In Europe and North America, 30 to 60% of adults' dietary energy intake comes from ultra-processed foods. A growing number of epidemiological studies suggest a link between high consumption of ultra-processed foods and an increased risk of obesity, cardiometabolic diseases and certain cancers.
Ultra-processed foods are also believed to be involved in the development of Alzheimer's disease. Decryption with Julie Kern in Health on Listening. © Futura
The hidden risks of ultra-processed foods
Emulsifiers are among the most commonly used food additives in these foods. They are often added to industrially processed and packaged foods such as certain pastries, cakes and desserts, ice creams, chocolate bars, breads, margarines and prepared meals, in order to improve their appearance, taste, texturetexture and their durationduration conservation. They include in particular mono- and diglycerides of fatty acids, carrageenans, modified starches, lecithins, phosphatesphosphatesTHE cellulosescelluloseserasers and pectinspectins.
As with all food additives, the safety of emulsifiers has been previously evaluated based on the scientific evidence available at the time. However, some recent research suggests that emulsifiers could disrupt the intestinal microbiota and increase the risk of inflammation, potentially promoting the occurrence of certain cancers. For the first time at the international level, a team from Inserm, Inrae, Université Sorbonne Paris Nord, Université Paris Cité and Cnam, grouped together within the Nutritional Epidemiology Research Team ( Cress-Eren), was interested in the relationships between dietary intake of emulsifiers and the risk of the appearance of several cancer sites in a large study in the general population.
A new understanding of food additives
The results, which were published in the journal PLoS Medicine, are based on the analysis of French data from 92,000 adults (average age 45 years; 79% women) who participated in the NutriNet-Santé cohort study (see box below) between 2009 and 2021.
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The NutriNet-Santé study is a public health study coordinated by the Nutritional Epidemiology Research Team (CRESS-EREN, Inserm/INRAE/Cnam/Université Sorbonne Paris Nord/Université Paris Cité), which, thanks to the commitment and the loyalty of more than 170,000 “nutrinauts”, advances research on the links between nutrition (diet, physical activity, nutritional status) and health. Launched in 2009, the study has already given rise to more than 270 international scientific publications. A call for the recruitment of new nutrinauts is still underway in order to continue to advance public research on the relationships between nutrition and health. By spending a few minutes a month responding, via Internet, on the secure platform etude-nutrinet-sante.fr, with various questionnaires relating to diet, physical activity and health, participants contribute to advancing knowledge, towards a healthier and more sustainable diet. .
Participants reported online all the foods and drinks consumed and their brand (for industrial products), over at least 3 days of food recording, with the possibility of updating their consumption data every 6 months. These recordings were linked to data basedata base in order to identify the presence and dose of food additives (including emulsifiers) in consumed products. Of the dosagesdosages laboratory tests were also carried out to provide quantitative data.
Used in the food industry, emulsifiers have the ability to stabilize ingredients which, without their contribution, would not be able to mix. They also help extend shelf life. © AkuAku, Adobe Stock
During follow-up, participants declared the occurrence of cancers (2,604 cases diagnosed), and a medical committee validated these declarations after reviewing medical records. Several risk factorsrisk factors well known for cancers, including age, sex, weight (BMIBMI), education level, family history, smoking, alcohol and activity levels physicalphysicalas well as the overall nutritional quality of the diet (for example, intake of sugarsugarin salt, in energyenergy) and menopausal status were taken into account.
After an average follow-up of 7 years, the researchers found that higher intakes of monoglycerides and diglycerides ofFatty acidsFatty acids (E471) were associated with increased risks of cancer overall (a 15% increase in risk among the highest consumers – 3e tertile – compared to the lowest consumers – 1er tertile), breast cancers (a 24% increase in risk), and prostate cancers (a 46% increase in risk). On the other hand, women with higher intakes of carrageenans (E407 and E407a) had a 32% greater risk of developing breast cancersbreast cancerscompared to the group with lower intakes.
This is the first observational study in mattermatter, which is therefore not sufficient, on its own, to establish a cause and effect link. The authors highlight certain limitations of this study. For example, the high proportion of women, higher education level on average, and overall more health-conscious behaviors among NutriNet-Santé study participants compared to the general French population, which may limit the generalization of the results.
Nevertheless, the study sample was large and the authors were able to account for a wide range of potentially confounding factors, while using detailed and unique data on food additive exposures, down to brand of industrial products consumed. Furthermore, the results remained unchanged after multiple sensitivity analyses, thus reinforcing their robustness.
“ If these results are to be reproduced in other studies around the world, they bring key new knowledge to the debate on the reassessment of regulations relating to the use of additives in the food industry, in order to better protect consumers », Explain Mathilde Touvier, research director at Inserm, and Bernard Srour, junior professor at Inrae, main authors of the study.