A large study from France has found that eating higher amounts of food preservatives—ingredients added to packaged foods to make them last longer—may slightly increase the risk of cancer.
The study was published in The BMJ and looked at how different preservatives might affect long-term health.
Preservatives are found in many processed foods and drinks. They help stop bacteria from growing and keep foods from going bad. Some research has shown that certain preservatives can damage cells or DNA, but it has been unclear whether they cause cancer in people.
To learn more, researchers studied data from over 100,000 adults in France between 2009 and 2023. These participants were part of a project called the NutriNet-Santé study. They were 15 years or older and had no cancer when the study began.
On average, they were 42 years old and most were women. Participants filled out detailed food diaries, listing brand names and what they ate. Their health was tracked for about 7.5 years using medical records and health surveys.
The study looked at 17 different preservatives, including common ones like citric acid, sulfites, sodium nitrite, potassium nitrate, and acetic acid. These were divided into two groups: antioxidants (which stop food from going stale) and non-antioxidants (which slow spoilage and bacteria growth).
During the study period, 4,226 people developed cancer. This included 1,208 cases of breast cancer, 508 prostate cancers, 352 colorectal cancers, and 2,158 other types.
Overall, 11 of the 17 preservatives were not linked to cancer. However, some were associated with a small but noticeable increase in cancer risk. For example, people who ate more potassium sorbate had a 14% higher risk of any cancer and a 26% higher risk of breast cancer. Sulfites were linked to a 12% higher risk of cancer.
Sodium nitrite was linked to a 32% higher risk of prostate cancer. Potassium nitrate was tied to a 13% higher risk of overall cancer and a 22% higher risk of breast cancer. Acetic acid, often used as a food acid, was linked to a 12% higher risk of cancer. Some antioxidant preservatives like sodium erythorbate also showed possible links to cancer.
The researchers say more studies are needed to better understand how these preservatives might affect the body. Some of these substances may affect the immune system or cause inflammation, which can raise cancer risk over time.
This was an observational study, which means it can’t prove that preservatives cause cancer. There could be other reasons why some people developed cancer, such as lifestyle or other health issues. But the study was large and used detailed food records collected over 14 years, which makes the results more reliable.
Based on these findings, the researchers suggest it may be time for health agencies to review how preservatives are regulated. They recommend that the food industry reduce the use of preservatives when they’re not needed. They also encourage people to eat more fresh and less processed foods when possible.
Experts from the U.S. agree that while preservatives help make food more affordable and prevent waste, we still don’t fully understand their long-term health effects. They support better labeling, stricter rules, and global efforts to monitor food additives.
Until more is known, public health advice already recommends eating less processed meat and alcohol, which are more clearly linked to cancer. People can take simple steps now—like choosing fresh foods—to protect their health, even as research continues.
If you care about cancer, please read studies that a low-carb diet could increase overall cancer risk, and vitamin D supplements could strongly reduce cancer death.
For more information about health, please see recent studies about how drinking milk affects the risks of heart disease and cancer and results showing higher intake of dairy foods linked to higher prostate cancer risk.
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