing challenges for sustainable agriculture.(4)
Residue in Food
Glyphosate residues have been detected in various foods. However, studies by regulatory bodies have generally found that these residues are within safety limits and are unlikely to pose significant health risks.(5)
Functional Health Concerns Related to Glyphosate Ingestion
Research into glyphosate’s potential effects on functional health—how our body systems work together—is still evolving. Some areas of interest include:
Gut Health
A study suggested that glyphosate might affect the gut microbiota by inhibiting beneficial bacteria, potentially leading to dysbiosis and other health issues.(6) However, the study primarily relies on in vitro (test tube) and animal studies, which may not fully translate to human health outcomes. Further research is needed to understand the real-world impact on the human gut microbiome, especially in typical dietary exposure scenarios.
Nutrient Absorption
Some evidence suggests that glyphosate could chelate minerals, such as manganese, making them less available for absorption in the body. However, most of these studies have been conducted under conditions that may not accurately represent typical human exposure levels. Therefore, more research is needed to determine whether there is a significant impact on nutrient absorption in humans at the levels found in food.(7)
Endocrine Disruption
Some studies have explored whether glyphosate may act as an endocrine disruptor, potentially interfering with hormone function. The evidence is mixed, with some laboratory studies suggesting possible effects, while others do not find significant endocrine-disrupting properties. The current research often involves high doses not typically encountered through diet, making it unclear whether such effects would occur at normal exposure levels. Further research, particularly epidemiological studies and long-term assessments, is needed to clarify the potential impact on the human endocrine system.(8)
What Does the Latest Research Say About Glyphosate?
Here’s a summary of current research findings:
Human Health
The scientific community remains divided, with some studies indicating potential health risks associated with glyphosate, while others do not find significant associations. The complexity of assessing the herbicide’s impact lies in variables like exposure level, duration, and individual susceptibility.(9)
Regulation and Safety
Regulatory bodies like the EPA and EFSA continuously review new data to ensure glyphosate’s safe use. They set maximum food residue limits that are intended to protect public health, and current data generally support the safety of these limits.(2,3)
Foods of Greater Concern for Glyphosate Exposure
Certain foods are more likely to contain glyphosate residues due to the methods used in their production. The U.S. Food and Drug Administration (FDA) and the U.S. Department of Agriculture (USDA) monitor and report on glyphosate levels in foods.
Grains and Cereals
Grains like wheat, oats, and barley are often treated with glyphosate as a desiccant, a drying agent used before harvest. Unfortunately, this practice can lead to higher residues in finished products like bread, cereals, and pasta. A study conducted by the Environmental Working Group (EWG) found glyphosate residues in over 95% of oat-based foods tested, with levels ranging from 0.1 to over 2.5 parts per million (ppm). However, these levels are generally below the safety limits set by regulatory bodies.(10)
Soy and Corn
These crops are frequently genetically modified to be glyphosate-resistant, allowing farmers to apply the herbicide without damaging the crops. As a result, the herbicide’s residues can be present in soy and corn products, including oils and processed foods. The FDA has found glyphosate residues in corn and soy products, but the levels typically remain below the EPA’s established safety thresholds.(5,11)
Legumes
Beans, lentils, and chickpeas may also contain glyphosate residues, especially when used as a desiccant. Testing has shown varying glyphosate levels in these foods, again generally within regulatory safety limits.(5)
Safe Levels and Regulatory Standards for Glyphosate Residues
The safety of glyphosate residues in food is determined by various regulatory bodies, which set maximum residue limits (MRLs) to protect public health. The EPA has established an acceptable daily intake (ADI), which is 1.75 milligrams per kilogram of body weight per day. The MRLs for glyphosate in various foods are set based on this ADI and other safety considerations.(2)
For example:
- Oats: The EPA’s MRL for glyphosate in oats is set at 30 ppm.(12)
- Corn: The MRL for corn is 5 ppm.(13)
- Soybeans: The MRL for soybeans is 20 ppm.(13)
These limits are established based on comprehensive risk assessments, including toxicity studies and dietary exposure assessments. The levels detected in foods are generally well below these MRLs, suggesting that typical dietary exposure is within safe limits.(5,11)
What Does This Mean for Your Diet?
