Higher intake of food preservatives, commonly used in industrially processed foods and drinks to prolong shelf life, has been associated with an increased risk of developing type 2 diabetes. This conclusion comes from a large-scale study conducted by researchers affiliated with several French research institutions, working within the Nutritional Epidemiology Research Team. Their findings draw on extensive health and dietary data collected from over 100,000 adults enrolled in the NutriNet-Santé cohort and were published in the journal Nature Communications.
Preservatives are part of the broader family of food additives and are now deeply embedded in the global food system. Their use has expanded alongside the growth of ultra-processed foods, which rely on additives to maintain freshness, texture, and safety during extended storage and transport. Data from the Open Food Facts World database indicate that, out of approximately three and a half million food and beverage products listed in 2024, more than 700,000 contained at least one preservative, underlining the scale of population exposure.
In their analysis, the researchers categorised preservative additives into two main groups. The first includes non-antioxidant preservatives, which prevent microbial growth or slow chemical reactions that cause spoilage. The second group consists of antioxidant additives, which delay deterioration by reducing or limiting oxygen exposure in food packaging. On ingredient labels, these substances are typically identified by European E-numbers, ranging from E200 to E299 for preservatives in the strict sense and from E300 to E399 for antioxidant additives.
Previous experimental research has raised concerns about the biological effects of some preservatives, suggesting they may damage cells or DNA and disrupt metabolic processes. However, until now, population-based evidence linking preservative exposure to type 2 diabetes has been limited. To address this gap, the research team examined long-term associations between dietary exposure to preservatives and the onset of type 2 diabetes within a large and well-characterised cohort.
Participants in the NutriNet-Santé study provided detailed information between 2009 and 2023, including medical history, socio-demographic background, lifestyle habits, and physical activity levels. They also regularly completed comprehensive 24-hour dietary records, specifying the names and brands of industrial food products consumed. These records were matched with several databases and laboratory measurements to estimate individual exposure to preservatives over time with a high level of precision.
During the follow-up period, 1,131 cases of type 2 diabetes were identified among 108,723 participants. After accounting for numerous potential confounding factors such as smoking, alcohol intake, and overall dietary quality, the analyses revealed clear associations. Higher overall consumption of preservative additives was linked to a 47% increase in type 2 diabetes incidence. Similar associations were observed for non-antioxidant preservatives and antioxidant additives, which were linked to 49% and 40% higher risks, respectively, compared with the lowest levels of consumption.
More information: Anaïs Hasenböhler et al, Associations between preservative food additives and type 2 diabetes incidence in the NutriNet-Santé prospective cohort, Nature Communications. DOI: 10.1038/s41467-025-67360-w
Journal information: Nature Communications Provided by INSERM (Institut national de la santé et de la recherche médicale)
