Food‐grade carrageenans and their implications in health and disease

Abstract

Food additives, often used to guarantee the texture, shelf‐life, taste, and appearance of processed foods, have gained widespread attention due to their increased link to the growing incidence of chronic diseases. As one of the most common additives, carrageenans have been used in human diets for hundreds of years. While classified as generally recognized as safe (GRAS) for human consumption, numerous studies since the 1980s have suggested that carrageenans, particularly those with random coil conformations, may have adverse effects on gastrointestinal health, including aggravating intestinal inflammation. While these studies have provided some evidence of adverse effects, the topic is still controversial. Some have suggested that the negative consequence of the consumption of carrageenans may be structure dependent. Furthermore, pre‐existing conditions may predispose individuals to varied outcomes of carrageenan intake. In this review, structure–function relationships of various carrageenans in the context of food safety are discussed. We reviewed the molecular mechanisms by which carrageenans exert their biological effects. We summarized the findings associated with carrageenan intake in animal models and clinical trials. Moreover, we examined the interactions between carrageenans and the gut microbiome in the pathogenesis of gastrointestinal disorders. This review argues for personalized guidance on carrageenan intake based on individuals’ health status. Future research efforts that aim to close the knowledge gap on the effect of low‐dose and chronic carrageenan intake as well as interactions among food additives should be conducive to the improved safety profile of carrageenans in processed food products.

K-Carrageenan Stimulates Pre-Osteoblast Proliferation and Osteogenic Differentiation: A Potential Factor for the Promotion of Bone Regeneration?

“…K-carrageenan and ι-carrageenan are commonly used for tissue engineering-related applications. K-carrageenan forms thermally reversible brittle and stiff gels, while ι-carrageenan forms elastic and soft gels [8]. λ-carrageenan does not form hydrogels and is even more fluidic compared to the other carrageenan isoforms.…”

Experimental Evaluation of Food-Grade Semi-Refined Carrageenan Toxicity

“…However, other toxicological studies have found no evidence that CGNs may upregulate pro-inflammatory molecules and promote intestinal inflammation [ 14 ]. Of note, data on the safety of CGNs obtained in cell culture experiments should not be overinterpreted as CGN and its interaction in the gut with colonic microbiome are poorly understood [ 15 , 16 , 17 , 18 ]. Yet, this is of great importance due to recent reports on the ability of CGNs to magnify pathogen-induced inflammation in the intestine of mice [ 19 ], contribute to inflammatory bowel disease aggravation [ 20 , 21 ], and enhance lipopolysaccharide (LPS)-induced production of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNFα) and interleukin-8 (IL-8) [ 19 , 22 ].…”

Effects of E407a on the viability, metabolic and functional activity of dermal fibroblasts

“…International regulatory authorities such as the U.S.-based Food and Drug Administration (FDA) and European Food Safety Authority (EFSA) have initiated the thoughtful reevaluation of food additives to guarantee their safety for consumers. Among the food additives whose safety is debated, carrageenans seem to be the most controversial [1][2][3][4][5]. Carrageenans are phycocolloids of heteropolysaccharide origin commercially produced from red algae and widely represented in human diet.…”

“…Cost-effectiveness and convenience of their application in technological processes make them indispensable in the production of processed and ultraprocessed food. The content of carrageenans, which are registered as native carrageenan (E407) and semi-refined form (E407a) can vary to a high extent and may reach 0.5-1% of weight for some dairy products, processed meat and fruit-based processed foods [5].…”

“…Of note, several mechanisms have been suggested to be implicated in carrageenan-mediated gut toxicity. For instance, carrageenan has been shown to inhibit gastric and intestinal proteases such as pepsin and trypsin, reducing in this manner dietary protein bioavailability [5]. Moreover, this food additive has been demonstrated to increase the intestinal permeability, compromising the barrier function [5].…”