A new study from France shows that people who eat more of certain preservatives in processed foods and drinks face a slightly higher chance of getting cancer. The research followed over 100,000 adults for about a decade and found links to overall cancer as well as breast and prostate cancers. It looked at additives like potassium sorbate, sulfites, sodium nitrite, and potassium nitrate, which are common in items like meats, drinks, and ready meals.
Background
Food preservatives help keep products fresh longer by stopping mold, bacteria, and spoilage. They show up in many store-bought foods, from sausages and bacon to sodas, wines, and packaged fruits. Companies add them to make sure food lasts on shelves and in homes without going bad quickly.
This study came out of a big health project called NutriNet-Santé, which started in 2009. It involves people across France who share details about what they eat every day. Researchers used data from 2009 to 2023, tracking 105,260 adults. These folks were at least 15 years old when they joined, with an average age of 42. Most were women, making up 79% of the group. None had cancer at the start.
Participants filled out 24-hour food logs many times, noting brands and amounts. On average, they did this for 7.5 years. The team linked this info to databases that list preservatives in foods. Over the follow-up, 4,226 people got cancer diagnoses. That included 1,208 breast cancers, 508 prostate cancers, 352 colorectal cancers, and 2,158 others.
Past lab work has shown some preservatives can harm cells or DNA in tests. But human studies have been few. This one aimed to check real-world eating habits and cancer rates over time.
Key Details
Researchers checked 17 preservatives split into two groups: non-antioxidants, which fight germs and chemical changes, and antioxidants, which block oxygen damage. Eleven preservatives showed no link to cancer. Total preservatives as a group also had no connection.
But higher amounts of some did tie to more risk. For non-antioxidants:
- Potassium sorbate linked to 14% higher overall cancer risk and 26% higher breast cancer risk.
- Sulfites, like potassium metabisulfite, tied to 12% higher overall cancer.
- Sodium nitrite and potassium nitrate, common in processed meats, raised overall cancer risk.
- Acetic acid and total acetates boosted overall cancer by 15% and breast by 25%.
For antioxidants, total erythorbates and sodium erythorbate showed higher cancer rates.
Where These Preservatives Hide
Processed meats top the list for nitrites and nitrates. Drinks and dressings often have sulfites. Fruits, veggies, and other ready foods carry sorbates and others. Almost everyone in the study—99.7%—ate some preservatives over two years.
The links held even after checking factors like age, weight, smoking, exercise, and family cancer history. Risks were modest, like a hazard ratio of 1.16 for high non-antioxidant intake versus low. That means a 16% higher chance in stats terms.
"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." – Study researchers
Mathilde Touvier, who leads the team at INSERM, noted this is the first big human study to measure preservative intake against cancer this way. Her group has also linked additives like sweeteners to health issues before.
What This Means
The findings do not prove preservatives cause cancer. They show a connection in this group, but other factors could play a role. The study counted on people reporting their own food intake, which can have small errors. It had more women, so prostate results come from fewer cases.
Still, the size and detail make it strong. Results match some animal tests where these chemicals showed harm. Nearly all adults eat these additives daily without knowing.
Health groups already push eating less processed food, more fresh items. Processed meats count as risky already, along with too much alcohol. This adds to that advice.
Regulators might look again at rules. Ideas include lower limits on these additives, better labels listing amounts, and checks like those for salt or bad fats. Food makers could switch to safer options or cut use where possible.
For now, people can pick fresh meats, home-cooked meals, and check labels for E200-E299 codes, which mark preservatives. Cutting back on ready meals and cured meats lowers exposure naturally.
The team calls for more work, like tests on how these chemicals act in bodies and bigger studies worldwide. Global teams could track additives like they do other food risks. France's food plan already aims to cut ultra-processed items, though some steps got paused.
Experts say while proof builds, simple changes help. Shop the edges of stores for produce, dairy, and fresh proteins. Make sauces and dressings at home to skip hidden extras. Over time, small shifts add up for health.
