Studies link some food preservatives to higher diabetes and cancer risk | Medical research

Higher consumption of certain food preservatives is associated with an increased risk of type 2 diabetes and cancer, two studies suggest.

The findings, published in the medical journals Nature Communications and BMJ, could have important public health implications given the ubiquitous use of these additives around the world, the researchers said.

Although more studies are needed, they said the findings should lead to a reassessment of regulations governing companies’ use of preservatives in products such as ultra-processed foods (UPF) to improve consumer protections worldwide.

Preservatives are substances added to packaged foods to extend shelf life. Previous experimental studies have shown that some preservatives can damage cells and DNA, but strong evidence linking preservatives to type 2 diabetes or cancer risk remains scarce.

In both studies, researchers set out to examine the association between exposure to preservatives and the risk of type 2 diabetes and cancer in adults, using diet and health data from 2009 to 2023. The results were based on more than 100,000 French people enrolled in the NutriNet-Santé study.

Beyond the overall effect of preservatives, 17 preservatives were analyzed individually.

In the cancer study published in the BMJ, of the 17 preservatives studied individually, 11 were not associated with cancer incidence, and no link was found between preservatives overall and cancer. However, higher consumers of several preservatives were associated with higher cancer risk than non-consumers or lower consumers.

For example, potassium sorbate was associated with a 14% increased risk of overall cancer and a 26% increased risk of breast cancer, while sulfites were associated with a 12% increased risk of overall cancer.

Sodium nitrite was associated with a 32% increased risk of prostate cancer, while potassium nitrate was associated with an increased risk of overall cancer (13%) and breast cancer (22%). Total acetates were associated with an increased risk of overall cancer (15%) and breast cancer (25%), while acetic acid was associated with a 12% increased risk of overall cancer.

Although more studies are needed to better understand these potential risks, researchers noted that several of these compounds could alter immune and inflammatory pathways, possibly triggering the development of cancer.

This was an observational study, so no definitive conclusions could be drawn about cause and effect. The researchers also could not rule out the possibility that other unmeasured factors could have influenced their results.

However, this was a large study based on detailed dietary records linked to dietary databases over 14 years and the results were consistent with existing experimental data suggesting cancer-related adverse effects of several of these compounds.

“This study provides new information for future reassessment of the safety of these food additives by health agencies, considering the balance between benefits and risks for food preservation and cancer,” the researchers wrote.

In the meantime, they called on manufacturers to limit the use of unnecessary preservatives and supported recommendations for consumers to eat fresh, minimally processed foods.

Professor William Gallagher, of University College Dublin, who was not involved in the study, said the findings had implications for public health. “These higher rates of cancer are modest but are significant when taken at the population level in terms of their potential impact,” he said.

In the type 2 diabetes study published in Nature Communications, higher overall consumption of preservatives, non-antioxidant preservatives, and antioxidant additives was associated with increased incidence of type 2 diabetes, by 47%, 49%, and 40%, respectively, compared to the lowest consumption levels.

Of the 17 preservatives studied individually, higher consumption of 12 of them was associated with an increased risk of type 2 diabetes.

“This is the first study in the world on the links between preservative additives and the incidence of type 2 diabetes,” said Mathilde Touvier, study coordinator. “Although the results require confirmation, they are consistent with experimental data suggesting harmful effects of several of these compounds. »