Two new studies suggest a link between the consumption of preservatives and an increased risk of cancer and type 2 diabetes
Higher consumption of food preservatives, widely used in industrially processed foods and beverages to extend their shelf life, has been linked to an increased risk of cancer and type 2 diabetes. These findings are the result of work carried out by researchers from Inserm, INRAE, Sorbonne Paris Nord University, Paris Cité University and Cnam, within the Nutritional Epidemiology Research Team (CRESS-EREN). They are based on health and dietary data from more than 100,000 adults participating in the NutriNet-Santé cohort study. They are the subject of two separate publications: one in The BMJ, the other in the journal Nature Communications.
Preservatives belong to the family of food additives and are widely used by the food industry worldwide. Of the three and a half million foods and beverages listed in the Open Food Facts World database in 2024, more than 700,000 contain at least one of these substances.
Additives with preservative properties have been grouped into two categories in the work carried out by Inserm researchers: non-antioxidants (which inhibit microbial growth or slow down the chemical changes that lead to food spoilage) and antioxidants (which delay or prevent food spoilage by eliminating or limiting oxygen levels in packaging). On packaging, they generally correspond to European codes between E200 and E299 (for preservatives in the strict sense) and between E300 and E399 (for antioxidant additives).
Experimental studies have suggested that certain preservatives may damage cells and DNA and have adverse effects on metabolism, but the links between these additives and the risk of cancer and type 2 diabetes remain to be established.
A research team led by Mathilde Touvier, Inserm Research Director, set out to examine the links between exposure to these preservatives and the risk of cancer on the one hand, and type 2 diabetes on the other. The team drew on data provided by more than 100,000 French adults participating in the NutriNet-Santé study (see box below).
Between 2009 and 2023, the volunteers reported their medical history, socio-demographic data, physical activity habits, and information about their lifestyle and health status. They also regularly provided detailed information on their food consumption by sending scientists complete records covering several 24-hour periods, including the names and brands of the industrial products they consumed. This information, cross-referenced with several databases (Open Food Facts, Oqali, EFSA) and combined with measurements of additives in food and beverages, made it possible to assess the participants’ exposure to additives, particularly preservatives, over the course of the study.
Beyond the total amounts of preservatives (58 detected in total in the participants’ food records; 33 preservatives in the strict sense and 27 antioxidant additives), 17 substances were analysed individually in relation to the pathologies studied [1]. The 17 preservatives are those consumed by at least 10% of the cohort participants.
The analyses took into account the socio-demographic profiles of the participants, their tobacco and alcohol consumption, the nutritional quality of their diet (calories, sugar, salt, saturated fats, fibre, etc.) and many other factors that could have biased the associations studied.
- [1] Sodium nitrite (E250), potassium sorbate (E202), sodium erythorbate (E316), citric acid (E330), lecithins (E322), ascorbic acid (E300), sodium ascorbate (E301), potassium metabisulphite (E224), potassium nitrate (E252), acetic acid (E260), sodium acetates (E262), calcium propionate (E282), alpha-tocopherol (E307), phosphoric acid (E338) and rosemary extracts (E392), tocopherol-rich extract (E306), sulphur dioxide (E220).
Higher consumption of food preservatives was associated with an increased risk of cancer: BMJ study
During the follow-up period, 4,226 participants (out of 105,260 participants in this study) were diagnosed with cancer, including 1,208 breast cancers, 508 prostate cancers, 352 colorectal cancers and 2,158 other cancers.
Total consumption of non-antioxidant preservatives was associated with an increased incidence of cancer overall and breast cancer specifically.
Of the 17 preservatives studied individually, 11 were not associated with cancer incidence.
However, higher consumption of several preservatives (mainly non-antioxidant preservatives) was associated with a higher risk of cancer compared to lower consumption:
Sorbates, particularly potassium sorbate, were associated with a 14% increase in overall cancer risk and a 26% increase in breast cancer risk.
Sulphites were associated with a 12% increase in the overall risk of cancer. In particular, potassium metabisulphite was associated with an 11% increase in the overall incidence of cancer and a 20% increase in breast cancer.
Sodium nitrite was associated with a 32% increase in the risk of prostate cancer, while potassium nitrate was associated with an increase in the risk of cancer in general (13%) and breast cancer (22%).
Acetates were associated with an increased risk of cancer in general (15%) and breast cancer (25%), while acetic acid was associated with a 12% increase in the risk of cancer in general.
Among antioxidant preservatives, only total erythorbates and specific sodium erythorbate were found to be associated with a higher incidence of cancer overall (12%) and breast cancer (21%).
Although further work is needed to better understand these potential risks, the researchers note that several experimental studies have observed that some of these compounds can alter immune and inflammatory pathways, which could trigger the development of cancer.
Higher consumption of food preservatives is associated with an increased risk of type 2 diabetes: study in Nature Communications
Between 2009 and 2023, 1,131 cases of type 2 diabetes were identified among the 108,723 participants in this study.
Higher consumption of preservative additives overall, non-antioxidant preservatives and antioxidant additives was associated with an increased incidence of type 2 diabetes, by 47%, 49% and 40% respectively, compared to the lowest levels of consumption.
Of the 17 preservatives studied individually, higher consumption of 12 of them was associated with an increased risk of type 2 diabetes: widely used non-antioxidant food preservatives (potassium sorbate (E202), potassium metabisulphite (E224), sodium nitrite (E250), acetic acid (E260), sodium acetates (E262) and calcium propionate (E282)) and antioxidant additives (sodium ascorbate (E301), alpha-tocopherol (E307), sodium erythorbate (E316), citric acid (E330), phosphoric acid (E338) and rosemary extracts (E392)).
‘These are the first two studies in the world on the links between preservative additives and the incidence of cancer and type 2 diabetes. Although the results of these two studies need to be confirmed, they are consistent with experimental data suggesting the harmful effects of several of these compounds,’ explains Mathilde Touvier, Inserm research director and coordinator of this work.
‘More broadly, 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,’ adds Anaïs Hasenböhler, a doctoral student at EREN who conducted these studies.
‘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,’ concludes Mathilde Touvier.
This work was funded by the European Research Council (ERC ADDITIVES), the National Cancer Institute, and the French Ministry of Health.
According to the Inserm press release: https://presse.inserm.fr/deux-nouvelles-etudes-suggerent-une-association-entre-la-consommation-de-conservateurs-et-un-risque-accru-de-cancer-et-de-diabete-de-type-2/71653/
Mathilde Touvier & Anaïs Hasenböhler
m.touvier@eren.smbh.univ-paris13.fr
anais.hasenbohler@eren.smbh.univ-paris13.fr
Photo credit: Mathilde Touvier
