Study Links Food Preservatives to Higher Type 2 Diabetes Risk

Higher consumption of food preservatives commonly used in processed foods and beverages is associated with an increased risk of developing type 2 diabetes, according to a large French cohort study published in Nature Communications.

The research was conducted by scientists from Inserm, INRAE, Sorbonne Paris Nord University, Paris Cité University, and Cnam, within the Nutritional Epidemiology Research Team (CRESS-EREN). It analyzed health and dietary data from more than 100,000 adults participating in the NutriNet-Santé cohort, one of the most extensive long-term nutrition studies in the European Union.

Preservatives are part of the broader family of food additives and are widely used by the global food industry to extend shelf life and maintain product stability. Data from the Open Food Facts World database show that, in 2024, more than 700,000 of the roughly 3.5 million listed food and beverage products contained at least one preservative.

In the study, additives with preservative functions were classified into two groups. Non-antioxidant preservatives inhibit microbial growth or slow chemical processes that lead to spoilage, while antioxidant additives limit oxidation, often by reducing oxygen exposure. On food labels, these substances generally correspond to EU codes E200 to E299 for preservatives in the strict sense and E300 to E399 for antioxidant additives.

While experimental research has previously suggested that some preservatives may affect cellular function, DNA integrity, and metabolism, population-level evidence linking these substances to type 2 diabetes has been limited. To address this gap, a research team led by Mathilde Touvier, Research Director, Inserm, examined long-term exposure to preservatives and diabetes incidence using detailed participant data collected between 2009 and 2023.

During this period, 108,723 adult participants regularly reported medical history, lifestyle factors, physical activity, and socio-demographic information. They also provided repeated 24-hour dietary records, including product brands and names. These data were cross-referenced with several databases, including Open Food Facts, Oqali, and the European Food Safety Authority, allowing researchers to estimate individual exposure to specific additives over time.

Overall, 58 preservative-related additives were identified in participants’ diets, including 33 preservatives in the strict sense and 27 antioxidant additives. Of these, 17 substances consumed by at least 10% of the cohort were analyzed individually. The statistical models accounted for a wide range of potential confounding factors, including smoking, alcohol consumption, overall diet quality, caloric intake, and nutrient composition.

Between 2009 and 2023, the study documented 1,131 new cases of type 2 diabetes. The analysis found that higher overall consumption of preservative additives was associated with a 47% higher incidence of type 2 diabetes compared with the lowest levels of intake. Similar associations were observed for non-antioxidant preservatives, linked to a 49% increase, and antioxidant additives, associated with a 40% increase.

At the individual level, higher intake of 12 of the 17 preservatives studied was associated with increased diabetes risk. These included widely used non-antioxidant preservatives such as potassium sorbate (E202), potassium metabisulphite (E224), sodium nitrite (E250), acetic acid (E260), sodium acetates (E262), and calcium propionate (E282), as well as antioxidant additives including sodium ascorbate (E301), alpha-tocopherol (E307), sodium erythorbate (E316), citric acid (E330), phosphoric acid (E338), and rosemary extracts (E392).

According to the researchers, this is the first large-scale epidemiological study to examine associations between preservative additives and the incidence of type 2 diabetes. While they stress that the findings require confirmation in other populations, they note that the results align with earlier experimental evidence suggesting potential metabolic effects of several of these compounds.

The authors argue that the findings contribute to ongoing discussions about the regulation of food additives and reinforce public health recommendations that encourage consumption of fresh, minimally processed foods and the reduction of unnecessary additives. The study was funded by the European Research Council, the French National Cancer Institute, and the French Ministry of Health.