Research Update: Organic Food Consumption and Cancer Risk

By Andrea Yoder

Last week a research paper entitled “Association of Frequency of Organic Food Consumption with CancerRisk:  Findings from the NutriNet-SantéProspective Cohort Study” was published in the Journal of the American Medical Association (JAMA).  This paper was written by a group of researchers in France.  The research presented in this article is part of a large-scale prospective web-based study that was launched in 2009 and is ongoing. The purpose of this large-scale study is to “study associations between nutrition and health, as well as the determinants of dietary behaviors and nutritional status.”  The volunteers in this study were recruited from the general French population and participate in the study by completing online self-administrated questionnaires.

The purpose of this portion of the study was to “prospectively examine the association between consumption frequency of organic foods….and cancer risk” in the participants.  This is the first research study of this type to be done prospectively.  The authors acknowledge that cancer rates worldwide continue to rise and are one of the leading causes of mortality in France.  Environmental exposure to toxic chemicals is considered by some to be a risk factor for cancer, however the focus of exposure in this context is most often related to occupational exposure.  However, there is a growing body of evidence linking cancer development to pesticide exposure and there is now some published research documenting pesticide residue levels in food as well as urinary markers of pesticides in humans.  What is not well documented is how the dose and/or effect of chemical cocktails impact cancer development in humans.  Thus, the purpose of this study was to observe the correlation between eating organic food and the development of cancers. 

If you are interested in reading this paper yourself and understanding more about the study design, population size and demographics, statistical evaluation, etc, the article is available in full text online.  For the purposes of this report, I’m going to jump to their conclusions.
 

Researchers found that participants with higher organic food scores (ie those who ate more organic food in their diet) were associated with overall heathier lifestyles with diets rich in nutrients.  They also found that those with high organic food scores had an overall lower risk of cancer.  With regards to specific types of cancer, they found that those with high organic food scores had a lower incidence of postmenopausal breast cancer, non-Hodgkin’s lymphoma, and all lymphomas.  No associations were observed with other cancer sites.  The researchers commented that “Epidemiological research investigating the link between organic food consumption and cancer risk is scarce, and, to the best of our knowledge, the present study is the first to evaluate frequency of organic food consumption associated with cancer risk using detailed information on exposure.”  They also comment that “While there is a growing body of evidence supporting a role of occupational exposure to pesticides for various health outcomes and specifically for cancer development, there have been few large-scale studies conducted in the general population, for whom diet is the main source of pesticide exposure.  It now seems important to evaluate chronic effects of low-dose pesticide residue exposure from the diet and potential cocktail effects at the general population level.  In particular, further research is required to identify which specific factors are responsible for potential protective effects of organic food consumption on cancer risk.”

Farmer Richard with some of our gorgeous, nutritious
radishes earlier this spring.

So what is the take-home message here?  It’s been eleven years since I worked as a clinical dietitian at a major medical university hospital on the east coast.  However, during my time as a clinician it was often a challenge to get the medical community I worked with to even acknowledge the major role even basic good nutrition plays in health both for disease prevention as well as healing and rehabilitation.  I recall little if any discussion of food quality, let alone discussion about the pros and cons of food produced in an organic system.  In that world, the sentiment always seemed to be that a calorie is a calorie and a carrot is a carrot.  No distinction was made between an organic carrot versus a conventional carrot.  So, for those who still question whether or not food produced without dangerous toxic chemicals has a positive impact on human health, I think it’s great that we are finally starting to discuss this topic and do the prospective research needed to fully evaluate this question from a scientific perspective.  I am also encouraged that this paper has been published in a major medical journal in this country.  I count this as progress and am hopeful that this research and these discussions will continue to move forward in a way that ultimately impacts our population in positive ways through greater knowledge and hopefully changes in dietary recommendations given by health professionals.

It’s obvious that Richard and I have a biased opinion about this topic as we have clearly chosen to produce food using organic methods.  We also seek out organic food for our own diets and believe that it is the best way to feed and nourish our bodies both by limiting exposure to potentially cancer-causing chemicals as well as providing our bodies with nutrients that help prevent cancer.  So, as always, we encourage everyone to make their own informed decisions about their food.  For this reason I hope we continue to see more research reports from well-designed studies to help us understand these issues surrounding the way our food is produced and the ultimate outcome for our health.