This post was originally published on here
Food preservatives are everywhere – in sodas, packaged snacks, cured meats, and countless other staples of modern diets. For years, scientists have debated whether these additives are purely practical tools or whether some carry hidden health risks.
A large new tracking study suggests the picture is more complicated than a simple yes-or-no answer.
The researchers found that higher intakes of a small number of specific preservatives were linked to a modestly higher cancer risk, even though preservatives overall showed no association.
Using detailed, long-term diet records, a research team from Sorbonne University argues the findings warrant a closer look at how certain additives are used and regulated, even as more research is needed to confirm what’s driving the link.
Food preservatives worry scientists
Preservatives are added to packaged foods to keep them stable for longer. They can prevent microbial growth or slow the chemical changes that cause food spoil. The public health upside is obvious: longer shelf life, fewer losses, and lower costs.
But there’s also a long-running concern. Some experimental studies have suggested that certain preservatives may damage cells or DNA.
Even so, strong evidence in humans has been limited, partly because it’s hard to measure real-world exposure accurately over long periods.
This study aimed to tighten that evidence by using unusually detailed dietary records linked to food product databases, and by tracking health outcomes for many years.
Following diets for years
The analysis included 105,260 participants aged 15 and older, with an average age of 42. About 79 percent were women.
Everyone included was cancer-free at the start and completed repeated 24-hour dietary records that captured brand-specific information, over an average follow-up of 7.5 years.
The researchers then identified cancer cases through health questionnaires and official medical and death records, tracking diagnoses up to December 31, 2023.
Over that period, 4,226 participants developed cancer. This included 1,208 breast cancers, 508 prostate cancers, 352 colorectal cancers, and 2,158 other cancers.
The team examined 17 individual preservatives. Among them were citric acid, lecithins, total sulfites, ascorbic acid, sodium nitrite, potassium sorbate, sodium erythorbate, sodium ascorbate, potassium metabisulfite, and potassium nitrate.
They also grouped preservatives into two categories. One group covered non-antioxidants, which mainly help stop microbial growth or slow spoilage-related reactions.
The other group covered antioxidant preservatives, which delay deterioration by limiting oxygen-related processes.
Which food preservatives mattered
The headline here is not “preservatives cause cancer.” The pattern was more specific than that. Out of the 17 preservatives studied individually, 11 were not associated with cancer incidence.
The researchers also found no link between total preservative intake overall and cancer incidence.
Where the signal did appear was in higher intakes of several preservatives, most of them in the non-antioxidant category.
Compared with non-consumers or lower consumers, higher consumers of certain compounds had higher rates of some cancers.
Food preservatives tied to cancer risk
One of the clearer associations involved sorbates. Total sorbates, especially potassium sorbate, were linked to a 14 percent higher risk of overall cancer and a 26 percent higher risk of breast cancer.
Sulfites also stood out. Total sulfites were associated with a 12 percent increased risk of overall cancer.
For prostate cancer, sodium nitrite was associated with a 32 percent increased risk. Potassium nitrate was linked to a 13 percent increased risk of overall cancer and a 22 percent increased risk of breast cancer.
Acetates showed up as well. Total acetates were associated with a 15 percent increased risk of overall cancer and a 25 percent increased risk of breast cancer. Acetic acid on its own was linked to a 12 percent higher risk of overall cancer.
Among antioxidant preservatives, the study found fewer signals. The researchers report that only total erythorbates and sodium erythorbate were associated with higher cancer incidence.
These are relative increases, and the study describes them as modest. Still, the authors argue they are meaningful enough to justify closer scrutiny, given how widespread exposure can be in heavily processed diets.
Biological clues, not conclusions
The researchers point out that several compounds flagged in the analysis have been linked, in other contexts, to changes in immune and inflammatory pathways. Those shifts could, in theory, help create conditions that support cancer development.
That said, the study does not establish a biological mechanism. Instead, it offers a plausible direction for future research rather than definitive proof.
The authors also note that their findings align with experimental evidence suggesting cancer-related effects for some of these compounds.
Implications for health agencies
Just as important is what the study cannot do. Because it is observational, it identifies statistical associations rather than testing cause and effect directly.
The researchers acknowledge that unmeasured factors could still influence the results, even with detailed dietary tracking over many years.
Even so, they argue the work has strengths that make it difficult to dismiss. The analysis draws on a large sample, long-term dietary records, and links to food composition databases.
“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,” the authors said.
How food guidance may shift
The authors urge manufacturers to limit unnecessary preservative use and support guidance encouraging people to choose freshly made, minimally processed foods when possible.
A linked editorial from U.S. researchers takes a more balancing tone. Preservatives can reduce food waste and lower costs, which can matter a lot for lower-income populations.
But they also argue that widespread use, limited monitoring, and uncertainty about long-term effects call for a more measured regulatory approach.
The team suggests that findings like these could encourage agencies to revisit existing rules. That could include stricter limits, clearer labeling, and stronger disclosure requirements.
The researchers also point to international monitoring efforts, similar to those already used for trans fats and sodium.
“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,” the experts concluded.
The study is published in the journal The BMJ today.
—–
Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates.
Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.
—–
