Associations between preservative food additives and type 2 diabetes incidence in the NutriNet-Santé prospective cohort

Experimental studies suggested potential adverse effects of preservative food additives, but epidemiological data are lacking. We aim to investigate associations between exposure to these compounds and type 2 diabetes incidence in the NutriNet-Santé prospective cohort (n = 108,723; 79.2%women; mean age=42.5 (SD = 14.6); France, 2009-2023). Dietary intakes are assessed using repeated 24h-dietary records. Exposure is evaluated through multiple composition databases and ad-hoc laboratory assays in food matrices. Associations between cumulative exposures to preservatives and diabetes incidence are characterised using multi-adjusted Cox models. The sum of total preservatives encompasses 58 substances. Among those, 17 are consumed by at least 10% of the study population and thus individually investigated. Thirteen (12 after multiple test correction) widely used individual preservatives are associated with higher diabetes incidence (n=1131cases): potassium sorbate, potassium metabisulfite, sodium nitrite, acetic, citric and phosphoric acids, sodium acetates, calcium propionate, sodium ascorbate, alpha-tocopherol, sodium erythorbate, and rosemary extracts. These findings call for their safety re-evaluation and support recommendations to favour fresh and minimally processed foods without superfluous additives. Trial registration: The NutriNet-Santé cohort is registered at clinicaltrials.gov (NCT03335644).