Socio-economic and cultural changes in recent decades have led to a significant increase in the consumption of processed foods, often rich in food additives such as emulsifiers. These compounds, found in products such as butter, milk, mayonnaise and pastries, play a crucial role in mixing immiscible ingredients such as oil and water. However, there is growing concern about their impact on health, particularly in relation to intestinal microbiota and metabolic syndrome.
What are food emulsifiers used for?
Emulsifiers are substances that enable two normally immiscible liquids, such as oil and water, to be mixed homogeneously. They play a crucial role in the texture, stability and shelf life of processed food products.
Emulsifiers can be natural or synthetic. Among the most common are :
- Lecithin: Naturally present in eggs and soya, used in chocolate and bakery products.
- Mono- and diglycerides of fatty acids: Used in bakery products to improve texture.
- Polysorbates: Used in ice cream to create a creamy texture.
- Carboxymethylcellulose (CMC): Used as a stabiliser and thickener in many food products.
Use of emulsifiers in the food industry
Emulsifiers are ubiquitous in processed foods, including :
- Bakery products: To improve texture and extend shelf life.
- Ice cream: To prevent the formation of ice crystals and maintain a smooth consistency.
- Sauces and dressings: To prevent ingredients from separating.
- Beverages: To stabilise juice mixes and dairy drinks.
Potential health effects of food emulsifiers
Recent research has highlighted the harmful effects of certain emulsifiers such as carboxymethylcellulose (CMC) on intestinal health. A controlled study revealed that consumption of CMC disrupts the composition of the intestinal microbiota and reduces the diversity of beneficial metabolites produced by these bacteria. These results suggest that emulsifiers may have deleterious effects not only on the intestine but also on overall metabolic health.
Disturbance of the intestinal microbiota
One of the key findings of these studies is the significant impact of emulsifiers on the intestinal microbiota, the set of micro-organisms present in the human digestive system. CMC and other emulsifiers can alter bacterial composition, favouring the growth of pathogenic bacteria while reducing populations of beneficial bacteria such as Bifidobacteria and Lactobacilli. This dysbiosis can lead to chronic inflammation and alteration of the intestinal barrier, increasing intestinal permeability and facilitating the passage of toxins and pathogens into the bloodstream.
Inflammation and chronic diseases
Studies have also shown that emulsifiers can cause intestinal inflammation by disrupting the mucus layer that protects the intestinal wall. This inflammation can play a crucial role in the development of chronic diseases such as Crohn’s disease, irritable bowel syndrome (IBS), and even certain types of cancer. Intestinal inflammation is often accompanied by increased production of pro-inflammatory cytokines, molecules that signal and exacerbate inflammation in the body.
Metabolic implications
In addition to intestinal effects, emulsifiers have significant metabolic implications. Disruption of the microbiota can influence lipid and carbohydrate metabolism, contributing to conditions such asobesity and type 2 diabetes. One study showed that mice fed emulsifiers had increased weight gain and insulin resistance, key indicators of diabetes.
Regulation and safety of emulsifiers
Regulations on emulsifiers vary from country to country. In general, regulatory bodies such as theEuropean Food Safety Authority (EFSA) and the Food and Drug Administration (FDA) in the United States assess the safety of emulsifiers before authorising them for use in foods. These assessments include toxicological tests to determine No Observed Adverse Effect Levels (NOAELs). However, ongoing monitoring and research into long-term effects remain essential to guarantee the safety of these additives.
Sources
- De Siena, M., et al (2022). “Food Emulsifiers and Metabolic Syndrome: The Role of the Gut Microbiota”. Foods, 11(15), 2205.
- Author et al (2021). “Gastroenterology Article. Journal of Gastroenterology.
- Author et al (2023). “Clinical Gastroenterology and Hepatology Article. Journal of Clinical Gastroenterology and Hepatology.
