Food preservatives linked to higher risk of cancer and type 2 diabetes

The consumption of larger quantities of certain widely used food preservatives is associated with a higher risk of type 2 diabetes and specific types of cancer, according to the results of two large French cohort studies published in the scientific journals BMJ and Nature Communications, Euronews reports.

The research, based on data from over 100,000 participants, found that individuals with a higher intake of certain preservative additives have approximately a 47% higher risk of type 2 diabetes and up to a 32% higher risk of certain types of cancer compared to those with lower consumption.

In the analysis related to diabetes, scientists divided preservatives into two main groups: non-antioxidant preservatives, which inhibit the growth of microorganisms or slow down chemical spoilage processes, and antioxidant preservatives, which prevent oxidation and extend the shelf life of foods.

The results show that a high intake of non-antioxidant preservatives is associated with a 49% higher incidence of type 2 diabetes, while for antioxidant additives, the risk is 40% higher among those with the highest consumption.

In the cancer study, researchers analyzed both total preservative intake and 17 individual substances. Although no link was found between total preservative consumption and overall cancer incidence, certain specific additives were associated with an increased risk of particular types of cancer.

These include:

• potassium sorbate, used in dairy products and baked goods – linked to a 14% higher risk of overall cancer and a 26% higher risk of breast cancer;
• sodium nitrite, frequently used in processed meats such as bacon, ham, and sausages – associated with a 32% higher risk of prostate cancer;
• potassium nitrate – linked to a 13% higher risk of overall cancer and a 22% higher risk of breast cancer;
• acetates, used as acidity regulators and flavorings – associated with a 15% higher risk of overall cancer and a 25% higher risk of breast cancer.

Processed meats, which contain high levels of chemical additives to extend shelf life, have long been linked to colorectal cancer. In 2015, the World Health Organization classified products such as ham, bacon, salami, and hot dogs as carcinogenic to humans (Group 1).

The authors emphasize that the results do not prove a direct causal relationship, as the studies are observational and the influence of other, unmeasured factors cannot be excluded.

“These data provide new arguments for a future re-evaluation of food additive safety by health agencies, taking into account the balance between the benefits of preservation and potential health risks,” the authors of the cancer study write.

Researchers are calling on manufacturers to limit the use of unnecessary preservatives and on consumers to opt for freshly prepared and minimally processed foods.

However, independent experts warn against premature conclusions. “Calls for changes in consumer behavior at this stage are premature, given the uncertainty and the possibility of false positive results,” commented Dr. Gavin Stewart from Newcastle University, who was not involved in the studies.

*The analyses are based on data from the French NutriNet-Santé cohort, which includes over 100,000 participants followed for an average of 7.5 years. Volunteers regularly provided information about their diet through detailed 24-hour food diaries, as well as data on health status, lifestyle, and physical activity. This allowed scientists to calculate individual exposure to various food additives.