A higher intake of food preservatives—commonly used in industrially processed foods and beverages to extend shelf life—has been linked to a modestly increased risk of cancer.

These are the findings of a French study published in ‘The BMJ’. While the researchers caution that further studies are needed to clarify these associations, they say the findings strengthen calls for a reassessment of regulations guiding the use of food additives, in order to better protect consumers.

Preservatives are added to packaged foods to prevent spoilage and prolong freshness. Although laboratory studies have suggested that some preservatives may damage cells and DNA, robust evidence directly linking them to cancer risk has been limited.

To bridge this gap, researchers analysed dietary and health data collected between 2009 and 2023 from 105,260 participants aged 15 years and above (average age 42 years; 79 per cent women) enrolled in the NutriNet-Santé cohort study.

All participants were cancerfree at the start and completed repeated 24-hour, brand-specific dietary records over an average follow-up period of 7.5 years. Cancer cases were tracked using health questionnaires and official medical and death records up to 31 December 2023.