Emulsifiers in processed foods may be linked to an increased risk of type 2 diabetes

Emulsifiers in processed foods may be linked to an increased risk of type 2 diabetes

In Europe and North America, 30 to 60% of dietary energy in adults comes from highly processed foods. A growing number of epidemiological studies indicate a connection between higher consumption of highly processed foods and a higher risk of diabetes and other metabolic disorders.

Emulsifiers are among the most commonly used additives. They are often added to processed and packaged foods such as certain industrial cakes, cookies and desserts, as well as yogurts, ice cream, chocolate bars, industrial breads, margarines and prepared or ready-to-heat meals to improve their appearance, taste and texture and to extend shelf life. These emulsifiers include, for example, mono- and diglycerides of fatty acids, carrageenans, modified starches, lecithins, phosphates, cellulose, gums and pectins.

As with all food additives, the safety of emulsifiers has been previously evaluated by food safety and health authorities based on the scientific evidence available at the time of their evaluation. However, some recent studies suggest that emulsifiers may disrupt the gut microbiota and increase the risk of inflammation and metabolic disorders, potentially leading to insulin resistance and the development of diabetes.

For the first time in the world, a team of researchers in France has examined the associations between dietary intake of emulsifiers, assessed over a maximum follow-up period of 14 years, and the risk of developing type 2 diabetes in a large study in the general population.

The results are based on analysis of data from 104,139 adults in France (mean age 43 years; 79% women) who participated in the NutriNet-Santé web cohort study (see box below) between 2009 and 2023.

Participants completed dietary records for at least two days and collected detailed information about all foods and beverages consumed and their commercial brands (in the case of industrial products). These dietary records were repeated every six months for 14 years and cross-referenced with databases to determine the presence and amount of food additives (including emulsifiers) in the products consumed. Laboratory studies were also conducted to provide quantitative data. This allowed measurement of chronic exposure to these emulsifiers over time.

During follow-up, participants reported the development of diabetes (1056 diagnosed cases) and the reports were validated using a multi-source strategy (including data on diabetes medication use). Several known risk factors for diabetes, including age, gender, weight (BMI), education level, family history, smoking, alcohol and physical activity, and the overall nutritional quality of the diet (including sugar intake). taken into account in the analysis.

After an average follow-up of seven years, researchers found that chronic exposure - assessed through repeated data - to the following emulsifiers was associated with an increased risk of type 2 diabetes:

• Carrageene (Gesamtmenge an Carrageenen und E407; 3 % erhöhtes Risiko pro Dosiserhöhung um 100 mg pro Tag)

• Trikaliumphosphat (E340; 15 % erhöhtes Risiko pro Dosiserhöhung von 500 mg pro Tag)

• Mono- und Diacetylweinsäureester von Mono- und Diglyceriden von Speisefettsäuren (E472e; 4 % erhöhtes Risiko bei einer Erhöhung um 100 mg pro Tag)

• Natriumcitrat (E331; 4 % erhöhtes Risiko pro Dosiserhöhung von 500 mg pro Tag)

• Guarkernmehl (E412; 11 % erhöhtes Risiko pro Dosiserhöhung von 500 mg pro Tag)

• Gummi arabicum (E414; 3 % erhöhtes Risiko pro Steigerung von 1000 mg pro Tag)

• Xanthangummi (E415; 8 % erhöhtes Risiko pro Dosiserhöhung von 500 mg pro Tag)

This study represents an initial investigation of these relationships and further research is now needed to establish causal relationships. The researchers noted several limitations to their study, such as the predominance of women in the sample, higher levels of education than the general population, and generally more health-promoting behaviors among participants in the NutriNet-Santé study. Therefore, caution should be exercised when generalizing the conclusions to the entire French population.

Still, the study is based on a large sample, and the researchers took into account a variety of factors that could have introduced confounding bias. They also used unique, detailed data on exposure to food additives, down to the brand name of the industrial products consumed. In addition, the results remain consistent through various sensitivity analyses[1], which strengthens their reliability.

'These findings currently come from a single observational study and cannot be used alone to establish a causal relationship. They need to be replicated in other epidemiological studies worldwide and complemented by toxicological and interventional experimental studies to further clarify the mechanisms linking these food additive emulsifiers to the onset of type 2 diabetes. However, our results represent key elements to enrich the debate on reassessing the regulations surrounding the use of additives in the food industry to better protect consumers“, explain Mathilde Touvier, research director at Inserm, and Bernard Srour, junior professor at INRAE, lead authors of the study.

In the next steps, the research team will examine the variations in certain blood markers and gut microbiota associated with the consumption of these additives to better understand the underlying mechanisms. Researchers will also study the health effects of additive mixtures and their possible “cocktail effects.” They will also work with toxicologists to test the effects of these exposures in in vitro and in vivo experiments to gather further evidence for a causal relationship.

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