Two major French studies have raised fresh concerns about the potential health risks associated with commonly used food preservatives, suggesting that some additives may be linked to increased risks of cancer and type 2 diabetes.
The studies, conducted through France’s large-scale NutriNet-Santé research programme, analysed dietary habits and medical records from more than 170,000 participants. Researchers say the findings are among the first to explore possible connections between long-term exposure to food preservatives and major chronic diseases.
The research was led by scientists from the French National Institute of Health and Medical Research and has attracted international attention because many of the preservatives examined are widely used in processed foods globally.
Several Preservatives Linked to Cancer Risk
One of the studies, published in The BMJ, followed more than 105,000 adults over a period of up to 14 years.
Researchers identified six preservatives that showed possible associations with increased cancer risks.
Among them was sodium nitrite, commonly found in processed meats such as bacon, sausages, ham, and deli products. The study linked higher consumption of sodium nitrite with an increased risk of prostate cancer.
Potassium nitrate, another preservative frequently used in processed meats, was associated with higher risks of breast cancer and overall cancer incidence.
Other preservatives highlighted in the research included potassium sorbate, potassium metabisulfite, acetates, and acetic acid, all of which are commonly used in products such as baked goods, wine, sauces, cheeses, and processed foods.
According to the researchers, some of these additives were linked to elevated risks of breast cancer and other forms of cancer.
Concerns Over Natural Additives
Scientists involved in the study also warned that some preservatives often regarded as “natural” may still carry health risks when used as food additives.
The researchers explained that substances such as vitamin C, vitamin E, and rosemary extracts may behave differently in processed foods than when consumed naturally through fruits, vegetables, and whole foods.
They noted that isolating compounds from their original food sources could affect how the body processes them, particularly through interactions with gut bacteria.
Diabetes Study Reveals Additional Risks
A second study, published in Nature Communications, examined nearly 109,000 participants and focused on the relationship between preservatives and type 2 diabetes.
Researchers reported that 12 out of 17 preservatives studied were associated with significantly higher risks of developing type 2 diabetes among individuals with the highest levels of exposure.
Some preservatives identified in the diabetes research overlapped with those linked to cancer risks, including potassium sorbate, potassium metabisulfite, sodium nitrite, acetic acid, and sodium acetate.
Additional additives examined included phosphoric acid, often found in soft drinks and processed foods, as well as certain antioxidant preservatives.
Experts Call for More Research and Healthier Diets
Although researchers stressed that more studies are needed to confirm the findings, health experts say the reports add to growing concerns about the long-term health effects of highly processed foods.
Medical specialists continue to encourage consumers to prioritise fresh, minimally processed foods, particularly fruits, vegetables, whole grains, and other plant-based options.
The researchers also called for further review of food additive regulations to strengthen consumer protection and improve public health awareness regarding preservative exposure.