It’s Organic September, and this month we’re raising awareness of organic food and giving you tips on how to buy organic food on a budget. You might wonder: “What role do organic foods play in breast cancer?” “Is there scientific evidence that shows whether an organic diet can lower your risk of breast cancer?”
In short, the answer is we don’t know (yet). There are not enough studies on breast cancer and eating organic food, and the few existing studies are purely observational. So, we can’t conclude whether an organic diet reduces the risk of breast cancer.
Why do we still advise women and men to buy organic produce as often as possible? Because organic food contains less pesticide residue, we have good reason to be concerned that pesticides could increase breast cancer risk.
What are pesticides?
Pesticides are substances that are used to control pests such as insects (insecticides), rodents (rodenticides), fungi (fungicides), and weeds (herbicides)). Many are toxic and potentially harmful to animals, plants, and humans.
What effect do pesticides have on our health?
When you come into direct contact with pesticides, they can affect your lungs, eyes, and skin and cause nausea. In high concentrations, they may even cause death. They can also have chronic, long-term effects, such as neurological or reproductive damage.
Some pesticides have the potential to disrupt our hormone systems. These types of chemicals are known as endocrine disrupting chemicals (EDCs). They can play a role in the development of cancers, such as non-Hodgkin lymphoma, colorectal and breast cancers.
We get exposed to a cocktail of pesticides primarily through the food we eat and the water we drink. Pesticide residues are often found in or on food after pesticides are used on food crops; these may be particularly harmful to our health. Many can build up in our bodies and are routinely found in fat tissue, blood and urine.
Why are we concerned about the potential link between pesticides and breast cancer?
Pesticides may increase breast cancer risk by acting as carcinogens (cancer-causing agents), causing gene mutations that lead to or promote cancer. They may also act as EDCs and disrupt sex hormones, including oestrogen.
High levels of natural oestrogen increase breast cancer risk. Similarly, EDCs that affect oestrogen by mimicking its actions or effectively increasing its concentration in the body may also increase risk. Exposure to such pesticides whilst in the womb may affect breast development in an unborn child, which can make them more vulnerable to developing breast cancer as adults.
Most studies examining direct pesticide exposure with breast cancer incidence show an elevated risk.
Bottom line
Although there is currently insufficient evidence to show eating organic food reduces breast cancer risk, organic food contains less pesticide residue. We know that certain pesticides are linked to breast cancer risk, so we recommend eating organic food whenever possible.
What can you do to lower your exposure?
For more information on the links between pesticides and breast cancer, see our pesticide factsheets, and for tips on how to reduce your exposure, visit our prevention hub.
Now more than ever, we need your help. Together we can help lower people’s risk of developing breast cancer. If you’ve found the information on our website helpful, then please consider making a donation today. Thank you.
References
- World Health Organization. Pesticides. World Health Organization. https://www.who.int/topics/pesticides/en/ (Accessed 25 Feb 2022).
- Pesticide Action Network UK. Impacts of pesticides on our health. https://www.pan-uk.org/health-effects-of-pesticides/ (Accessed 24 Feb 2022).
- Mnif, W. et al. (2011). Effect of endocrine disruptor pesticides: a review. International journal of environmental research and public health, 8(6), 2265–2303. https://doi.org/10.3390/ijerph8062265
- Nicolopoulou-Stamati, P. et al. (2016). Chemical Pesticides and Human Health: The Urgent Need for a New Concept in Agriculture. Frontiers in public health 4: 148. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4947579/
- Genuis, S. J. et al. (2016). Human Elimination of Organochlorine Pesticides: Blood, Urine, and Sweat Study. BioMed research international, 2016, 1624643. https://doi.org/10.1155/2016/1624643
- Kaur, K. et al. (2018). Occupational Pesticide Exposure, Impaired DNA Repair, and Diseases. Indian Journal of Occupational and Environmental Medicine 22: 2: 74–81. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6176703/
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- Mesnage, R. et al. 2017. Evaluation of estrogen receptor alpha activation by glyphosate-based herbicide constituents. Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association 108: Pt A: 30–42. https://pubmed.ncbi.nlm.nih.gov/28711546/
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- Mekonen, S. et al. (2021). Exposure to organochlorine pesticides as a predictor to breast cancer: A case-control study among Ethiopian women. PloS one, 16(9), e0257704. https://doi.org/10.1371/journal.pone.0257704
- Yang, K. J. et al. (2020). Organophosphate Pesticide Exposure and Breast Cancer Risk: A Rapid Review of Human, Animal, and Cell-Based Studies. International journal of environmental research and public health, 17(14), 5030. https://doi.org/10.3390/ijerph17145030
- Band, P. R. et al. (2000). Identification of occupational cancer risks in British Columbia. A population-based case-control study of 995 incident breast cancer cases by menopausal status, controlling for confounding factors. Journal of Occupational and Environmental Medicine 42: 3: 284–310. https://pubmed.ncbi.nlm.nih.gov/10738708
- Park, Y. M. et al. (2019). Association Between Organic Food Consumption and Breast Cancer Risk: Findings from the Sister Study (P18-038-19). Current Developments in Nutrition 3: Supplement_1. https://academic.oup.com/cdn/article/3/Supplement_1/nzz039.P18-038-19/5517295
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