Two major studies published simultaneously in Paris on January 7, 2026 put a spotlight on something most families eat every single day: the chemical preservatives hidden inside processed foods. Researchers at France’s National Institute of Health and Medical Research (INSERM) released two large-scale analyses showing that higher consumption of common food preservatives was associated with a modestly higher risk of cancer in one study and a notably elevated risk of type 2 diabetes in the other. Both papers drew on the same massive French health database, and both were authored by the same lead researcher. The findings quickly drew international attention, partly because the preservatives involved are approved for use in the United States – and are ingredients most of us eat without a second thought.
The research was led by Mathilde Touvier, director of research at the French National Institute of Health and Medical Research and principal investigator of the NutriNet-Santé cohort. The NutriNet-Santé study is a long-running French nutrition project that began in 2009 and compares over 170,000 participants’ web-based reports on diet and lifestyle with their medical data stored in the French national health care system. The doctoral student who conducted both analyses, Anaïs Hasenböhler, is a doctoral candidate in nutritional epidemiology at the Université Sorbonne Paris Nord.
Before diving into what the studies found, it’s worth being clear on what food preservatives actually are. They are substances added to packaged foods to stop them from spoiling too quickly – either by slowing the growth of mold and bacteria, or by limiting oxygen exposure inside packaging. Sodium nitrite, the pink-tinted salt in bacon and deli meats, is one example. Potassium sorbate, the white powder in your favorite bottled salad dressing or block of cheese, is another. These are not obscure industrial chemicals – they are government-approved, considered safe, and present in an enormous portion of everything on grocery store shelves.
What the Cancer Study Found
The cancer study, published in The BMJ, closely examined the impact of 58 preservatives on some 105,000 people who were free of cancer in 2009 and were followed for up to 14 years. Researchers wanted to know whether eating more of these additives over the long term translated into higher cancer rates – and the answer, for a specific handful of preservatives, was yes.
When researchers looked at all preservatives combined, they found no overall link with cancer risk. In addition, 11 of the 17 preservatives studied individually showed no association with cancer incidence. That context matters enormously. The finding is not that preservatives as a group cause cancer – it is that certain specific ones showed concerning patterns in this particular observational study. During the follow-up period, 4,226 participants were diagnosed with cancer. These cases included 1,208 breast cancers, 508 prostate cancers, 352 colorectal cancers, and 2,158 other types of cancer.
Sodium nitrite, a chemical salt commonly used in processed meats such as bacon, ham, and deli meats, was associated with a 32% increase in the risk of prostate cancer. Its cousin, potassium nitrate, was associated with a 22% higher risk of breast cancer and a 13% increase in all cancers. Sorbates, especially potassium sorbate, were associated with a 26% higher risk of cancer and a 14% increase in all types of cancers. These water-soluble salts are used in wine, baked goods, cheeses, and sauces to prevent molds, yeast, and some bacteria.
To put those figures in proportion: the level of increased risk remained moderate. For comparison, heavy smoking raises the risk of getting lung cancer by more than 15 times. The associations found in this study are real, but they are not in the same league as the most powerful known carcinogens.
Which Food Preservatives Are Most Linked to Cancer Risk?
Sodium nitrite was associated with a 32% higher risk of prostate cancer. Potassium nitrate was linked to a 13% increased risk of overall cancer and a 22% higher risk of breast cancer. Total acetates were associated with a 15% higher risk of overall cancer and a 25% higher risk of breast cancer. Acetic acid alone was linked to a 12% increase in overall cancer risk.
Sodium erythorbate and other erythorbates, which are made from fermented sugars, were associated with a 21% higher incidence of breast cancer and a 12% increase in cancer overall. Erythorbates are used to prevent discoloration and spoilage in poultry, soft drinks, and baked goods. That last part is worth pausing on. Erythorbates are derived from fermented sugars and are classified as antioxidant preservatives – the kind that sound almost wholesome on a label. Yet in this dataset, they still showed a link to elevated cancer rates.
