In recent years, attention towards ultra-processed foods has grown, and now two new scientific studies add an important piece to the debate. According to what is published in magazines BMJ And Nature Communications, Some commonly used food preservatives may be associated with an increased risk of type 2 diabetes and specific forms of cancer.
We are talking about food additives present in very popular products such as cured meats, cheeses, industrial bread, packaged sweets, processed dried fruit and snacks.
The work was based on data from the NutriNet-Santé cohort, a population study involving over 100,000 French adults followed for more than a decade, from 2009 to 2023. Participants provided detailed information on their medical history, lifestyle, physical activity and above all on nutrition, completing repeated 24-hour food diaries in which they also indicated brands and commercial names of the products consumed.
Thanks to specific databases such as Open Food Facts, Oqali and EFSA, researchers were able to cross-reference this data with precise measurements of additives present in foods and drinks, thus estimating each participant’s long-term exposure to various preservatives.
What did the researchers discover? The data collected shows that people who take high doses of some additives have a 47% greater risk of developing type 2 diabetes and a 32% greater risk of developing certain cancers, compared to those who consume lower quantities. A discovery that should lead health authorities to reconsider food safety regulations.
What are preservatives and where are they “hiding”
Preservatives belong to the large family of food additives and are used extensively by industry to extend the shelf life of products. In 2024, the global database Open Food Facts listed around three and a half million foods and drinks and more than 700,000 of these contained at least one preservative.
Researchers have distinguished preservatives into two main categories. The first includes non-antioxidant preservatives, which slow spoilage by limiting microbial growth or chemical reactions in foods. The second includes antioxidant preservatives, which protect foods by reducing or controlling exposure to oxygen.
On product labels, these additives generally appear with European codes between E200 and E299 for preservatives in the strict sense, and between E300 and E399 for antioxidants. We find them practically everywhere: in cured meats and processed meats, in cheeses, in packaged baked goods, in dried fruit, in chocolates, in drinks, in ready-made sauces, in savory snacks and in many other large-scale retail products.
The link to type 2 diabetes
Over the observation period, 1,131 cases of type 2 diabetes were recorded among the 108,723 study participants. The results were therefore unequivocal: those who consumed greater quantities of preservatives showed a significantly higher risk of developing the disease.
In particular, high intake of non-antioxidant preservatives was associated with a 49% increase in the risk of type 2 diabetes. Antioxidant preservatives also showed a worrying link, with a 40% increased risk in subjects who consumed the most.
The analysis took into account numerous factors that could influence the risk of diabetes, such as age, sex, education level, smoking habits, alcohol consumption and general diet quality (calories, sugars, salt, saturated fats, fibre).
Potentially dangerous preservatives
In the diabetes study, researchers examined in detail 17 specific preservatives, selected because at least 10% of participants consumed them. Among these, 12 were associated with an increased risk of type 2 diabetes. Here is the list:
Non-antioxidant preservatives linked to diabetes:
Antioxidant preservatives linked to diabetes:
Specific preservatives associated with cancer risk
The study published on Nature Communications took a different approach, focusing on the link between specific preservatives and well-defined cancers. Although no association has emerged between overall preservative consumption and overall cancer risk, some additives have shown worrying correlations with specific cancers. These are:
Processed meats, which contain particularly high concentrations of nitrates and nitrites, have been under the magnifying glass of the scientific community for years. In 2015, the World Health Organization classified products such as ham, bacon, salami and frankfurters as Group 1 carcinogens, mainly due to the link to colorectal cancers.
The reactions of the scientific community
This is the first study in the world on the links between preservative additives and the incidence of type 2 diabetes. Although the results require confirmation, they are consistent with experimental data that suggest the harmful effects of several of these compounds – explained Mathilde Touvier, coordinator of the research.
Anaïs Hasenböhler, a doctoral student at EREN who conducted the studies, added:
These new data add to other elements in favor of a reevaluation of the regulations governing the general use of food additives by industry, in order to improve consumer protection.
However, not all experts agree on the need for immediate changes. Gavin Stewart, a researcher at Newcastle University who was not involved in the study, urged caution. According to him, it would be premature to recommend changes in consumer behavior, highlighting the risk of false positive results and the uncertainty linked to the analysis of numerous subgroups.
What to do
Although these are observational studies, which do not allow a direct cause-effect relationship to be established, the researchers believe that the data collected justify the recommendations of the French National Nutrition and Health Programme, i.e. favoring fresh and minimally processed foods and limiting unnecessary additives as much as possible.
In practice, this means reducing the consumption of packaged and ultra-processed products, preferring foods prepared at home with simple ingredients. When shopping, it is worth reading the labels carefully, considering that the longer the list of ingredients and full of incomprehensible acronyms, the more likely it is that the product contains numerous additives.
Sources: Nature / BMJ
