Common preservatives in processed foods may carry hidden cancer risks—prompting new calls to rethink what’s added to our diets.
A large French study tracking more than 100,000 people over a decade has found that higher consumption of certain food preservatives—commonly found in processed foods and drinks—is linked to a modestly higher cancer risk. While many preservatives showed no association, several widely used ones, including potassium sorbate, sulfites, sodium nitrite, and potassium nitrate, were tied to increased risks of overall cancer and specific types such as breast and prostate cancer.
TheDigger Intelligence Unit
A large study from France published by The BMJ reports that people who consume higher amounts of food preservatives may face a slightly increased risk of developing cancer. These additives are commonly used in industrially processed foods and drinks to extend shelf life.
The researchers emphasize that more studies are needed to fully understand the relationship. Still, they say the findings raise important questions about current regulations and suggest that safety standards for food preservatives may need to be re-examined to better protect consumers. This growing scrutiny sets the stage for a closer look at why preservatives are drawing increased attention.
Why Preservatives Are Under Scrutiny
Food preservatives are added to packaged products to prevent spoilage and extend the time food remains safe to eat. Previous laboratory research has shown that some preservatives can damage cells and DNA. However, until now, there has been limited real-world evidence directly linking these additives to cancer risk.
To explore this issue more closely, researchers analyzed long-term dietary and health data collected between 2009 and 2023. Their goal was to determine whether exposure to specific preservative food additives was associated with cancer risk in adults.
A Large and Detailed Long-Term Study
The study followed 105,260 participants aged 15 years and older (average age 42 years; 79% women) from the NutriNet-Santé cohort. All participants were cancer-free at the start and regularly completed detailed 24-hour brand-specific dietary records over an average period of 7.5 years.
Researchers then tracked cancer diagnoses using health questionnaires along with official medical and death records through December 31, 2023.
Preservatives Examined in the Study
The analysis focused on 17 individual preservatives, including citric acid, lecithins, total sulfites, ascorbic acid, sodium nitrite, potassium sorbate, sodium erythorbate, sodium ascorbate, potassium metabisulfite, and potassium nitrate.
These preservatives were divided into two groups. Non-antioxidants stop germs from growing or slow down changes that make food go bad. Antioxidants help keep food fresh by reducing the amount of air that enters the packaging.
Cancer Cases Identified
During the follow-up period, 4,226 participants were diagnosed with cancer. These cases included 1,208 breast cancers, 508 prostate cancers, 352 colorectal cancers, and 2,158 other types of cancer.
When researchers looked at all preservatives combined, they found no overall link with cancer risk. In addition, 11 of the 17 preservatives studied individually showed no association with cancer incidence.
Specific Preservatives Linked to Increased Risk
Higher intake of several individual preservatives was linked to a greater risk of cancer, particularly among non-antioxidant preservatives. These included potassium sorbate, potassium metabisulfite, sodium nitrite, potassium nitrate, and acetic acid.
Total sorbates, especially potassium sorbate, were associated with a 14% higher risk of overall cancer and a 26% higher risk of breast cancer. Total sulfites were linked to a 12% increase in overall cancer risk.
Sodium nitrite was associated with a 32% higher risk of prostate cancer. Potassium nitrate was linked to a 13% increased risk of overall cancer and a 22% higher risk of breast cancer.
Total acetates were associated with a 15% higher risk of overall cancer and a 25% higher risk of breast cancer. Acetic acid alone was linked to a 12% increase in overall cancer risk.
Among antioxidant preservatives, only total erythorbates and sodium erythorbate were associated with a higher incidence of cancer.
Possible Biological Explanations
The researchers note that several of the preservatives linked to cancer risk may affect immune function and inflammation. These changes could potentially contribute to cancer development, although more research is needed to confirm these mechanisms.
Because this was an observational study, it cannot prove that preservatives directly cause cancer. The authors also acknowledge that other unmeasured factors, such as lifestyle or genetic influences, may have affected the results. Additionally, the study relied on self-reported dietary information, which may be subject to reporting bias or inaccuracies.
Why the Findings Still Matter
Despite these limitations, the researchers point out that the study was large, relied on detailed dietary data linked to food databases, and followed participants for more than a decade. They add that the findings align with existing experimental research suggesting that some of these compounds have cancer-related effects.
Based on the results, they conclude: “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.”
Implications for Consumers and Policy
The researchers encourage food manufacturers to reduce the use of unnecessary preservatives and support guidance for consumers to choose freshly prepared, minimally processed foods whenever possible.
In a related editorial, US researchers note that preservatives do offer clear benefits, including longer shelf life and lower food costs, which can be especially important for lower-income populations. However, they argue that the widespread, often poorly monitored use of these additives, combined with uncertainty about their long-term health effects, calls for a more balanced regulatory approach.
They suggest that findings from NutriNet-Santé could prompt regulators to revisit existing policies. Possible steps include stricter limits on preservative use, clearer labeling, mandatory disclosure of additive content, and international monitoring efforts similar to those used for trans fatty acids and sodium.
At the individual level, public health guidance is already more definitive about reducing processed meat and alcohol intake, offering actionable steps even as evidence on preservatives evolves. Taken together, these findings underscore the growing importance of re-evaluating food safety standards, empowering both individuals and policymakers to make more informed choices for long-term health.