This connects to a broader finding in the research. While “natural” preservatives are often linked to lower cancer risk when eaten as whole foods, they may be harmful when used as additives, Touvier said. “The hypothesis here is when you isolate one substance from its original matrix of a whole fruit or vegetable, the action on our health can be different depending on the way our gut microbiota will digest it,” she said. In other words, vitamin C from an orange and sodium ascorbate from a bottle of salad dressing are not necessarily the same thing once your digestive system gets involved.
What the Diabetes Study Found
The second paper, published in Nature Communications, tackled a different but equally serious chronic disease: type 2 diabetes. This is the form of diabetes that develops over time due to lifestyle and metabolic factors, and it affects tens of millions of Americans.
A 14-year study of 108,723 adults found that high consumption of everyday preservatives like potassium sorbate and sodium nitrite significantly increases type 2 diabetes risk. Of the 17 preservatives studied individually, the results were striking in their breadth. Higher intake of food preservatives, including both non-antioxidant and antioxidant additives, is associated with an increased risk of type 2 diabetes, with incidence rates rising by 47%, 49%, and 40% respectively for higher consumption groups. Twelve commonly used preservatives, such as potassium sorbate (E202) and citric acid (E330), showed significant associations with elevated diabetes risk.
What Did French Studies Find About Food Preservatives and Diabetes?
The twelve preservatives linked to higher diabetes rates included six non-antioxidant preservatives and six antioxidant additives. These included widely used non-antioxidant food preservatives – potassium sorbate (E202), potassium metabisulfite (E224), sodium nitrite (E250), acetic acid (E260), sodium acetates (E262), and calcium propionate (E282) – and antioxidant additives including sodium ascorbate (E301), alpha-tocopherol (E307), sodium erythorbate (E316), citric acid (E330), phosphoric acid (E338), and rosemary extracts (E392).
The scale of that list deserves a moment of honest reflection. In 2024, the Open Food Facts World database listed around three and a half million food and beverage products. More than 700,000 of those products contained at least one preservative. Citric acid – one of the 12 linked to higher diabetes rates in this French research on food additives – is in everything from store-bought hummus to energy drinks to canned tomatoes. If you eat packaged food at all, and virtually everyone does, you are eating these compounds regularly.
Twelve of the 17 preservatives researchers examined were linked with nearly a 50% higher risk of developing type 2 diabetes in people who consumed the highest levels. Five of the same preservatives that were linked to cancer – potassium sorbate, potassium metabisulfite, sodium nitrite, acetic acid, and sodium acetate – also raised the risk of developing type 2 diabetes. That overlap between both diseases in five of the same compounds is one of the most striking patterns in the entire pair of studies.
How the Research Was Done – and Why It Matters
Observational studies like these are important to understand properly, because what they can tell us is limited in a specific and meaningful way. This is an observational study, so no firm conclusions can be drawn about cause and effect, and the researchers can’t rule out the possibility that other unmeasured factors may have influenced their results. The study tracks what people eat and what happens to their health over time. It does not – and cannot – prove that a specific preservative directly caused a specific cancer or case of diabetes. That would require controlled experimental trials of a kind that are essentially impossible to run on humans over a 14-year period.
What makes these papers stronger than a typical food survey is the method. The study followed more than 100,000 French adults between 2009 and 2023. Participants regularly provided information about their medical history, socio-demographic background, physical activity, lifestyle habits, and overall health. They also submitted detailed food records covering multiple 24-hour periods. These records included the names and brands of industrial food products they consumed. Researchers cross-referenced this information with several databases – Open Food Facts, Oqali, and EFSA – and combined it with measurements of additives in foods and beverages.
The studies also controlled for confounding factors – things like tobacco use, alcohol intake, physical activity levels, and medication use – that could otherwise skew the results. The finding that specific classes of preservatives are associated with increased risk of select cancers was robust to all of these adjustments, indicating it is a matter that warrants respect and requires further research. Still, experts warned that “any calls for changes in consumer behavior would be premature given the uncertainty surrounding analysis of multiple subgroups and the potential for false-positive errors,” according to Gavin Stewart, a reader in interdisciplinary evidence synthesis from Newcastle University, who did not participate in the study.
