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

The subject has recently made headlines in the press. "Eating organic really reduces the risk of cancer by 25%," according to Provence. " Eating organic reduces the risk of cancer by 25%, according to BFM. Other media have been more cautious. "Organic food significantly reduces the risk of cancer," for the world. "An" badociation "between organic foods and reduced risk for two cancers", according to Le Figaro.

All these articles speak about the results of the French study «Association between the frequency of consumption of organic products and the risk ofcer " published on October 22 in the journal Jama Internal Medicine. The researchers followed 68,946 people (78% women, mean age 44 years) from 2009 to 2016 via the NutriNet-Santé nutrition study. The participants were divided into four groups according to the frequency with which they consume organic products. The researchers then badyzed the distribution of the 1,340 cases of cancer in the four groups, with Q1 for those eating little bio and Q4 for those who eat the most. The disparity of the groups has been neutralized. The Q1 group contains fewer women, more smokers and more meat than the Q4 group. Result: INRA speaks well of a "25% reduction in cancer risk (all types) observed among" regular "consumers of organic foods compared to more" casual "consumers". This 25% represents the difference between the number of cancer cases observed between the two groups. In other words, there are 2.1% of patients in Q1 and 1.5% of patients in Q4. Which leads to a difference of 0.6 point between the two groups. While this 25% may seem important, it nevertheless relates to a very small number of cancers compared to the entire panel.

According to the study, the results are even more marked "For bad cancer in postmenopausal women (-34%) and lymphomas (-76%)". These data are important because another study of British women found no link between organic food and cancer, except "Maybe for non-Hodgkin's lymphoma". Lymphomas are among the pathologies badociated with occupational exposure to pesticides, according to Inserm.

If this study is an observation and does not imply a causality, the authors emit two hypotheses to explain this relationship between organic food and lower cancer risk: "The presence of synthetic pesticide residues is much more common and at higher doses in foods from conventional agriculture, compared to organic foods. Another possible explanation is that potentially higher levels of some micronutrients (carotenoid antioxidants, polyphenols, vitamin C or more beneficial fatty acid profiles) in organic foods. " However, other studies must confirm, refute or refine these results. Indeed, when one goes down from a level of badysis, the data of the present survey prove not significant for the men for example.

Olivier Monod