Used to improve the texture, flavor, color and shelf life of products, food additives, particularly emulsifiers, have become very common. They are found, for example, in many biscuits, desserts and industrial breads, margarine and even prepared meals. While these chemical compounds are approved for food use, experts warn against excessive consumption due to their potential harm.
For a long time in the sights of scientists, certain emulsifiers were suspected of causing chronic inflammation of the intestine in laboratory animals. In humans, however, their impacts on health remained poorly understood. Last September, French researchers realized that they could be more harmful than expected by promoting the appearance of cardiovascular pathologies. The results were then published in the British Medical Journal.
Over a period of seven years, scientists invited 100,000 French adults to report their eating habits as well as any major cardiovascular events (stroke, etc.). Extensive statistical analyzes made it possible to evaluate the association between the quantity of emulsifiers consumed by the participants, estimated from the dosages of the products reported, and cardiovascular risk. Result: regular consumption of additives derived from cellulose (named E460 to E468) was associated with an increased risk of cardiovascular diseases. And this is independent of other known risk factors such as age, sex, smoking, physical activity or even family history. “Even if we have not shown a causal link, but only a strong association, this is the first study that quantifies the exposure to all these emulsifiers and their effect on long-term cardiovascular health”, underlines Professor Mathilde Touvier, research director at Inserm in nutritional epidemiology who led the study.
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The impact on cardiovascular health seemed more significant for emulsifiers E460 (microcrystalline cellulose, powdered cellulose) and E466 (carboxymethylcellulose), used to thicken foods by giving them a creamier and more consistent texture as is the case. case in most sauces, creams, desserts or industrial soups. Other suspected emulsifiers included mono- and diglycerides of fatty acids (E471-E472 and their derivatives), used for their thickening and preservative power. “Some emulsifiers, such as E472b, were more specifically associated with the risk of cerebrovascular diseases, which affect blood flow in the brain, while others, such as E472c and trisodium phosphate (E339), were more linked to the risk of coronary heart disease, affecting the arteries which irrigate the heart,” specifies Professor Touvier.
For the moment, researchers do not yet understand how additives could promote certain cardiovascular pathologies more than others. “This could depend on the nature of the emulsifier, their combination, the dose ingested, but also the individual response of individuals,” explains Soraya Taleb, Inserm research director at the Paris cardiovascular research center.
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However, there is already some avenue for reflection on the mechanism of action involved. Several studies carried out on rodents and humans suggest that they disrupt the balance of the intestinal microbiota, that is to say the community of microorganisms living in the digestive system. “According to our work, certain additives target bacteria necessary for the proper functioning of the intestine, both in animals and humans,” explains Benoît Chassaing, researcher at Inserm and co-author of the study.
This induces an imbalance in the microbiota which causes local inflammation of the intestine which can lead to more global dysregulation of the body. “It’s the leaky gut theory: local inflammation of the intestine increases the permeability of this organ,” explains Soraya Taleb. “Thus, it is likely that bacterial components escape more easily and end up in the bloodstream, causing a chain of inflammation of the vessels. However, it is accepted that chronic inflammation of the vessel wall promotes the development of cardiovascular diseases, in particular atherosclerosis (bad fat deposits on the vessel wall, Editor’s note), a major cause of myocardial infarction and of stroke. »