One specific limitation worth noting: the sample is not necessarily representative of the general population, being mostly made up of women (78.7%) with healthier than average lifestyles. That means the results may not translate perfectly to populations with different dietary patterns or demographics.
Are Common Food Additives in the US Linked to Chronic Disease?
Yes – and the significance of that question is not lost on the researchers. The six preservatives linked to cancer are considered GRAS, or “generally recognized as safe,” in food by the US Food and Drug Administration. Those include sodium nitrite, potassium nitrate, sorbates, potassium metabisulfite, acetates, and acetic acid. All of them are approved for use in American food products.
Touvier stated these are “very important findings for preservatives that are not only widely used in the French and European markets, but also in the United States.” The World Health Organization has also noted concerns about processed meats specifically – the World Health Organization has long considered processed meat a carcinogen, with a direct link to colon cancer. That classification predates the 2026 studies but reinforces the general direction of the evidence on nitrites in particular.
The researchers at INSERM are also looking ahead. Other studies based on the NutriNet-Santé cohort are awaiting publication and aim to analyze links between mixtures of food additives and the risk for high blood pressure and cardiovascular disease. Molecular epidemiology research is underway to identify blood markers of inflammation and oxidative stress – a process where unstable molecules damage cells from within – and to study metabolic disturbances related to additive exposure. Stool samples have also been collected to examine impacts on the gut microbiota. In short, these two studies are the opening chapters, not the whole story.
As The Globe and Mail noted in its January 2026 coverage, all 12 of the preservatives linked to higher diabetes risk in this research are currently permitted for use in Canada and the United States – making the findings relevant far beyond France’s borders.
What This Means for Your Family’s Grocery Cart
The reassuring part: this research does not suggest you need to throw out everything in your pantry. As Touvier told AFP, “consuming products with preservatives does not mean you will immediately develop cancer.” These are elevated statistical risks in a population study, not certainties. And as this research on food preservatives makes clear, the strength of association for these preservatives is far weaker than for well-established risk factors like heavy smoking or heavy alcohol use.
The practical part: Touvier’s message for the general public is to “choose the least processed foods when shopping in the supermarket.” That advice is consistent with what nutrition researchers and public health bodies have been saying for years. A 2025 science advisory from the American Heart Association reinforced that the best approach to managing risk from ultra-processed foods, including their additive content, is a diet built primarily on whole, minimally processed ingredients.
The researchers added that “these new data add to others in favour of a reassessment of the regulations governing the general use of food additives by the food industry in order to improve consumer protection.” Regulatory change, however, moves slowly. That means individual choices at the grocery store remain the most immediate lever available.
Read More: “Fit Grandma” Says Eating 150 Eggs a Month is One of Her Secrets to Staying Healthy
What to Do Now
The biggest takeaway from this French research is not panic – it is awareness. Reading ingredient lists has real value, and knowing which preservatives to watch for in processed foods is now a more informed exercise than it was before January 2026. Sodium nitrite appears on the labels of most cured meats: bacon, hot dogs, deli turkey, and salami. Potassium sorbate shows up in packaged cheeses, wines, baked goods, and fruit drinks. Potassium metabisulfite is common in wine and dried fruits. Sodium nitrite and potassium sorbate were linked to both cancer and diabetes risk in these studies – making them the two preservatives worth paying the most attention to if you’re trying to limit your family’s exposure.
Two concrete steps require no overhaul of your diet: first, cut back on processed deli meats and replace them more often with fresh-cooked proteins – this reduces sodium nitrite exposure in the most direct way possible. Second, when you’re choosing packaged snacks, dressings, or drinks, spend 10 seconds scanning the ingredient list for the names above. You will not eliminate all exposure, and that is fine. The goal is reduction over time, not perfection on any given Tuesday. Researchers are still working to understand the exact biological mechanisms – how these compounds may affect immune function, gut bacteria, and metabolic processes – and more targeted advice may follow as those findings emerge. For now, the single most evidence-supported step any family can take is a familiar one: eat more food that does not come in a package.
Disclaimer: This article was created with AI assistance and edited by a human for accuracy and clarity.