A recent study published in The BMJ reports that higher consumption of food preservatives, commonly found in processed foods and beverages, is linked to a modest increase in cancer risk. The research was conducted by a team in France who analyzed dietary and health data from 2009 to 2023.
The study included 105,260 adults aged 15 and older, with an average age of 42 years. Most participants were women. All participants were cancer-free at the start of the study and provided regular detailed dietary records over an average period of 7.5 years. Researchers tracked cancer diagnoses using health questionnaires and official medical records up to December 31, 2023.
Seventeen individual preservatives were studied, including citric acid, lecithins, sulfites, ascorbic acid, sodium nitrite, potassium sorbate, sodium erythorbate, sodium ascorbate, potassium metabisulfite, and potassium nitrate. These additives were grouped into non-antioxidants—which inhibit microbial growth or slow spoilage—and antioxidants—which prevent food deterioration by limiting oxygen exposure.
During the follow-up period, there were 4,226 cases of cancer among participants: 1,208 breast cancers, 508 prostate cancers, 352 colorectal cancers, and 2,158 other types.
Of the preservatives studied individually, eleven showed no association with cancer incidence. There was also no observed link between total preservative intake and overall cancer risk. However, higher intakes of several non-antioxidant preservatives—such as potassium sorbate (linked to a 14% increased risk for all cancers and a 26% increased risk for breast cancer), total sulfites (12% increased overall risk), sodium nitrite (32% increased prostate cancer risk), potassium nitrate (13% increased overall risk; 22% for breast cancer), total acetates (15% overall; 25% breast) and acetic acid (12% overall)—were associated with greater risks compared to lower or non-consumers.
Among antioxidant preservatives studied, only total erythorbates and specifically sodium erythorbate were associated with higher rates of cancer.
Researchers note that while more studies are needed to understand these potential risks fully—and acknowledge this observational study cannot prove causation—the results align with experimental data suggesting some compounds may negatively affect immune or inflammatory pathways involved in cancer development.
The authors state: "This study brings new insights for the future re-evaluation of the safety of these food additives by health agencies, considering the balance between benefit and risk for food preservation and cancer."
They recommend manufacturers reduce unnecessary use of preservatives and encourage consumers to choose freshly made or minimally processed foods when possible.
A linked editorial from US researchers highlights that while preservatives extend shelf life and help lower food costs—important factors especially for low-income populations—the widespread use without sufficient long-term monitoring raises concerns about potential health effects. They suggest regulatory agencies might consider stricter limits on additive use or clearer labeling requirements based on findings like those from NutriNet-Santé. The editorial notes global initiatives similar to those used for trans fats could help inform policy decisions regarding food additives.
"At the individual level," they write,"public health guidance is already more definitive about the reduction of processed meat and alcohol intake offering actionable steps even as evidence on the carcinogenic effects of preservatives is evolving."
