His work examines the link between organic food consumption and the risk of cancer. Has this link been studied yet?
Regarding the direct link between cancer and consumption of organic products, there was only one study of an English team, conducted in 2014 with 600,000 women over a period of 9 years, thus of great statistical power. This study found no significant association between the consumption of organic foods and the risk of cancer, all types combined. However, she observed a decrease in the risk of non-Hodgkin's lymphoma in women reporting more frequent use of organic foods.
What about your study?
Our analysis involved a sample of about 70,000 people (78% women, mean age 44 years) of the French NutriNet-Santé cohort over a period of about 4.5 years. We use a measure of consumption of organic products finer than the English study, although it is not quantitative. Participants reported on the study via
a frequency of use questionnaire ("never", "occasionally", "most of the time") for 16 food groups (fruits, vegetables, soy products, etc.). We then divide the population into four equal size groups according to the consumption of organic products.
One of the difficulties of such a study is that those who eat organic products also have, on average, healthier behaviors, a more balanced diet and less smoke than others. In our analyzes, we take into account these so-called confounding factors, which tend to confuse the results. To do this, we use specific statistical models that minimize all of these biases through various adjustments. Thus, we compare the risks of cancer occurring among small consumers of organic and fat, all being the same.
And what are the results?
We found that individuals who report consuming organic foods more often have a 25% lower risk of developing cancer than non-consumers or episodic organic consumers. This association is particularly strong for postmenopausal breast cancer, with a 34% risk reduction and non-Hodgkin's lymphoma, with a 75% reduction.
What can we conclude?
We considered several hypotheses to explain these results. The main one is that organic products have far fewer synthetic pesticide residues than their counterparts in conventional agriculture. But although several clues support this path, our study does not demonstrate this link. It is important to emphasize that this is observational and that, despite these first important results, we must be cautious about their interpretations and their implications. We do not demonstrate a causal link, but we only find an association between the consumption of organic foods and a reduced risk of cancer.
In addition, there are only two studies on the subject, counting ours, which is very little. Other epidemiological work in other populations is necessary. It is based on the convergence of the results of observational studies along with experimental approaches that it will be possible to aim for causation and make recommendations.