Here’s how to approach concerns about glyphosate and functional health:
Food Safety
Regulatory limits for glyphosate residues are set to ensure safety. A varied diet rich in fruits, vegetables, and whole grains remains a cornerstone of good health. For those concerned about pesticide exposure, choosing organic foods is an option, as they are grown without synthetic pesticides.
Discussing Concerns with a Registered Dietitian
If you have specific concerns about glyphosate or its potential effects on your health, we can discuss these in detail. Understanding the science can help you make informed dietary choices that align with your health goals and values.
Environmental and Ethical Choices
Choosing organic or non-GMO foods can be part of a healthy diet and may align with your environmental and ethical beliefs.
Final Thoughts About Glyphosate and Human Health
Glyphosate is a complex and sometimes controversial topic, particularly regarding its potential effects on functional health. It’s essential to approach this issue with a clear understanding of the facts. Maintaining a balanced diet, being informed about the foods we eat, and making choices that support our health and values are key.
Research on this herbicide and other chemicals is ongoing. Staying informed about the latest findings helps us make educated decisions about our diet and health. As always, if you have concerns about your diet and health goals, reach out to our Registered Dietitians for personalized advice and assistance.
References:
- International Agency for Research on Cancer. Glyphosate. 2015. Available at: https://monographs.iarc.fr/wp-content/uploads/2018/06/mono112-10.pdf
- U.S. Environmental Protection Agency. EPA Reaffirms Safe Use of Glyphosate. 2020. Available at: https://www.epa.gov/ingredients-used-pesticide-products/glyphosate
- European Food Safety Authority. Conclusion on the peer review of the pesticide risk assessment of the active substance glyphosate. EFSA Journal. 2015;13(11):4302. doi:10.2903/j.efsa.2015.4302
- Duke SO, Powles SB. Glyphosate: a once-in-a-century herbicide. Pest Management Science. 2008;64(4):319-325. doi:10.1002/ps.1518
- U.S. Food and Drug Administration. Pesticide Residue Monitoring Program. 2016. Available at: https://www.fda.gov/food/pesticides/pesticide-residue-monitoring-program
- Mesnage R, Antoniou MN. Facts and Fallacies in the Debate on Glyphosate Toxicity. Frontiers in Public Health. 2017;5:316. doi:10.3389/fpubh.2017.00316
- Samsel A, Seneff S. Glyphosate, pathways to modern diseases II: Celiac sprue and gluten intolerance. Interdisciplinary Toxicology. 2013;6(4):159-184. doi:10.2478/intox-2013-0026
- Thongprakaisang S, Thiantanawat A, Rangkadilok N, Suriyo T, Satayavivad J. Glyphosate induces human breast cancer cells growth via estrogen receptors. Food and Chemical Toxicology. 2013;59:129-136. doi:10.1016/j.fct.2013.05.057
- Mink PJ, Mandel JS, Sceurman BK, Lundin JI. Epidemiologic studies of glyphosate and cancer: A review. Regulatory Toxicology and Pharmacology. 2012;63(3):440-452. doi:10.1016/j.yrtph.2012.04.007
- Environmental Working Group. Breakfast With a Dose of Roundup? 2018. Available at: https://www.ewg.org/childrenshealth/glyphosateincereal/
- Benbrook CM. Trends in glyphosate herbicide use in the United States and globally. Environ Sci Eur. 2016;28(1):3. doi:10.1186/s12302-016-0070-0
- U.S. Environmental Protection Agency. Glyphosate tolerances in oats. Available at: https://www.ecfr.gov/current/title-40/chapter-I/subchapter-E/part-180/subpart-C/section-180.364. U.S. Environmental Protection Agency. Glyphosate; Pesticide Tolerances. Available at: https://www.federalregister.gov/documents/2019/04/10/2019-07026/glyphosate-pesticide-tolerances
