New research has highlighted a potential association between high consumption of certain food preservatives and an increased risk of developing cancer. While researchers stress that the findings demonstrate correlation rather than direct causation, the study adds to growing evidence pointing to the possible health risks of highly processed foods. Experts, therefore, advise limiting their intake where feasible.

Food preservatives are deeply embedded in modern diets, commonly found in meats, dairy products, sauces, snack foods, and frozen meals. These chemical additives play a vital role in extending shelf life and preventing spoilage. However, a recent study published in The BMJ suggests that frequent exposure to some of these preservatives may carry notable health risks, particularly an elevated cancer risk.

One of the study’s authors, Dr. Mathilde Touvier, a research professor at the French National Institute for Health and Medical Research, emphasized that the findings require further confirmation. Nonetheless, she recommended a precautionary approach, advising consumers to avoid preservatives when possible. The research drew on data from the NutriNet-Santé study, a large-scale nutrition project launched in 2009, in which more than 100,000 participants provided detailed dietary records over several years.

The study cohort—nearly 80% of whom were women—was monitored between 2009 and 2023 for cancer diagnoses. During this period, more than 4,200 participants developed cancer. After adjusting for confounding factors such as smoking, family cancer history, and overall dietary quality, researchers examined the effects of 17 commonly consumed preservatives. While eleven showed no measurable association with cancer, six widely used preservatives were linked to a higher cancer risk when consumed in large quantities.

These included sulfites, potassium sorbate, potassium nitrate, acetates, acetic acid, and sodium erythorbate. High intake of these preservatives was associated with a 12% to 15% increase in overall cancer risk. Certain additives also showed stronger associations with specific cancers. Sodium nitrite, frequently used in cured meats, was linked to a 32% higher risk of prostate cancer, while potassium sorbate—commonly found in cheese, snack foods, and frozen meals—was associated with a 26% increased risk of breast cancer.

Although the study was robust in identifying dietary patterns, it was not designed to establish direct causation or fully explain the biological mechanisms involved. Dr. Edward Giovannucci, a professor of nutrition and epidemiology at Harvard T.H. Chan School of Public Health and co-author of an accompanying editorial, praised the study’s methodology but noted that further research is required to clarify causality.

Some insights, however, emerge from earlier laboratory and animal studies. According to Dr. Touvier, food preservatives have been linked to cellular toxicity, abnormal cell growth, and increased inflammation—processes associated with cancer development. Dr. Giovannucci also noted that preservatives may act indirectly; for instance, sulfites are commonly present in alcoholic beverages, and alcohol itself is a known carcinogen, making it difficult to isolate individual effects.

Also researchers agree that more comprehensive studies are needed. “We cannot say more than what we have here,” Dr. Touvier said. Existing public health guidelines already recommend limiting processed meats and alcohol—both established carcinogens that often contain several of the preservatives identified in the study.

On whether consumers should avoid all preservative-containing foods, experts urge moderation rather than alarm. While Dr. Giovannucci acknowledged that cooking fresh meals from scratch is ideal, he recognized its impracticality for many people. He cautioned against panic, describing the findings as preliminary, though important enough to warrant continued research.

Still, a clear consensus remains. “It is very clear that highly processed foods, including those that contain many additives, have negative health effects,” said Dr. Timothy Rebbeck, a professor of cancer prevention at Dana-Farber Cancer Institute and Harvard T.H. Chan School of Public Health. He advised prioritizing whole, minimally processed foods to reduce cancer risk and improve overall health. Dr. Touvier echoed this recommendation, encouraging home cooking and the avoidance of unnecessary food additives whenever possible.