Does organic eating really reduce the risk of cancer by 25%?

A French study of more than 60,000 people shows that regular consumption of organic foods reduces the risk of cancer by 25%. The risk reduction would concern postmenopausal breast cancer and lymphoma (lymphatic system cancers). Interesting results but which do not constitute irrefutable proof ...

Summary

1. Pesticides again pointed the finger ...
2. Promote organic food to prevent cancer?
3. An additional argument in favor of organic, but not irrefutable proof

This large-scale study is the first to assess the link between regular consumption of organically produced foods and the risk of cancer. It was conducted on 68,946 people in France. The participants were followed from May 2009 to November 2016. They were invited to indicate via a questionnaire the frequency of their consumption of organic products (never, occasionally, often). The questionnaire covered 16 foods.

Pesticides again pointed the finger ...

The analysis of the responses shows that the risk of cancer is reduced by 25% among large consumers of organically labeled foods. "Our work has identified a lower risk associated with high consumption of organic foods, for postmenopausal breast cancer, non-Hodgkin's lymphoma (NHL) and other lymphomas." This link has not been demonstrated. for other cancers, "says the authors of the study.

During the study, 1340 cancers appeared in the participants: 459 breast cancers, 180 prostate cancers, 135 skin cancers, 99 colorectal cancers, 47 non-Hodgkin's lymphomas, and 15 lymphomas.

Unsurprisingly, the ban on synthetic pesticides in organically labeled foods would explain this reduction in cancer risk. "Organic farming allows for less or no contamination of food by pesticides compared to conventional agricultural foods, but a 2015 study by the International Agency for Research on Cancer recognized the carcinogenic nature of some pesticides, "says the study. The authors of the study pointed out that diet is the main source of pesticide exposure in humans.

Promote organic food to prevent cancer?

Another French study published in early October established a link between domestic exposure of pesticides and increased risk of cancer in children (especially leukemias and brain cancers). Anti-mosquito products and pet treatments (against fleas and ticks) would be involved.

"This study, the results of which need to be confirmed by other studies, shows that the promotion of organically labeled foods to the general public could be a promising strategy for preventing cancer," suggests the researchers.

An additional argument in favor of organic, but not irrefutable proof

Although this is the first study to be carried out on a large cohort, these results must nevertheless be qualified. Some reservations in the study were advanced by the authors and highlighted in a commentary published in the same medical journal. Critics include:

• All non-consumers of organic products were statistically treated in the same way by the study, be it financial problems, difficult availability or lack of interest. This does not reduce the biases associated with different "health behaviors" between consumers of organic products and others. In this study, the comparison of the largest consumers of organic and the others reveals many differences: smokers/nonsmokers, high BMI / normal BMI, age, consumption of meat, fibers, hormonal treatment, levels of education, socio-economic ... Statistical corrections are however supposed to compensate for these differences;
• The authors hypothesize that the frequency of consumption of organic products is directly related to exposure to pesticides. This seems logical and confirmed by some studies (which linked this consumption to biomarkers characteristic of pesticides found in urine) ... but not by others;
• The participants in the study were volunteers who were particularly concerned about their health, mostly women (78%). A sample not necessarily representative of a general population;
• The exact quantities of organic products consumed were not reported by the participants;
• The follow-up period was short (7 years), failing to observe the long-term effects of a predominantly organic diet or a diet from conventional agriculture.

Admittedly, this study constitutes an additional argument in favor of a consumption of organic products but it does not allow, either, to close the debate ...

Other good habits can reduce the risk of cancer: quitting, eating well, reducing alcohol use, and regular physical activity.