Scientists link emulsifiers in processed foods to allergy and immune disorders

Scientists link emulsifiers in processed foods to allergy and immune disorders

From your pantry to your gut, scientists show how everyday food additives can silently fuel allergies, gut disorders, and chronic inflammation.

In a review article published in the journal Allergology and ImmunopathologyResearchers discussed the potential health effects of various food additives, with a particular focus on food allergies and inflammatory diseases.

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Maternal consumption of polysorbate 80 during pregnancy may disrupt intestinal barrier function in offspring, increasing lifelong susceptibility to inflammation and metabolic disorders, according to mouse studies.

Excessive consumption of ultra-processed foods is a known risk factor for cardiometabolic diseases, including hypertension, dyslipidemia, type 2 diabetes and obesity. Recent evidence has also linked ultra-processed food consumption to an increased risk of overall cancer mortality as well as cancer-specific mortality, particularly mortality associated with ovarian cancer.

Despite health adversities, the consumption of these foods is increasing worldwide, especially in Western countries, as these products are very tasty, consumable and inexpensive.

Ultra-processed foods contain high amounts of salt, sugar, saturated and trans fats, food additives, flavor enhancers, sweeteners and preservatives. These ingredients make ultra-processed foods nutritionally poor and contribute to adverse health effects associated with their consumption.

Regarding allergic reactions and intolerance associated with ultra-processed foods, recent studies have increasingly suggested the role of food additives in triggering food allergies and inflammation in vulnerable people.

Given the scarcity of information, the authors of this review aimed to examine the association between the consumption of ultra-processed foods and the risk of inflammatory diseases, particularly allergic diseases.

They examined various electronic databases to identify the most recent articles (published since 2015) that reported the collaboration between food additives and health risks. After final screening and assessment, 43 articles were included in the review.

Check the results

Artificial food colors such as tartrazine (yellow #5) are associated with rare but serious hypersensitivity reactions, including worsening asthma symptoms in children with pre-existing respiratory diseases.

Food additives, including flavor enhancers, artificial food colors, emulsifiers, stabilizers, thickeners, pH control agents and preservatives, are widely used in the food industry to improve the taste, texture, color and shelf life of various foods, including ultrashortened foods. These additives are either from natural sources (such as plants, animals or minerals) or chemically synthesized.

The U.S. Food and Drug Administration (FDA) has recognized approximately 450 substances generally recognized as safe (GRAS) and approved an additional 3,000 food additives for use in foods. However, there is no regulatory mechanism for continuous monitoring of their safety, and some of these additives have been found to have negative health effects.

Flavor enhancer

The most commonly used flavor enhancers are hydrolyzed vegetable protein and monosodium glutamate (MSG). Although rare, MSG has been found to trigger allergic reactions in people with high sensitivity. However, the article notes that studies have often failed to reproduce these reactions under controlled conditions, and consistent evidence for MSG-triggered allergies remains limited.

Artificial food colors

Food additives such as annatto, carmine and tartrazine are commonly used for coloring purposes. Existing evidence suggests that annatto and carmine may induce severe allergic reactions (anaphylaxis) in addition to hives or swelling in some cases. Tartrazine can also cause hives in rare cases.

Emulsifiers, stabilizers and thickeners

Carrageenan, a common thickener in dairy alternatives and processed meats, directly stimulates IL-8 secretion in intestinal cells - an important cytokine that drives inflammatory bowel disease.

Lecithin, carrageenan, guar gum and xanthan gum are examples of emulsifiers used in food products to stabilize mixtures and prevent separation. Carrageenan, guar gum and xanthan gum are also used in foods as stabilizers and thickeners.

Studies have linked carrageenan and guar gum to gastrointestinal symptoms and rare allergic reactions. Specifically, carrageenan was found to trigger inflammatory responses by binding to BCL10 (B-cell lymphoma/leukemia 10) and subsequently activating the NFKB pathway. It also increases CXCL-8 (IL-8) secretion and contributes to inflammatory cascades.

According to existing evidence, the negative health effects of emulsifiers are associated with their ability to alter intestinal microbial diversity, increase the abundance of bacteria with anti-inflammatory potential, reduce the thickness of the intestinal mucosa mucosa, and increase intestinal permeability by disrupting intestinal junction proteins.

All of these factors collectively induce the production of proinflammatory mediators and stimulate inflammatory pathways, leading to the development of metabolic, allergic and autoimmune diseases.

Some emulsifiers such as polysorbate 20 and polysorbate 80 have also been found to alter the expression of genes involved in various biological processes, including development, cell signaling, proliferation, apoptosis and inflammatory response. Proteome pathway analysis has shown that these emulsifiers can trigger Th1 or Th2 type immune responses, suggesting an immunological mechanism linking emulsifiers to disease.

PH control agents such as lemons and lactic acid are commonly used to regulate food acidity. Reactions to manufactured citric acid are rare, and lactic acid is generally well tolerated, although it may cause confusion in those with milk allergies when labeled with calcium-related terms.

preservatives

Preservatives, including nitrates or nitrites and sulfites, are used in foods to extend shelf life and reduce spoilage. While nitrates or nitrites have been linked to allergic reactions, including hives and itching, sulfites have been found to trigger severe allergic reactions and worsen asthma symptoms.

Health watchdogs caused by food additives

“Calcium lactate” label for processed foods confuses consumers with milk allergies because the additive is chemically different from dairy products, sharing terminology that addresses incidental exposure.

Studies have linked some food emulsifiers, including carboxymethylcellulose and polysorbate 80, to the pathogenesis of inflammatory bowel disease (IBD). In terms of mode of action, the results show that these emulsifiers can promote pro-inflammatory gut microbiota, disrupt intestinal mucosal integrity and intestinal barrier integrity, activate inflammatory pathways, and induce cell cycle disruption in individuals at higher risk of developing IBD.

Animal studies have reported that in utero exposure of pupal mice to polysorbate 80 can result in disruption of intestinal barrier function, induction of low-grade inflammation, and intestinal dysbiosis characterized by increased abundance of pathogenic bacteria and decreased abundance of beneficial bacteria.

Because obesity is known to be closely linked to unhealthy diet and altered gut microbiota, food additive-induced gut dysbiosis is considered a major risk factor for obesity and other metabolic diseases.

In this context, evidence suggests that consumption of ultra-processed foods may increase the risk of obesity, metabolic syndrome, IBD, dyslipidemia and dyspepsia (digestive disorders).

Unhealthy components present in ultra-processed foods such as food additives are known to increase the risk of eosinophilic esophagitis by disrupting the esophageal barrier and inducing inflammation. In particular, advanced glycation end products (AGEs) present in processed foods can affect the esophageal mucosa and promote allergic sensitization and inflammation.

Di-2-ethylhexyl phosphate (DEHP) and its primary toxic metabolite mono-2-ethylhexyl phthalate (MEHP-AF) are the typical endocrine disrupting chemicals with adverse health effects. Food Emulsifier's Polysorbate 80 was found to improve the bioavailability of MEHP-AF by increasing its intestinal absorption.

Review highlights

The review identifies food emulsifiers as the most harmful food additive, potentially increasing the risk of food allergies and inflammatory diseases by altering gut microbiota, disrupting intestinal barrier integrity and inducing inflammation.

The authors also note the importance of maintaining epithelial barrier function and microbial diversity as protective factors against food antigen translocation and immune dysregulation.

As mentioned by the authors, further research is needed to better understand the mechanisms controlling the association between food additives and immunological diseases and to develop strategies to mitigate potential risks.

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