This study had a number of limitations that cast doubt on its conclusions, the most prominent being that it relied on participants’ dietary self-reports, which are notoriously subject to recall bias: people often report what they wish they had eaten rather than what they actually ate.
Moreover, the researchers did not collect information regarding how long before entry into the study that the women had been eating organic food or which organic foods they ate—produce, dairy products, or meat. In addition, the definitions of “organic” and of the frequency categories were left to the participants to decide for themselves.
Pesticide exposure is a known cancer risk, but the researchers didn’t take blood samples and cannot say whether the eaters of organic food had lower exposure to pesticides.
There’s More to Organic Than Cancer
Even if eating organic foods doesn’t prevent cancer, there are plenty of other benefits to doing so. Conventional agriculture uses millions of tons of synthetic fertilizer, and the runoff disrupts the ecology of waterways and coastal ocean areas.2
Conventional agriculture also uses high quantities of pesticides and herbicides, possibly harming the health of agricultural workers who are exposed to them.3
If you’re still not convinced, consider this: US Department of Agriculture regulations on organic foods prohibit using sewage sludge as fertilizer.4 In other words, it is okay to use it on conventional produce. Regardless of how you feel about that, you’ll certainly find me in the organics aisle at the grocery store.
- Bradbury KE, Balkwill A, Spencer EA, et al. Organic food consumption and the incidence of cancer in a large prospective study of women in the United Kingdom. Brit J Cancer. 2014;110(9):2321-2326.
- Biello D. Fertilizer runoff overwhelms streams and rivers—creating vast “dead zones.” Scientific American. May 14, 2008. http://www.scientificamerican.com/article/fertilizer-runoff-overwhelms-streams/. Accessed May 21, 2014.
- Mostafalou S, Abdollahi M. Pesticides and human chronic diseases: evidences, mechanisms, and perspectives. Toxicol Appl Pharm. 2013;268(2):157-177.
- United States Department of Agriculture. Organic production and handling standards. Updated October 2011. http://www.ams.usda.gov/AMSv1.0/getfile?dDocName=STELDEV3004445. Accessed May 21, 2014.