Doctor: Eloi Chazelas
Title: Chronic exposure to food additives and risk of cancer
Supervisor: Mathilde Touvier
Doctoral school: ED 146 Doctoral school Galilée, University Sorbonne Paris Nord
Date of thesis defense: 12/2021
Jury: Fabrice Pierre, Serge Hercberg
This thesis is divided into three parts. In a first descriptive part, we estimated the exposure to food additives in the general population and in particular to mixtures of additives. We first studied the distribution of food additives in a large-scale database of food and beverage products available on the French market (Open Food Facts) and identified mixtures frequently present. Then, we estimated the average daily consumption of a wide range of additives among French adults from the NutriNet-Santé cohort, identified the main additive mixtures and associated socio-demographic and behavioral profiles.In a second part, we studied the associations between sweetened beverage consumption and the risk of cancer and cardiovascular diseases. We observed a positive association between sugary sweetened beverage consumption and overall and breast cancer risk. Artificially sweetened beverages were not associated with cancer risk in this study, but the statistical power was probably limited due to the relatively low consumption of this type of beverage in this population. In a second study, we showed that the highest consumers of sugary sweetened beverages but also artificially sweetened beverages had a higher risk of cardiovascular disease. Finally, we observed a positive association between the consumption of sweeteners, in particular acesulfame K and aspartame, and the risk of cancer (all sites, breast cancer and obesity-related cancers).In the last part, we examined the relationship between nitrite and nitrate intakes and cancer risk, distinguishing between natural food sources (food and drinking water) and food additive sources in the NutriNet-Santé cohort. No association was detected for total nitrite and nitrate intakes, nor for intakes from natural sources. In contrast, we found an association between nitrate intakes from food additives and breast cancer risk, particularly for potassium nitrate. We also observed an association between the consumption of nitrite food additives (more particularly sodium nitrite) and the risk of prostate cancer.This thesis work paves the way for a large research program that will provide unique data on the different facets of food processing in relation to long-term health. It will address the lack of human data on the subject and thus feed into the expertise of national and international health agencies, helping to guide EU policy-making (regulation, labelling), all with the aim of promoting the nutritional prevention of chronic diseases.