Higher intake of food preservatives linked to increased risk of type 2 diabetes

Analysis of dietary data from more than 100,000 adults in France has shown that higher consumption of commonly used food preservatives is associated with a substantially increased incidence of type 2 diabetes

Higher consumption of food preservatives – widely used in industrially processed foods and beverages to extend shelf life – has been linked to an increased risk of type 2 diabetes (T2DM), according to research conducted by scientists from the National Institute of Health and Medical Research (Institut national de la santé et de la recherche médicale, or Inserm), the National Research Institute for Agriculture, Food and Environment, Sorbonne Paris Nord University, Paris Cité University and the National Conservatory of Arts and Crafts in France.

The work was carried out within the Nutritional Epidemiology Research Team, known as CRESS-EREN located in Paris, and drew on extensive health and dietary data from more than 100,000 adults participating in the ‘NutriNet-Santé’ cohort study.

Preservatives form part of the wider family of food additives and are used extensively by the global food industry. In 2024, of the three and a half million foods and beverages listed in the Open Food Facts World database, more than 700,000 products contained at least one preservative substance. These additives are typically included to inhibit microbial growth, slow chemical changes that lead to spoilage, or limit oxidation during periods of storage prior to consumption.

In the analysis conducted by the Inserm-led research team, additives with preservative properties were classified into two broad groups. The first included non-antioxidant preservatives, which act primarily to inhibit microbial growth or to delay chemical degradation.

The second comprised antioxidant additives, which limit or eliminate oxygen in packaging in order to delay spoilage. On product labelling, these substances generally correspond to European additive codes E200 to E299 for preservatives in the strict sense and E300 to E399 for antioxidant additives.

Previous experimental studies have suggested that certain preservatives may damage cells and DNA and may disrupt metabolic processes. However, until now, population-level evidence that links exposure to these additives with T2DM has remained limited.

To address this gap, a team led by Dr. Mathilde Touvier, research director at Inserm, examined the association between dietary exposure to preservatives and the incidence of T2DM. The analysis was based on data from more than 100,000 French adults enrolled in the NutriNet-Santé study.

Between 2009 and 2023, participants reported their medical history, socio-demographic characteristics, physical activity levels and a wide range of lifestyle and health-related factors. They also provided repeated, detailed records of their food consumption, covering several 24-hour periods. These records included the names and brands of industrial food products consumed. By cross-referencing this information with multiple databases, including Open Food Facts, France’s Observatory of Food Quality and the European Food Safety Authority, and by combining these data with quantitative measurements of additives in foods and beverages, the researchers were able to estimate individual exposure to preservatives across the study period.

In total, 58 preservative-related substances were detected in participants’ dietary records, comprising 33 preservatives in the strict sense and 27 antioxidant additives. Of these, 17 preservatives were selected for individual analysis because they were consumed by at least 10% of the cohort.

The statistical analyses accounted for a wide range of potential confounding factors, including age, sex, socio-demographic profile, tobacco use, alcohol consumption, physical activity and the overall nutritional quality of the diet. Dietary variables such as total energy intake, sugar, salt, saturated fat and fibre were also considered in order to reduce the risk of bias in the observed associations.

During the follow-up period from 2009 to 2023, slightly more than a thousand cases of T2DM were identified among the 108,000 plus participants that had been included in the analysis. Higher overall consumption of preservative additives was associated with a 47% increase in the incidence of T2DM compared with the lowest levels of intake. When examined separately, higher consumption of non-antioxidant preservatives was associated with a 49% increase in risk, while higher intake of antioxidant additives was associated with a 40% increase in risk.

At the level of individual substances, higher consumption of 12 of the 17 preservatives analysed was associated with an increased risk of T2DM. 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).

Several antioxidant additives were also implicated, including sodium ascorbate (E301), alpha-tocopherol (E307), sodium erythorbate (E316), citric acid (E330), phosphoric acid (E338) and rosemary extracts (E392).

“This is the first study in the world on the links between preservative additives and the incidence of T2DM. Although the results need to be confirmed, they are consistent with experimental data suggesting the harmful effects of several of these compounds,” said Dr. Touvier.

“More broadly, these novel data add to [the knowledge base] in favour of a reassessment of the regulations governing the general use of food additives by the food industry in order to improve consumer protection,” added Anaïs Hasenböhler, a doctoral student at the Nutritional Epidemiology Research Team who carried out the analyses.

“This work once again justifies the recommendations made by the National Nutrition and Health Programme to consumers to favour fresh, minimally processed foods and to limit unnecessary additives as much as possible,” Touvier concluded.

For further reading please visit: 10.1038/s41467-025-67360-w