Food preservatives are widely used to extend shelf life and reduce food waste, but new research suggests higher exposure to some of these additives may be linked to an increased risk of type 2 diabetes.
In a study published in Nature Communications, researchers from INSERM (France’s national medical research institute) and several partner institutions analyzed health and dietary data from more than 100,000 adults enrolled in the NutriNet-Santé cohort. Over a follow-up period spanning more than a decade, higher consumption of food preservatives was associated with a greater incidence of type 2 diabetes.
The study focused specifically on preservatives, a category of food additives used to slow spoilage and prevent microbial growth. Using detailed dietary records that included brand-level product information, researchers estimated participants’ exposure to dozens of preservative additives commonly found in industrially processed foods and beverages.
Between 2009 and 2023, 1,131 participants developed type 2 diabetes. Compared with those with the lowest exposure, individuals with higher overall intake of preservatives had a 47% higher relative risk of developing the disease. Similar associations were observed for both non-antioxidant preservatives and antioxidant additives.
When researchers examined individual compounds, higher intake of 12 widely used preservatives was linked to increased diabetes risk. These included non-antioxidant preservatives such as potassium sorbate, sodium nitrite and calcium propionate, as well as antioxidant additives like citric acid, sodium ascorbate and rosemary extracts.
“This is the first study in the world on the links between preservative additives and the incidence of type 2 diabetes,” said Mathilde Touvier, an INSERM research director and senior author of the study. “Although the results need to be confirmed, they are consistent with experimental data suggesting the harmful effects of several of these compounds.”
Importantly, the researchers adjusted their analyses for a wide range of factors that could influence diabetes risk, including calorie intake, sugar, salt, saturated fat, fiber, physical activity, smoking, alcohol use and overall nutritional quality of the diet. Even with those adjustments, the associations with preservatives remained.
The findings do not prove that preservatives cause diabetes. As an observational study, the research can only identify statistical links, not direct cause-and-effect relationships. The authors also caution that preservatives are rarely consumed in isolation and often reflect broader dietary patterns.
“These new data add to others 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,” said Anaïs Hasenböhler, a doctoral researcher involved in the study.
Touvier emphasized that the results support existing public health advice rather than introducing new dietary rules.
“This work once again justifies the recommendations made by the National Nutrition and Health Programme to consumers to favor fresh, minimally processed foods and to limit unnecessary additives as much as possible,” she said.
For consumers, the study underscores a familiar but nuanced message. Preservatives play a functional role in modern food systems, but frequent consumption of additive-heavy foods may carry health tradeoffs beyond calories and nutrients alone. Researchers say more studies are needed to confirm these findings in other populations and to better understand how individual additives may influence metabolic health over time.
The study was funded by the European Research Council, the French National Cancer Institute and the French Ministry of Health.