In Europe and North America, 30 to 60% of dietary energy intake in adults is provided by ultra-processed foods. Recent epidemiological studies have linked high intakes of ultra-processed foods with higher risks of obesity, mortality and chronic diseases (cardiovascular disease, type 2 diabetes, cancer, etc.). Emulsifiers are among the most commonly used additives in industrial foods. They are often added to processed and packaged foods such as certain industrial cakes, cookies and desserts, as well as ice creams, candy bars, breads, margarines and ready meals, in order to improve their appearance, taste and texture and lengthen shelf life. These include celluloses, monoand diglycerides of fatty acids, modified starches, lecithins, carrageenans, phosphates, gums and pectins.
As with all food additives, the safety of emulsifiers is regularly evaluated on the basis of the scientific evidence available at a given time. However, some recent studies suggest that emulsifiers can disrupt the gut microbiota and increase the risk of inflammation, leading to potentially increased susceptibility to cardiovascular problems.
In order to explore this question in greater depth, French researchers undertook to evaluate the links between exposure to emulsifiers and the risk of cardiovascular disease, including coronary heartand cerebrovascular disease, i.e. conditions that affect blood circulation and blood vessels in the heart and brain.
Their conclusions are based on the analysis of data from 95,442 French adults (average age 43 years; 79% women) with no history of cardiovascular disease who voluntarily participated in the NutriNet-Santé cohort study (see box below) between 2009 and 2021.
During the first two years of follow-up, the participants completed at least three (and up to 21) days of online dietary records. Each food or drink consumed was then matched against databases to identify the presence and level of food additives, including emulsifiers. Laboratory assays were also performed in order to provide quantitative data.
The participants were asked to declare any major cardiovascular events, such as heart attack or stroke, which were validated by an expert committee following examination of their medical records. Deaths related to cardiovascular disease were also recorded using the French national registry of deaths.
Several well-known risk factors for heart disease, including age, sex, weight (BMI), educational level, family history, smoking and levels of physical activity, as well as overall quality of the diet (e.g. consumption of sugar, salt, energy and alcohol) were taken into account.
After an average follow-up of seven years, the scientists found that the higher intakes of total celluloses (food additive codes E460 [1] to E468) were associated with higher risks of cardiovascular disease. In particular, this combination was specifically observed for intakes of E460 (microcrystalline cellulose, powdered cellulose) and E466 (carboxymethylcellulose).
On the other hand, higher intakes of monoand diglycerides of fatty acids (E471 and E472) were associated with higher risks for all the diseases studied. Among these emulsifiers, lactic ester of monoand diglycerides of fatty acids (E472b) was associated with a higher risk of cardiovascular and cerebrovascular disease, and citric acid ester of monoand diglycerides of fatty acids (E472c) was associated with a higher risk of cardiovascularand coronary heart disease.
High intake of trisodium phosphate (E339) was also associated with an increased risk of coronary heart disease.
No association was detected in this study between the other emulsifiers and the development of cardiovascular diseases.
Given its observational nature, the study cannot therefore establish causality on its own, and the scientists acknowledge it to have certain limitations. For example, the high proportion of women, the higher educational background and overall more health-conscious behaviors among the NutriNet-Santé study participants compared with the general French population, which may limit the generalizability of the results.
That being said, the study sample was large and the authors were able to consider a wide range of potentially confounding factors, while using detailed and unique data on food additives, down to the brand of the products consumed. In addition, the results remained unchanged after multiple sensitivity analyses, thereby strengthening their robustness.
"While these findings need to be replicated in other studies worldwide, they bring new key knowledge to the debate on re-evaluating the regulations around the use of additives in the food industry, in order to better protect consumers,” explains Mathilde Touvier, Research Director at Inserm, and Bernard Srour, Junior Professor at INRAE, principal authors of the study.
NutriNet-Santé is a public health study coordinated by the Nutritional epidemiology research team (EREN-CRESS, Inserm/INRAE/Cnam/Université Sorbonne Paris Nord/Université Paris Cité) which, thanks to the commitment and loyalty of over 170,000 participants (known as Nutrinautes), advances research into the links between nutrition (diet, physical activity, nutritional status) and health. Launched in 2009, the study has already given rise to over 270 international scientific publications. In France, a drive to recruit new participants is still ongoing in order to continue to further research into the relationship between nutrition and health.
By devoting a few minutes per month to answering questionnaires on diet, physical activity and health through the secure online platform etude-nutrinet-sante.fr , participants in France contribute to furthering knowledge of the links between diet and health.
[1] Food additives are identified in the list of ingredients by a European code consisting of the letter "E”, followed by a number making it possible to easily identify the category. For example, E100 for colorants, E200 for preservatives, E400 for emulsifiers and texture agents.
