Study Links Some Common Food Preservatives to Higher Cancer Rates

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New research published in BMJ suggests some commonly used food additives may be linked to higher cancer risk over time.

“These findings may have important public health implications given the ubiquitous use of these additives in a wide range of foods and beverages,” wrote the team of investigators.

Many packaged and processed foods contain preservatives — additives used to extend shelf life, prevent spoilage, and maintain color or texture. In 2024, over 20% of foods listed in the Open Food Facts World database contained at least one of these additives, and while they are considered safe under current regulations, investigators continue to question their long-term health effects with frequent, long-term consumption. A large French study set out to examine whether higher intake of certain food preservative additives is linked to cancer risk.

The team followed more than 105,000 adults from the NutriNet-Santé study over an average of 7.5 years. Participants repeatedly recorded everything they ate using detailed 24-hour food diaries, allowing scientists to estimate long-term intake of specific preservatives found in industrially processed foods. These estimates were strengthened using food composition databases and laboratory testing of commonly consumed products. People with cancer at the start of the study were excluded.

The mean age of patients was 42 years and most (78.7%) were women. During follow-up, more than 4,200 participants developed cancer, including breast (1,208 cases), prostate (508 cases) and colorectal (352 cases) cancers. Investigators found that higher intake of several commonly used preservatives was associated with a modest but statistically significant increase in overall cancer risk.

Some preservatives were also linked specifically to breast cancer or prostate cancer. These included certain sorbates, sulfites, nitrates, nitrites, acetates and related compounds that are frequently used in processed meats, baked goods, sauces, packaged snacks and other industrial foods.

Importantly, the increases in risk were not dramatic, but they were consistent. For example, people with higher intake of some preservatives had an estimated cancer risk at age 60 that was about 1–2 percentage points higher than those who consumed little or none. While that difference may seem small for an individual, it could have meaningful public health implications when applied across large populations with regular exposure.

Not all preservatives were associated with cancer risk. In fact, 11 of the 17 additives studied showed no link. Investigators emphasized that the study also does not prove that preservatives directly cause cancer. It shows an association, meaning other unmeasured factors could play a role. However, the prospective design, long follow-up and detailed dietary data strengthen confidence that these findings deserve attention.

Investigators noted they carefully adjusted for many lifestyle and dietary factors to reduce bias, and laboratory studies provide biological evidence that some preservatives could play a role in cancer development. Although the study relied on online dietary reporting and included more women and health-conscious participants than the general population, overall eating patterns and geographic distribution were similar to national data, supporting the relevance of the findings. Some preservatives were too rarely consumed to study and longer follow-up is still needed, but results remained consistent across multiple analyses, suggesting the observed associations are unlikely to be due to chance alone.

The team concluded that more research, including biological and experimental studies, is needed to understand how these preservatives might influence cancer development. In the meantime, the findings support existing advice to prioritize freshly prepared, minimally processed foods and limit frequent consumption of ultra-processed products whenever possible.

“Public health policies should be strengthened to promote and make accessible and affordable fresh, seasonal, homemade products to consumers, or even canned and other industrial foods, although minimally processed, that limit the use of preservatives and superfluous additives,” investigators concluded. “Health professionals (general practitioners, dietitians) could play a key role in conveying these prevention recommendations to their patients.”